Agronomy Notes

September 11, 2000

Contents

SOYBEANS

Dr. Alan Blaine

The August crop report projected the Mississippi state average for soybeans at 27 bushels per acre. This is the same as the August prediction last year, and since this year is hotter and drier, this figure is undoubtedly high. This crop had an excellent potential, but the much needed one or two last rains never materialized. This is the third year in a row that a significant portion of the state's soybean crop has not received that last rain. Harvest has begun and (as expected) yields have been quite variable. Some early maturing varieties have cut in the low teens with some irrigated cutting over 40 bushels per acre. Yields on late IV's held up better than most expected (on early plantings), but dropped significantly as late April/early May plantings have started to be harvested. The potential on irrigated beans is as good as ever; growers must be careful to not stop watering too soon. This has been a long summer, and from an irrigation standpoint, an expensive crop. However, with commodity prices like they are, growers must strive to obtain as high a yield as possible. Although yield responses will vary, late irrigation adds significantly to final yield. The last irrigation is the one that determines seed size. Although Mississippi soybean farmers planted an early crop this year, the bulk of it was planted from April 25 to mid-May. Group IV's planted in early May will act more like a Group V. The significance of this is that what was thought of as early really wasn't. There has been a big break in planting dates this year (dryland). As a whole, plantings after April 23 really took it on the chin as far as yields were concerned. Although this data is fairly early, extended dry weather has taken a toll on all varieties. Following a year like this one, many growers may second guess Group IV's; however, without a significant rain event by the time you read this, the V's will be hit even harder. Growers must continue to stay focused on maturity groups and planting dates, particularly on dryland acres. Insect pressure has been evident statewide, but the severest pressure has been observed south of Highway 82. Loopers continue to be the predominant problem in the delta. Several fields that were fast approaching maturity or lacking adequate moisture escaped the need for spraying. In heavy looper areas, the use of Dimilin allowed growers to delay a worm application by 7 to 9 days. The strategy here was to (hopefully) avoid the need to spray twice for loopers. Dimilin will only suppresses loopers but it does an excellent job of controlling VBC, green cloverworm and salt marsh caterpillars. In several fields where Dimilin was applied, growers have yet to spray for worms; however, they are not through with this crop yet. Several pests not normally a problem have been present in actively high numbers, and include Three Cornered Alfalfa hoppers, Bean Leaf beetles, grasshoppers and stink bugs. The presence of these pests has varied; we need a good hard winter (something we have not had in the last three years) to help reduce these pests. Several calls have come in regarding using a desiccant. The best option is a tank mix of paraquat and sodium chlorate at a rate of .25 lb active of paraquat and 3 pounds of sodium chlorate. If applying by air, use 7 to 10 gallons of water; if by ground, 15 to 20. Please note this word of caution: this mixture will knock off green leaves and dry stems in the top of the canopy, but it will not make a green butter bean become a harvestable dry soybean. If drying seed is your objective, save your money. With the general lack of moisture statewide, shattering could be a problem. At this time of the year drydown is rapid, so harvest timing is critical under hot, dry conditions. This may require you to leave rice or corn to cut beans and then move back. Keep this in mind when making harvesting plans.

SOIL TESTING

Dr. Keith Crouse

Early fall is a good time to improve pastures and hay fields. During the past few weeks, the lab has been receiving soil samples that were cropped for cool season forages, and soil acidity appears to be the major fertility problem for these fields. This can easily be taken care of by applying recommended lime. Most cool season grasses grow best at a pH level above 6.0. Soil potassium removal can range from approximately 30 pounds per ton of hay to even higher amounts by some of the hybrid Bermuda grass varieties. Potassium's role in plants is to reduce lodging and increase winter hardiness and disease resistance; increase photosynthesis; aid in carbohydrate metabolism and the breakdown and translocation of starches; activate various enzymes; and adjust stomatal movement and water relations. Potassium fertilizer may need to be applied to hay fields and fertilizer recommendations depend on the crop being grown. Therefore, to know what is needed, take a good random soil sample and have it tested.

CORN

Dr. Erick Larson

Avoid late harvest - Many producers are delaying corn harvest until grain moisture reaches a level where little or no dockage is assessed because of poor market price. However, delaying harvest also has substantial risks. Droughty conditions have weakened stalk integrity substantially and promoted further deterioration by stalk rots. Thus, stormy weather could potentially wreak havoc on these fields, substantially outweighing moisture savings in an instant. Producers should analyze these potential harvest benefits and risks before delaying harvest too long. Corn can be relatively susceptible to lodging because of its height and heavy ear load. Growers should harvest early maturing hybrids and those possessing below average stalk quality promptly and before other hybrids. Rainy, humid weather could also deteriorate grain quality and seed weight, while significantly slowing drying rate as harvest is delayed.

WHEAT

Dr. Erick Larson

Wheat Varieties - The 2000 MSU Wheat Variety Trials are now available at your county extension office. Variety evaluation should be based primarily upon your area of the state, variety yield history, expected planting date, soil type and variety disease resistance. For north Mississippi and the Delta, the best varieties include AgriPro Shiloh, Mallard and Patton, Southern States 522W, Northrup King Coker 9663, Pioneer 2684, Roane and Terral TV 8555. In south Mississippi variety choices become more limited due to the warmer winter climate. This eliminates use of many Ohio-valley adapted varieties that need substantial cool temperatures to trigger seed head development (vernalization). The highest yielding varieties that meet these vernalization requirements for south Mississippi are Pioneer 2684, NK Coker 9663 and 9835, Terral LA422, AgriPro Shelby and Mason. Specific recommendations and variety traits are listed on the MSU-ES Small Grains web site.

SOIL AND NUTRIENT MANAGEMENT

Dr. Larry Oldham

Nutrient Management Plans are not schemes to dominate the world, but in reality are rather innocent creatures. Each contains several basic features, but true planning documents are complete business plans for management of significant crop inputs. The components of a plan include a fairly recent aerial photo of the site, with current fields delineated, in addition to a soil map. United States Geological Survey quad maps should also be included in the plan. These maps indicate the location and nature (perennial or intermittent) of streams on the property. Stream locations and other designated sensitive areas are extremely important in the Phosphorus Index environmental risk assessment tool. Plans also include crop rotations/sequences with realistic yield goals. For each crop the plan will include the recommended nutrient rates, timing, form, and method of application. If organic sources are to be used, the plan will included a nutrient analysis of the material. If manures are to be applied, the plan should include a complete nutrient budget. Another component of the plan is guidance for implementation, such as operating details, maintenance, follow-up soil testing, and other general agronomic information.

RICE

Dr. Joe Street

Rice harvest is underway and initial yields look pretty good. It is too early to tell how the yields will turn out and what effect the high temperatures have had on the yield and milling quality. High daytime temperature (above 95 F ) will reduce pollination and high nighttime temperature reduces grain fill or weight. While daytime temperatures have been high, the nighttime temperatures have generally been in the 70's, which should not adversely influence grain fill. Milling yield was somewhat erratic last year, especially with Priscilla and with some fields of Lemont. Although no research data are available, observations indicate that most producers who started harvesting Priscilla at about 21 percent moisture and were able to finish before the moisture level dropped to less than 16 percent had good milling yields. Priscilla has a large grain, and rapid dry down affects it more than varieties such as Cypress with smaller grain size. With this weather, rice will dry rapidly and thus an early start at higher moisture levels may prove beneficial. The primary production problem continues to be insects. The stinkbug population has continued to be high, especially in fields adjacent to Milo. Several fields have had two insecticide applications for stinkbug control. For producers with late rice, stinkbugs can cause significant reductions in quality and should be controlled when the threshold level is reached. During the first two weeks of heading, treat when an average of three stinkbugs is found per 10 sweeps with a sweep net. Later, during the milk to soft dough stage, treat when an average of five stinkbugs is found per 10 sweeps. Although it is more expensive, Karate Z appears to be more effective for the early application because of the residual effect. At the later stage, ethyl parathion has been effective. Karate has a 21-day pre-harvest interval and methyl parathion has a 15-day interval. Malathion may be applied seven days before harvest. In general, diseases have not been a major problem during this growing season. Sheath blight was erratic and has not been as bad as expected. Bacterial panicle blight, which is relatively new to Mississippi, has not been positively identified at this point. Samples have been collected for lab analysis to confirm its presence, but to date, it has not been a problem. There are reports that Bacterial Panicle Blight has been observed in Arkansas, primarily on Cocodrie and Cypress. These two varieties make up less than 10 percent of Mississippi's rice acreage. A little false smut (orange balls surrounding the grain) has been observed, but nothing severe has been noted at this time. So far, the mills are not docking for the presence of false smut. September is Rice Month. Try to eat more rice and support local activities celebrating the rice industry. The annual rice luncheon sponsored by Delta Rice Promotions and the Bolivar County Farm Bureau will be September 15 at Delta State University. Plan to attend.

FORAGES AND PASTURES

Dr. Malcolm Broome

Overseeding Permanent Summer Pastures - Overseeding part of the permanent summer pasture sod can help with winter feed requirements as a component of any year- round forage production program in Mississippi. This will allow you to get more grazing days from each acre of grass and this year could certainly help meet the forage need due to a lack of hay in many areas of the state. Ryegrass overseeded on grazed-down, permanent sods of bahiagrass or hybrid and common bermudagrass will be an ideal choice. Excess grass must be grazed off, harvested for hay, or clipped down closely (3 inches of less) in October. Ryegrass can be sown at 40 pounds per acre on the surface with no soil disturbance or light seedbed preparation such as a pasture renovator, or disk can be used. If soil is lightly disturbed, harrowing (to smooth) and then cultipacking after planting will shorten germination time. This approach will generally not supply any grazing until mid- or late January. Overseeding should not begin before October 1 in northern Mississippi, and October 20 in southern Mississippi. Be sure permanent pasture is dormant before applying nitrogen so regrowth will not cause competition with the young ryegrass. Southern counties in the state could have this problem due to late frost. Overseeded ryegrass should be fertilized with 60 to 70 pounds of actual nitrogen per acre at or shortly following planting to help grass get maximum growth before cold weather. Also, any needed lime, phosphate and potash can be applied at this time. Another topdress nitrogen application will be needed about mid-February. It is best to not overseed over one-half of permanent pasture areas; it is better to plant only the amount of pasture your herd can heavily graze during the spring. Overseeded pastures need to be heavily grazed in April and early May to keep the ryegrass from growing up and setting back the permanent grass. If close grazing is not possible, or not needed, clip the excess forage and store it as hay, haylage or balage. Do this by early May to keep your summer grass from being severely penalized. This program works especially well for brood cows that are calving in the fall and winter or it can also be used as backup grazing in a stocker program. A permanent summer pasture requires more management if overseeded with ryegrass, but the improved grazing justifies the effort. If you think you will be short of hay by February 2001, this will be a cost effective way to meet your forage needs.

COTTON

Dr. Will McCarty

The 2000 cotton crop season is at a close. A crop that had one of the best starts in recent times suffered the serious effects of perhaps the hottest and driest July-August on record. The crop was very well fruited with good horse-power going into early July. Fruit retention on the 2000 crop is perhaps the best I have seen. This is in part due to low insect pressure and in large part due to clear skies resulting in higher solar radiation all summer. Of course, clear skies means no clouds and in turn - no rain. So this may be a catch 22 deal. As dry weather and heat persisted, our cotton did not do a classic "shed" of fruit. This is of concern because the plants may not have been able to adequately feed all bolls and quality may be effected. The fact that fruit shed has been minimal may be an advantage in irrigated fields, although, high temperatures will probably result in irrigated yields being below record level. The USDA crop estimate placed our crop at 1,360,000 planted acres and a forecasted (July report) yield of 738 pounds per acre. I do not expect us to harvest that acreage, and our yield per harvested acre could be 100 or more pounds below the July NASS prediction. Below are a few tips to consider as we finish this crop and prepare for next year: Variety Selection - Post defoliation is an excellent time to make critical observations of all varieties in your area. Look very closely at your varieties and varieties planted in your area on similar soil types to your own. Look at plant height, node of first fruiting branch, fruit retention, boll size, boll integrity, presence of diseases such as vert wilt etc., root growth and crop uniformity. Make notes about each variety - so you want forget what you see - and then record yields of each variety after harvest. This will be a very good year to sort varieties for their ability to handle stress. It is very evident that some varieties have faired much better under irrigation than dry land and some have faired better on dryland than others. This has been a great year for plant breeders and growers alike to make variety decisions. Tillage decisions - Interest in no-till, reduced till production has increased greatly. The main driving factor in this decision and movement is economics - (labor, machinery, time = money). Technology exist today to allow growers to produce cotton in reduced till systems. I have observed tremendous difference in how cotton held up, till vs no-till, this year. Stale bed and no-till cotton that was not cultivated seemed to hold up longer than conventional till cotton on the same soil types. There are so many options to consider there is no way to address them here. If you are interested in no-till or reduced-till cotton production, give your local county agent a call and he will be glad to work with you in devising a system. Each time you can reduce a trip across a field it will allow you to either save money or work more cotton acreage for the same money. There are advantages and I feel that cotton production, on many soil types and soil resource areas, must move in that direction to remain sustainable. Soil testing - fall is an excellent time to take soil samples. I suggest you do so as soon as possible. Getting samples pulled early may allow you sufficient time to incorporate lime or other needed nutrients during a tillage rotation. Observe fields closely and mark problem areas for separate sampling. Nematode sampling - reniform nematodes have developed into a major pest in Mississippi cotton. I highly encourage each cotton grower to sample their fields for the presence of this pest. After confirmation of presence and levels of infestation, a control, or management strategy may be developed. In most cases, management of this pest will involve both crop rotation and nematicides. There are no resistant varieties and generally, for long term management, nematicides will need a crop rotation program to be very successful. Final Reminder on Harvesting ñ move modules to the gin yard as fast as possible. Do not let modules set in fields until rains (and it will probably rain sometime) cause mud problems moving them or results in grade reductions.

Upcoming meetings

December 6-7 Cotton Short Course - MSU January 5 - Agri-Day in conjunction with Tri-State Soybean Forum - Tunica February 13-16 - Agronomic Professional Continuing Education Workshop - MSU

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