Agronomy and Crop Sciences Commons^™

Potential Use Of Ethephon To Control Lodging Of Soybeans, Larry J. Grabau, Robert C. Pearce, J. V. Konsler

Agronomy Notes

Lodging is sometimes a serious problem with soybeans in Kentucky, especially with the full season crop. However, under, excellent growing conditions, or if planting rates are too high, substantial lodging of double crop soybeans can also occur. If lodging occurs early during seed fill, it can reduce yields directly by causing poorer light use and increasing diseases. If lodging occurs late during seed fill, it will have little direct effect on yield, but may have an indirect effect by slowing down harvest and increasing harvest losses. Thus, the use of an inexpensive chemical to reduce soybean lodging is attractive. Our …

Effect Of Banded Fertilizer On Manganese Toxicity Of Burley Tobacco, J. L. Sims, Kenneth L. Wells, E. C. Greer

Agronomy Notes

Relatively large amounts (1500 to 3000 lbs per acre) of inorganic fertilizers are commonly broadcast preplant in the production of burley tobacco. Such high rates of fertilizer increase both the salt content of the soil solution and soil acidity, often causing reduced stands, manganese toxicity, plant molybdenum and calcium deficiencies, delayed growth and maturity, and reduced yield and quality of cured leaf. Manganese toxicity alone is thought to cost growers 30-40 million dollars each year from yield loss and the costs associated with growing extra acreage the following year to make up their quota¥ Improved fertilizer management systems are needed …

The Effect Of Oil Well Brines On Agricultural Fields And Water, V. P. Evangelou, M. Marsi, Kenneth L. Wells

Agronomy Notes

What is Brine and Where Does it Come From?
Brine is the salty water trapped in rock formations associated with oil and gas deposits. It consists mostly of sodium chloride but can also contain other things such as organics, bromide, some heavy metals and boron. Its source as a pollutant is usually oil stripper wells which produce less than 10 barrels of oil per day with typically a 10:1 ratio of brine to oil. Such wells are distributed throughout Kentucky and are often located on farmland. In some cases, brine rises to the land surface even where no oil wells …

Does Chemical Leaf Burn Of Double Crop Soybeans Reduce Yield?, Larry J. Grabau, Todd W. Pfeiffer, S. Nevins

Agronomy Notes

Most farmers who have applied acifluorfen (sold as Blazer or Tackle) for postemergence control of broadleaf weeds in soybean fields are aware that leaf crinkling, bronzing, and necrosis can result. Despite this, studies in Kentucky, Illinois, Arkansas, and South Carolina have shown that full season soybeans have plenty of time to recover from leaf burn caused by this herbicide, and no yield losses have been found. However, double crop soybeans are usually planted much later than the full season crop. This delay in planting may reduce the time for plants to complete vegetative growth before beginning the seed production process. …

Automated Sorting Of Oriented Tobacco Leaves, Larry G. Wells, M. J. Bader

Biosystems and Agricultural Engineering Faculty Publications

A mechanism has been developed which removes cured burley tobacco leaves from plants so that midribs are oriented parallel. A photosensor was utilized to count leaves as they were removed and a microprocessor determined the number of leaves allocated to each of three grades. Experiments indicated that 84% of leaves removed could be correctly sorted with a 2.4% material loss at an effective rate of approximately 2.4 times that of conventional methods.

Managing Diseases Of Alfalfa, Paul C. Vincelli, Garry D. Lacefield, Jimmy C. Henning

Agriculture and Natural Resources Publications

Alfalfa can be a vigorous and productive forage crop for Kentucky farmers. Like all farm crops, however, alfalfa is subject to infectious diseases that can limit forage production. Managing these diseases is an important part of economical alfalfa production.

Alfalfa diseases can cause reduced forage yield, reduced forage quality, and decreased stand persistence. Sometimes, the effects of infectious diseases can be dramatic, such as sudden stand loss in a fall-seeded crop caused by Sclerotinia crown and stem rot. Often, the effects of diseases on alfalfa are more subtle but no less important. For example, alfalfa plants with Phytophthora root rot …

Stubble Losses Of Kentucky Soybeans, Larry J. Grabau, Todd W. Pfeiffer

Agronomy Notes

Double crop soybeans in Kentucky tend to be shorter than plants from full season plantings. Since lowest pod height is related to plant height, double crop soybeans may be subject to greater harvest losses due to pods remaining below the level at which the combine header is operated. While it would be possible to lower the header closer to the soil to pick up some of those pods, that would slow down harvest and increase the risk of picking up stones and other trash. Although the actual cutting heights used in Kentucky are not known, some producers use combines with …

Some Effects Of Shifting To Conservation Tillage Systems For Intensive Production Of Corn And Soybean, Kenneth L. Wells, H. C. Vaught, David Heisterburg

Agronomy Notes

About three-fourths of Kentucky's cropland base occurs on sloping land with some degree of erosion hazard. During the past decade, production of soybeans and corn increased rapidly in Kentucky, particularly on sloping land. This resulted in severe erosion on many farms, particularly in the "intensive grain producing counties. Much of this field erosion could be greatly reduced by developing a system for each field that would incorporate use of such agronomic practices as sod waterways, no-till planting, contour plowing, minimum tillage, strip cropping, double-cropping, winter cover crops, crop residue management and rotations. It is believed that the current acreage of …

Principle Of Fall Turf Management, C. T. Dougherty, A. J. Powell Jr.

Agronomy Notes

Management of cool-season turfgrasses in the fall is mainly directed toward fertilization, broadleaf weed control and mowing. Fertilizer and weed control recommendations are made with great authority because of a good research base. Fall mowing height has not received as much attention, especially since mowing is often considered a curse by the end of along growing season. In the summer, Kentucky bluegrass and tall fescue turf is mowed high (3-4 inches) to insulate the sward against moisture and temperature stress and to prevent germination of light-sensitive seed of crabgrass and other warm-season annuals. In the fall, however, the mowing height …

An Aeration Duct Design Model For Flat Grain Storage, Thomas C. Bridges, Douglas G. Overhults, Samuel G. Mcneill, G. M. White

Biosystems and Agricultural Engineering Faculty Publications

Traditionally most grain is stored in circular type bins which provide a convenient means for handling and management. With the excess grain production and government loan programs of the past few years, some producers have used rectangular structures and covered piles to complement their round storages. The recommended management practices used with round bins are still required in those alternative storages and may be more critical in obtaining a quality end product.

One such recommended practice used with round bins is aeration. This practice is used to maintain a uniform temperature in the grain mass, preventing condensation and "hot" spots …

Using Performance Test Results In Soybean Variety Selection In Kentucky, Todd W. Pfeiffer

Agronomy Notes

Many soybean varieties are available to, soybean producers in Kentucky each year. Information is available from company advertisements, private yield tests, and public performance tests which producers can use when selecting a variety. The question arises as to how this information relates to variety performance on a particular farm. The value of yield test data lies in the predictive ability of that data. How well does data from a set of environments predict relative performance among varieties over the wide range of possible environments in which those varieties can be grown? The first objective of this note is to discuss …

Forage Production On Reclaimed Surface Mined Land In Eastern Kentucky, William O. Thom, H. B. Rice

Agronomy Notes

Forage crop production for hay or pasture can be important for the utilization of the many acres of reclaimed surface mined land in eastern Kentucky. Even though grasses and legumes are seeded during reclamation to provide ground cover and reduce soil loss, these areas are not usually managed for forage crop production. On the other hand, these vast land areas have the capability to provide significant amounts of desirable grasses or grass-legume mixtures for cattle when well-managed.

Potash Studies On Burley Tobacco In Owen County, Kentucky, Kenneth L. Wells, Kim D. Strohmeier, Anastasios D. Karathanasis, V. P. Evangelou

Agronomy Notes

Since the late 1970's, farmers in the Wheatley Community of Owen county have reported seeing potassium (K) deficiency on tobacco during the growing season. Most of them had been following University of Kentucky fertilizer recommendations for burley production. Analyses of cured leaf samples from one such crop in 1980 confirmed K deficiency. It was decided that the problem warranted conducting some field experiments in order to define the problem and hopefully develop a solution. Consequently, we located a field on the Harold Malcomb farm near Wheatly, that tested low in soil K and designed a field experiment with the objectives …

The Effect Of Three Tillage Systems On Bulk Density And Porosity Of A Pembroke And A Beasley Soil After Three Years, Kenneth L. Wells, John H. Grove

Agronomy Notes

Many grain producers in Kentucky use a 3 crop in 2 year rotation of corn followed by small grain-soybeans, and commonly no-till the soybeans and corn in order to intensively use sloping land for continuous grain production. Because of the intensity of machinery traffic in this system, growers are concerned that continuous no-till management may cause compaction, and that such fields may need occasional primary tillage. In order to obtain' information regarding things situation, we conducted a test for 3 years on the farm of' Philip Lyvers, in Marion County, Kentucky, in a field which was being used in a …

1987 Update Of Agronomic Performance Of Tall Fescue Varieties, Paul B. Burrus Ii, Garry D. Lacefield, J. Kenneth Evans

Agronomy Notes

Tall fescue (Festuca arundinacea, Schreb.) is a well adapted, widely used pasture species occupying approximately 5.5 million acres in Kentucky and 35 million acres in the south central United States.

Commercial tall fescue varieties have been developed from plant materials of either northern European or Mediterranean origin. Varieties developed at the University of Kentucky -- Kentucky 31, Kenmont, Kenwell, Kenhy, and Johnstone -- trace to plant materials of northern European origin. The Kentucky varieties have later maturity dates and have greater resistance to certain foliar diseases during summer than varieties that are of Mediterranean origin (i.e., Alta, Fawn, Goar, and …

Adjusting Soil Ph On Heavy Textured Soils Of The Eden Hills, Kenneth L. Wells, R. M. Jones

Agronomy Notes

The Eden Hills Area (also known as The Hills of the Bluegrass) of Kentucky lies adjacent to the Inner Bluegrass Area in a crescent shape within which a large area of several counties occur. Carroll, Owen, Grant, Gallatin, Pendleton, and Robertson Counties occur almost entirely within this physiographic region and several other counties have sizable acreages within it. Soils of the area have formed largely on Ordovician aged calcareous siltstones of the Garrard Formation and interbedded calcareous shales, thin limestones, and siltstones of the Eden Formation. Soils developed from these formations occur on strongly sloping to steep landscapes and have …

Effect Of Fertilizer Rates And Placement Practices On Yield Of Burley Tobacco, Kenneth L. Wells, G. D. Cantrill, J. L. Sims

Agronomy Notes

Management of fertilizer practices in production of burley tobacco is very important in control of manganese (Mn) toxicity of the crop. In addition to the use of agricultural limestone, the use of fertilizers in the appropriate amounts, the appropriate kinds, and in the appropriate manner can strongly influence acidity in the rooting zone during the growth of burley. Studies of these effects have made up a major thrust of the University of Kentucky's research programs on fertility of burley, and have largely been conducted by J.L. Sims and his students during the past 15 years.

Production Of Aflatoxin On Damaged Corn Under Controlled Environmental Conditions, D. M. Wieman, G. M. White, Joseph L. Taraba, I. J. Ross, Clair L. Hicks, Bruce E. Langlois

Biosystems and Agricultural Engineering Faculty Publications

Aflatoxin B₁ production by Aspergillus flavus (NRRL 6432) was determined on physically damaged corn stored at 35,25 and 20°C and at relative humidities of 97 and 92%. Production at lower relative humidities of 80 and 85% were also tested at 25°C. Production lag times were significantly different for all test conditions. Lag times ranged from 46 h at 97% relative humidity and 35°C to 173. 8 h at 20°C and 92% relative humidity. Aflatoxin B, concentration doubled every 6 to 10 hours after a level of 10 ppb had been reached. Production rate constants were not significantly different between …

Abatement Of Nitrate Pollution In Groundwater And Surface Runoff From Cropland Using Legume Cover Crops With No-Till Corn, M. Scott Smith, Jac J. Varco

KWRRI Research Reports

Agricultural practices can have a significant impact on water quality. The effects of leguminous winter cover crops on leaching of NO^-₃; from soil have been investigated in this project. Legume cover crops, by fixation of atmospheric N, can reduce the amount of fertilizer N required to produce summer grain crops. The methods initially used to evaluate cover crop effects on No; transport included suction probe lysimeters and measurement of NO^-₃; in soil samples collected to a depth of 90 cm. These measurements demonstrated extreme spatial variability in NO^-₃; distribution and water …

In-The-Row Subsoiling Of Tobacco, Lloyd W. Murdock, George Everette, Ted Howard, Bill Green, Richard Barnhisel

Agronomy Notes

Tobacco is probably more adversely affected by soil compaction than, the other crops grown in Kentucky. ThIs Is due to the characteristIcs of the plant and the unusual cultural practIces under which it is grown.

Soil compaction increases soil density while reducing pore space and root penetration. The reduced pore space reduces the aeration of the soil, which reduces tobacco growth especially during wet periods. The effects of soil compaction on tobacco are due to both impedance of root growth and lack of aeration.

1986 Update Of Agronomic And Animal Performance Of Different Tall Fescue Varieties, Paul B. Burrus Ii, Robert C. Buckner, James A. Boling, Lowell P. Bush, N. Gay, R. W. Hemken, Garry D. Lacefield, J. Kenneth Evans, M. R. Siegel

Agronomy Notes

The objective of the tall fescue breeding program at the University of Kentucky is the development of varieties characterized by superior nutritive value (including reduced levels of perloline and loline alkaloids), minimal infestation of the fungal endophyte, Acremonium coenophialum), higher palatability, improved disease resistance, and wider adaptation through the derivation of intergeneric and interspecific hybrids of ryegrass and tall fescue species. Kentucky 31, Kenwell, and Kenhy were varieties released from this breeding program. Johnstone tall fescue, developed cooperatively by the Kentucky Agricultural Experiment Station and USDA-ARS, is the most recently released variety. It is characterized as having low levels of …

Effect Of Tillage Tools On Improving Corn Yields From A Compacted Soil, Kenneth L. Wells, John H. Grove, Morris J. Bitzer, B. C. Milam

Agronomy Notes

An experiment was conducted on a 2-5% sloping Mercer silt loam soil on a farm in Bourbon/Harrison Counties where very poor corn was grown in 1984 because of soil compaction and drought. Soil test levels of the experimental area were: pH 4.8. and 99, 316, 2070. and 120 lbs/A of P, K, Ca, and Mg, respectively. Examination of the field showed that the compacted zone occurred uniformly in the 0-5 inch surface layer of soil. Cause of this compacted layer was thought to be due to excessive disk tillage in prior years when preparing the field for tobacco production and …

Grain Sorghum And Soybean Variety Tests On Reconstructed Prime Land - 1985, R. I. Barnhisel, Morris J. Bitzer, William O. Thom

Agronomy Notes

Prime farmland disturbed by surface mining must by law be returned to a productivity level equal to that before mining. The coal operator has several test crops that can be selected to determine whether these production standards have been met before final bond release will be made. Grain sorghum and soybeans are two of the crops that may be used. The purposes of this research are (1) to determine the crop yield potential of restored prime farmland from surface mined areas, (2) to determine varietal adaptation on restored prime farmland as compared to non-mined prime farmland, and (3) to provide …

Hybrid Reactions To Phytotoxic Effects Of The Corn Herbicide, Eradicane Extra, C. G. Poneleit, K. O. Evans, W. W. Witt, R. M. Bullock

Agronomy Notes

Although corn hybrids are primarily evaluated only for yield performance in the Kentucky Hybrid Corn Performance Test, the 1984 test (Poneleit and Evans, 1985) provided a unique opportunity to evaluate hybrid reactions to an unusual hybrid-herbicide interacting Of seven non-virus test locations, four were treated with Eradicane Extra or Eradicane for weed control. At the Princeton location Eradicane Extra, at 8 pints/acre, was used for johnsongrass rhizome suppression and seedling control. In late July, a routine check revealed that numerous plants had unusual appearances that were similar to abnormalities reported earlier as caused by Eptam and Eradicane (Poneleit et aI, …

Row Widths For Full Season Soybeans In Kentucky, Todd W. Pfeiffer, Morris J. Bitzer, James H. Herbek, Jereme Orf, D. Pilcher, Charles Tutt, L. Zen

Agronomy Notes

Soybean yields in Kentucky have increased steadily in the past 20 years as a result of improved varieties and production practices. To achieve even higher yields new varieties and better production practices need to be developed and tested. One possibility for increasing soybean yields is to plant in narrow rows using varieties which respond to this practice. Although previous research in Kentucky has not shown a yield advantage for full season soybeans planted in narrow rows, researchers in other states have recently shown increases in yield with narrowing row widths. A number of new varieties have also been developed specifically …

Evaluation Of A Skip-Row Planting System Or Plant Run-Over As Management Practices On Full Season Soybeans In Narrow Rows, Todd W. Pfeiffer, Morris J. Bitzer, Jereme Orf, D. Pilcher

Agronomy Notes

In recent years there has been an increased interest in narrow row and solid seeded soybeans in Kentucky. Soybeans seeded in narrow rows have an earlier canopy closure which allows a longer time for the soybean plants to intercept the maximum amount of sunlight. The shading effect which results from earlier canopy closure also aids in weed suppression. More farmers are now seeding full season soybeans in narrow rows or solid seeded stands; because cultivation is eliminated, however, some are hesitant to adopt narrow row production practices for fear of inadequate chemical weed control. With the recent increase in effective …

Storage Of Burley Tobacco In Bales And Bundles, Linus R. Walton, M. E. Casada, Joseph L. Taraba, James H. Casada, W. H. Henson Jr., Larry D. Swetnam

Biosystems and Agricultural Engineering Faculty Publications

Bales and bundles of burley tobacco were stored for seven months from spring to fall. Leaves darkened during storage at all moisture levels and stalk positions with the exception of the bottom stalk position, which darkened only slightly. There was no difference in color change and dry weight loss between burley tobacco in bales and bundles. Normal and high moisture bales and bundles were often graded as unsound because of a deviant odor caused by bacterial activity. A bale weight loss of about 8% occurred at normal moisture with the loss being divided evenly between moisture and dry weight losse.

Agronomic And Animal Performance Of Different Tall Fescue Varieties, Robert C. Buckner, James A. Boling, Paul B. Burrus Ii, Lowell P. Bush, Nelson Gay, R. W. Hemken, Garry D. Lacefield, M. R. Siegel

Agronomy Notes

The objective of the tall fescue breeding program is the development of varieties characterized by superior nutritive value (including reduced contents of perloline and loline alkaloids and minimal infestation of the fungal endophyte, Acremonium coenophialum), palatability, disease resistance, and adaptation through the utilization of intergeneric and interspecific hybrid derivatives of ryegrass and tall fescue species. Kentucky 31, Kenwell, and Kenhy were previously released from this breeding program. Johnstone tall fescue, developed cooperatively by the Kentucky Agricultural Experiment Station and USDA-ARS, was released March 1, 1982 as a new variety. Johnstone is characterized as having low levels of perloline alkaloid and …

Mineralogy And Soil Productivity, Anastasios D. Karathanasis

Agronomy Notes

The soil that is often called "dirt" is not as dirty as many people think. If we remove the 5 to 10% of the soil material, composed of organic matter and amorphous Fe, Al and Si hydrous oxides, the remaining 90 to 95% is a mixture of crystalline or subcrystalline minerals. We are able to see and identify with the naked eye, the large crystalline particles of the sand fraction. For the smaller mineral particles of the silt and clay fractions microscopic or other more sensitive methods (x=ray diffraction, thermal) are needed for their identification and quantification. While little attention …

Equilibrium Moisture Properties Of Corn Cobs, G. M. White, Thomas C. Bridges, Samuel G. Mcneill, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

Equilibrium moisture content-equilibrium relative humidity data for broken corn cobs have been determined for both desorption and adsorption conditions for three temperature levels and five moisture levels. The Modified Henderson and Chung equilibrium moisture equations have been fitted to these data by using non-linear regression procedures to estimate equation parameters. Both equations adequately represented the experimental data. A test of varietal differences indicated no significant difference in cob desorption ERH values for three selected corn varieties.