In Colombia, bean crops contribute significantly to the region’s agriculture. New research on the use of kaolin (aluminosilicate clay) contains information that can help bean producers limit the use of conventional pesticides. The authors of the study in HortScience said previous experiments in temperate regions have shown that kaolin foliar sprays have insecticidal attributes. The researchers studied the greenhouse whitefly Trialeurodes vaporariorum, one of the most prevalent pests in the region’s bean crops. The study design consisted of three experiments using four treatments: no insecticide, synthetic chemical insecticides, foliar applications of kaolin at 2.5 percent and foliar applications of kaolin at 5 percent (weight/volume). Foliar applications of kaolin at both doses controlled 80 percent of the population of whitefly in different stages (eggs, nymphs and adults) in all three experiments. Analyses showed that the percentage of efficacy of the two doses of kaolin was similar to that obtained in bean plants treated with synthetic chemical insecticides (90 percent).
This article appears in the March 2016 issue of Acres U.S.A.