|Shapiro, David - UNIVERSITY OF FLORIDA|
|Obrycki, John - IOWA STATE UNIVERSITY|
|Jackson, Jan - PIONEER HI-BRED, INT.|
Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 28, 1999
Publication Date: N/A
Interpretive Summary: Many crops, including corn, are now grown in sustainable systems, i.e., reduced tillage. When such practices are implemented efficacy of insect- management practices are changed. Research was conducted to determine if tillage practices change the efficacy of an insect-killing nematode in protecting corn from the black cutworm which damages corn by cutting plants sat the soil surface. An insect-killing nematode, Steinernema carpocapsae is efficacious in killing the cutworm. Researchers learned, however, that nematodes survive for a longer time in no-till plots than in conventionally tilled plots. The increased ground cover protects nematodes from desiccation and/or ultraviolet light. This research describes the compatibility between soil conservation practices and a non-chemical insect-management tool which will in turn benefit growers and consumers by reducing chemical loading of the environment.
Technical Abstract: We determined the effects of conventional tillage versus no-till on the persistence of Steinernema carpocapsae (Weiser). During two consecutive years, nematodes (at 2.5 x 104 and 1.0 x 105 infective juveniles/M2) were applied to small field plots planted with com. Nematode persistence was monitored by exposing Galleria mellonella (L.) larvae to soil samples from no-till (approximately 75% coverage of soybean stubble) and conventional till plots. Persistence of S. carpocapsae was significantly greater in no- till plots than in conventional tillage plots. In no-till plots that received the higher rate of nematode application, larval mortality did not significantly decrease during the study period (3 - 5 d) and remained above 85%. In conventional till plots treated with nematodes, however, larval mortality fell from over 96% to below 11% and 35% in the first and second trial, respectively. The increased ground cover in no-till plots may have benefitted nematode persistence through protection from desiccation or ultraviolet light.