Evaluating compatibility of entomopathogenic nematodes with high tunnel management practices

High tunnel systems, where crops are grown in the ground beneath an often unheated, semi-permanent, manually ventilated, polyethylene tunnel, provide a unique environment resembling, but separate from, both greenhouse and field conditions. This production system is relatively new to the U.S.; therefore, management practices and pest pressures in this system are generally understudied. Entomopathogenic nematodes (EPNs) have been evaluated in both field and greenhouse conditions, but little is known of their efficacy in high tunnel soils. Characteristics of high tunnel farming that serve to extend the growing season for crops may also prolong the period of suitable soil conditions for EPN activity by influencing soil matric potential, soil temperature, and host availability. This study focuses on the effects of high tunnel management practices on EPN persistence in the soil. Infective juveniles of three EPN species, Steinernema feltiae, S. carpocapsae, and Heterorhabditis bacteriophora were applied to soils in high tunnels on 9 farms in Indiana. These high tunnels were diverse in terms of crop production and management practices. EPN persistence was assessed through laboratory waxworm bioassay. Determining compatibility of various management practices with EPN applications can better inform the use of these biological control agents for pest management by high tunnel growers.