Agronomy Notes

12-14-2000

Contents

 

CORN

Dr. Erick Larson

Taco Fiasco Serves GMO Notice

The contamination of Taco Bell taco shells with StarLink Bt corn should serve notice that the agricultural industry needs to take unapproved GMO products more seriously. Corn grain containing the StarLink gene is approved only for domestic feed and non food industrial uses in the U.S. Aventis (the company that developed the technology), the seed companies that sold StarLink products, the regulatory agencies that partially approved it, and the producers who grew it failed to acknowledge the potential pitfalls of marketing this product in a market that is not prepared to segregate specific unapproved GMO products. Aventis is accepting responsibility for redirecting remaining StarLink corn to the appropriate non food channels. Who will pick up the bill next time? Ultimately, producers will, in the form of lower commodity prices as exports decline because the U.S. cannot guarantee zero tolerance of GMO products in exported commodities.

Unapproved GMO Corn

Each genetic trait is evaluated on an individual basis and there may be multiple genetic events for a similar type (function) of trait. For example, Bt protection for corn borers is available as YieldGard (MON 810 and Bt11), and NaturGard/KnockOut (E176) from different seed companies. These GMO corn events currently do not have European Community approval:

Roundup Ready Corn: Monsanto (MON GA21 Glyphosate herbicide tolerance)

YieldGard/Roundup Ready Corn: Monsanto (MON 810/MON GA21 Corn borer resistance + Glyphosate herbicide tolerance)

Yieldgard/Liberty Link: Pioneer Hi-Bred Int'l. (MON810/T25 Corn borer resistance + Glufosinate herbicide tolerance)

Isolation Requirement

Approved products may also require isolation from unapproved hybrids, in order to retain genetic purity, since corn is a cross-pollinated crop. The current corn industry isolation standard for preserving identity is a minimum distance of 660 feet from other hybrids.

Hybrid Selection

The new MSU Corn for Grain Variety Trials bulletin is now available, and provides useful data for selecting hybrids to plant in 2001. Growers are encouraged to plant several hybrids based upon three primary criteria: grain yield, stalk strength and maturity. High grain yield is obviously a primary consideration because grain is sold on a weight basis. However, variety trials may not reflect harvestable yield in a field situation unless stalk strength is also considered. Leaning or broken stalks can significantly reduce harvest efficiency in terms of harvest loss, time and fuel. Hybrid maturity influences harvest date and can impact profit through its effect on grain moisture. Hybrids may differ in maturity by as much as two weeks. Producers who market their grain at harvest may benefit from growing earlier-maturing hybrids, since markets usually decline through harvest.

 

PASTURE AND FORAGES

Dr. Malcolm Broome

It is generally recognized that nitrogen fertilizer will probably continue to become more expensive due to the current petroleum prices. Yet nitrogen is the big growth element for forages and the one nutrient that, when it is lacking, reduces forage quality. A group of plants (clovers) has the ability to obtain nitrogen from the atmosphere and "fix" it in nodules on the roots. When clover is grown properly, this "fixed" nitrogen translates into savings of dollars per acre. A number of studies have shown that annual clovers, ladino or white clover, and red clover often fix 60 to 150, 100 to 150, and 150 to 200 pounds per acre per year, respectively. At a cost of 30 cents per pound for nitrogen, this represents a value of $18 to $60 per acre per year.

Nitrogen fixation is not the only benefit from establishing clovers into existing grass sods. The addition of clover to grasses can result in higher yields. A 1998 test in Kentucky growing red clover with tall fescue produced higher yields than tall fescue alone fertilized with 180 pounds of nitrogen per acre. Clover also increased profitability, intake, digestibility, nutrient content, and animal performance. For example, growth rates of beef steers in a two-year study were increased approximately one-half pound per day when ladino clover was planted into endophyte-infected tall fescue.

Clovers generally lengthen the growing season or provide a better seasonal distribution of growth. The addition of clovers to Bermuda grass, bahiagrass, or dallisgrass provides forage production during the winter months when these warm-season forages are dormant. Annual clovers, such as arrowleaf or crimson, grow well when sod-seeded into these warm-season grasses.

Bloat is often mentioned as the negative side of grazing clovers and can be a serious problem in a pasture that is predominantly clover. With proper management and variety selection this problem can be greatly reduced. Never turn hungry animals onto lush pastures of clover and winter annual grasses. Maintain at least 50 percent of the forage mix in the pasture in grass. Also, provide salt-molasses blocks containing surfactants, a detergent-type compound that reduces development of stable foam in the rumen(stomach), to help prevent bloat. These blocks are expensive, but can prevent animal death. Another solution is to feed a commercially available ionophore which can also reduce bloat potential.

Used properly, clovers have many positive benefits. Clovers can reduce nitrogen fertilizer expenses and shorten total "stored feed" feeding days while increasing animal gains or milk production. In some cases, conception rates could increase. As with most livestock operations, management plays a key role. With proper management, clovers can add to increased profits and economic sustainablility of the operation. Extension information sheets IS 910, IS 1083, and IS 1306 provide more information on clovers. Contact your Extension county agent for a copy of these sheets or other forage information.

 

NUTRIENT AND SOIL MANAGEMENT

Dr. Larry Oldham

Mississippi State University Extension Service is offering Conservation Tillage Planter Clinics at three Mississippi locations for producers, consultants, and others interested in retrofitting planting equipment for optimum performance in all soil and field conditions. Please contact your local Extension office if you plan to attend. Clinics run from 8:30 a.m. until 1:00 p.m. at the locations listed. Lunch will be provided.

January 17, 2001-Lee County AgriCenter, Verona, MS

January 18, 2001 -National Guard Armory, Yazoo City, MS

January 19, 2001-Dulaney Farms, Clarksdale, MS

Significant developments have occurred recently in nutrient management planning. The Mississippi Natural Resources Conservation Service (NRCS) and the Extension Service have been fine tuning a computer program that makes it less tedious and time consuming to prepare a site-specific plan. As the software becomes adapted, the time needed to write a plan will diminish from days to hours.

The program requires input (by field) of fertilizers (whether animal by-product or strictly inorganic) and factors such as soil series and distance to surface water. The program has been shown to county NRCS staff and Extension agents, but the final version has not yet been shipped. The first field version should be available to NRCS planners in early January and to others later in the year.

On another front, the Certified Crop Adviser program is in the process of formalizing a Memorandum of Agreement with the MS-NRCS that will give CCAs third-party vendor status as providers of nutrient management and other conservation practices. For nutrient management, an approved planner process is being developed for both NRCS staff and third-party vendors who will be writing plans. This is a requirement of national NRCS guidelines. Most initial applicability of the Nutrient Management software and planning process is in south-central Mississippi in the poultry producing region. However, there is wide interest among crop consultants and advisers in other areas wishing to include this service to their clients.

 

SOYBEANS

Dr. Alan Blaine

Over the last several weeks numerous calls have come in regarding varietal information.

Although many will feel it is too early to be considering varieties, this is far from the truth. With more than 250 varieties available for sale, variety selection is a monumental task. Variety selection is the most important aspect of soybean production, and a choice you will have to live with all year long.

Many varieties that looked good last year proved failures this season. This was especially true of a couple of new varieties that looked very promising. In some situations, some new varieties did well once again in the small plot variety trials, but did not perform satisfactorily in some large scale production fields. This variability emphasizes the need for studying a variety's yield history, preferably at least two years' worth of yield data. Although the 2000 growing season was quite extreme, several varieties consistently performed in the top 10 to15 percent. These are the varieties growers should plant on the bulk of their soybean acreage this coming year.

The major criterion for variety selection is yield. This criterion is so important it should be your first, second and third reasons for choosing a variety.

Although some consider herbicide tolerance the number two criterion for variety selection, your second concern should be disease resistance. Producers have observed significant differences in disease pressure in recent years, but it is probably due mainly to the use of a proper seed treatment and early planting. Stem canker still remains our primary disease concern, but earlier maturing varieties and earlier planting dates seem to have minimized its effects. While stem canker has not gone away, these practices appear to be having a positive impact.

Some soybean varieties may be environment-specific (irrigated versus dryland) but a top performer is often a top performer at numerous locations. Concentrate on top performers in Mississippi and neighboring states, particularly Louisiana and Arkansas. Look hard at consistent performance.

After 2000, producers will have an even shorter list of top varieties available because several previously on the list did not cut it this year. Variability observed this year reaffirms the need to plant several varieties on your farm to judge their performance at your location under your management.

In 2001, Mississippi will have approximately 40 fields in the SMART program, probably with less than five total varieties being planted on these fields throughout the state. This includes both the Delta and hill areas, irrigated and dryland.

Variety trial yield data is available in your county Extension office. You may obtain a copy there or you may access this information on the Internet. Dr. Zhang at Stoneville is in the process of finalizing a database you will probably find quite helpful. The internet address is <http://visit.to/deltasoy> or http://i.am/deltasoy. At this site, the 2000 yield information and a couple of years' yield data is available. Dr. Zhang is still working to finalize the two to three year averages, but yields for individual years are correct. Please let us know what you think of the website.

Producers often ask what their soybean checkoff money is doing. The deltasoy database is a prime example; it will allow us to get yield information to producers much faster than in the past. Take some time and look at the yield trials. Focus on consistent performance and make varietal decisions soon, because the best varieties go first.

 

SOIL TESTING

Dr. Keith Crouse

Maintenance of soil levels for all crops requires a regular soil testing program. Maintaining acceptable soil pH assures that calcium or magnesium will not be depleted by leaching, erosion or removal from the soil by crops. Also, it promotes better overall availability of essential nutrients for healthy crop growth, and increases the efficiency of fertilizers applied.

Availability of various plant nutrients is affected somewhat differently by changes in the soil pH. Macronutrients such as nitrogen, phosphorus, potassium, calcium, magnesium and sulfur will increase in availability with an increase in soil pH. Mirconutrients such as iron, manganese, boron, copper and zinc, with the exception of molybdenum, will decrease in availability.

There is still plenty of time to take a soil sample before planting a crop. A fertilizer recommendation is only as good as the soil sample submitted; therefore, a representative soil sample is very important in any soil testing program. Forms and sample boxes can be picked up at local county Extension office.

Remember that clients can view their soil sample results on the web. The address is <http://www.ext.msstate.edu/special/soiltest.cgi>. To access soil test results, a client needs to know his AAA number, customer account number, county and report type, such as soil (field crops, pastures, commercial crops) or horticulture (gardens, flowers, lawn grasses, etc.).

 

COTTON

Dr. Will McCarty

According to the November 2000 Crop Report, Mississippi was to pick 1,280,000 acres and yield 638 pounds per acre for a production of 1,750,000 bales. This compares to 1,180,000 acres harvested in 1999 with a yield of 704 pounds per acre and a production of 1,731,000 bales. Quality of the 2000 crop was affected by environmental conditions. While staple length averaged 34, a little more than 30 percent of the bales classed had a length of 33 and shorter, which placed them in the discount range. Average strength was 26.77 compared to 28.02 in 1999; uniformity was 87.0, and mike was 4.51 (4.56 in 1999), with 0.6 (0.7 in 1999) percent being below 35 and 13.9 (16.5 in 1999) percent being above 50.

In general terms the crop was short - short on yield, short length and short on strength.

Book Cotton Seed Early&emdash;Complete results of variety testing will be available soon. For Preliminary Results of the 2000 Cotton Variety Test, you may call your county Extension agents office or visit the following Web site: http://ext.msstate.edu/anr/plantsoil/. Click on cotton and then variety trials. (If you have trouble with this site please call Will McCarty or ask for Charlotte @ 662-325-2311.

Variety selection is a management decision that growers make only once a season. Growers make fertility decisions two or three times, herbicide decisions three or four times, and may make insecticide decisions 6 to 12 times. They make a variety decision one time. Regardless of how good a job you do with irrigation, fertility, tillage, weed and insect control, selecting the wrong variety can offset any other management work that you do.

To make good variety selection decisions, the first thing a grower must do is to plant more than one variety. Like a grower told me recently, "Planting more than one variety is not a sign of indecisiveness; it's a sign of intelligent, preventative defense." You cannot predict what the weather will be like next season so planting several varieties will improve your chances of a good crop. Looking back at the last couple of years, it seems that different varieties perform better in different environmental conditions.

In selecting varieties, growers should use their university variety trials in their respective states as their first source of information. When they review the results of their university variety trials, they should look at the different soil types the trials were conducted on, and always consider more than one year of data.

The next best source of information is their personal experience. The next source is their neighbors' experience on comparable soil types. Look at how varieties perform on similar soil types, under similar management, in your farming community over multiple years.

Then plant the bulk of your acreage in a variety that has proven to be consistent. Plant the remainder of the acreage in two or three varieties that show potential, but need further investigation.

Additionally, when making a variety decision, a grower has to make up his mind what is important to him. Will he select a variety for convenience or for yield? Or will he select a variety that will give him a balance of convenience and yield? For example, do you plant the highest yielding variety that oftentimes might be a conventional variety and give up the convenience that transgenic varieties offer in weed and/or insect control?

In these days of high tech, transgenic cotton, we sometimes forget about disease resistance packages and tolerance. If a grower has a known history of Verticillium and Fusarium wilts, he should select varieties with tolerances to these diseases. Additionally, if a grower has droughty-type soils and cannot irrigate, those stress conditions seem to bring on bronze wilt in some varieties. If you know that your farm has the tendency to stress occasionally, you may want to avoid varieties that show the potential for bronze wilt.

Tillage Programs-It is never too late in a cotton production program to make or adjust tillage decisions. Going into the year 2001, it could be the best interest of growers to consider reduced-till production systems. Each time an unnecessary trip is eliminated, you can see potential savings; however, reducing trips across the field will generally increase management requirements. Also, reducing tillage and planting no-till or stale-bed will generally require adjustments to seed treatments, herbicide, and perhaps fertilizer programs.

When planting into a stale bed, burn-down applications are critical. When the field is planted, all vegetation in the field should be dead or about to die. Plan to plant clean and keep the field clean. Burn-down programs may vary, depending on location and vegetation present. These decisions will need to be made on a field by field basis. Generally, it is best to burn down several weeks before planting this allows applications to be made on smaller weeds for easier kills and allows lower rates of materials to be used. Also, burning down early will reduce the risk of vegetation, removing all the water from the beds in dry years. Such situations will delay planting.

Control Traffic Systems&emdash;A system that controls traffic or confines traffic to a particular set of rows has shown tremendous promise in research and demonstrations. Confining all trips across the field to the same middle, coupled with down-the-row sub-soiling and ripping non-traffic middles, is a system that can reduce trips across the field while maintaining or increasing yields.

Skip Row Production - Many cotton growers are taking another look at skip row production. We haven't grown skip row on a large scale for a long time&emdash;the practice was extremely popular from the '60s through the mid'80s. Changes in the government programs were one reason why we moved away from skip row production. However, some growers never abandoned skip row production. Today, less than 10 percent of Mississippi's cotton is farmed skip row.

We have some producers going to a 30-inch row with a 60-inch skip. The most commonly used skip row configurations are a 38-inch row with a 60- to 64-inch skip. As one long-time cotton farmer told me the other day, "The lower the price, the wider the skip."

Economic and efficiency considerations are some reasons for the renewed interest in skip row production. The typical two and one skip pattern on a land acre basis will yield 94 percent as much as solid cotton on a land acre basis. However, you're only planting 66 percent as much cotton. Simply put, if you plant solid in a 100-acre field and make a bale per acre, you'll make 100 bales. If you plant a two and one skip in that same 100-acre block of land, you'll plant 66 acres of cotton and make 94 bales.

Skip row also offers efficiency benefits. For example, the outside rows can take advantage of the moisture and nutrients stored in the skip. The crop normally holds up better and longer under dry conditions throughout the season.

Additionally, plant size is as not a big of a consideration in skip row as it is in solid planted cotton&emdash;you want the plant to get large enough to fill up the skip. Skip row also relaxes plant growth regulator management. You may be able to apply PGRs a little later or maybe a little less.

From an economic standpoint, basically a two and one skip will reduce any down the row input by as much as 30 percent. For example, there are potential savings in fields where nematicide rates of infurrow insecticides are used. Also, costs can be substantially reduced where any pre-emerge herbicide or anything applied on the band down the row.

Significant savings also have been seen in harvesting efficiency as well as harvest cost. You spread the heads out on the picker and pick a little more cotton with the same harvesting equipment.

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