Every year, truck farms, meristem operations and plant cultivators sustain great damage due to organisms that infect sets (e.g. plantlets), young plants, mother plants and seeds, destroying them or rendering them useless. If, for example, viruses enter a cultivation, it can be assumed that 100% of the plants will be damaged. The only option open to the truck farms then is the radical measure of destroying the entire culture.
Specifically active agents are commercially available with which a few phytopathogens can be combated without influencing the vitality of the plant. These agents, designated as pesticides, are systemically effective but usually have only a narrow spectrum of activity.
On the other hand, a significantly broader spectrum of activity is offered by common disinfecting agents based on aldehydes, phenols, halogens, peroxides and quaternary ammonium compounds. If these “surface disinfecting agents” get on the plant or are directly applied to the plant, this always entails irreversible damage to the plant. This means that such disinfecting agents can only be used on working surfaces, positioning surfaces and devices such as, e.g., knives and the like. The surfaces must be freed thereafter from adhering remnants of active substances in order not to endanger the plants during subsequent working steps.
However, a sufficient inactivation is not even assured on surfaces since these agents always exhibit significant gaps in their activity against phytopathogenic organisms.
DE OS 32 27 126 and DE OS 32 29 097 teach that certain combinations of anionic surfactants, aliphatic and aromatic carboxylic acids as well as a few heteroaromatic acids are capable of comprehensively killing off or inactivating viruses, bacteria and fungi without gaps in their activity.
The microbes tested according to the above-cited Offenlegungsschriften and patents were primarily human-pathogenic organisms with a low infectiousness like those recommended as test microbes by, among others, the German Society for Hygiene and Microbiology (DGHM) and the German Society for Veterinary Medicine (DVG).
The application of the teaching to highly infectious and resistant phytopathogenic organisms displayed a microbicidal and virus-inactivating activity that was just as persevering as had already been shown to be the case with the human-pathogenic test germs.
However, further tests for plant compatibility with the same agents regularly resulted in a damaging of the test plants in the form of severe scorching, so that the use on plants appeared to be excluded.
It was surprisingly found that the use of certain acid combinations and surfactant combinations in the presence of glycols overcomes the previous deficiency in the combating of phytopathogenic organisms, and that, when applied directly onto a plant, they retain a pronounced bactericidal, fungicidal and viricidal activity and do not damage the plant cells (roots, stems, leaves, flowers and fruit) in the application concentration.
The present invention relates to agents for treating plants and their environment with the goal of killing off phytopathogenic bacteria, fungi, viruses and viroids and of hindering their spread. Even pathogens (e.g., viruses) that are already on plants can be killed off or inactivated by these agents by moistening roots, stems, leaves and flowers without damaging the plant cells. The biological behavior of the plant is also not altered by the treatment. Working areas in the vicinity of the plants (e.g., tables, knives, positioning surfaces) that could cause a contamination are also freed in a long-lasting manner of noxious organisms therewith without phytotoxic residues having to be subsequently removed.
The invention is further described in the following non-limiting examples.
Bactericidal Activity on the Plant (Biotest)
A. Young plant pelargoniums and begonias were contaminated by spraying with Xanthomonas campestris. A leaf surface of 1 cm2 had 104 KBE after the contamination.
A treatment with example 4 in concentrations of 1.0%, 2.0% and 3.0% was conducted, also with a spraying method, one hour after the inoculation.
Specimens were taken one hour after the treatment. The germs of the treated and of the untreated controls (without example 4) were removed from the leaves by ultrasound (wash liquid of 0° C.) and their number determined.
B. Pelargoniums and begonias were treated by spraying with example 4.
The contamination with Xanthomonas campestris took place, also with a spraying method, 24 hours after the treatment with example 4.
Specimens were taken one hour after the contamination. The germs of the treated and of the untreated controls (without example 4) were removed from the leaves by ultrasound (wash liquid of 0° C.) and their number determined.
Scorching, lesions on the leaf edges and the leaf blades, germ reduction and leaf compatibility are cited in the following table:
Plant Compatibility
Maximal tolerable concentrations of formulation examples 2, 4 and 5 on plant organs [numerical and sign data require no translation]
1orchid type
The test for a sufficient inactivation of phytopathogenic organisms gave in the following results:
Required Contact Times of Examples 1–5 for Killing Off the Indicated Bacterial Strains
Xanthomonas
Pseudomonas
Erwinia
pelargonii
solanaceum
amylovora
Required Contact Times of Examples 1–5 for Killing Off the Indicated Fungus Test Strains
Fusarium
Thielaviopsis
Phythophtora
Cylindrocladium
oxysporum
basicola
scoparium
Required Contact Times of Examples 1–5 for Inactivating the Indicated Viral Strains (Suspension Test)
The test for a sufficient inactivation of phytopathogenic organisms gave in the following results:
Required Contact Times of Examples 1–5 for Killing Off the Indicated Bacterial Strains
Xanthomonas
Pseudomonas
Erwinia
pelargonii
solanaceum
amylovora
Number | Date | Country | Kind |
---|---|---|---|
198 50 994 | May 1998 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP99/07151 | 9/25/1999 | WO | 00 | 5/4/2001 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO00/27192 | 5/18/2000 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4414128 | Goffinet | Nov 1983 | A |
4904683 | Ligtvoet et al. | Feb 1990 | A |
Number | Date | Country |
---|---|---|
3229097 | Feb 1984 | DE |
343885 | Mar 1986 | DE |
4233806 | Apr 1994 | DE |
0091213 | Oct 1983 | EP |
WO96 11572 | Apr 1996 | WO |
WO-9611572- | Apr 1996 | WO |