Tests employing an experimental "Slosser"-type, row-crop spray-boom and an air-blast sprayer showed that weekly applications of DDT at 1.5 and 2 lbs. per acre, respectively, starting in early July and continuing until the first week of September, controlled the European corn borer, Ostrina nubilalis (Hübner), on peppers. In a preliminary study of the combined effects on yields of insect control, disease control, and improved soil fertility the air-blast sprayer was used to apply the pesticides and the different fertilizer treatments were applied as side dressings. Yields in the sprayed plots ranged from 8 to 12 tons of fruit per acre which was from 2 to 4 tons higher than on the unsprayed. Greater corn borer infestations occurred in unsprayed peppers at the high fertility level than at the lower levels. Weekly DDT sprays at 1.5 lbs. per acre in the row-cropsprayer test, starting when nightly collections by a black-light trap first reached 5, 10, and 20 moths gave 95%, 71% and 37% control, respectively. In this same test DDT also gave excellent control of the cabbage looper, Trichopulusia ni (Hübner), when weekly applications were started either June 30 or July 7, and when applied either with or without a sticker, but control was significantly poorer with weekly sprays beginning August 15 or later. Populations of the green peach aphid, Myzus persicae (Sulzer), were very high in the DDT-treated plots. The addition of Thiodan® (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide) at 0.5 lb. per acre in three applications gave good aphid control, but the addition of mineral oil (70-sec.) in four applications did not.