Patent Application
20240206469
The present invention relates to phosphorus use efficiency enhancers as plant growth promotors or P-boosters, a method for promoting growth of a plant, a mixture for promoting growth of a plant, a fertilizer mixture, a process for its production and a method of fertilizing soils.
The use of nitrogen and phosphorus in the form of fertilizers are necessitated by cropping to fulfil in the food demand of a growing population. Fertilizer application should be site-specific to ensure optimum crop production with minimum environmental pollution.
The use of phosphorus fertilizers and hence the rate of phosphorus accumulation in agricultural soils increased almost three-fold between 1960 and 1990. However, the rate of phosphorus accumulation has declined somewhat since 1990.
Even under the best conditions only about 25% of applied fertilizer phosphorus is taken up by the crop during the first cropping season. It is generally understood that at high soil pH levels, phosphorus is precipitated by calcium and magnesium and at low soil pH levels predominately by iron and aluminium. Thus, the historical problem with the soil chemistry of phosphorus fertilizers has been rapid fixation reactions which limit phosphorus availability. Residual phosphorus not taken up by the crop and remaining on or near the soil surface has a possible environmental impact through the combined effects of soil erosion and higher phosphorus concentrations in run-off water. A phosphorus fertilizer product that is more efficient, that produces greater crop responses, has a positive impact on returns to crop producers, and less environmental footprint is highly desirable.
Rock phosphate itself is seldom used directly as a fertilizer because of its low availability of phosphorus and transport cost. Instead, finely ground rock phosphate is treated with sulfuric acid to yield monocalcium phosphate monohydrate and is known as superphosphate. About 85-90% of phosphate in superphosphate is water soluble. In another process, finely ground rock phosphate is reacted with sulfuric acid to produce phosphoric acid (54% P2O5), also called green acid, and gypsum, which is removed as a by-product. Phosphoric acid usually is not used directly as a fertilizer because it is corrosive, but is used to manufacture other fertilizers. The reaction of phosphoric acid with finely ground rock phosphate yields triple superphosphate (TSP). Mono ammonium phosphate (MAP) and diammonium phosphate (DAP) are the products of reactions between phosphoric acid and ammonia. Phosphoric acid can be heated to drive off water to produce superphosphoric acid (68-70% P2O5), which when reacted with ammonia yields ammonium polyphosphate.
Phosphorus fertilization rates often are given in terms of P, not P2O5. The proportion of P in P2O5 is used to calculate the equivalent quantity of P in a fertilizer: 2P/P2O5=(2×31 g/mol)/142 g/mol=0.437. Thus, the percentage of P in a 12-24-12 fertilizer is: 24% P2O5×0.437=10.5% P.
Many phosphorus fertilizers include nitrogen and potassium, which make them more complete fertilizers. A few are only phosphorus fertilizers: superphosphate (CaH4O8P2) contains 25-28% soluble phosphate; Tennessee phosphates contain 60-70% of the relatively insoluble calcium phosphate-Ca3(PO4)2 (the primary natural form; water solubility=0.002 g/100 g); triple super phosphate contains 48-49% P2O5, which provides 41-42% water-soluble P2O5; and African phosphates, found in Tunisia and Algeria, contain 55-65% calcium phosphate. Superphosphate is produced by the action of concentrated sulfuric acid on powdered phosphate rock:
Ca3(PO4)2(s)+2H2SO4(aq)=2CaSO4(aq)+Ca(H2PO4)2(s)
Triple superphosphate (originally known as double superphosphate) is produced by the action of concentrated phosphoric acid on ground phosphate rock:
Ca3(PO4)2(s)+4H3PO4(aq)=3Ca2+(aq)+6H2PO41−(aq)=3Ca(H2PO4)2(s)
The active ingredient, monocalcium phosphate, is identical to that of superphosphate, but does not included calcium sulfate that is formed when sulfuric acid is used. The phosphorus content of triple superphosphate (17-23% P; 44-52% P2O5) is roughly three times greater than superphosphate (7-9.5% P; 16-22% P2O5). Ammonium and di-ammonium phosphates —(NH4)3PO4— are popular because of the added nitrogen.
Guano typically contains 8-16% nitrogen (the majority of which is uric acid), 8-12% equivalent phosphoric acid, and 2-3% equivalent potash. It is the excrement of seabirds, cave-dwelling bats, and pinnipeds.
Phosphate starvation has a substantial negative effect on plant growth and yield. Phosphorus is an essential element in multiple important plant components and plant physiological processes. Phosphate starvation signaling on the other hand induces a number of mechanisms in the plant to cope with the starvation, for example an increase in phosphate uptake transporters and induction of lateral roots or modulations of the root system architecture in order to forage for more phosphate. Phosphate starvation signaling also induces root hairs and root hair elongation to increase uptake of phosphate. The increased root hair number and root hair surface moreover result in more uptake of nutrients in general and water. Phosphate starvation signaling also result in beneficial symbiotic interactions, for example with arbuscular mycorrhizal fungi, or with ascomycete fungi, such as Colletotrichium tofieldiae. These fungi can make an extensive network in the soil to capture and translocate not only phosphate, but also other nutrients to the plants. Phosphate starvation signalling also interact with immune signalling, and affects as such the establishments of, possibly beneficial, microbial colonization or the microbiome in the soil. Phosphate starvation signaling also activates secretion of different substances, including phosphate releasing enzymes, such as phosphatases, acid phosphatases, phosphodiesterases and nucleases, and including acids, such as citrate and malate. These substances make phosphate available for the plant from P-containing resources in the soil such as rock phosphate or mineralized phosphate and organic phosphates, such as organophosphates, plant residues, green manure, microbial biomass, farm yard manure and other biological or organic residues. In summary, activation of phosphate starvation signaling mechanisms increases the yield potential or reduces the required amount of phosphate for the same yield.
The phosphate starvation signaling is quite conserved and involves SPX proteins, for example SPX1 in Arabidopsis thaliana (Arabidopsis). SPX1 and homologous SPX proteins in other plants negatively control the phosphate starvation response via inhibition of PHOSPHATE RESPONSE1 (PHR1), a transcription factor and main regulator of the phosphate starvation signaling. Puga M I, et al.: Proceedings of the National Academy of Sciences 2014, 111:14947-14952 describes that SPX1 is a phosphate-dependent inhibitor of PHOSPHATE STARVATION RESPONSE 1 in Arabidopsis.
Rice SPX1 and SPX2 inhibit phosphate starvation responses through interacting with PHR2 in a phosphate-dependent manner, see Wang Z, et al. Proceedings of the National Academy of Sciences 2014, 111:14953-14958. As a consequence, SPX loss of function mutants in for example both Arabidopsis and rice do not negatively control the phosphate starvation response and have a higher phosphate uptake. Similarly, new substances that suppress expression of SPX genes are expected to positively affect phosphate use efficiency. Additionally, Arabidopsis SPX1 is described to be controlled by PHR1 and induced during phosphate starvation, and could be used as a biomarker of phosphate deficiency. Characterization of a sub-family of Arabidopsis genes with the SPX domain reveals their diverse functions in plant tolerance to phosphorus starvation, see Duan K, et al. The Plant Journal 2008, 54:965-975.
Another gene in Arabidopsis that is controlled by the PHR1 transcription factor is PHT1;4, encoding a phosphate transporter. PHT1;4 is also induced upon phosphate starvation. This gene has previously been used as a biomarker to screen a library with 3600 biologically active and characterized compounds, which yielded alleviators of phosphate starvation.
US 2015/0272119 A1 discloses 4-chloro-thiophenolic compounds which shall alleviate phosphate starvation symptoms in plants and promote the growth of phosphate deprived plants. In contrast to PHT1;4, which is part of the phosphate starvation response, SPX1 is not only part of the phosphate starvation response, but also functions more upstream in the pathway and contributes to the signalling itself.
The object underlying the present invention is to provide compounds as fertilizer additives that can act as plant growth promotors by enhancing the phosphorus use efficiency of plants. Preferably, the compounds shall mitigate/alleviate the phosphate starvation stress of plants, and/or enhance the phosphorus or phosphate (fertilizer) use efficiency and/or improve the phosphorus or phosphate uptake of plants.
The objects are achieved by the use of a compound of the general formula (I)
with the following definitions:
According to the present invention, it has been found that compounds of the above general formula (I) can be successfully employed as plant growth promotors. They enhance the phosphorus use efficiency of plants. They mitigate/alleviate the phosphate starvation stress of plants. They enhance the phosphorus or phosphate (fertilizer) use efficiency and are therefore “P-boosters”. They improve the phosphorus or phosphate uptake of plants.
More specifically, they preferably suppress the expression of phosphate starvation biomarkers in plants, more specifically suppress the SPX1 biomarker or suppress the Arabidopsis gene SPX1.
According to the present invention it has been found that the suppressor of SPX1 has positive/circumventing effects on phosphate stress parameters and plant growth, specifically on Arabidopsis, rice, soybean and maize in non-optimal phosphate conditions, thereby being able to enhance the phosphorus or phosphate fertilizer use efficiency.
The compounds suppress the expression of the Arabidopsis gene SPX1, a (negatively regulated) phosphate starvation biomarker, implying a reduction of phosphate starvation.
The object is achieved by the use of a compound of the general formula (I)
with the following definitions:
The use is preferably for suppressing
The use is more preferably
The object is furthermore achieved by a method for promoting growth of a plant, comprising adding to growing medium or soil in which the plant is grown, a compound as defined above.
The invention furthermore relates to a mixture containing at least one compound of general formula (I) as defined above,
and at least one additional agrochemical agent, preferably selected from the group consisting of
The invention furthermore relates to a fertilizer mixture, containing
The invention furthermore relates to a process for producing the fertilizer mixture as defined above by introducing the compound of the general formula (I) into the fertilizer, and/or applying the compound of the general formula (I) to the surface of the fertilizer.
The invention furthermore relates to a method of fertilizing soils exploited agriculturally or horticulturally including home and garden, wherein a fertilizer mixture containing compounds A and B
The compounds of general formula (I) suppress Arabidopsis SPX1 and promote plant growth in phosphate starvation conditions. The positive effect was validated on plant growth in diverse plants. The results show that the activity of the substance class is retained in a number of variants, which structurally characterize the class of molecules with this activity.
The results show that the use of SPX genes as a biomarker to screen for SPX suppressing molecules is a potent approach to discover new plant growth promoting or phosphate stress reducing substances.
The invention also relates to the use of SPX genes as a biomarker to screen for SPX suppressing molecules and a screening method for potentially SPX suppressing molecules, involving the SPX genes as biomarker.
When the compounds of general formula (I) are employed in combination with a phosphorus-containing fertilizer, the phosphorus uptake of the plant can be increased, leading to a higher yield and growth of the plant.
Besides suppressing the SPX1 biomarker, the compounds according to the present invention can also alleviate, mitigate or inhibit in vivo expression of the PHT1;4 gene and coding of the high affinity phosphate transporter PHT1;4 in Arabidopsis thaliana, as described in US 2015/0272119 A1.
According to the present invention it has been found that the structural element depicted in formula (I) is responsible for the suppression of the Arabidopsis gene SPX1 or phosphate starvation biomarker.
The term “independently” defines that the meaning for each residue can be selected independent of the meaning for another member or binding position of the mentioned residues. For example, R2 and R3 can be the same or different.
The compounds according to the present invention are typically employed in connection with a phosphorus-containing fertilizer.
Furthermore, the fertilizer can contain further elements, like nitrogen or potassium, e.g. in NP- or NPK-fertilizers.
The compounds according to the present invention can be combined with a nitrification inhibitor and/or urease inhibitor.
Nitrogen sources are mainly ammonium (NH4+) and nitrate (NO3− and urea). In practical application, an average N-fertilizer loss of up to 50% can be observed. Often the nitrogen is converted via the nitrogen cycle into inaccessible N-forms, e.g. by microbial conversion into the greenhouse gas N2O or into nitrate.
One approach to limit the amount of N-emissions as much as possible is to inhibit nitrification, i.e. the conversion of NH4+ or NH3 into NO3− and hydrolysis of urea via UI.
In contrast to NO3−, the positively charged NH4+ binds to the negatively charged soil particles and will hardly leach from the soil. Therefore, NH4+ is the preferred N-source and should be kept available in soil for plant uptake. NH4+ may however be converted into NO3− via nitrification, a microbial process of the global N cycle whereby NH3, which is in a pH-dependent equilibrium with NH4+, is converted into NO3− via nitrite (NO2−) by soil micro-organisms.
Hence, nitrification is a central step that causes the entering of NH4+ in the N cycle and its subsequent conversion into undesired leachable or volatile N-forms.
The first step in nitrification, NH3 oxidation, is in agricultural soils and substrates predominantly performed by ammonia-oxidizing bacteria (AOB). They first oxidize NH3 into hydroxylamine (NH2OH), which is catalyzed by the ammonia-monooxygenase (AMO) enzyme. Subsequently, the hydroxylamine oxidoreductase (HAO) enzyme catalyzes the second step: NH2OH oxidation to form nitrite (NO2).
Nitrification inhibitors, which are currently commercially distributed, include dicyandiamide (DCD), nitrapyrin (2-chloro-6-(trichloromethyl)-pyridine) or 3,4-dimethylpyrazole phosphate (DMPP).
Therefore, the compounds according to the present invention can be advantageously used together with or combined with or in admixture with nitrification inhibitors which are preferably inhibiting ammonia-oxidizing bacteria (AOB) or archaea (AOA).
Furthermore, specifically if the fertilizer contains urea, the compound can also be used together or combined with or in admixture with an urease inhibitor, which is preferably selected from N-n-butylthiophosphoric triamide (NBTPT or NBPT) and/or N-n-propylthiophosphoric triamide (NPTPT or NPPT).
The compounds according to the present invention can as well be combined with a nitrification inhibitor and an urease inhibitor, specifically in case of fertilizers containing ammonium and urea and a source for phosphorus.
If the compound of the present invention is combined with a nitrification inhibitor, the weight ratio of compound of the present invention to nitrification inhibitor is preferably in the range of from 0.01 to 100:1, more preferably 0.1 to 10:1.
If the compound according to the present invention is combined with a urease inhibitor, the weight ratio of compound of the present invention to urease inhibitor is preferably in the range of from 0.01 to 100:1, more preferably 0.1 to 10:1.
If the nitrification inhibitor is combined with N-n-butylthiophosphoric triamide (NBTPT) and/or N-n-propylthiophosphoric triamide (NPTPT), the weight ratio of nitrification inhibitor(s) to urease inhibitor is preferably in the range of from 0.1 to 10:1, more preferably 0.5 to 8:1, most preferably 1 to 6:1.
Furthermore, the compounds of the present invention can be combined with an inorganic and/or organic and/or organomineral fertilizer, specifically a fertilizer which contains a phosphorus source.
Furthermore, it is possible to combine the compounds of the present invention with at least one customary agrochemical (auxiliary) agent.
Therefore, the present invention defines a mixture of the compounds of general formula (I) as defined above, with
The term “additional or further” describes biostimulants and/or plant growth regulators that are different from the compounds of general formula (I).
A combination with at least one phosphorus source, nitrification inhibitor and/or urease inhibitor is preferred.
The compounds of the invention are preferably employed in combination with a fertilizer, more preferably a phosphorus source and possibly an (ammonium) nitrogen-containing fertilizer, e.g. solid or liquid inorganic, organic and/or organomineral fertilizer, or manure. The compound is for example employed on solid fertilizers, or is employed in liquid organic or inorganic or organomineral fertilizers or manure.
The compounds of general formula (I) are mostly known per se and can be synthesized according to standard techniques. They partly are commercially available compounds and can be obtained from ENAMINE Ltd., UkrOrgSynthesis Ltd., or Vitas-M Laboratory, Ltd. or from Merck Millipore, Burlington, MA, USA, or Merck KGaA.
In the compounds of formula (I), heteroatoms of the same or different chemical element are not adjacent. Preferably, heteroatoms are not directly linked to each other in these compounds.
The compounds of formula (I) preferably contain 1 to 6 cyclic structures in the molecule, more preferably 1 to 5 cyclic structures in the molecule. Preferably, wherein the compound of the general formula (I) has the general formula (Ia)
In a preferred embodiment, the compound of the general formula (I) has the formula 8.14 or 8.14.6
In a preferred embodiment, the compound of the general formula (I) is any one of the compounds shown in Table 5.
More preferably, wherein the compound of general formula (I) has the general formula (Ib)
with the following definitions:
In an alternative preferred embodiment, the compound of general formula (I) wherein the compound of the general formula (I) has the general formula (Ic)
with the following definitions:
According to a further preferred embodiment, wherein the compound of the general formula (I) has the general formula (Id)
with the following definitions:
According to a further preferred embodiment, the compound of the general formula (I) has the general formula (Ie)
with the following definitions:
R6 hydrogen, C1-12-hydrocarbon residue, which can contain one or two halogen atoms and/or one to three heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur.
R7, R8 independently C1-8-alkyl, C3-8-cycloalkyl, which can both contain one or two halogen atoms and/or one or two heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur, or phenyl.
The cyclic structure depicted in general formula (Ib) preferably cannot be condensed with a further cyclic structure. In addition to the cyclic structure depicted in general formula (I) preferably 0 to 6, more preferably 0 to 5, most preferably 0 to 4 further cyclic structures are present, one of these additional cyclic structures can be condensed with the ring depicted in formula (I).
Condensed or annellated cyclic structures are cyclic structures in which two cyclic structures share two chemical elements, preferably two carbon atoms, in their respective ring structures
The additional cyclic structures can be saturated or unsaturated or aromatic. If two condensed cyclic structures are present, it is possible that one cyclic structure is aromatic and the other cyclic structure is non-aromatic.
If two cyclic structures are not condensed, they can be directly covalently linked with each other. Alternatively, they can be linked by a spacer which can contain carbon atoms, heteroatoms or both. For example, the spacer can be a C1-6-alkylene group, a heteroatom selected from the group consisting of oxygen, sulfur and nitrogen, or the spacer can for example be an amido group —C(═O)—NH—. If the cyclic groups are linked by a nitrogen atom, this nitrogen is preferably —NH— or —NR— with R being C1-4-alkyl, more preferably R being methyl or ethyl.
Cyclic structures can also be described as structural elements that form part of the compounds of general formula (I).
In general formula (I) and (Ic), n has a value of 0; 1; 2 or 3, preferably 0; 1 or 2, more preferably 0 or 1. The one or more residues R4 can be identical or different and can be located in any of the possible positions of the ring.
Preferably, one or two residues R1 and R5 are present in the positions depicted in formula (Ia) or (Id).
R1 and R5 are independently hydrogen, halogen, NO2, C1-12-hydrocarbon residue, which can contain one or two halogen atoms and/or one to three heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur.
Preferably, only one of R1 and R5 is different from hydrogen.
Preferably, either R4 of R5 is hydrogen and the other residue is hydrogen, C1-4-alkyl, NO2, —NH—C(O)—R9 with R9 being C1-4-alkyl, preferably methyl or ethyl, more preferably methyl.
R1 can be NH2, C1-30-hydrocarbon residue which can contain 1 to 3 halogen atoms and/or 1 to 6 heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur. The number of heteroatoms is preferably from 1 to 5.
More preferably, R1 is NH2 or NR10R11, wherein R10, R11 independently are H, C1-12-hydrocarbon residue which can contain one or two halogen atoms and/or one to three heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur. R10 and R11 together can form a five- to eight-membered heterocyclic radical, which can contain one or two halogen atoms and/or one to three further heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur in addition to the nitrogen of NR10R11. Further cyclic structures can be covalently linked with or annelated to this heterocyclic ring structure.
The compounds of general formula (I) preferably contain no or one sulfur atom. Preferably R1 is hydrogen, NH2 or a C1 to C4 hydrocarbon or C1 to C4 car-boxy group, even more preferably, R1 is NH2.
According to one embodiment, R1 has the structure as shown in formula (Ic), (Id), or (Ie). R2 and R3 preferably are independently hydrogen or C1-4 alkyl, more preferably hydrogen, methyl or ethyl, most preferably hydrogen or methyl. As an alternative, R2 and R3 can form a heterocyclic radical, R2 and R3 together preferably being an 1,2-ethylene residue, which can contain further substituents as for example depicted in formula (Ib) as R6.
Thus, R2 and R3 can be covalently linked as an 1,2-ethylene group, which can be substituted by a C1-8-hydrocarbon residue, which can contain one or two halogen atoms and/or one to three heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur. In formula (Ia), R2 most preferably is hydrogen or methyl, and R3 is methyl.
In formula (Ib), R6 is preferably hydrogen or C1-4-alkyl, more preferably hydrogen, methyl or ethyl, most preferably hydrogen or methyl.
Preferably, R7 and R8 independently are hydrogen or C1-6-alkyl, which can contain one heteroatom, selected from the group consisting of nitrogen, oxygen and sulfur, or are cyclopropyl.
Most preferably, R7 and R8 independently are hydrogen, C1-4-alkyl or cyclopropyl.
In the examples, specific residues R1 to R8 are disclosed for formula (I) to (Ie). Each of these residues can be employed for limiting the compounds of general formula (I) to (Ie), irrespective of the other residues. Thus, the compounds of general formula (I) to (Ie) can contain one or more of the residues R1 to R8 as disclosed in each of the examples.
The compounds of the invention are plant additives which can alleviate phosphate starvation symptoms in plants and promote the growth of phosphate deprived plant and can be described as P-boosters.
They substantially improve the whole plant growth in low P, especially low P conditions, suggesting that these compounds unlock a mechanism restricting growth.
Advantageously, the compound according to the present invention is useful for reducing the need for phosphate fertilizer for growing plants.
The term “plant” includes any monocot or dicot plant, such as a plant of the Fabaceae or Brassicaceae family, in particular Medicago sativa (Alfalfa).
In another embodiment, said plant is grown under phosphate limiting conditions. As used herein, the term “under phosphate limiting conditions” means under low phosphate conditions, i.e., under a content of phosphate that is not optimum for the growth of the specific plant.
The mixture of the present invention provides a plant additive composition comprising: a compound of formula (I) as defined above and a formulation adjuvant, such as a carrier, a solvent or a surface-active agent.
By “plant additive composition” is meant any kind of soil additive, soil amendment, fertilizer or soil conditioner, which can of course be used to modify a soil, but also in hydroponic cultures.
More particularly, said plant additive composition is a composition for promoting plant growth and/or for alleviating P starvation symptoms.
The plant additive composition according to the present invention is typically not intended for use as an herbicide, in particular as a defoliant, a desiccant, an herbage killer, a germination inhibitor or a weed killer.
The plant additive composition can be a liquid or solid (typically granulated or powdered) composition, such as dusting powders, gels, wettable powders, water-dispersible granules, water-dispersible tablets, effervescent compressed tablets, emulsifiable concentrates, microemulsifiable concentrates, oil-in-water emulsions, oil flowables, aqueous dispersions, oil dispersions, suspoemulsions, capsule suspensions, emulsifiable granules, soluble liquids, water-soluble concentrates (with water or a water-miscible organic solvent as carrier), or impregnated polymer films.
In a particular embodiment, the plant additive composition further comprises at least one primary nutrient selected from the group consisting of nitrogen and potassium, and/or at least one secondary nutrient selected from the group consisting of calcium, magnesium, sodium and sulfur, and/or at least one micronutrient selected from the group consisting of boron, cobalt, copper, iron, manganese, molybdenum and zinc.
Advantageously, said plant additive composition comprises a compound of formula (I) as defined above and at least one or the 2 primary nutrients as defined above.
Advantageously, said plant additive composition comprises a compound of formula (I) as defined above and at least one or the 2 primary nutrients and the 4 secondary nutrients as defined above.
Advantageously, said plant additive composition comprises a compound of formula (I) as defined above, nitrogen, potassium, calcium, magnesium, sodium, sulfur, boron, cobalt, copper, iron, manganese, molybdenum and zinc.
Advantageously, a liquid plant additive composition comprises a solvent such as a polar water-soluble solvent, a micelle or a surfactant.
The present invention provides a method for promoting the growth of a plant, comprising adding to the growing medium or soil on which said plant is grown, a compound of formula (I) as defined above, or a plant additive composition comprising a compound of formula (I) as defined above and a formulation adjuvant as defined above.
The method according to the present invention is not intended for promoting the growth of a plant by inhibiting the growth of another plant (e.g., a weed). Preferably, said plant is grown under phosphate limiting conditions.
The growing medium includes liquid, semi-solid or solid medium suitable to support the growth of a plant. By way of example, it can be a mineral nutrient solution or an inert material such as heydite, clay pellets, perlite, vermiculite or rockwool. Advantageously, the growing medium contains the nutrients required to support the growth of the plant.
The present invention provides the use of a compound of formula (I) as defined above for preparing a plant additive composition as defined above useful for promoting the growth of a plant. Preferably, said plant is grown under phosphate limiting conditions.
The P-boosters are described as those of general formula (I). One or more compounds of formula (I) can be employed as P-boosters and in the fertilizer discussed below. Furthermore, it is possible to employ mixtures of one or more compounds of general formula (I) and one or more compounds of general formula (II), as well as mixtures of one or more compounds of at least two of general formula (I). This is reflected by the expression formula (I).
It is expected that the P-booster of the present invention possesses favorable toxicological properties, has a low vapor pressure, and is sorbed well in the soil. As a consequence, the P-booster is neither emitted to the atmosphere by sublimation to any significant extent nor is easily leached by water. As a result, first of all, economic advantages arise, such as a high profitability in view of the longer-lasting effect of the P-booster, and environmental advantages, such as a reduction in the burdening of air (climate gas-reducing) and of surface waters and ground water.
The P-boosters can be applied to soils or substrates which are fertilized with an inorganic or organic or organomineral fertilizer. Typically, they are employed in a fertilizer mixture comprising such fertilizer and the compound of general formula (I). Typically, the compound of general formula (I) is employed in an amount of 10 to 10000 ppm by weight, more preferably 100 to 10000 ppm by weight, preferably 1 to 100, and even more preferably 1 to 20 weight ppm based on the fertilizer without water. The application amount is based on the dry fertilizer.
The P-booster according to the present invention can be employed in substance, in solution, dispersion or emulsion. Therefore, the invention also relates to a solution, dispersion or emulsion containing the compound of general formula (I) of the present invention preferably in an amount of from 0.1 to 50 wt %, more preferably 0.5 to 30 wt %, most preferably 1 to 20 wt %.
Preferably, according to the present invention, fertilizers are employed for forming a fertilizer mixture, containing compounds A and B
The water fraction in compound A and in the fertilizer mixture is often not more than 1.5 wt %, preferably not more than 1.0 wt %, more preferably not more than 0.5 wt %, most preferably not more than 0.3 wt %, and is therefore negligible in the balance of quantities. Compounds A and B preferably make up at least 95 wt %, more preferably at least 98 wt % of the fertilizer mixture.
The nitrogen content of component A (without water), is often at least 12 wt %, preferably at least 20 wt %, more preferably at least 22 wt %. For example, the nitrogen content may be 25 to 29 wt %, particularly 26 to 28 wt %. The nitrogen content can be divided between fast-acting nitrate nitrogen and slow-acting ammonium nitrogen.
The inorganic fertilizers preferably are ammonium- and/or urea-containing fertilizers, more preferably ammonium-containing fertilizers which can additionally contain urea.
Urea-containing fertilizers are further described in WO 2016/207210.
Fertilizers typically provide, in varying proportions:
The fertilizers employed according to the present invention can be of natural or synthetic origin and are applied to soil or to plant tissues to supply one or more plant nutrients essential to the growth of plants. The fertilizers employed according to the present invention should provide at least nitrogen as nutrient. Further nutrients are for example K and P. Multinutrient fertilizers/complex fertilizers provide two or more nutrients. Inorganic fertilizers exclude carbon-containing materials except ureas. Organic fertilizers are usually plant- or animal-derived matter. Organomineral fertilizers (combination of inorganic and organic fertilizers) can be employed as well.
The main nitrogen-based straight fertilizer is ammonia or its solutions. Ammonia nitrate is also widely used. Urea is another popular source of nitrogen, having the advantage that it is solid and non-explosive. A further nitrogen-based fertilizer is calcium ammonium nitrate.
The main straight phosphate fertilizers are the superphosphates. “Single superphosphate” (SSP) consists of 14-18% P2O5, again in the form of Ca(H2PO4)2, but also phosphogypsum (CaSO4·2H2O). Triple superphosphate (TSP) typically consists of 44-48% of P2O5 and no gypsum. A mixture of single superphosphate and triple superphosphate is called double superphosphate. More than 90% of a typical superphosphate fertilizer is water-soluble.
Diammonium phosphate (DAP) quickly became the item of commerce as most widely used by the growers today, and it has the highest concentration of phosphate and nitrogen at 18 N-46P2O5-0K2O
Monoammonium phosphate (MAP) is essentially the same as DAP, but it has a lower concentration of nitrogen at 11 N-52 P2O5-0K2O. It is completely water soluble and has granular material; it mixes well and frequently serves as an ingredient in bulk-blended fertilizers.
Granulated triple superphosphate (GTSP) is very similar to the superphosphate fertilizer that provides 46% P2O5, some calcium and sulfur to plants. GTSP is formed by reaction of phosphate rock with phosphoric acid.
Superphosphoric acid is an acid used to make a concentrated or fluid fertilizer.
Phosphoric acid is used in granulation plants where ammonia is added to phosphoric acid to produce the ammoniated phosphate fertilizer
Phosphate fertilizers are obtained by extraction from phosphate rock, which contains two principal phosphorus-containing minerals, fluorapatite Ca5(PO4)3F (CFA) and hydroxyapatite Ca5(PO4)3OH. These minerals are converted into water-soluble phosphate salts by treatment with sulfuric (H2SO4) or phosphoric acids (H3PO4).
In the nitrophosphate process or Odda process, phosphate rock with up to a 20% phosphorus (P) content is dissolved with nitric acid (HNO3) to produce a mixture of phosphoric acid (H3PO4) and calcium nitrate (Ca(NO3)2). This mixture can be combined with a potassium fertilizer to produce a compound fertilizer with the three macronutrients N, P and K in easily dissolved form.
The main potassium-based straight fertilizer is muriate of potash (MOP).
Major two-component fertilizers provide both nitrogen and phosphorus to the plants. These are called NP fertilizers. The main NP fertilizers are monoammonium phosphate (MAP) and diammonium phosphate (DAP). The active ingredient in MAP is NH4H2PO4. The active ingredient in DAP is (NH4)2HPO4. About 85% of MAP and DAP fertilizers are soluble in water. NPK fertilizers are three-component fertilizers providing nitrogen, phosphorus and potassium. NPK fertilizers can be produced by mixing straight fertilizers as mentioned above in bulk or in each granule, as in Nitrophoska®. In some cases, chemical reactions can occur between the two or more components.
NPK fertilizers are at least three-component fertilizers providing nitrogen, phosphorus and potassium. NPK fertilizers can be produced by mixing straight fertilizers as mentioned above in bulk or in each granule, as in Nitrophoska®. In some cases, chemical reactions can occur between the two or more components.
For example, monoammonium and diammonium phosphates, which provide plants with both N and P, are produced by neutralizing phosphoric acid (from phosphate rock) and ammonia:
NH3+H3PO4→(NH4)H2PO4
2 NH3+H3PO4→(NH4)2HPO4
Besides the main constituents, like N, P and K, micronutrients (trace elements) may be present in the fertilizers. The main micronutrients are molybdenum, zinc, boron and copper. These elements are typically provided as water-soluble salts.
Preferred fertilizers contain ammonium or urea. Examples of preferred ammonium-containing fertilizers are NPK fertilizers, calcium ammonium nitrate, ammonium sulfate nitrate, ammonium sulfate and ammonium phosphate.
Further preferred ingredients of the fertilizer compositions are for example trace elements, further minerals, standardizers, binders.
Organic fertilizers can describe those fertilizers with an organic or biologic origin, i.e. fertilizers derived from living or formerly living materials, like animals or plants or algae. Fertilizers of an organic origin include animal wastes, plant wastes e.g. from food processing or agriculture, compost, and treated sewage sludge (biosolids). Animal sources can be manures, but also products from the slaughter of animals, like blood meal, bone meal, feather meal, hides, hooves, and horns.
Soil amendments, like peat or coir, bark and sawdust can also be included.
Fertilizers can include without limitation, ammonium sulfate, ammonium nitrate, ammonium sulfate nitrate, ammonium chloride, ammonium bisulfate, ammonium polysulfide, ammonium thiosulfate, aqueous ammonia, anhydrous ammonia, ammonium polyphosphate, aluminum sulfate, calcium nitrate, calcium ammonium nitrate, calcium sulfate, calcined magnesite, calcitic limestone, calcium oxide, hampene (chelated iron), dolomitic limestone, hydrate lime, calcium carbonate, diammonium phosphate, monoammonium phosphate, potassium nitrate, potassium bicarbonate, monopotassium phosphate, magnesium nitrate, magnesium sulfate, potassium sulfate, potassium chloride, sodium nitrates, magnesian limestone, magnesia, disodium dihydromolybdate, cobalt chloride hexahydrate, nickel chloride hexahydrate, indole butyric acid, L-tryptophan, urea, urea-formaldehydes, urea ammonium nitrate, sulfur-coated urea, polymer-coated urea, isobutylidene diurea, K2SO4-2MgSO4, kainite, sylvinite, kieserite, Epsom salts, elemental sulfur, marl, ground oyster shells, fish meal, oil cakes, fish manure, blood meal, rock phosphate, super phosphates, slag, bone meal, wood ash, biochar, algae, algae extract, struvite, manure, bat guano, peat moss, compost, green sand, cottonseed meal, feather meal, crab meal, fish emulsion or a combination thereof. The micronutrient fertilizer material can comprise boric acid, a borate, a boron frit, copper sulfate, a copper frit, a copper chelate, a sodium tetraborate decahydrate, an iron sulfate, an iron oxide, iron ammonium sulfate, an iron frit, an iron chelate, a manganese sulfate, a manganese oxide, a manganese chelate, a manganese chloride, a manganese frit, a sodium molybdate, molybdic acid, a zinc sulfate, a zinc oxide, a zinc carbonate, a zinc frit, zinc phosphate, a zinc chelate or a combination thereof. In a particular embodiment, said fertilizer or fertilizer composition does not comprise insoluble selenium, selenium mineral, soluble selenium or salts thereof.
The treated (inorganic, organic or organomineral) fertilizers according to the invention are preferably present in powder form, prill form or in granule form.
Besides the compound of the general formula (I), formulations comprising the compound and agronomical adjuvants can be used for including the P-booster in the fertilizer. Agronomical adjuvants are, for example, solvents, dispersants, pH-adjusting agents, fillers, stability improvers, surfactants.
The P-booster can be included in the fertilizer mixture by mixing it or the formulation containing it with a solid or liquid fertilizer or fertilizer formulation. Preferably, the fertilizer mixture is in solid form and the P-booster is applied to the surface of the (inorganic, organic or organomineral) fertilizer.
In a process for producing the fertilizer mixture of the present invention, the P-booster or the formulation containing it can be introduced into the (inorganic, organic or organomineral) fertilizer and/or applied to the surface of the fertilizer.
Granules of fertilizers are impregnated or coated with the P-booster, for example by being sprayed with a formulation like a solution or a dispersion of the P-booster and subsequent drying. The method is known, for example, from DE-A-41 28 828. The sealing of the impregnated granules with, for example, a paraffin wax, which is an additional proposal in the latter document, is possible, but generally unnecessary.
Granulating assistants which can be employed for preparing solid fertilizer compositions can be lime, gypsum, silicon dioxide or kaolinite.
An alternative is the addition of the nitrification inhibitor during the actual production of the fertilizer or in the slurry, for example.
As a rule, the P-boosters are customarily applied to the soil in amounts effective for the desired action.
Delivery of the P-booster in liquid fertilizer formulations may be accomplished, for example, by fertigation with or without excess water as described in DE-C-102 30 593.
The fertilizer mixture can contain at least one nitrification inhibitor. Preferably, this at least one further nitrification inhibitor is inhibiting ammonia-oxidizing bacteria (AOB) and is preferably selected from the group consisting of 2-(3,4-dimethyl-pyrazol-1-yl)-succinic acid, 3,4-dimethylpyrazole (DMP), 3,4-dimethylpyrazolephosphate (DMPP), dicyandiamide (DCD), 1H-1,2,4-triazole, 3-methylpyrazole (3-MP), 2-chloro-6-(trichloromethyl)-pyridine, 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazol, 2-amino-4-chloro-6-methyl-pyrimidine, 2-mercapto-benzothiazole, 2-sulfanilamidothiazole, thiourea, sodium azide, potassium azide, 1-hydroxypyrazole, 2-methylpyrazole-1-carboxamide, 4-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 2,4-diamino-6-trichloromethyl-5-triazine, carbon bisulfide, ammonium thiosulfate, sodium tri-thiocarbonate, 2,3-dihydro-2,2-dimethyl-7-benzofuranol methyl carbamate and N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-alanine methyl ester. Also nitrification inhibitors inhibiting ammonia-oxidizing archaea (AOA) can be employed together with the compound of general formula (I).
When the nitrification inhibitor is employed, the weight ratio of the compound of general formula (I) to the nitrification inhibitor is preferably 0.01 to 100:1, more preferably 0.1 to 10:1.
Furthermore, the fertilizer mixture can contain at least one urease inhibitor, which is preferably selected from N-n-butylthiophosphoric triamide (NBTPT) and/or N-n-propylthiophosphoric triamide (NPTPT). A urease inhibitor is typically added when the fertilizer contains urea. Urea nitrogen is liberated as ammonium by the action of urease, and the ammonium can undergo nitrification. Therefore, it can be advantageous to combine a urease inhibitor with the nitrification inhibitor.
If the compound of general formula (I) of the present invention is combined with N-n-butylthiophosphoric triamide (NBTPT) and/or N-n-propylthiophosphoric triamide (NPTPT), the weight ratio of P-booster(s) to urease inhibitor is preferably in the range of from 0.01 to 100:1, more preferably 0.1 to 10:1.
Thiophosphoric triamides are known to be relatively easily converted to the corresponding phosphoric triamides and thiophosphoric diamides as well as other metabolites. Since, generally speaking, moisture cannot be entirely excluded, thiophosphoric triamide and the corresponding phosphoric triamide are frequently present in a mixture with one another. In this specification, therefore, the term “(thio)phosphoric triamide” identifies not only the pure thiophosphoric triamides and phosphoric triamides, respectively, but also mixtures thereof.
According to the present invention, also mixtures of N-(n-butyl)thiophosphoric triamide and N-(n-)propylthiophosphoric triamide can be employed, as described in EP-A-1 820 788.
The fertilizer mixtures can contain other ingredients, like coatings, for example of inorganic or organic polyacids, which are described in U.S. Pat. No. 6,139,596.
Furthermore, coatings of powders, prills and granules can be formed of inorganic material, such as sulfur- or mineral-based coatings, or with an organic polymer. Respective coatings are described in WO 2013/121384 on page 23, line 37 to page 24, line 16.
As stated above, the agrochemical formulations comprising the compounds of formula (I) are used in “effective amounts”. This means that they are used in a quantity which allows to obtain the desired effect which is a (synergistic) increase of the health or growth of a plant but which does not give rise to any phytotoxic symptom on the treated plant.
For use according to the present invention, the agrochemical formulations comprising the compounds of formula (I) can be converted into the customary formulations, for example solutions, emulsions, suspensions, dusts, powders, pastes and granules. The use form depends on the particular intended purpose; in each case, it should ensure a fine and even distribution of the agrochemical formulations comprising the compounds of formula (I) to the present invention. The formulations are prepared in a known manner to the person skilled in the art.
The agrochemical formulations may also comprise auxiliaries which are customary in agrochemical formulations. The auxiliaries used depend on the particular application form and active substance, respectively. Examples for suitable auxiliaries are solvents, solid carriers, dispersants or emulsifiers (such as further solubilizers, protective colloids, surfactants and adhesion agents), organic and inorganic thickeners, bactericides, anti-freezing agents, antifoaming agents, if appropriate colorants and tackifiers or binders (e.g. for seed treatment formulations).
Suitable solvents are water, organic solvents such as mineral oil fractions of medium to high boiling point, such as kerosene or diesel oil, furthermore coal tar oils and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons, e.g. toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives, alcohols such as methanol, ethanol, propanol, butanol and cyclohexanol, glycols, ketones such as cyclohexanone and gamma-butyrolactone, fatty acid dimethylamides, fatty acids and fatty acid esters and strongly polar solvents, e.g. amines such as N-methylpyrrolidone.
Solid carriers are mineral earths such as silicates, silica gels, talc, kaolins, limestone, lime, chalk, bole, loess, clays, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers, such as, e.g. ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas, and products of vegetable origin, such as cereal meal, tree bark meal, wood meal and nutshell meal, cellulose powders and other solid carriers.
Suitable surfactants (adjuvants, wetters, tackifiers, dispersants or emulsifiers) are alkali metal, alkaline earth metal and ammonium salts of aromatic sulfonic acids, such as ligninsulfonic acid, phenolsulfonic acid, naphthalenesulfonic acid, dibutylnaphthalene-sulfonic acid and fatty acids, alkylsulfonates, alkyl-arylsulfonates, alkyl sulfates, laurylether sulfates, fatty alcohol sulfates, and sulfated hexa-, hepta- and octadecanolates, sulfated fatty alcohol glycol ethers, furthermore condensates of naphthalene or of naphthalenesulfonic acid with phenol and formaldehyde, polyoxy-ethylene octylphenyl ether, ethoxylated isooctylphenol, octylphenol, nonylphenol, alkylphenyl polyglycol ethers, tributylphenyl polyglycol ether, tristearyl-phenyl polyglycol ether, alkylaryl polyether alcohols, alcohol and fatty alcohol/ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl ethers, ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol esters, lignin-sulfite waste liquid and proteins, denatured proteins, polysaccharides (e.g. methylcellulose), hydrophobically modified starches, polyvinyl alcohols, polycarboxylates types, polyalkoxylates, polyvinylamines, polyvinylpyrrolidone and the copolymers thereof. Examples for thickeners (i.e. compounds that impart a modified flowability to formulations, i.e. high viscosity under static conditions and low viscosity during agitation) are polysaccharides and organic and inorganic clays such as Xanthan gum.
A biostimulant is any substance or microorganism, in the form in which it is applied to plants, seeds or the root environment with the intention to stimulate natural processes of plants benefiting nutrient use efficiency and/or tolerate to abiotic stress, regardless of its nutrient content, or any combination of such substances and/or microorganisms intended for this use.
A plant biostimulant is any microorganism or substance based on natural resources, in the form in which it is applied to plants, seeds or the soil and any other substrate with the intention to stimulate natural processes of plants to benefit their nutrient use efficiency and/or their tolerance to stress, regardless of its nutrients content, or any combination of such substances and/or microorganisms intended for this use.
A ‘pesticide’ is something that prevents, destroys, or controls a harmful organism (‘pest’) or dis-ease, or protects plants or plant products during production, storage and transport.
The term includes, amongst others: herbicides, fungicides, insecticides, acaricides, nematicides, molluscicides, rodenticides, growth regulators, repellents, rodenticides and biocides as well as plant protection products.
Plant protection products (PPP) are ‘pesticides’ that protect crops or desirable or target plants. They are primarily used in the agricultural sector but also in forestry, horticulture, amenity areas and in home gardens. They contain at least one active substance and have one of the following functions:
They may also contain other components including safeners and synergists.
An active substance is any chemical, plant extract, pheromone or micro-organism (including viruses), that has action against ‘pests’ or on plants, parts of plants or plant products.
The most common use of pesticides is in the form of plant protection products (PPPs).
The term ‘pesticide’ is often used interchangeably with ‘plant protection product’, however, pesticide is a broader term that also covers non plant/crop uses, for example biocides.
Biocides, like herbicides, bactericides, molluscicides, algicides, phytotoxicants, fungicides, and their mixtures can be added.
Bactericides may be added for preservation and stabilization of the formulation. Examples for suitable bactericides are those based on dichlorophene and benzylalcohol hemi formal (Proxel® from ICI or Acticide® RS from Thor Chemie and Kathon® MK from Rohm & Haas) and isothiazolinone derivatives such as alkylisothiazolinones and benzisothiazolinones (Acticide® M BS from Thor Chemie). Examples for suitable anti-freezing agents are ethylene glycol, propylene glycol, urea and glycerin. Examples for anti-foaming agents are silicone emulsions (such as e.g. Silikon® SRE, Wacker, Germany or Rhodorsil®, Rhodia, France), long chain alcohols, fatty acids, salts of fatty acids, fluoroorganic compounds and agrochemical formulations comprising the compounds of formula (I) thereof.
Suitable colorants are pigments of low water solubility and solvent-soluble, e.g. water-soluble, dyes.
Examples for adhesion promoters, like tackifiers or binders, are polyvinylpyrrolidons, polyvinylacetates, polyvinyl alcohols and cellulose ethers (Tylose®, Shin-Etsu, Japan).
Granules, e.g. coated granules, impregnated granules and homogeneous granules, can be prepared by binding the active substances to solid carriers. Examples of solid carriers are mineral earths such as silica gels, silicates, talc, kaolin, attaclay, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers, such as, e.g., ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas, and products of vegetable origin, such as cereal meal, tree bark meal, wood meal and nutshell meal, cellulose powders and other solid carriers.
Anticaking agents like oils and/or waxes can be added.
The agrochemical formulations generally comprise between 0.01 and 95%, preferably between 0.1 and 90%, most preferably between 0.5 and 90%, by weight of active substances. The compounds of the agrochemical formulations comprising the compounds of formula (I) are employed in a purity of from 90% to 100%, preferably from 95% to 100% (according to their NMR spectrum).
The compounds of the agrochemical formulations comprising the compounds of formula (I) can be used as such or in the form of their agricultural compositions, e.g. in the form of directly sprayable solutions, powders, suspensions, dispersions, emulsions, oil dispersions, pastes, dustable products, materials for spreading, or granules, by means of spraying, atomizing, dusting, spreading, brushing, immersing or pouring. The application forms depend entirely on the intended purposes; it is intended to ensure in each case the finest possible distribution of the compounds present in the agrochemical formulations comprising the compounds of formula (I).
Aqueous application forms can be prepared from emulsion concentrates, pastes or wettable powders (sprayable powders, oil dispersions) by adding water. To prepare emulsions, pastes or oil dispersions, the substances, as such or dissolved in an oil or solvent, can be homogenized in water by means of a wetter, tackifier, dispersant or emulsifier. Alternatively, it is possible to prepare concentrates composed of active substance, wetter, tackifier, dispersant or emulsifier and, if appropriate, solvent or oil, and such concentrates are suitable for dilution with water.
The active substance concentrations in the ready-to-use preparations can be varied within relatively wide ranges. In general, they are from 0.0001 to 10%, preferably from 0.001 to 1%, by weight of compounds of the agrochemical formulations comprising the compounds of formula (I).
The compounds of the agrochemical formulations comprising the compounds of formula (I) may also be used successfully in the ultra-low-volume process (ULV), it being possible to apply compositions comprising over 95% by weight of active substance, or even to apply the active substance without additives.
Various types of oils, wetters, adjuvants, herbicides, fungicides, other pesticides, or bactericides may be added to the active compounds, if appropriate not until immediately prior to use (tank mix). These agents can be admixed with the compounds of the agrochemical formulations comprising the compounds of formula (I) in a weight ratio of 1:100 to 100:1, preferably 1:10 to 10:1.
Compositions of this invention may also contain fertilizers (such as ammonium nitrate, urea, potash, and superphosphate), phytotoxicants and plant growth regulators (plant growth amendments) and safeners. These may be used sequentially or in combination with the above-described compositions, if appropriate also added only immediately prior to use (tank mix). For example, the plant(s) may be sprayed with a composition of this invention either before or after being treated with the fertilizers.
In the agrochemical formulations comprising the compounds of formula (I), the weight ratio of the compounds generally depends from the properties of the compounds of the agrochemical formulations comprising the compounds of formula (I) or (III) or (IV).
The compounds of the agrochemical formulations comprising the compounds of formula (I) can be used individually or already partially or completely mixed with one another to prepare the composition according to the invention. It is also possible for them to be packaged and used further as combination composition such as a kit of parts.
The user applies the composition according to the invention usually from a pre-dosage device, a knapsack sprayer, a spray tank or a spray plane. Here, the agrochemical composition is made up with water and/or buffer to the desired application concentration, it being possible, if appropriate, to add further auxiliaries, and the ready-to-use spray liquid or the agrochemical composition according to the invention is thus obtained. Usually, 50 to 500 liters of the ready-to-use spray liquid are applied per hectare of agricultural useful area, preferably 50 to 400 liters.
In a particular embodiment the absolute amount of the active compounds, represented by formula (I), is used in a range between 1 mg/liter to 100 mg/liter, particularly in a range between 1 mg/l to 20 mg/l, particularly in a range between 1 mg/l to 25 mg/l, particularly in a range between 2 mg/l to 200 mg/l, particularly between 2 mg/l to 100 mg/l, particularly between 2 mg/l to 50 mg/l, particularly between 2 mg/l to 25 mg/l, particularly between 4 mg/l to 40 mg/l, particularly between 4 mg/l to 20 mg/l, particularly between 4 mg/l to 16 mg/l, particularly between 4 mg/l to 12 mg/l.
According to one embodiment, individual compounds of the agrochemical formulations comprising the compounds of formula (I) formulated as composition (or formulation) such as parts of a kit or parts of the inventive mixture may be mixed by the user himself in a spray tank and further auxiliaries may be added, if appropriate (tank mix).
“Agrochemical”, as used herein, means any active substance that may be used in the agrochemical industry (including agriculture, horticulture, floriculture and home and garden uses, but also products intended for non-crop related uses such as public health/pest control operator uses to control undesirable insects and rodents, household uses, such as household fungicides and insecticides and agents, for protecting plants or parts of plants, crops, bulbs, tubers, fruits (e.g. from harmful organisms, diseases or pests); for controlling, preferably promoting or increasing, the growth of plants; and/or for promoting the yield of plants, crops or the parts of plants that are harvested (e.g. its fruits, flowers, seeds etc.).
An “agrochemical composition” as used herein means a composition for agrochemical use, as herein defined, comprising at least one active substance of a compound of formula (I), optionally with one or more additives favoring optimal dispersion, atomization, deposition, leaf wetting, distribution, retention and/or uptake of agrochemicals. As a non-limiting example such additives are diluents, solvents, adjuvants, surfactants, wetting agents, spreading agents, oils, stickers, viscosity-adjusting agents (like thickeners, penetrants), pH-adjusting agents (like buffering agents, acidifiers), anti-settling agents, anti-freeze agents, photo-protectors, defoaming agents, biocides and/or drift control agents.
A “carrier”, as used herein, means any solid, semi-solid or liquid carrier in or on(to) which an active substance can be suitably incorporated, included, immobilized, adsorbed, absorbed, bound, encapsulated, embedded, attached, or comprised. Non-limiting examples of such carriers include nanocapsules, microcapsules, nanospheres, microspheres, nanoparticles, microparticles, liposomes, vesicles, beads, a gel, weak ionic resin particles, liposomes, cochleate delivery vehicles, small granules, granulates, nano-tubes, bucky-balls, water droplets that are part of an water-in-oil emulsion, oil droplets that are part of an oil-in-water emulsion, organic materials such as cork, wood or other plant-derived materials (e.g. in the form of seed shells, wood chips, pulp, spheres, beads, sheets or any other suitable form), paper or cardboard, inorganic materials such as talc, clay, microcrystalline cellulose, silica, alumina, silicates and zeolites, or even microbial cells (such as yeast cells) or suitable fractions or fragments thereof.
The terms “effective amount”, “effective dose” and “effective amount”, as used herein, mean the amount needed to achieve the desired result or results. More exemplary information about amounts, ways of application and suitable ratios to be used is given below. The skilled artisan is well aware of the fact that such an amount can vary in a broad range and is dependent on various factors such as the treated cultivated plant as well as the climatic and soil conditions.
As used herein, the terms “determining”, “measuring”, “assessing”, “monitoring” and “assaying” are used interchangeably and include both quantitative and qualitative determinations.
It is understood that the agrochemical composition is stable, both during storage and during utilization, meaning that the integrity of the agrochemical composition is maintained under storage and/or utilization conditions of the agrochemical composition, which may include elevated temperatures, freeze-thaw cycles, changes in pH or in ionic strength, UV-irradiation, presence of harmful chemicals and the like. More preferably, the compounds of formula (I), (II) as herein described remain stable in the agrochemical composition, meaning that the integrity and the activity of the compounds are maintained under storage and/or utilization conditions of the agrochemical composition, which may include elevated temperatures, freeze-thaw cycles, changes in pH or in ionic strength, UV-irradiation, presence of harmful chemicals and the like. Most preferably, said compounds of formula (I), (II) remain stable in the agrochemical composition when the agrochemical composition is stored at ambient temperature for a period of two years or when the agrochemical composition is stored at 54° C. for a period of two weeks. Preferably, the agrochemical composition of the present invention retains at least about 70% activity, more preferably at least about 70% to 80% activity, most preferably about 80% to 90% activity or more. Examples of suitable carriers include, but are not limited to alginates, gums, starch, β-cyclodextrins, celluloses, polyurea, polyurethane, polyester, or clay.
The agrochemical composition may occur in any type of formulation, preferred formulations are powders, wettable powders, wettable granules, water dispersible granules, emulsions, emulsifiable concentrates, dusts, suspensions, suspension concentrates, suspoemulsions, capsule suspensions, aqueous dispersions, oil dispersions, aerosols, pastes, foams, slurries or flowable concentrates.
In yet another embodiment the invention provides the use of the agrochemical compositions of the invention for enhancing abiotic stress tolerance in plants.
The agrochemical composition according to the invention can be applied once to a crop, or it can be applied two or more times after each other with an interval between every two applications. The agrochemical composition according to the invention can be applied alone or in mixture with other materials, preferably other agrochemical compositions, to the crop; alternatively, the agrochemical composition according to the invention can be applied separately to the crop with other materials, preferably other agrochemical compositions, applied at different times to the same crop.
In yet another embodiment the invention provides a method for the manufacture of (‘or the production of’ which is equivalent wording) an agrochemical composition according to the invention, comprising formulating a molecule of formula (I) as defined herein before, together with at least one customary agrochemical auxiliary agent. Suitable manufacturing methods are known in the art and include, but are not limited to, high or low shear mixing, wet or dry milling, drip-casting, encapsulating, emulsifying, coating, encrusting, pilling, extrusion granulation, fluid bed granulation, co-extrusion, spray drying, spray chilling, atomization, addition or condensation polymerization, interfacial polymerization, in situ polymerization, coacervation, spray encapsulation, cooling melted dispersions, solvent evaporation, phase separation, solvent extraction, sol-gel polymerization, fluid bed coating, pan coating, melting, passive or active absorption or adsorption.
Customary agrochemical auxiliary agents are well-known in the art and preferably include, but are not limited to aqueous and/or organic solvents, pH-adjusting agents (like buffering agents, acidifiers), surfactants, wetting agents, spreading agents, adhesion promoters (like tackifiers, stickers), carriers, fillers, viscosity-adjusting agents (like thickeners), emulsifiers, dispersants, sequestering agents, anti-settling agents, coalescing agents, rheology modifiers, defoaming agents, photo-protectors, anti-freeze agents, additional or further biostimulants (including bacterial and/or fungal inoculants or microorganisms beside non-microbial materials), biocides (preferably selected from herbicides, bactericides, phytotoxicants, fungicides, pesticides/plant protection products and mixtures thereof), additional or further plant growth regulators, safeners, penetrants, anticaking agents, mineral and/or vegetable oils and/or waxes, colorants and drift control agents or any suitable combination thereof.
If the P-boosters are considered as biostimulants and/or plant growth regulators, the additional auxiliary agent can refer to additional or further biostimulants and/or plant growth regulators which are different from the P-boosters.
The insecticide can include an organophosphate, a carbamate, a pyrethroid, an acaricide, an alkyl phthalate, boric acid, a borate, a fluoride, sulfur, a haloaromatic substituted urea, a hydrocarbon ester, a biologically-based insecticide, or a combination thereof. The herbicide, used to remove unwanted plants, can comprise a chlorophenoxy compound, a nitrophenolic compound, a nitrocresolic compound, a dipyridyl compound, an acetamide, an aliphatic acide, an anilide, a benzamide, a benzoic acid, a benzoic acid derivative, anisic acid, an anisic acid derivative, a benzonitrile, benzothiadiazinone dioxide, a thiocarbamate, a carbamate, carbanilate, chloropyridinyl, a cyclohexenone derivative, a dinitroaminobenzene derivative, a fluorodinitrotoluidine compound, isoxazolidinone, nicotinic acide, isopropylamine, an isopropylamine derivative, oxadiazolinone, a phosphate, a phthalate, a picolinic acid compound, a triazine, a triazole, a uracil, a urea derivative, endothall, sodium chlorate, or a combination thereof. The fungicide can comprise a substituted benzene, a thiocarbamate, an ethylene bis dithiocarbamate, a thiophthalidamide, a copper compound, an organomercury compound, an organotin compound, a cadmium compound, anilazine, benomyl, cyclohexamide, dodine, etridiazole, iprodione, metlaxyl, thiamimefon, triforine, or a combination thereof. The fungal inoculant can comprise a fungal inoculant of the family Glomeraceae, a fungal inoculant of the family Claroidoglomeraceae, a fungal inoculant of the family Acaulosporaceae, a fungal inoculant of the family Sacculospraceae, a fungal inoculant of the family Entrophosporaceae, a fungal inoculant of the family Pacidsproraceae, a fungal inoculant of the family Diversisporaceae, a fungal inoculant of the family Paraglomeraceae, a fungal inoculant of the family Archaeosporaceae, a fungal inoculant of the family Geosiphonaceae, a fungal inoculant of the family Ambisporacea, a fungal inoculant of the family Scutellosproaceae, a fungal inoculant of the family Dentiscultataceae, a fungal inoculant of the family Racocetraceae, a fungal inoculant of the phylum Basidiomycota, a fungal inoculant of the phylum Ascomycota, a fungal inoculant of the phylum Zygomycota, a fungal inoculant of the genus Glomus or a combination thereof. The bacterial inoculant can include a bacterial inoculant of the genus Rhizobium, bacterial inoculant of the genus Bradyrhizobium, bacterial inoculant of the genus Mesorhizobium, bacterial inoculant of the genus Azorhizobium, bacterial inoculant of the genus Allorhizobium, bacterial inoculant of the genus Burkholderia, bacterial inoculant of the genus Sinorhizobium, bacterial inoculant of the genus Kluyvera, bacterial inoculant of the genus Azotobacter, bacterial inoculant of the genus Pseudomonas, bacterial inoculant of the genus Azosprillium, bacterial inoculant of the genus Bacillus, bacterial inoculant of the genus Streptomyces, bacterial inoculant of the genus Paenibacillus, bacterial inoculant of the genus Paracoccus, bacterial inoculant of the genus Enterobacter, bacterial inoculant of the genus Alcaligenes, bacterial inoculant of the genus Mycobacterium, bacterial inoculant of the genus Trichoderma, bacterial inoculant of the genus Gliocladium, bacterial inoculant of the genus Klebsiella, or a combination thereof.
Also, the mixture can comprise additionally at least one microorganism selected from the list consisting of Bacillus subtilis strain 713, Bacillus amyloliquefaciens MBI 600, Bacillus pumillus QST2808, Pseudomonas fluorescens, Bradyrhizobium japonicum, Trichoderma vireus, Pseudomonas putida, Trichoderma harzianum Rifai strain T22, Penicillium bilaii, Mesorhizoblum, Azospirillum, Azotobacter vinelandii and Clostridium pasteurianum, Glomus species.
The N compounds of general formula (I) employed according to the present invention can be employed in combination with these auxiliaries. The auxiliaries used depend on the particular application form and the active substance and preferably include solvents, solid carriers, dispersants or emulsifiers, such as solubilizers, protective colloids, surfactants and adhesion agents. Furthermore, organic and inorganic thickeners, bactericides, anti-freezing agents, anti-foaming agents, if appropriate, colorants and tackifiers or binders can be employed in combination with the nitrification inhibitors and in the fertilizer mixture. Suitable auxiliaries are discussed in WO 2013/121384 on pages 25 to 26.
Further possible preferred ingredients are oils, wetters, adjuvants, biostimulants, herbicides, bactericides, other fungicides and/or pesticides. They are for example discussed in WO 2013/121384 on pages 28/29.
The fertilizer mixtures are preferably in solid form, including powders, prills and granules. Furthermore, it is possible to deliver the nitrification inhibitor in the form of a formulation, solution or dispersion separately or simultaneously with a fertilizer.
For respective applications, reference can be made to U.S. Pat. No. 6,139,596 and WO 2013/121384 as well as WO 2015/086823 and WO 2016/207210.
The present invention also relates to a method of fertilizing soils exploited agriculturally or horticulturally, wherein a fertilizer mixture containing compounds A and B A. an inorganic and/or organic and/or organomineral fertilizer and
In parallel with the improvement of the utilization of phosphorus and possibly nitrogen in the phosphorus and possibly ammonium- or urea-containing mineral, organic and organomineral fertilizers, the use of the P-boosters, according to the present invention, and of compositions containing them has the effect that there is an increase, in some cases considerably, in the yields and production of biomass of crop plants.
The plants to be treated or rooted in soil to be treated according to the invention are preferably selected from the group consisting of agricultural, silvicultural, ornamental and horticultural plants, each in its natural or genetically modified form. Preferably, non-transgenic agricultural plants are treated.
Preferred agricultural plants are field crops selected from the group consisting of potatoes, sugar beets, wheat, barley, rye, oat, sorghum, rice, maize, cotton, rapeseed, oilseed rape, canola, soybeans, peas, field beans, sunflowers, sugar cane; cucumbers, tomatoes, onions, leeks, lettuce, squashes; even more preferably the plant is selected from the group consisting of wheat, barley, oat, rye, soybean, maize, oilseed rape, cotton, sugar cane, rice and sorghum.
In a preferred embodiment of the invention, the plant to be treated is selected from the group consisting of tomato, potato, wheat, barley, oat, rye, soybean, maize, oilseed rape, canola, sunflower, cotton, sugar cane, sugar beet, rice, sorghum, pasture grass and grazed land.
In another preferred embodiment of the invention, the plant to be treated is selected from the group consisting of tomato, potato, wheat, barley, oat, rye, soybean, maize, oilseed rape, canola, sunflower, cotton, sugar cane, sugar beet, rice and sorghum.
In an especially preferred embodiment of the invention, the plants to be treated are selected from the group consisting of tomato, wheat, barley, oat, rye, maize, oilseed rape, canola, sugar cane, and rice.
In one embodiment, the plant to be treated according to the method of the invention is an agricultural plant. “Agricultural plants” are plants of which a part (e.g. seeds) or all is harvested or cultivated on a commercial scale or which serve as an important source of feed, food, fibres (e.g. cotton, linen), combustibles (e.g. wood, bioethanol, biodiesel, biomass) or other chemical compounds. Preferred agricultural plants are for example cereals, e.g. wheat, rye, barley, triticale, oats, sorghum or rice, beet, e.g. sugar beet or fodder beet; fruits, such as pomes, stone fruits or soft fruits, e.g. apples, pears, plums, peaches, almonds, cherries, strawberries, raspberries, blackberries or gooseberries; leguminous plants, such as lentils, peas, alfalfa or soybeans; oil plants, such as rapeseed, oilseed rape, canola, linseed, mustard, olives, sunflowers, coconut, cocoa beans, castor oil plants, oil palms, ground nuts or soybeans; cucurbits, such as squashes, cucumber or melons; fiber plants, such as cotton, flax, hemp or jute; citrus fruit, such as oranges, lemons, grapefruits or mandarins; vegetables, such as spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, cucurbits or paprika; lauraceous plants, such as avocados, cinnamon or camphor; energy and raw material plants, such as maize, soybean, rapeseed, canola, sugar cane or oil palm; tobacco; nuts; coffee; tea; bananas; vines (table grapes and grape juice grape vines); hop; turf; natural rubber plants.
Pasture grass and grassland are composed of grass or grass mixtures comprising for example Bluegrass (Poa spp.), Bentgrass (Agrostis spp.), Ryegrasses (Lolium spp.), Fescues (Festuca spp., hybrids, and cultivars), Zoysiagrass (Zoysia spp.), Bermudagrass (Cynodon spp.), St. Augustine grass, Bahiagrass (Paspalum), Centipedegrass (Eremachloa), Carpetgrass (Axonopus), Buffalograss and Grama grass. Pastures may be also composed of mixtures comprising afore mentioned grasses, for example Ryegrass, and Trifolium species, for example Trifolium pratensis and Trifolium repens, Medicago species like Medicago sativa, Lotus species like Lotus corniculatus, and Melilotus species, for example Melilotus albus.
In one embodiment, the plant to be treated according to the method of the invention is a horticultural plant. The term “horticultural plants” are to be understood as plants which are commonly used in horticulture—e.g. the cultivation of ornamentals, herbs, vegetables and/or fruits. Examples for ornamentals are turf, geranium, pelargonia, petunia, begonia and fuchsia. Examples for vegetables are potatoes, tomatoes, peppers, cucurbits, cucumbers, melons, watermelons, garlic, onions, carrots, cabbage, beans, peas and lettuce and more preferably from tomatoes, onions, peas and lettuce. Examples for fruits are apples, pears, cherries, strawberry, citrus, peaches, apricots and blueberries. In horticulture, often a substrate replaces (part of) the soil.
In one embodiment, the plant to be treated according to the method of the invention is an ornamental plant. “Ornamental plants” are plants which are commonly used in gardening, e.g. in parks, gardens and on balconies. Examples are turf, geranium, pelargonia, petunia, begonia and fuchsia.
In one embodiment, the plant to be treated according to the method of the invention is a silvicultural plant. The term “silvicultural plant” is to be understood as trees, more specifically trees used in reforestation or industrial plantations. Industrial plantations generally serve for the commercial production of forest products, such as wood, pulp, paper, rubber tree, Christmas trees, or young trees for gardening purposes. Examples for silvicultural plants are conifers, like pines, in particular Pinus spec, fir and spruce, eucalyptus, tropical trees, like teak, rubber tree, oil palm, willow (Salix), in particular Salix spec, poplar (cottonwood), in particular Populus spec, beech, in particular Fagus spec, birch, oil palm, and oak.
The following definitions apply:
The term “P-booster” is to be understood as compounds of formula (I) that improve the phosphorus acquisition and/or use of the plants treated therewith, and/or can lead to improved plant growth.
The term “plants” is to be understood as plants of economic importance and/or men-grown plants. They are preferably selected from agricultural, silvicultural, ornamental and horticultural plants, each in its natural or genetically modified form. The term “plant” as used herein includes all parts of a plant, such as germinating seeds, emerging seedlings, herbaceous vegetation, as well as established woody plants, including all belowground portions (such as the roots) and aboveground portions.
The term “soil” is to be understood as a natural body comprised of living (e.g. microorganisms (such as bacteria and fungi), animals and plants) and non-living matter (e.g. minerals and organic matter (e.g. organic compounds in varying degrees of decomposition), liquid, and gases) that occurs on the land surface, and is characterized by soil horizons that are distinguishable from the initial material as a result of various physical, chemical, biological, and anthropogenic processes.
The term “nitrification inhibitor” is to be understood as any chemical substance which slows down or retards the nitrification process which is typically occurring in (fertilized) soil. Nitrification inhibitors retard the natural transformation of ammonium into nitrate and target microorganisms and preferably ammonia-oxidizing bacteria (AOB), preferably by inhibiting the activity of the bacteria, such as Nitrosomonas spp. and/or Nitrosospira spp. They may additionally act on ammonia-oxidizing archaea (AOA). The nitrification inhibitor is most often combined with a fertilizer, preferably an (ammonium) nitrogen-containing fertilizer, e.g. solid or liquid inorganic, organic and/or organomineral fertilizer, or manure.
The term “nitrification” is to be understood as the biological oxidation of ammonia (NH3) or ammonium (NH4+) with oxygen into nitrite (NO) followed by the oxidation of these nitrites into nitrates (NO) by microorganisms. Besides nitrate (NO) nitrous oxide is also produced though nitrification. Nitrification is an important step in the nitrogen cycle in soil.
The term “fertilizers” is to be understood as (chemical) compounds applied to promote plant and fruit growth. Fertilizers are typically applied either through the soil (for uptake by plant roots) or by foliar feeding (for uptake through leaves). The term “fertilizers” can be subdivided into two major categories: a) organic fertilizers (composed of decayed plant/animal matter) and b) inorganic fertilizers (composed of chemicals and minerals). Organic fertilizers include slurry, worm castings, peat, seaweed, sewage, and guano. Manufactured organic fertilizers include compost, blood meal, bone meal and seaweed extracts. Further examples are enzymatically digested proteins, fish meal, and feather meal. The decomposing crop residue from prior years and manure are another source of fertility. In addition, naturally occurring minerals, such as mine rock phosphate, sulfate of potash and limestone, are also considered as belonging to inorganic fertilizers. Inorganic fertilizers are usually manufactured through chemical processes (such as the Haber-Bosch process), also using naturally occurring deposits, while chemically altering them (e.g. concentrated triple superphosphate). Naturally occurring inorganic fertilizers include Chilean sodium nitrate, mine rock phosphate, and limestone. As a third category organomineral fertilizers can be mentioned, as a combination of inorganic and organic fertilizers.
The term “fertilizer comprising urea” (urea fertilizer) is defined as synthetic fertilizers comprising urea, excluding any naturally occurring fertilizers comprising urea (for instance manure as an example for a naturally occurring fertilizer comprising urea). Examples of fertilizer comprising urea are urea ammonium nitrate (UAN), isobutylidene diurea (IBDU), crotonylidene diurea (CDU) and urea formaldehyde (UF). Urea is usually made as granulated material or prills. Urea fertilizer can be produced by dropping the liquid urea from a prill tower while drying the product. Urea can also be obtained as a liquid formulation, which may be used for foliar application, e.g. on potatoes, wheat, vegetables and soybeans as well as liquid application to the field. It is commonly mixed with ammonium nitrate to form UAN with 28% N.
The term “locus” (plant habitat) is to be understood as any type of environment, soil, area or material where the plant is growing or intended to grow. Especially preferred according to the invention is soil.
The invention is further illustrated by the following examples which show that the compounds of formula (I) are strong P-boosters.
We report on a substance that suppresses Arabidopsis SPX1 and promotes plant growth in phosphate starvation conditions. We validate its positive effect on plant growth in diverse plants, and show that the activity of this substance is retained in a number of variants, which structurally characterize the class of molecules with this activity.
These results show that the use of SPX genes as a biomarker to screen for SPX suppressing molecules is a potent approach to discover new plant growth promoting or phosphate stress reducing substances.
All Arabidopsis plant experiments were performed using the Arabidopsis thaliana Columbia-0 background. The Arabidopsis pSPX1::GUS line is described in the Plant Journal 2008, 54: 965-975. For rice, the cultivar Nipponbare was used. For maize, the cultivars DKC 2931 and B104 were used for regular pot experiments and sand-based pot experiments, respectively. For soybean, the cultivar Primus was used. Medium-based plant experiments used a modified Murashige and Skoog medium (modMS—20 mM NH4NO3, 0.1 mM H3BO3, 3 mM CaCl2, 0.1 μM CoCl2*6H2O, 0.1 μM CuSO4*5H2O, 0.1 mM Na2EDTA*2H2O, 0.1 mM FeSO4*7H2O, 1.5 mM MgSO4*7H2O, 0.1 mM MnSO4*H2O, 1 μM Na2MoO4*4H2O, 5 μM KI, 19 mM KNO3, 0.03 mM ZnSO4*7H2O, 0.1 g/L myo-inositol and 0.5 g/L MES (pH 5,7)), or a regular half strength Murashige and Skoog medium (MS1/2) with 300 μM phosphate (low phosphate: 300 μM KH2PO4, 9.9 mM KCl), 600 μM phosphate (suboptimal phosphate: 600 μM KH2PO4, 9.6 mM KCl) or 1.25 mM phosphate (high phosphate: 1.25 mM KH2PO4), except when stated otherwise. The medium was solidified due to the addition of 0.6% Gelrite, unless stated otherwise. In case of vertical plates (root length and root hair measurements), the medium was supplied with 0.5% of sucrose and 1 μM (low phosphate, 1 μM KH2PO4, 9.9 mM KCl), 10 μM (low phosphate 10 μM KH2PO4, 9.9 mM KCl) or 1.25 mM KH2PO4 (high phosphate). Arabidopsis seeds were stratified for 2 days at 4° C. before germination. Seedlings were germinated in climate-controlled growth chambers at 22° C. under continuous light (100 μmol m−2 s−1). Husked rice seeds were germinated on wetted Whatman paper for 2 days at 37° C. and then transferred to Sterivent boxes or square Petri dishes with solid medium. Maize and soybean seeds were wetted 24 hours at room temperature prior to sowing in pots.
For the chemical activity assessment 3 to 8 seeds per well of Arabidopsis pSPX1::GUS line were sown in 96-well plates containing 150 μl of low phosphate modMS liquid medium containing 1% of sucrose. Compounds were added in 50 μM concentration, starting from a 5 mM stock of compounds solved in DMSO. Different chemical substances were separately added to different wells. Per plate, 16 control wells were used, 8 containing only the low phosphate medium and 1% DMSO, and 8 containing high phosphate medium and 1% DMSO. 7 days after germination, plates were scanned using a flatbed scanner (EPSON Expression 11000XL) and analyzed for leaf size. After scanning, the growth medium was replaced by GUS staining solution (see Plant Mol. Biol. Rep. 1994, 12: 37-42 for details) and incubated for 1.5 hours at 37° C. The plates were scanned a second time and analyzed for GUS signal area. Measurements of both leaf area and GUS signal area were conducted by filtering out and measure the green and blue signal, respectively using ImageJ software. If the green leaf area was 50% or less than the control, samples were omitted. Additionally, all results were visually screened for leaf size and GUS signal.
Arabidopsis primary root growth experiments were done on MS1/2 on vertical standing plates and roots were measured 11 days after germination. Roots were imaged using a flatbed scanner (EPSON Expression 11000XL) and root length was measured using ImageJ software. Arabidopsis shoot biomass was determined in 11 days after germination and growth on vertical standing plates with modMS. Arabidopsis leaf area was measured 21 days after germination on horizontal plates with modMS medium. Plates were scanned from the top using a flatbed scanner (EPSON Expression 11000XL) and the visible leaf area was measured using ImageJ software. Rice plate experiments used vertically standing Petri dishes containing MS1/2 medium (low phosphate—0.001 mM) solidified with 0.8% washed agar. Plant height was measured 11 days after germination. Rice box experiments used modMS medium and a low phosphate condition of 0.025 mM phosphate. Plant height was measured 13 days after germination. All growth experiments occurred with 10 μM of compound and in low phosphate conditions, unless stated otherwise. Controls always received the same DMSO concentration.
Regular Arabidopsis, soybean and maize pot experiments used an unfertilized potting soil, which was supplemented at the start of the experiment with 50 ml H2O containing 0.25 g/l NH4NO3 and 0.44 g/l (high phosphate) or no (maize and soybean) or 0.11 g/l KH2PO (Arabidopsis) for low phosphate conditions. For the sand-based maize pot experiment, sand was supplemented with 50 ml H2O containing 0.25 g/l NH4NO3 and 0.38 g/l (high phosphate) or 0.02 g/l (low phosphate) KH2PO4. Potassium was balanced via addition of KCl. Compound concentration was 10 μM, calculated based on the total water content after watering, and was added at the start of the experiment (Arabidopsis) or once a week (maize). Indexed chlorophyll contents were received via a SPAD 502 Plus Chlorophyll Meter. All parameters in the sand experiment, except the rate of leaf 4 (measured the first 4 days after emergence), were measured 19 days after sowing. Measurements in the pot experiments with potting soil were done after 4 weeks of growth, except for leaf 5, which was measured at 26 days. One long-term maize pot experiment was conducted with the DKC 2931 (2.5 months) and B104 (3 months) cultivars on the PHENOVISION phenotyping platform as described in Frontiers in Plant Science 2021, 12: 640914, except that an unfertilized potting soil was used and that plants were fertilized with a low-phosphate Hoagland solution. The 2.5× overconcentrated low-phosphate Hoagland solution contained 0.034 g/l KH2PO and 200 mL of this solution was applied twice a week. 1.4 mL of a 10 mM compound solution was added each two weeks to each pot, corresponding to 9.6 mg/g nutrients. 13 plants per condition were used. During the experiment, pictures were taken twice a week for each plants from 6 different angles and the top. Pictures were used to extract the plant height and to extract the projected plant area from each side and calculate an estimated plant volume over time.
Col-0 ecotype Arabidopsis seeds were sown in 96-well plates containing 150 μl of low phosphate modMS liquid medium containing 1% of sucrose. Compounds was added in 50 μM concentration (1% DMSO). 7 days after germination, plates were scanned using a flatbed scanner (EPSON Expression 11000XL) and wells containing non-germinated seedlings were excluded from the following analysis. Plants were removed from each well and 50 μl of medium was recovered from each well and used for molybdenum blue staining as described in Plant Physiology 2008, 146:1673-1686. To measure the phosphate level in soil, Olsen P extraction was used on 1 g of air dried soil, 500 ul of extract was used for molybdenum blue staining as described in The Plant cell 2013, 25:1641-1656. Values were expressed relative to the low phosphate control.
Col-0 ecotype Arabidopsis seeds were sown in 96-well plates containing 150 μl of low phosphate modMS liquid medium containing 1% of sucrose. Compounds was added in 50 μM concentration (1% DMSO). Eight plants per repeat were collected 7 days after germination and put into a fresh Eppendorf. Extraction and quantification of anthocyanin levels was carried out according to The Plant cell 2013, 25:1641-1656. Anthocyanin levels were quantified by measuring absorption at 530 and 657 nm using a spectrophotometer and normalized to fresh weight input, and expressed relative to the low phosphate control. For pot experiments, the same procedure was followed with one 4-week old plant per sample.
Roots were imaged using a stereomicroscope or a VHX-6000. Number and length of the root hairs parallel to the medium surface was determined at 4 to 6 mm above the root meristem. Root hair length was measured using the ImageJ software.
To identify new substances that suppress the expression of the SPX1 phosphate starvation biomarker, we used an Arabidopsis SPX1 reporter line pSPX1::GUS. After 7 days of growth in low phosphate conditions, the SPX1 biomarker, visualized by blue GUS staining, is typically clearly induced in the roots. But the molecule 6-amino-1,3-dimethyl-5-[2-(2-methyl-2,3-dihydro-1,4-benzoxazin-4-yl)acetyl]pyrimidine-2,4-dione (named compound 8) practically completely suppressed the SPX1 biomarker, and hence reduces phosphate starvation response. This observation was confirmed in two experimental repeats. 2. The Application of compound 8 reduces phosphate starvation stress Two typical plant responses towards phosphate deficiency are the production of anthocyanin and growth inhibition of the primary root. To confirm the reduction of the phosphate starvation effect by compound 8, its effect on primary root growth and anthocyanin levels were evaluated in Arabidopsis.
Upon treatment with 10 μM compound 8, the primary root length of 11-day-old Arabidopsis plants grown in low phosphate is almost double the length of the control without compound (Table 1). Moreover, the anthocyanin level in the leaves is reduced after treatment with compound 8, both when growing the plants in pots or in a 96-well plate assay (Table 1). These observation shows that compound 8 reduces the phosphate starvation response.
To further validate the positive effect of compound 8, growth experiments were performed in different growing systems and using different plant species. In different experiments, compound 8 showed a clear positive effect on the shoot biomass, leaf area, formation of ears or plant height in Arabidopsis, rice, soybean and maize, both in plate, box or pot experiments (Table 1). Also in an extensive long-term experiment with two different maize cultivars, compound 8 has a clear promotive effect on growth and on ear setting (Table 1, Table 2). The phosphate levels in the soil after 4 weeks of Arabidopsis growth, shows a reduction if treated with compound 8 (Table 1). This indicates that compound 8 treatment results in higher phosphate uptake.
Interestingly, we also observed that compound 8 increased both the number of root hairs and the average length of root hairs, which together result in an increased total root hair length (Table 1). Root hairs and the root hair surface are known to be important for phosphate uptake. The induction of the root hairs and the accompanying increase in absorptive area might therefore explain the positive and phosphate starvation reducing effect of compound 8.
To explore the chemical space of the new phosphate fertilizer enhancer, a variety of structural homologs of compound 8 were characterized by evaluating their effect on the SPX1 phosphate starvation biomarker and/or on root hair development (Table 5). This shows that structures with the general formula (I) retain compound 8 activity and reduce phosphate starvation.
For a subset of compounds, we performed a more extensive analysis on their root hair inducing effect in a dose-response experiment (Table 3). This confirms that the more simple structures 8.14 and 8.14.6 still retain the activity of compound 8. The higher effect at lower doses moreover suggest a stronger activity. Altogether, this shows that structures with the general formula (I) retain compound 8 activity and reduce phosphate starvation. As all structures induce root hairs and/or suppress the phosphate starvation response, it can be assumed that they, similar to compound 8, have a positive effect on phosphate uptake and hence plant growth in general. To validate this, we performed a maize growth experiment using compound 8 and the, based on the increase of total root hair length, stronger variant 8.14.6. The experiment was conducted in pots with a mixture of unfertilized potting soil and sand, and leaf 5 was measured after 29 days (Table 4). This shows that compound 8.14.6 has even a stronger growth-promoting effect, and confirms that variants of compound 8 that suppress the SPX1 phosphate starvation marker or that induce root hairs or root hair elongation can be expected to have a growth-promoting effect.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21166312.5 | Mar 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/058202 | 3/29/2022 | WO |
