Life Sciences Commons^™

Role Of Soil Management In Control Of Soil-Borne Diseases, Gretchen F. Sassenrath, Christopher R. Little, Xiaomao Lin

Kansas Agricultural Experiment Station Research Reports

Soil-borne diseases are a significant cause of crop yield reduction. Alternative soilmanagement methods can enhance the soil’s natural disease-controlling organisms. This study explores the effect of alternative production methods on a primary soybean disease, charcoal rot, caused by the fungus Macrophomina phaseolina. Treatments that could potentially enhance or reduce the disease pressure were implemented, and soil tests were conducted for nutrients, soil properties, and disease presence. Manure increased the nutrient levels in the soil, as expected, but did not influence disease control. Solarization increased the temperature within the plots and increased the number of colony-forming units (CFUs) of M. …

An Appraisal Of The Potential For Soybeans In The United Kingdom, C. A. Sawyer, G. P. F. Lane, W. P. Davies

IGC Proceedings (1993-2023)

Soybean is a most important crop worldwide, accounting for 56% of world oilseed production and 69% of world protein meal consumption in 2003 (Soystats, 2004). Since their introduction in the early 1800's, forage soybeans have been grown widely in USA. Used originally as a forage crop, this use largely had been forgotten until Dr T. E. Devine (United States Department of Agriculture, Agricultural Research Service; USDA-ARS) released 4 new forage cultivars. Soybeans potentially offer UK farmers a high quality protein source in a short season and also meet the requirements of supermarket chains to remain GM free. This paper aims …

Understanding The Etiology Of Taproot Decline Of Soybean Caused By Xylaria Necrophora, José E. Ortiz Solórzano

LSU Master's Theses

Taproot decline (TRD) of soybean is caused by Xylaria necrophora. However, the mechanisms by which it infects soybean and produces symptoms are unknown. Symptoms of TRD include foliar interveinal chlorosis and necrosis and root necrosis, yet X. necrophora appears to be restricted to the roots. While Xylaria species are predominantly wood decomposers, a few are pathogens. More importantly, they produce secondary metabolites (SMs) with multiple bioactivities, including phytotoxicity and antimicrobial activity. Preliminary experiments suggested that X. necrophora was producing SMs responsible for TRD symptoms. We evaluated cell-free culture filtrates (CFs) for phytotoxicity on soybeans, testing for changes in chlorophyll …

Baseline Sensitivity To Dmi Fungicides In Cercospora Spp. And Corynespora Spp. In Arkansas Soybeans, Evan Buckner

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Cercospora spp. and Corynespora spp. are two common foliar fungal pathogens in Arkansas amongst other soybean producing areas. Two primary diseases caused by Cercospora spp. are Cercospora Leaf Blight (CLB, caused mainly by C. kikuchii) and Frogeye Leaf Spot (C. sojina). Both diseases affect foliage, and when lesions collapse, leaves may fall prematurely resulting in yield loss. In the specific case of CLB, this is a disease on the rise since 2000, and also causes seed infection reducing seed quality. Target spot is a disease caused by Corynespora cassiicola, and is of less damaging for farmers in larger …

Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz

Graduate Theses and Dissertations

Soybeans (Glycine max) are one of the major row crops in the United States, particularly in Arkansas. Soybean cyst nematode (SCN, Heterodera glycines) and southern root-knot nematode (RKN, Meloidogyne incognita) are two of the most damaging pests that cause major economic losses in soybeans. Little is known concerning the effects of common and alternative agronomic practices on nematodes in fields with nematode population densities below threshold levels. Therefore, the objective of this study was to evaluate the effects of the combination of tillage (conventional tillage and no-tillage), irrigation (irrigated and non-irrigated), wheat (Triticum aestivum) residue burning (burned and no burned), …

Soybean Cyst Nematode Hatching Behavior, Aaron K. West, Sita Thapa, Nathan E. Schroeder

PRECS student projects

The ability of soybean cyst nematodes (SCN. Heterodera glycines) to lay dormant as eggs within a cyst for up to 11 years, has made this parasite a principal target for soybean crop pest management. Research on SCN hatching will improve understanding of SCN biology will uncover new mechanisms for their control. This poster summarizes three experiments using hatching stimulants, soybean root exudate (SRE) zinc chloride, testing whether it affects post hatch development.

Soybean Sudden Death Syndrome Influenced By Macronutrient Fertility On Irrigated Soybeans In A Corn/Soybean Rotation, Eric Adee, Dorivar Ruiz Diaz, C. R. Little

Kansas Agricultural Experiment Station Research Reports

The effects of nitrogen (N), phosphorus (P), and potassium (K) fertilization on a corn/ soybean cropping sequence were evaluated from 1983 to 2016, with corn planted in odd years. There was a negative relationship between the P rate applied during the corn years and the severity of sudden death syndrome (SDS) in 2014 and 2016 soybean.

Sudden Death Syndrome And Soybean Planting Date, Eric Adee, C. R. Little, I. A. Ciampitti

Kansas Agricultural Experiment Station Research Reports

The effect of planting date on severity of sudden death syndrome (SDS) and yield was evaluated for the second year in two studies at the Kansas River Valley experiment fields in 2016. One study was established to promote SDS and the other to minimize SDS. In both studies the severity of SDS was greatest with the earlier planting dates. The yield was greatest with the earlier planting date, except for the most susceptible variety. The severity of SDS was not as great as had been observed in previous years. There is a very positive benefit to planting in early May …

Pythium: Characterization Of Resistance In Soybean And Population Diversity, Keiddy Esperanza Urrea Romero

Graduate Theses and Dissertations

Pythium spp. are an important group of pathogens causing stand losses in Arkansas soybean production. New inoculation methods and advances in molecular techniques allow a better understanding of cultivar resistance and responses of Pythium communities to cultural practices. The objectives of this research were to i) characterize the resistance of soybean to P. aphanidermatum with two phenotyping assays that evaluated the seed rot phase of the disease; and ii) understand the effect of long term crop rotation on species diversity and iii) to determine the effect of location, temperature and continuous soybean and soybean-rice rotation on Pythium spp. diversity in …

A Novel Partitivirus That Confers Hypovirulence On Plant Pathogenic Fungi, Xueqiong Xiao, Jiasen Cheng, Jinghua Tang, Yanping Fu, Daohong Jiang, Timothy S. Baker, Said A. Ghabrial, Jiatao Xie

Plant Pathology Faculty Publications

Members of the family Partitiviridae have bisegmented double-stranded RNA (dsRNA) genomes and are not generally known to cause obvious symptoms in their natural hosts. An unusual partitivirus, Sclerotinia sclerotiorum partitivirus 1 (SsPV1/WF-1), conferred hypovirulence on its natural plant-pathogenic fungal host, Sclerotinia sclerotiorum strain WF-1. Cellular organelles, including mitochondria, were severely damaged. Hypovirulence and associated traits of strain WF-1 and SsPV1/WF-1 were readily cotransmitted horizontally via hyphal contact to different vegetative compatibility groups of S. sclerotiorum and interspecifically to Sclerotinia nivalis and Sclerotinia minor. S. sclerotiorum strain 1980 transfected with purified SsPV1/WF-1 virions also exhibited hypovirulence and associated traits similar …

The Effects Of Salinity On Pythium Disease Of Rice And Soybean, Terea Jeanette Stetina

Graduate Theses and Dissertations

Increasing salinity is an important factor limiting agricultural productivity worldwide. In addition to direct effects on growth and yield, diseases also may be affected. This study characterized the effects of soil salinity on seedling disease of soybean and rice caused by Pythium spp. Controlled environment experiments on soybean used two cultivars which differed in chloride tolerance and soil treated with a CaCl₂ solution to create a range of electrical conductivity (EC) levels. For soybean, soil was either not infested or infested with Pythium sylvaticum or P. aphanidermatum (pathogenic to soybean), or P. oligandrum (not pathogenic to soybean). Twenty-one days …

Effects Of Environment And Genotype On Charcoal Rot Development On Soybeans, Micah Diane Doubledee

Graduate Theses and Dissertations

Charcoal rot of soybean, caused by the soilborne fungus Macrophomina phaseolina (Tassi) Goid, is a disease associated with high soil temperature and low soil moisture. Above-ground symptoms, which can be difficult to distinguish from drought symptoms, include low vigor, dead leaves that remain attached to the plant, early senescence and yield loss. Irrigation limits damage, but does not prevent colonization of the tissue by the pathogen. No soybean line is immune to M. phaseolina, but a few lines may have moderate resistance. The objectives of this research were to 1) determine the effects of genotype and drought on the development …

Kentucky Plant Disease Management Guide For Soybeans, Donald E. Hershman

Agriculture and Natural Resources Publications

This guide contains information on the biology and management of the most important diseases of soybeans in Kentucky. Fundamental information on symptoms, disease cycle, and management is provided. For some diseases, more extensive information on biology and management is also available in other Extension publications. Additional sources of information are listed under individual diseases.

Disease management in soybeans relies heavily on using disease-resistant varieties, when available, and employing sound agronomic practices. It is important to integrate both of these strategies into a comprehensive disease management program. Failure to consider one or the other will compromise the success of your efforts. …

Fusarium Blight Of The Soy Bean And The Relation Of Various Factors To Infection, Richard O. Cromwell

Nebraska Agricultural Experiment Station: Historical Research Bulletins

An investigation was outlined (1) to determine the parasitism of Fusarium on soy bean, (2) to establish its relationship to Fusaria of the section Elegans in so far as a comparison of the cultural characters permitted, and (3) by means of cross- inoculations and field studies to determine the relationship of this disease of soy beans to the wilt disease of cowpeas (Vigna sinensis Hassk.) caused by Fusarium tracheiphilum Smith. The results of these investigations up to the close of the summer of 1916 have been reported. The studies were continued at the North Carolina Experiment Station until the …