In years of heavy thrips populations, the choice of proper materials, including the more effective organic phosphates, and timing of applications are extremely important to avoid damage in nectarines. In a year of low thrips populations, and especially when the one-thrips-nymph-per-blossom level does not occur until late in the bloom period, choice of material and timing of applications are not as critical; and treatment may be unnecessary or of little economic value. This report summarizes four years of research in Kern County.

Assistance with plot design and statistical analysis for this project was obtained from Edward S. Sylvester, Professor of Entomology and Entomologist in the Experiment Station and Gordon A. Rowe, Extension Economist, Agricultural Extension Service and Assoc., Giannini Foundation of Agricultural Economics, U. C., Berkeley.