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United States Department of Agriculture

Agricultural Research Service

Title: Effects of Killed Cover Crops Mulch on Weeds, Weed Seeds, and Herbivores

Authors
item Pullaro, Th0mas - COLLEGE OF CHARLESTON
item Marino, Paul - COLLEGE OF CHARLESTON
item JACKSON, DAVID
item HARRISON, HOWARD
item Keinath, Anthony - CLEMSON UNIVERSITY

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 10, 2005
Publication Date: July 1, 2006
Citation: Pullaro, T.C., Marino, P.C., Jackson, D.M., Harrison Jr, H.F., Keinath, A.P. 2006. Effects of killed cover crops mulch on weeds, weed seeds, and herbivores. Agriculture, Ecosystems and Environment. 115:97-104.

Interpretive Summary: Because of the elimination of methyl bromide for most agricultural uses, alternative methods for disease and weed control must be developed for vegetable production systems. The feasibility of using a killed cover crop mulch as an option to methyl bromide fumigation for weed, insect, and disease management was investigated for spring bell pepper and fall collard at the U.S. Vegetable Laboratory in Charleston, SC, 2000-2001. Beneficial predators of weed seeds and insects were much more prevalent in cover crop mulch plots than in standard production plots. The red imported fire ant was the main predator of weed seeds and pest insects, however other beneficial arthropod predators also predominated in the killed cover crop plots. There were no significant differences in crop yields among treatments for either bell pepper or collards. The results suggest that fire ants were more abundant where there was mulched cover and were important predators of weed seed and pest insects in killed cover crop plots. This study supports the use of killed cover crop mulches as a viable alternative to pesticide-based management techniques for vegetable growers.

Technical Abstract: The feasibility of using a killed cover crop mulch as an alternative to methyl bromide fumigation for weed and disease management was investigated for spring bell pepper (Capsicum annuum L.) and fall collard (Brassica oleracea L., acephala Group). Experiments were conducted at the U.S. Vegetable Laboratory in Charleston, SC, 2000-2001. Invertebrate seed predators removed significantly more weed seeds from cover crop mulch plots (5047) than from standard production plots (1860). Predation of beet armyworm (Spodoptera exigua [Hübner]) pupae was 33% greater in cover crop mulch compared with conventional production plots. Red imported fire ant (Solenopsis invicta Buren) was the main predator of weed seeds and pest insects. There were 5734 fire ants captured in mulched cover crop plots compared to 1278 in conventional production plots. In the two bell pepper experiments, weed cover was 31.8% less in standard production than in cover crop mulch plots. The mean number of invertebrates (other than fire ants) captured in pitfall traps was 5.8 ± 0.1/plot versus 3.8 ± 0.8/plot for cover crop and conventional treatments, respectively. There were no significant differences in crop yields among treatments for either crop. The results suggest that fire ants were more abundant where there was mulched cover and were important predators of weed seed and pest insects in killed cover crop plots.

Last Modified: 9/10/2014
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