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Direct Drilling Of Soybean In A Pensacola Bahiagrass Pasture In The Northwest Region Of Rio Grande Do Sul, Brazil, R. B. Medeiros, J. Riboldi, J. C. De Saibro, J. E. G. Zambra

IGC Proceedings (1997-2023)

The response of methods of soil preparation (M₁=conventional tillage, and with notillage using the following herbicides M₂=50% Paraquat plus 50% Orizalin; M₃=50% Paraquat plus 50% Diquat and M₄=Paracol (20% Paraquat plus 20 Diuron)) and row spacing (E₁=17 cm, E₂=24 cm, E₃=51 cm and E₄=68 cm) on soybean grain yield direct drilled in an eight-year-old grazed sward of Bahiagrass cv. Pensacola (Paspalum notatum var. saurae Parodi) were studied in southern of Brazil. The results showed that direct drilling of soybean on Pensacola accompanied by …

Forage Productivity Of Panicum Maximum Pastures In Two Different Agropastoral Systems, Tsutomu Kanno, Manuel C. M. Macedo, J. A. Bono, J. D. G. Santos Jr., M. R. Correa, L. G. R. Beretta

IGC Proceedings (1997-2023)

Forage productivity was evaluated for Panicum maximum pastures established after 4 years of soybean cultivation in the summer (PM-SO), and 4 years of rotation of soybeans in the summer and millet for winter grazing (PM-MI). In the PM-MI pasture, biomass and dry matter production were much lower than in the PM-SO, and the amount of copper and nitrogen in the top part of the plants in PM-MI were significantly lower than that in PM-SO. Thus, it was considered that the shortage of copper and nitrogen restricted photosynthesis and forage production in PM-MI.

Detecting Recent Crop Phenology Dynamics In Corn And Soybean Cropping Systems Of Kentucky, Yanjun Yang, Bo Tao, Liang Liang, Yawen Huang, Christopher J. Matocha, Chad D. Lee, Michael Sama, Bassil El Masri, Wei Ren

Geography Faculty Publications

Accurate phenological information is essential for monitoring crop development, predicting crop yield, and enhancing resilience to cope with climate change. This study employed a curve-change-based dynamic threshold approach on NDVI (Normalized Differential Vegetation Index) time series to detect the planting and harvesting dates for corn and soybean in Kentucky, a typical climatic transition zone, from 2000 to 2018. We compared satellite-based estimates with ground observations and performed trend analyses of crop phenological stages over the study period to analyze their relationships with climate change and crop yields. Our results showed that corn and soybean planting dates were delayed by 0.01 …

Modeling The Relationship Between Estimated Fungicide Use And Disease-Associated Yield Losses Of Soybean In The United States I: Foliar Fungicides Vs Foliar Diseases, Ananda Y. Bandara, Dilooshi K. Weerasooriya, Shawn P. Conley, Carl A. Bradley, Tom W. Allen, Paul D. Esker

Plant Pathology Faculty Publications

Fungicide use in the United States to manage soybean diseases has increased in recent years. The ability of fungicides to reduce disease-associated yield losses varies greatly depending on multiple factors. Nonetheless, historical data are useful to understand the broad sense and long-term trends related to fungicide use practices. In the current study, the relationship between estimated soybean yield losses due to selected foliar diseases and foliar fungicide use was investigated using annual data from 28 soybean growing states over the period of 2005 to 2015. For national and regional (southern and northern United States) scale data, mixed effects modeling was …

A Transcriptional Regulatory Network Of Rsv3-Mediated Extreme Resistance Against Soybean Mosaic Virus, Lindsay C. Demers, Neelam R. Redekar, Aardra Kachroo, Sue A. Tolin, Song Li, M. A. Saghai Maroof

Plant Pathology Faculty Publications

Resistance genes are an effective means for disease control in plants. They predominantly function by inducing a hypersensitive reaction, which results in localized cell death restricting pathogen spread. Some resistance genes elicit an atypical response, termed extreme resistance, where resistance is not associated with a hypersensitive reaction and its standard defense responses. Unlike hypersensitive reaction, the molecular regulatory mechanism(s) underlying extreme resistance is largely unexplored. One of the few known, naturally occurring, instances of extreme resistance is resistance derived from the soybean Rsv3 gene, which confers resistance against the most virulent Soybean mosaic virus strains. To discern the regulatory mechanism …

Dissecting The Economic Impact Of Soybean Diseases In The United States Over Two Decades, Ananda Y. Bandara, Dilooshi K. Weerasooriya, Carl A. Bradley, Tom W. Allen, Paul D. Esker

Plant Pathology Faculty Publications

Soybean (Glycine max L. Merrill) is an economically important commodity for United States agriculture. Nonetheless, the profitability of soybean production has been negatively impacted by soybean diseases. The economic impacts of 23 common soybean diseases were estimated in 28 soybean-producing states in the U.S., from 1996 to 2016 (the entire data set consisted of 13,524 data points). Estimated losses were investigated using a variety of statistical approaches. The main effects of state, year, pre- and post-discovery of soybean rust, region, and zones based on yield, harvest area, and production, were significant on “total economic loss” as a function of …

Feeding A Growing Population--Feasibility Of Leghemoglobin As Visual Marker For Facilitating Plant Genetics Based Nutritional Improvement, Rebecca E. Caldbeck

Oswald Research and Creativity Competition

As the population continues to expand, it is becoming increasingly relevant to find sustainable and affordable sources of high-nutritional value food, specifically protein and fatty acids.

One such crop of interest is Glycine max, commonly known as soybean. The leguminous plant is of high importance globally with its far-reaching economic applicability. Soybeans are a versatile crop with a wide-ranging habitat, making them a readily available food source. Besides their abundance, this crop is also one of the most economical sources of protein on the planet.

With their already blanketed global reach, the introduction of improved genetics to facilitate improved nutritional …

Glycerol-3-Phosphate Mediates Rhizobia-Induced Systemic Signaling In Soybean, M. B. Shine, Qing-Ming Gao, R. V. Chowda-Reddy, Asheesh K. Singh, Pradeep Kachroo, Aardra Kachroo

Plant Pathology Faculty Publications

Glycerol-3-phosphate (G3P) is a well-known mobile regulator of systemic acquired resistance (SAR), which provides broad spectrum systemic immunity in response to localized foliar pathogenic infections. We show that G3P-derived foliar immunity is also activated in response to genetically-regulated incompatible interactions with nitrogen-fixing bacteria. Using gene knock-down we show that G3P is essential for strain-specific exclusion of non-desirable root-nodulating bacteria and the associated foliar pathogen immunity in soybean. Grafting studies show that while recognition of rhizobium incompatibility is root driven, bacterial exclusion requires G3P biosynthesis in the shoot. Biochemical analyses support shoot-to-root transport of G3P during incompatible rhizobia interaction. We describe …

Ecophysiological Analysis Of Yield Determination In Soybean Of Different Relative Maturities, Maria Morrogh Bernard

Theses and Dissertations--Plant and Soil Sciences

Soybean yield differences are a combination of the genotype, environmental conditions, and management practices. Understanding how these factors interact through the analysis of the components involved in yield determination, provides a way to increase potential and actual yields in Kentucky.

Two irrigated experiments were conducted to quantify differences in the mechanisms of yield determination across soybean maturity groups (MG) 2 to 5 (Chapter 1), and to quantify management options (seeding rate and choice of MG cultivar) that increase yield potential of double crop soybean systems (Chapter 2).

Results showed that cultivars used different physiological strategies to achieve high yields, but …

The Soybean Rfg1 Gene Restricts Nodulation By Sinorhizobium Fredii Usda193, Yinglun Fan, Jinge Liu, Shanhua Lyu, Qi Wang, Shengming Yang, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

Sinorhizobium fredii is a fast-growing rhizobial species that can establish a nitrogen-fixing symbiosis with a wide range of legume species including soybeans (Glycine max). In soybeans, this interaction shows a high level of specificity such that particular S. fredii strains nodulate only a limited set of plant genotypes. Here we report the identification of a dominant gene in soybeans that restricts nodulation with S. fredii USDA193. Genetic mapping in an F2 population revealed co-segregation of the underlying locus with the previously cloned Rfg1 gene. The Rfg1 allele encodes a member of the Toll-interleukin receptor/nucleotide-binding site/leucine-rich repeat class of …

Draft Genome Sequence Of Cercospora Sojina Isolate S9, A Fungus Causing Frogeye Leaf Spot (Fls) Disease Of Soybean, Fanchang Zeng, Chaofan Wang, Guirong Zhang, Junmei Wei, Carl A. Bradley, Ray Ming

Plant Pathology Faculty Publications

Fungi are the causal agents of many of the world's most serious plant diseases causing disastrous consequences for large-scale agricultural production. Pathogenicity genomic basis is complex in fungi as multicellular eukaryotic pathogens. The fungus Cercospora sojina is a plant pathogen that threatens global soybean supplies. Here, we report the genome sequence of C. sojina strain S9 and detect genome features and predicted genomic elements. The genome sequence of C. sojina is a valuable resource with potential in studying the fungal pathogenicity and soybean host resistance to frogeye leaf spot (FLS), which is caused by C. sojina. …

Increasing Renewable Oil Content And Utility, William Richard Serson

Theses and Dissertations--Plant and Soil Sciences

Since the dawn of agriculture man has been genetically modifying crop plants to increase yield, quality and utility. In addition to selective breeding and hybridization we can utilize mutant populations and biotechnology to have greater control over crop plant modification than ever before. Increasing the production of plant oils such as soybean oil as a renewable resource for food and fuel is valuable. Successful breeding for higher oil levels in soybean, however, usually results in reduced protein, a second valuable seed component. We show that by manipulating a highly active acyl-CoA: diacylglycerol acyltransferase (DGAT) the hydrocarbon flux to oil in …

Genetic And Functional Analysis Of Host Genes Involved In Pathogenic And Symbiotic Legume-Microbe Interactions, Fang Tang

Theses and Dissertations--Plant and Soil Sciences

Legumes form symbiotic and pathogenic interactions with microbes. Understanding the molecular mechanisms underlying the legume-microbe interactions would help us to improve crop production in a sustainable manner. This thesis covers two independent research projects. The first project was to study the role of alternative splicing in RCT1-mediated disease resistance. RCT1 is a TIR-NBS-LRR-type plant resistance (R) gene in Medicago truncatula that confers broad-spectrum resistance to Colletotrichum trifolii, a fungal pathogen that causes anthracnose disease in Medicago. RCT1 undergoes alternative splicing at both coding and 3'-untranslated regions, thereby producing multiple transcript variants in its expression profile. …

Evaluation Of Input-Intensive Soybean Management Systems And The Effect Of Lactofen Application On Soybean Physiology, John M. Orlowski

Theses and Dissertations--Plant and Soil Sciences

In an effort to maximize yields, many soybean growers have begun moving to intensive, input-based soybean management systems. However, limited reliable information exists about the effect of these inputs on soybean yield. The purpose of this study was to evaluate the effect of individual inputs and combinations of inputs as part of high-yield management systems on soybean seed yield and to determine the effect of one of these inputs, lactofen, on soybean physiology. Small plot studies were established in nine states across the Midwest. A number of commercially available soybean inputs were evaluated individually and in combination to determine their …

Sensing Development Of A Soybean Canopy Under P Or K Nutritional Stress, Martin M. Navarro

Theses and Dissertations--Plant and Soil Sciences

The normalized difference vegetative index (NDVI) has been correlated with physiological plant parameters and used to evaluate plant growth. There is little information about the use of this technique to detect soybean nutrient deficiencies. The objective of this work was to determine the ability of the NDVI sensor to detect P and K deficiencies, and grain yield reduction, in soybean. During 2010 and 2011, NDVI measurements were made on a soybean field trial site known to exhibit yield responses to both P and K nutrition. Four replicates of 8 levels each of P and K nutrition were evaluated. The NDVI …

Viral Vectors Useful In Soybean And Methods Of Use, Said A. Ghabrial, Chunquan Zhang, Honcgang Gu

Plant Pathology Faculty Patents

The invention provides Bean pod mottle virus (BPMV) vectors useful for expression of heterologous proteins in plants such as soybean. The BPMV vectors are also useful for virus-induced gene silencing. The invention also provides methods for expressing a heterologous polypeptide in a plant such as soybean. The invention additionally provides methods for virus-induced gene silencing, particularly in a soybean plant, which can be used to determine the function of a gene of interest.

Corn And Soybean Profitability 2010, Gregory S. Halich

Agricultural Economics Presentations

No abstract provided.

Early Maturing Varieties And Soybean Cyst Nematodes: Will This Marriage Work?, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Soybean cyst nematode (SCN) is widely distributed in Kentucky’s soybean growing areas. The use of SCN-resistant varieties has long been a recommended production practice for infested fields. However, continuous use of such varieties can result in a shift to a race of SCN which is able to vigorously attack previously resistant varieties. For this reason, many states recommend that producers periodically grow a crop of SCN-susceptible soybeans within a crop rotation when SCN populations are at minimal levels (causing less than a 5% loss in yield). The UK Plant Pathology Department recommends a four year rotation in SCN-infested fields [PPA3; …

Preliminary Maturity Group Ii Soybean Variety Trials, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

On-farm research with early maturing soybean varieties in Kentucky in both 1993 and 1994 has indicated that Maturity Group (MG) II varieties yield competitively with our traditional MG IV varieties. In those tests, four MG II varieties were compared with a single, high yielding MG IV variety (Asgrow A4715) over a range of planting dates on a total of 27 farms across both years. Asgrow A4715 averaged 43 bu/A, while the best MG II variety (Jack) averaged 39 bu/A. Such on-farm strip tests are valuable for comparing varieties under true production conditions. However, strip tests can effectively compare only a …

Early Maturing Varieties And Soybean Cyst Nematodes: Will This "Marriage" Work?, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Soybean cyst nematode (SCN) is widely distributed in Kentucky's soybean growing areas. The use of SCN-resistant varieties has long been a recommended production practice for infested fields. However, continuous use of such varieties can result in a shift to a race of SCN which is able to vigorously attack previously resistant varieties. For his reason, many states have long recommended that producers periodically grow a crop of SCN-susceptible soybeans within a crop rotation when SCN populations are too low to cause yield reductions. In Kentucky, the UK Plant Pathology Department recommends a four year rotation in SCN-infested fields [PPA3; "Wanted: …

An Evaluation Of Twelve Maturity Group Ii Soybean Varieties At Lexington, Kentucky, Larry J. Grabau, Colleen C. Steele

Agronomy Notes

In both 1993 and 1994, the Kentucky Soybean Promotion Board funded an on-farm test of a small set of Maturity Group (MG) II varieties. Those studies showed that several MG II varieties were competitive with a high-yielding MG IV variety. However, other MG II varieties did not perform as well in those tests, indicating that variety selection is an important management consideration if this early maturing cropping system is to be successful in Kentucky soybean producers' fields. MG II varieties used in past University of Kentucky tests have been chosen based on their performance in university variety trials where such …

Grain Quality Of Early Maturing Soybean Grown In Kentucky, M. V. Kane, Colleen C. Steele, Larry J. Grabau, C. T. Mackown, David F. Hildebrand

Agronomy Notes

Interest in grain quality of US soybean has grown in recent years. For example, in 1990, there was much interest in "component pricing" of soybean grain, Under that plan, growers would be paid a price for their grain that reflected the value of the protein and oil it actually contained, rather than the common price paid to all growers, regardless of any variation in protein and oil content. However, the soybean processing industry is evidently not excited about the complexity of testing individual lots for protein and oil and keeping track of pricing structures depending on those results. As a …

Growth Of Early Maturing Soybean, M. V. Kane, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Production of early maturing soybean varieties has grown in popularity across the southeastern US in recent years. Many growers in Mississippi, Arkansas, and Texas have seen this system as a way to avoid late season drought. However, several Kentucky growers have had good success with the use of Maturity Group (MG) II soybeans in the recent seasons which had generally good rainfall patterns. Some growers are glad to get competitive yields from MGII soybean while gaining the opportunity to harvest some of their soybean acreage before corn is ready to harvest.

On-Farm Testing Of Early Maturing Soybean, Colleen C. Steele, Larry J. Grabau, N. Gift

Agronomy Notes

Maturity Group (MG) II soybean varieties have performed well in University of Kentucky tests over the past several years. Early planted (late April/early May) tests in the relatively dry years of l986 through 1989 showed MG II yields to exceed those of MG III or MG lV. Over the generally wetter years 1990 through 1993, MG III and lV yields were slightly better than those of MG II varieties. Across eight years of data, MG II yield averages were virtually identical to those of MG III and lV. Perhaps growers could plant a portion of their soybean acreage to MG …

Planting Dates For Early Maturing Soybean, M. V. Kane, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Early maturing soybean cropping systems have been gaining in popularity with producers across the southeastern US, as well as in Kentucky. To our south, some producers in Texas, Arkansas, and Mississippi are using varieties that are two or three Maturity Groups (MG) earlier than those traditionally grown. The main intent in those states has been to avoid late summer drought by using early maturing varieties coupled with early planting. Previous Kentucky research in this area has also emphasized early planting(late April). However, a number of Kentucky growers have had good success using later planting dates for early maturing varieties, particularly …

An Evaluation Of Twelve Maturity Group Ii Soybean Varieties At Lexington, Kentucky, Larry J. Grabau, Colleen C. Steele

Agronomy Notes

In 1993, an on-farm study funded. by the Kentucky Soybean Promotion Board showed that the best Maturity Group (MG) II variety tested was quite competitive with the best available MG IV variety. However, other MG II varieties did not fare as well, indicating that careful variety selection will be essential for on-farm success with this MG II cropping system. MG II varieties used in past University of Kentucky tests have been chosen based on their performance in university variety trials where they are normally grown, for example, in Iowa, Illinois, Indiana, and Ohio. Such tests include relatively large numbers of …

Reduced Scepter Rates For Broadleaf Weed Control In Soybean, D. S. Jones, H. Lin, M. V. Kane, Larry J. Grabau

Agronomy Notes

Public agencies are placing greater scrutiny on herbicide applications by farmers. For example, the corn herbicide atrazine is now classified as a restricted use pesticide, with limits placed on allowable rates. While soybean growers may share some of this concern for the environment, rate reduction is more likely to be attractive for economic reasons. Some growers are already cutting back on herbicide rates. For example, Missouri data shows that the average application rates for soybean herbicides were only 75% of the labelled rate. While reduced rates might save growers money, and may be kinder to the environment, there is a …

Growing Soybean Varieties From Multiple Maturity Groups Can Reduce Yearly Yield Volatility, Todd W. Pfeiffer

Agronomy Notes

In the Kentucky Soybean Performance Test program, varieties of maturity groups (MG) 3, 4 and 5 are tested to provide information on their relative yields. The difference in maturity between the earliest and the latest maturing variety in the test in any year is approximately 30 days. In general, although some regional differences appear, the long-term state-wide and within region yield of the different maturity groups (average yield of a 11 varieties in a maturity group) is equal (Table 1). As I've inspected results from the Kentucky Soybean Performance Tests for the last decade, it appeared that some of the …

An Early-Planted, Early Maturing Soybean Cropping System: Yield And Harvest Losses, Larry J. Grabau, M. V. Kane, H. Lin, Dennis B. Egli

Agronomy Notes

Most soybean varieties used In Kentucky, whether grown full season or double-cropped behind wheat or barley, are from Maturity Groups (MG) IV or V. Some MG III varieties are also grown; however, virtually no MG 1/ or earner varieties are planted. Agronomists and soybean producers in Kentucky· have generally felt that MG IV and V varieties produce the highest yield. Since the driest months in Kentucky are August, September,and October, MG IV and V varieties frequently encounter moisture stress during the important seed fill stage. The use of earlier maturing varieties was initially proposed as a means of getting a …

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. …