Location: Southern Horticultural Research
Project Number: 6062-21430-002-14-S
Project Type: Specific Cooperative Agreement
Start Date: Sep 9, 2013
End Date: Sep 8, 2018
The objective of this cooperative research is to profile certain pesticide residues from foliar and seed applications when applied to corn, cotton, and soybeans to ultimately develop better management decisions to minimize exposure to honey bees.
Experiments will be conducted to examine the uptake of three neonicitinoid insecticides in three plant systems across three states. The study will be planted in a randomized complete block with 4 replications. Leaf samples will be collected pre-bloom. The first full expanded leaf will be taken from a minimum of 10 leaves per plot. Corn will be planted using four treatments of three rates of clothianidin (250, 500, and 1250) and an untreated check. The study will be planted in a RCB design with 4 replications. Random leaf samples from plants in each plot will be collected at various vegetative stages. Leaf samples will be collected from the uppermost fully expanded leaf. Sufficient leaf tissue for testing purposes should be taken. This will depend on plant stage but should be no less than 20 plants at smaller stages and no fewer than 10 plants at older stages. Soybeans will be planted using three treatments: thiamethoxam, clothianidin, and an untreated check. The study will be planted in a randomized complete block with 4 replications. The uppermost fully expanded trifoliate will be collected from 25 random plants per plot. A soil sample will be taken for each test at the same time as the first and last tissue sample. All samples will be labeled clearly with the date of collection, growth stage, and treatment. A study will be conducted to determine when and at what densities European honey bees (Apis mellifera L.) visit agronomic crops across two regions in Mississippi, the “Delta” and the “Hills”. Fields of cotton, corn, soybeans, grain sorghum, sweet potatoes, and peanuts will be scouted for honey bees. Fields will be scouted at three time intervals. For each time interval and location, weather parameters will be measured. Honey bees were sampled in natural landscapes along 2 meter by 100 meter transects Additional sampling methods will be used to sample cotton and soybeans. A study will be conducted to determine the rate at which flowering plants absorb and translocate various concentrations of three systemic insecticides (imidacloprid, clothianidin, and thiamethoxam) from the soil into the flower head. In this experiment Dutch white clover will be used. A solution of water and various concentrations of all three neonicotinoids tested will be added to each pot of top soil. A composite sample of the top soil used in the experiment will be sent off to a lab to ensure that it is free of neonicotinoid compounds. Dutch white clover seeds will be placed into the pots five days after the initial saturation. Plants will be grown in a greenhouse setting and watered normally. Five days after flowering, the heads will be collected. Samples will be immediately sealed in plastic storage bags and placed in cooler containing blue ice or plastic containers with frozen water solution. Samples will be transferred into a storage unit kept at a temperature of -10°C within 30 to 45 minutes after sampling. All samples will be labeled clearly with the date of collection and treatment. All samples will be analyzed at the USDA, AMS, National Science Laboratory, Gastonia, NC for pesticide residues.