Row Covers for Excluding Insect Pests from Broccoli and Summer Squash Plantings

Abstract

Tests were conducted to determine the effectiveness of various row covers for excluding certain insect pests from broccoli, Brassica oleracea L. Italica group, and summer squash, Cucurbita pepo var. melopepo (L.) Alef., plantings. Kimberley Farms (Kimberley- Clark Corporation) and Agronet (CDK International Corporation) fabric row covers effectively excluded Lepidoptera from broccoli, as well as several species of flea beetles and striped cucumber beetles, Acalymma vittata (F.) from summer squash. Aslit, clear-plastic row cover was also effective in excluding pests of squash, but allowed more lepidopterous insects to reach broccoli plants than the fabric row covers. None of the row covers was initially successful in excluding Delia spp. from broccoli plantings. The presence of Delia spp. adults under row covers was most likely the result of life stages in the soil before the placement of the row covers and the subsequent development and emergence of the adults. Once in place, however, row covers appeared to be successful in preventing the entrance of the adults from the outside into the covered plantings. Delays in maturation of broccoli and summer squash were detected during one year for plants under row covers. No significant differences, however, were found in the total harvest means for head or fruit numbers and weights.