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Full-Text Articles in Physical Sciences and Mathematics

Genomic Approaches For Dissecting Complex Traits Related To Quality Production Of Range Grasses, Masumi Ebina Jan 2015

Genomic Approaches For Dissecting Complex Traits Related To Quality Production Of Range Grasses, Masumi Ebina

IGC Proceedings (1997-2023)

Tropical grasses have been widely used as warm-season forage grasses in the warm temperate zone since the early 20th century because of their high yields; they have also been used as perennial forages in their native tropical areas. Increasing demand for animal production sparked by economic development in tropical countries is requiring breeders to improve native forage grasses in these countries. Considerable efforts have been made to breed accessions with improved characteristics and to develop new cultivars. However, cross-breeding is not common, owing to a lack of genetic information and to complexities related to polyploidy, high sterility rates, outcrossing, and …


Tillage And Subsoiling Effects On Soil Compaction And Yield Of Burley Tobacco, Edwin L. Ritchey, Robert C. Pearce, John H. Grove Jan 2012

Tillage And Subsoiling Effects On Soil Compaction And Yield Of Burley Tobacco, Edwin L. Ritchey, Robert C. Pearce, John H. Grove

Plant and Soil Sciences Research Report

Historically, tobacco producers have relied heavily on surface tillage to prepare fields for transplanting. This typically involved moldboard plowing, followed by several secondary tillage operations, such as discing then leveling with a soil finisher. Transplanter developments and modifications in the late 1990’s, coupled with new chemicals for weed control, made no-till (NT) tobacco a viable option for tobacco producers in Kentucky (KY).


The Effect Of Rate And Source Of Potassium Fertilizer On Cured Leaf Yield Of Burley Tobacco And Leaf Content And Soil Test Levels Of Potassium And Magnesium, Kenneth L. Wells, James E. Dollarhide, Mark Reese Jan 1995

The Effect Of Rate And Source Of Potassium Fertilizer On Cured Leaf Yield Of Burley Tobacco And Leaf Content And Soil Test Levels Of Potassium And Magnesium, Kenneth L. Wells, James E. Dollarhide, Mark Reese

Soil Science News and Views

In response to questions being asked by tobacco growers about the effectiveness of sulfate of potash magnesia (SPM; 21% K2O and 11% Mg) as coinpared to sulfate of potash (SP; 50% K2O), field studies were conducted during 1993-1994 to compare the two potassium (K) sources for use on burley tobacco. Any effect of SPM on yield of tobacco should be due to Mg since the only difference between the two sources in kind of nutrient contained is the presence of magnesium (Mg) in SPM. To compare the two K sources, we selected field sites low enough …


Effect Of Subsoiling On Yield Of Burley Tobacco, Kenneth L. Wells, Kim D. Strohmeier Jan 1995

Effect Of Subsoiling On Yield Of Burley Tobacco, Kenneth L. Wells, Kim D. Strohmeier

Soil Science News and Views

Compaction of tobacco fields caused by overworking or working soils when they are too wet has become a topic of concern to burley producers in recent years. Despite the viewpoint of some producers that annual subsoiling of tobacco fields is a profitable practice, particularly on soils which percolate water slowly, the University of Kentucky College of Agriculture recommends subsoiling only for a defined compaction problem. In such cases, some field studies have shown increased yields of burley to tillage practices that penetrate and shatter the compacted layer. Questions persist, however, about the effectiveness of single shank subsoilers used annually by …


Effectiveness Of Surface Application Of Phosphorus And Potassium On Yield Of No-Till Corn Grown On Soils Testing Low Or Medium Below A Depth Of 3 Inches, Grant W. Thomas Jan 1990

Effectiveness Of Surface Application Of Phosphorus And Potassium On Yield Of No-Till Corn Grown On Soils Testing Low Or Medium Below A Depth Of 3 Inches, Grant W. Thomas

Soil Science News and Views

When crops are grown continuously under no-tillage or very minimum tillage, there is a tendency for phosphorus (P) and potassium (K) to become concentrated at or near the soil surface. This occurs when P and K fertilizers are broadcast on the surface and not mixed with the soil as would occur with plowing. The result is a stratification of P and K such that the surface few inches become very high in those nutrients, but soil test levels remain largely unaffected below that. The question is whether high yields of no-till crops can be obtained under these conditions.


The Effect Of Fall And Spring Tillage Of A Compacted Soil On Corn And Tobacco Yields, Kenneth L. Wells, Roy V. Catlett Jan 1990

The Effect Of Fall And Spring Tillage Of A Compacted Soil On Corn And Tobacco Yields, Kenneth L. Wells, Roy V. Catlett

Soil Science News and Views

Soil compaction is being diagnosed in increasing instances as the cause of poor crop performance in Kentucky. While the basic causes of compaction can usually be identified, it is much more difficult to prescribe techniques to solve the problem. Following identification of compacted soil as being the cause of poor corn growth in a field in Shelby County, Kentucky, a study was conducted to compare three tillage tools on production of corn and tobacco. The compacted zone was within the top 6-inch layer of soil.


Control Measures For Manganese Toxicity Of Burley At Transplating Time, Kenneth L. Wells, J. L. Sims May 1987

Control Measures For Manganese Toxicity Of Burley At Transplating Time, Kenneth L. Wells, J. L. Sims

Soil Science News and Views

Manganese (Mn) toxicity of burley tobacco is viewed by tobacco specialists in Kentucky as the greatest single factor which reduces yields. Estimates are that this problem adds 30 to 50 million dollars to the cost of burley production because of the greater acreage (and all associated costs) required by growers to produce their allotment. And, even though the cause and cure of Mn toxicity has been known for about 50 years, many growers are caught each year at transplanting time with no knowledge as to whether Mn toxicity may be a problem in their fields. The solution to Mn toxicity …


Effect Of Soil Water Stress And Irrigation On Growth, Yield And Quality Of Burley Tobacco, Ronald E. Phillips, J. E. Leggett Jul 1986

Effect Of Soil Water Stress And Irrigation On Growth, Yield And Quality Of Burley Tobacco, Ronald E. Phillips, J. E. Leggett

Soil Science News and Views

An experiment was conducted for a period of three years, 1982, 1983 and 1984, in order to evaluate the effects of soil water stress and irrigation on growth, yield and quality of burley tobacco at Spindletop Farm, Lexington. The variety KY 21 was grown all three years. Three treatments were used in the experiment: (1) check, rainfall only, not irrigated, (2) well watered, rainfall plus supplemental irrigation, and (3) water stressed beginning 50 days after transplanting. The soil of treatment 3 was covered with black plastic to prevent rainfall from entering the soil.


Cutting Production Costs In 1986, Kenneth L. Wells, John H. Grove Jan 1986

Cutting Production Costs In 1986, Kenneth L. Wells, John H. Grove

Soil Science News and Views

With the stressful economic situation that continues to face Kentucky farmers in 1986, the College of Agriculture is continually asked, "What are some of the things which can be done to ease the cost-price squeeze?" In response to this question, the following suggestions for improved, more cost efficient soil and crop production management are offered: These management techniques to get the highest possible yields without added costs are sometimes overlooked although they can offer increased yield potential at no added cost.


Fertilizing Alfalfa For Optimum Yields, William O. Thom Oct 1984

Fertilizing Alfalfa For Optimum Yields, William O. Thom

Soil Science News and Views

Alfalfa is one of the most important forage crops in Kentucky. It is grown on a wide range of soil types, has the ability to produce high yields, and will respond to good management including a sound soil fertility program.


Developing A Fertilizer Program For Tobacco, J. L. Sims Aug 1984

Developing A Fertilizer Program For Tobacco, J. L. Sims

Soil Science News and Views

Use of adequate amounts of required fertilizer nutrients are necessary to increase both yield and quality of tobacco if they are lacking in a soil. However, to insure maximum profits from the tobacco crop, careful consideration must be given to fertilizer management (kinds, rates, and methods and times of fertilizer application), the chemical and physical characteristics of the soil, and the crops grown in rotation with tobacco. To develop a profitable fertilization program for tobacco requires thoughtful planning on the part of the grower. Late summer and early fall is a good time to make these plans for the future.