Using Cover Crops to Manage Arthropods on Truck Farms

Abstract

Biological and cultural control: Cover crops as nexus Cover crops represent an important nexus in sustainable vegetable culture; they affect many aspects of production, including pest man-agement. Many of the arthropod pests that attack vegetable crops are themselves attacked by natural enemies, including predatory and parasitic arthropods. If cover crops are used to reduce pest dispersal, colonization, or reproduction on vegetable crops, this is usually termed cultural control. This method involves: 1) maintenance of the cover crop as a sink for various pests, 2) use of cover crops to confuse pests visually or olfactorally and thus reduce their colonization of vegetable crops, 3) cover crops having nutritional effects on host plants, and 4) cover crops causing microclimatic changes that reduce pest success. However, if the aim of the methodology is to enhance performance of natural enemies, strict constructionists consider this an aspect of biological control. At times, cultural and biological controls may The preparation of this manuscript was funded in part by the Wallace Genetic Fund, Inc. HORTSCIENCE, VOL. 27(7), JULY 1992 operate simultaneously [see reviews by Altieri and Letourneau (1982) and Andow (1988)]. The dynamics of arthropod dispersal to and from cover and veg-etable crops are still poorly documented (see Kennedy and Margolies, 1985) and management options to enhance cultural and biological control only crudely formulated. The present article focuses mainly on cover crops as sinks and sources of pests, and reviews relevant literature, yet also entails considerable speculation. Yin/yang (sink/source) dynamics