Location: Crop Genetics Research
Project Number: 6066-22000-075-001-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2016
End Date: May 31, 2021
Objective:
The objectives of this research are to (1) characterize plant growth and development and yield responses to reniform nematode in susceptible and resistant cotton lines and define the relationships between soil fertility and reniform nematode severity with respect to plant damage and yield loss and (2) evaluate impacts of integrated reniform nematode management practices on cotton yield, quality and reniform nematode population densities.
Approach:
Cotton growth and development on resistant and susceptible lines challenged with reniform nematode will be characterized to improve our understanding of how the nematode affects host plant development and crop yield. A multi-year field trial will be conducted to measure the effects of plant infection by the nematodes on leaf surface area, mainstem length, mainstem nodes, number of bolls, plant biomass, seed cotton yield, lint percent, and HVI fiber properties. Net assimilation rate, leaf area index, crop growth rates, leaf area duration, and biomass duration will be calculated and the effect of the reniform nematode on these growth parameters will be determined.
Additional crop production practices that alone, or in combination with resistance, can improve control of or reduce damage by the reniform nematode need to be identified to maximize grower profits. Soil fertility, crop rotation, and nematicides will be evaluated to determine if their inclusion in a cotton production system will help mitigate losses to the reniform nematode.
The effect of soil fertility on severity of plant damage from reniform nematode will be assessed in the greenhouse or growth chamber, where both levels of nutrients (N, P, K) and reniform nematode densities can be effectively manipulated. Mainstem length, mainstem nodes, and number of leaves will be measured weekly, with additional plant growth parameters measured 40 to 60 days after inoculation (gas exchange and chlorophyll fluorescence, leaf area, and biomass).
Field research examining 4-year rotations of cotton lines susceptible or resistant to reniform nematode with non-host or poor host crops such a corn, peanut, or resistant soybean will be conducted to develop crop production recommendations that improve reniform nematode management, increase cotton yields, and maximize grower profits. Data on reniform nematode soil populations, crop yield, and crop quality will be collected and analyzed to identify superior crop rotation sequences.
New nematicides will be evaluated for their utility in controlling reniform nematode in field trials on cotton lines that are susceptible or resistant to reniform nematode to determine if there is any advantage to using these pesticides. Research will be conducted in at least two naturally-infested fields, with trials taking place for at least two years. New nematicides will be compared to the standard in-furrow nematicide aldicarb and to nontreated controls. Soil samples will be collected at planting, 6 weeks after planting, and at harvest to measure effects of the treatments on reniform nematode population densities. At harvest, cotton yields and fiber properties will be determined.
