Patent Application
20110083519
This invention relates to a method and device for measuring the susceptibility of corn plants to stalk lodging and brittle snap. The invention provides a way of measuring and recording stalk lodging and brittle snap so the data can be specifically used to provide meaningful information in hybrid corn breeding to facilitate the development of corn plants having good stalk lodging and brittle snap properties.
Corn is an important and valuable field crop. Thus, a continuing goal of plant breeding is to develop stable, high yielding corn hybrids that are agronomically sound. The reasons for this goal are obvious: To maximize the amount of grain produced on the land and to supply food for both animals and humans.
The overall goal of a corn plant breeder is to combine, in a single variety/hybrid, various desirable traits of the parental lines. For field crops, these traits may include resistance to diseases and insects, tolerance to heat and drought, reducing time to crop maturity, greater yield, and better agronomic qualities. The mechanical harvesting of many crops has placed increased importance on the uniformity of plant characteristics such as germination, stand establishment, growth rate to maturity, and fruit size.
In order to have the plants stand tall and withstand the various mechanical forces applied by wind, rain, harvesting equipment, etc., it is important that the plant stalk have good mechanical properties and that the roots are firmly anchored into the soil. Otherwise, the stalks may bend, break or be pulled out, leading to the loss of a harvestable ear.
It has become common place for corn plant breeders to use a set of fairly standard definitions for characterization of the mechanical properties of roots and stalks. For example, brittle snap is a measure of the stalk breakage below the ear during ear development and is an indication of whether a hybrid will snap or break near the time of flowering, under severe winds. Data is often presented as a percentage of plants that do not snap after a wind event.
Stalk lodging, is a trait measured near harvest time, and is scored as the percentage of plants that do not exhibit stalk breakage at the base of the plant, when measured either by observation of natural lodging in the field, or by physically pushing on stalks, and then determining the percentage of plants that break or do not break at the base of the plant.
Root lodging is a trait scored as the percentage of plants in a plot or field that do not exhibit excess leaning of the plant from the normal vertical axis. Typically, plants that lean from the vertical axis at an approximately 30 degree angle or greater would be counted as lodged. Root lodging often is reported as a rating of one to nine where a higher score indicates less root lodging potential (one is very poor, five is intermediate, and nine is very good, respectively for resistance to root lodging). There are two types of root lodging, early root lodging and late root lodging. Early root lodging occurs right before flowering. Late root lodging occurs within approximately two weeks of anticipated harvest or after pollination. Late root lodging is more problematic because of the inability of the plant to recover before harvest, which results in consequent yield losses.
Both early and late root lodging occur as a result of the interaction between the root system, the soil and the wind force pushing the plants during a storm. In moisture saturated soils, frictional forces between the root system and the soil particles are significantly reduced allowing the root to rotate when a lateral force is applied to the stalks. This rotation is in the direction of the force vector after the consequent lodging.
As those skilled in agricultural arts know, nearly every part of the corn plant has a use. Corn is used as human food, livestock feed, and as a raw material in many industries. The food uses of corn, in addition to human consumption of corn kernels, include products of both dry- and wet-milling industries. The principal products of corn dry milling are grits, meal and flour, while the corn wet-milling industry provides starch, syrups, and dextrose for food use. Corn oil is recovered from corn germ, which is a by-product of both dry- and wet-milling industries.
Corn is also used extensively as livestock feed primarily for beef cattle, dairy cattle, hogs, and poultry.
Industrial uses of corn are mainly from corn starch, from the wet-milling industry, and corn flour from the dry-milling industry. The industrial applications of corn starch and flour are based on its functional properties, such as, viscosity, film formation, adhesive properties, and the ability to suspend particles. Corn starch and flour have applications in both the paper and textile industries. Other industrial uses include applications in adhesives, building materials, foundry binders, laundry starches, explosives, oil-well muds, other mining applications, and for ethanol production.
Plant parts other than the grain of corn are also used in industry. Stalks and husks are made into paper and wallboard and cobs are used for fuel and to make charcoal.
Growers thus are interested in producing corn plants that have the very best grain or plant quality properties, produce the highest yield and therefore have the greatest potential for income.
An embodiment of the present invention provides a method and means of objectively measuring the susceptibility of corn plants to stalk lodging and brittle snap.
A further embodiment of the present invention provides a device which objectively measures a corn plants' susceptibility to stalk lodging and brittle snap that is relatively inexpensive, easy to make and easy to use.
An embodiment of the present invention provides a method and device that can be used to test more effectively a hybrid's susceptibility to stalk lodging and brittle snap earlier in the product development cycle of a new hybrid than existing standard methods. Moving the testing for these traits much earlier in the development cycle allows for selection and advancement of the more desirable lines more easily, and at a point in the process when seeds of a new hybrid are relatively limited in numbers, which poses constraints with traditional methods that typically require more plants per hybrid for evaluation of stalk lodging and brittle snap. Also, traditional methods of scoring for such lodging and brittle snap depend on growing the plants in many locations in an attempt to have some locations present where naturally occurring environmental conditions occur, especially damaging winds that occur at key developmental stages. The present invention allows testing of the plants as needed, and is not dependent on the chance that a damaging wind might or might not occur, and so provides for a more reliable and resource efficient approach to testing for such traits. These embodiments as well as numerous benefits of the present invention will become apparent from the detailed description of the invention which follows hereinafter.
A device to identify the susceptibility of corn plants to stalk lodging and brittle snap is provided. The device is used to push on a corn stalk and the force used to push on the stalk, and the vibration of the stalk during the test is recorded. As material breaks within the stalk, an accelerometer measures stalk vibration in response to the breaking events; the data is recorded to allow meaningful measurements and analysis of susceptibility of plant stalks to breakage. This allows for screening of various hybrids for their susceptibility to stalk lodging and brittle snap.
The device is used to measure the susceptibility of corn plants to stalk lodging and brittle snap. When used to push on a corn stalk, the force applied on the stalk and the vibration of the stalk due to stalkbreakage during the test is recorded. Stalksbreak as a consequence of the applied lateral force. These breakage events are measured by an accelerometer, which measures stalk vibration. A software program (using Matlab, available from The Mathworks, Inc., Natick, Mass.) was written to correlate the number of breakage events in the accelerometer response and the input force to the known strength of the hybrid. It is within the skill of the art to determine the appropriate threshold of signal to noise ratio for optimal use of the device. The device can be used in early hybrid development to test for susceptibility to stalk lodging and brittle snap, before a large number of seeds are available for broad field testing, thus moving the opportunity for testing for these traits earlier in the development cycle of a new hybrid.
An accelerometer 24 is attached to the plant, as illustrated in
Turning from the schematic of
The backing plate 30 can be made from a variety of materials, including but not limited to, metals, plastics, Teflon®, nylon and wood. Specifically, an aluminum backing plate 30 is satisfactory. Force transducer 22 is mounted to the backing plate 30 so that the force 50 applied on the transducer 22 is measured. Stalk holder 34, is a plate with a V-notch in its front, and which can also be made from numerous materials as described above, is mounted, for example, with a screw to the center mounting plate of the force transducer 22. The notch portion of the V-notch of stalk holder 34 is applied against the longitudinal axis of the corn stalk to allow the force 50 to be applied perpendicular to the stalk. In this way, the user is assured force 50 is applied at the correct location. Other suitable notch shapes may be used in the present invention such as a U-notch or any variation that enables the stalk to be held in place while the test is run.
The force transducer 22 can be, but does not necessarily have to be a Loadstar AS-C-50-025 load sensor, available from Loadstar Sensors, Inc., Fremont, Calif. It is within the skill in the art to determine the suitability of other readily available force transducers. As illustrated in
The accelerometer 24 (one suitable example is PCB 35 2A60, available from PCB Piezotronics, Depew, N.Y.) is then positioned adjacent to corn stalk 10 at its lower end, either at the first or second internodes 12 and 14, respectively. As illustrated in
As illustrated, microphone 28 may be held near to the ground 60 at the base of the stalk 10 in order to record the sound of the breaking events. However, the sound captured from the breaking root events, as opposed to the vibrations, has been found to be a less reliable predictor since the former is subject to also capturing background noise from a variety of other sources in the vicinity.
A further embodiment of the present invention is shown in
An accelerometer 24 is attached to the plant, as illustrated in
The devices described herein can be used to push on individual plants to simulate stalk lodging and brittle snap. During the push, the force, the stalk vibration and the sound (optional) are measured. As illustrated in the schematic of
The accelerometer and the microphone signals were amplified and passed through an anti-aliasing filter with a 15,000 Hz cutoff frequency. The force transducer signal was input directly to the data acquisition system.
While the embodiments described above use a pushing force it is within the skill in the art to modify the apparatus to use a pulling force on a corn stalk. The pulling force applied to the stalk and the vibration of the stalk due to stalk lodging or brittle snap during the test is recorded as described above.
During field testing as described below in the Examples, the data acquisition system was located at the edge of the field and 150 foot long cables were used to connect the computer based data acquisition system with the power supply of the microphone, accelerometer and the force transducer. It should be noted that each device was located within approximately 3-5 feet of its power supply. The cable lengths used here did not produce any discernable loss in measuring signals. All electronic devices in the field testing were powered by one portable gas powered generator, and may be powered by other readily available appropriate sources of power.
The following examples are illustrative and not limiting. One of skill will recognize a variety of non-critical parameters that can be altered to achieve essentially similar results.
Two Pioneer hybrids were assessed, one with weak roots and one with strong roots, based on earlier testing and characterization of the hybrids. The testing consisted of twenty plants and forty measurements per treatment. The accelerometer 24 was place on the internode just below the primary ear node of the corn stalk. Two measurements were taken for each plant. The primary ear node was snapped by hand first and the node directly below the primary node was snapped second. All leaves were stripped from the plant before measurements were taken.
The counts of stalk fiber failure were taken from the function. The brittle snap data was analyzed using ANOVA and Tukey analysis.
Four Pioneer maize hybrids (hybrids 1-4) with differences in their resistance to stalk lodging were measured. The machine was placed at a distance of between 15 and 20 cm above the ground near the top of the second internode. At the time of the test, the plants were at the R1 developmental stage. The null hypothesis tested was that hybrids with more resistance to stalk lodging will show no difference in the number of fibers recruited to failure than a weaker hybrid.
Four additional hybrids (hybrids 5-8) were tested with contrasting scores for stalk lodging, specifically two early and two late cycle hybrids were tested.
Testing was performed when the plants were at the R1 stage of development. The soil was not saturated but it had visible moisture and was loose which could allow for some root mass rotation.
From this information it can be seen that a unique handheld device reliable in predicting important mechanical properties of plants has been designed and developed which enables the collection of meaningful and important data to facilitate plant breeding and product development processes. All publications and patent applications mentioned in the specification are indicative of the level of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims. Thus, many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, though examples are presented herein, one skilled in the art will appreciate that the data may be analyzed in many different manners consistent with the parameters of the study being investigated. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. The following examples are offered to further illustrate but not limit both the system and/or device and/or method.
From this information it can be seen that a unique handheld device reliable in predicting important mechanical properties of corn stalks has been designed and developed which enables the collection of meaningful and important data to facilitate corn breeding and product development processes.
