Skip to main content
ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Research Project #438156

Research Project: GxExM Systems Approach to Crop Disease Management

Location: Soil Dynamics Research

2021 Annual Report

The new research will initially focus on managing the cotton leaf roll dwarf virus (CLRDV), also known as “cotton blue disease.” The project will have the following objectives: 1. Identify alternative (other than cotton) plant hosts for CLRDV which may contribute to its spread within cropping systems in the US cotton belt. 2. Understand seasonal population dynamics of insect vectors responsible for the spread of CLRDV within the landscape and their interactions with disease- or insect-tolerant germplasm. 3. Identify agronomic practices and management strategies for diverse germplasm for reducing risk of virus spread, disease expression, and yield loss caused by CLRDV.

The funds will be used to study the key epidemiological factors responsible for spread of cotton leaf roll dwarf virus (CLRDV) in cotton. Research will be undertaken on crop management to investigate production practices that minimize crop susceptibility to the disease, which include cultivar selection, crop health inputs, rotation, and cover crop selection as well as establish the relationship between symptom onset, host growth stage, and losses in lint yield and quality. Key epidemiological mechanisms for both the virus and the vector will be identified. On the cotton production landscape, aphid vector host selection along with dispersal and colonization patterns will be studied. This will allow strategies to be tested for alternative and sustainable management practices. It will build on the current field knowledge and strengthen the tools necessary to mitigate yield impacts at the grower level. Laboratory, field and controlled environment experiments will be utilized to build on the current knowledge to better understand the impact that winter crop production and common management practices have on virus and vector epidemiology. In addition, germplasm response to the virus in terms of symptomology and genotypic response will be addressed in order to identify resistance to either the vector or the virus providing a GxExM approach to this research.

Progress Report
A new project has been established via Congressionally Mandated funds that will initially focus on cotton leaf roll dwarf virus (CLRDV), a destructive insect-borne viral disease, that is challenging cotton production across the U.S. cotton belt. Disease and economic losses caused by this virus are variable, but 100% yield loss has been observed in the most severely diseased fields. Information on what factors cause symptom expression and yield loss outcomes is needed. Knowledge about the vectors is also lacking. Collaborations are being developed between NSDL and Auburn University to identify management strategies to minimize risk of CLRDV. Joint projects include greenhouse studies to identify alternative hosts for CLRDV and evaluate aphid transmission of CLRDV to potential hosts; field studies to investigate how fertility levels impact symptomology of CLRDV, evaluate herbicide effects on symptomology, determine how cover crops affect aphid levels and subsequent CLRDV occurrence, and how tillage practices may impact CLRDV occurrence. Funds received have been allocated to purchase field and laboratory equipment to enhance research infrastructure capability associated with viral disease work in cotton. In addition, bi-monthly phone calls have been established between relevant NPLs, ARS units in Auburn, Alabama, Ft. Detrick, Maryland, Stoneville, Mississippi, and Auburn University to strengthen communication and coordinate future research activities.