Effects of different tillage systems in irrigated cotton on population dynamics of boll weevil
| Problem: | Currently, the use of conventional insecticides is the predominant cotton protection strategy for reducing boll weevil damage. Environmental and social concerns have escalated the need for alternative agricultural systems in the last decade. One alternative is to substitute cultural input for synthetic chemicals for boll weevil management. Tillage operations are among important cultural control techniques. |
| Objective: | Determine the effects of conservation and conventional tillage systems on soil surface temperatures, soil moisture, plant canopy structure, light interception, timing of fruit set, and how these factors affect boll weevil populations throughout the growing season. |
| Approach: | Conservation tillage (experimental) and adjacent conventionally tilled (control) cotton fields will be sampled weekly beginning 60-70 days after cotton is planted until defoliation. We will estimate boll weevil survival in both fields: (1) from naturally infested fruit collected from the soil surface and (2) from cohorts of laboratory infested squares placed under plants and in the middle of the crop rows. Boll density and damage, weather conditions and phenology of cotton plants will also be recorded. |
| Accomplishment: | In dryland, no-tillage cotton more bolls and lint were produced and had fewer boll weevils than conventional tillage cotton. Conservation tillage system in dryland cotton agroecosystems may contribute to lower boll weevil numbers by disrupting the life cycle of the insect and essential habitat. |
Sasha M Greenburg