PR-432 2000 AGRONOMY RESEARCH REPORT Kentucky Agricultural Experiment Station University of Kentucky College of Agriculture Department of Agronomy Lexington, Kentucky 40546 2000 AGRONOMY RESEARCH REPORT edited by Michael Barrett Mention of a trademark or proprietary product is for experimental purposes and does not constitute a guarantee or warranty by the Ken- tucky Agricultural Experiment Station and does not imply its approval to the exclusion of other products that may also be suitable. Contents Overview Agronomy Research 2000: Summaries and Reports of Applied and Field Research .......................... 5 General Research Precision Agriculture Opportunities for Kentucky: Agronomic Research at the University of Kentucky .......................................................................................................... 7 New Crop Opportunities for Specialty Grains ...................................................................................... 8 Agronomy Research Report 2000 for Plant Cell Biology and Gene Expression Groups .................... 9 Assessing Soil Fertility Map Quality in Kentucky ............................................................................. 10 Soil Electrical Conductivity Variability ...............................................................................................11 Topography and Community Substrate Use ........................................................................................11 Vegetation Effects on Fecal Bacteria Removal in Homeowner-Constructed Wetlands ..................... 12 Management of Seeded-Bermudagrass during the Establishment Year ............................................. 13 Impacts of Typical Cultural Practices on the Severity of Gray Leaf Spot of Perennial Ryegrass ..................................................................................................................... 14 Strategies for the Control of Poa annua in Golf Turf.......................................................................... 15 Forage Production The Economic Value of Better Alfalfa Varieties................................................................................. 17 Research Evaluating Varieties of Alfalfa and Tall Fescue for Tolerance to Overgrazing by Cattle .................. 17 Yield and Persistence of Red Clover versus Ladino (White) Clover during Drought ....................... 19 Pubescence, Drying Rate, and Dustiness in Red Clover .................................................................... 20 Vegetative Establishment of Kura Clover ........................................................................................... 20 The Effects of Different Amounts of Stretch Film Plastic on Alfalfa Baled Silage ........................... 21 Cow-Calf Production on Reclaimed Surface-Mined Pastures in Eastern Kentucky .......................... 22 Weed Control A Field Survey of Weed Species Observed in Kentucky Soybeans ................................................... 24 Research Comparison of Weed Management Strategies with Roundup Ready® Corn ..................................... 26 Italian Ryegrass Control in No-Till Corn............................................................................................ 28 Impact of Wheat Herbicides on Double-Cropped Soybeans .............................................................. 29 Tobacco Research Tobacco Breeding and Genetics ......................................................................................................... 31 Regional Burley Tobacco Variety Test................................................................................................ 32 Maleic Hydrazide (MH) Residues in Burley Tobacco ....................................................................... 33 Effects of Foliar Fertilization on Dark Tobacco Yield and Value ...................................................... 34 Grain Crops No-Till Wheat ..................................................................................................................................... 35 Research Making No-Till Wheat Production Profitable: On-Farm Testing ....................................................... 36 Nitrogen Management for No-Tillage Wheat Following Corn or Full-Season Soybean ................... 37 No-Tillage WheatLong-Term Effects ............................................................................................. 38 Comparative Performance of Wheat Varieties in No-Till and Conventional-Till Trials.................... 39 Corn Residue Management for No-Till Wheat ................................................................................... 40 Greenhouse and Field Evaluation of Resistance to Fusarium Head Blight in Soft Red Winter Wheat .............................................................................................................. 41 Hybrid Corn Performance Test ........................................................................................................... 43 Value-Added Corn Breeding ............................................................................................................... 44 Grain Quality Laboratory .................................................................................................................... 44 1999 Kentucky Corn for Silage Yield and Quality Performance Trial............................................... 44 Correlation of Corn Yield Variability as Affected by Soil Characteristics ......................................... 45 Effect of Row Width, Plant Population, and Hybrids on Corn Grain Yields ..................................... 46 Compaction on No-Till Corn and Soybeans ....................................................................................... 47 Using Poultry Litter as a Nutrient Source for Corn ............................................................................ 48 Nutrient Concentration Changes in Poultry Litter with Storage Time and Method ........................... 49 Kentucky Soybean Performance Tests ................................................................................................ 51 Wheat Cultivar Effect on Double-Crop Soybean Growth and Yield.................................................. 51 Directory ............................................................................................................................................. 54 Agronomy Research 2000 Summaries and Reports of Applied and Field Research The Department of Agronomy of the University of Kentucky between 3 and 6 bushels per acre lower than tilled yields. has a tradition of excellence in both basic and applied research. However, when the input costs for both systems were subjected Basic research by faculty in the department, working in areas to a partial budget analysis, no-till actually came out slightly such as plant biochemistry, physiology, molecular biology, and ahead ($1.60 per acre). Since we did not factor in a dollar value genetics, has the long-term objective of increasing crop plant for reduced topsoil erosion under no-till management, it would productivity and value. seem that growers should give careful consideration to this Problem-solving applied research within the department is system. aimed at near-term benefits to Kentucky agriculture. In addition In response to increased interest in no-till wheat production, to research on crop productivity, another major focus of the no-till variety trials were grown at two locations in the state in department is research designed to preserve soil and water conjunction with conventional tests in order to compare varietal quality for agricultural and other uses. performance under the two production methods. Two years of The University of Kentucky recognized this unique combi- data indicate that, in general, varieties perform equally well in nation of excellence in basic and applied research and its both conventional and no-till systems. contributions to Kentuckys economy when it designated the Corn: Recent corn-row width studies conducted in many department as a distinguished, nationally competitive re- corn-producing states have shown responses to row widths search program and one of 20 targets of opportunity for the narrower than 30 inches, but these responses have occurred University. As such, the department is looked upon as one of the mostly in areas of the Central and North Central United States. programs to help lead the way in establishing the University of After five years of research on the effect of row width and plant Kentucky as a top 20 research university by the year 2020. population on corn yields in Kentucky, there does not appear to The Agronomy Research Report is published in even years be any advantage for 20-inch rows over 30-inch rows. The to inform professional agronomists, crop producers, and crop research indicated that in Kentucky, plant population is more consultants about recent developments in the University of important for obtaining high corn yields than narrow rows and Kentucky Department of Agronomy. While the department that a final population of 26,000 to 30,000 plants per acre is conducts both basic and applied research studies, this report needed for corn with a high-yield potential. emphasizes recent findings of applied and field experiments Soybean: Soybean has genes that produce a wide range of with importance to Kentucky agriculture. It contains brief pubescence densities. Higher-than-normal pubescence reduces updates on continuing projects and initial reports