Residues in three peanut varieties grown in dieldrin treated soil.

Three commercial peanut varieties (Starr Spanish, Florunner, and Florigiant) were grown in field plots treated with 0, 1, and 4 kg dieldrin per hectare. Soil samples were taken at planting; soil and aerial portions were sampled 10 weeks into the growing season. Peanuts were grown to maturity (16 weeks), harvested, and dried before shelling. Soils, hay, shells, and meats were analyzed for dieldrin content. All soil levels of insecticide caused detectable residues in all plant parts; furthermore, the dieldrin content of each plant part was proportional to the soil level in which it was grown. Varietal difference was detected only in the residue content of the shells where the Florunner variety contained significantly greater dieldrin levels than Starr Spanish and Florigiant. It appears possible to predict dieldrin levels in peanuts when soil residue levels are known.