@article{hummel_walgenbach_barbercheck_kennedy_hoyt_arellano_2002, title={Effects of production practices on soil-borne entomopathogens in western North Carolina vegetable systems}, volume={31}, ISSN={["0046-225X"]}, DOI={10.1603/0046-225X-31.1.84}, abstractNote={Abstract Populations of endemic soil entomopathogens (nematodes and fungi) were monitored in vegetable production systems incorporating varying degrees of sustainable practices in Fletcher, NC. Two tillage types (conventional plow and disk versus conservation tillage), two input approaches (chemically versus biologically based), and two cropping schedules (continuous tomato versus 3-yr rotation of corn, cucumber, cabbage, and tomato) were employed in large plots from 1995 to 1998. A Galleria mellonella (L.) trap bioassay was used to identify and monitor activity of Steinernema carpocapsae, Heterorhabditis bacteriophora, Beauveria bassiana, and Metarhizium anisopliae populations during the vegetable growing season (April–September). Seasonal detection of entomopathogens was significantly higher in conservation compared with conventional tillage systems. The strip-till operation did not affect levels of detection of S. carpocapsae. Pesticide use significantly reduced detection of entomopathogenic fungi. Type of ground cover significantly affected temperature in the upper 12 cm of soil; highest soil temperatures were observed under black plastic mulch and bare ground, whereas lowest temperatures were observed under rye mulch and clover intercrop. The high soil temperatures associated with certain ground covers may have reduced entomopathogen detection or survival. Although type of tillage appeared to be the primary factor affecting survival of endemic soil entomopathogens in our system, other factors, such as pesticide use and type of ground cover, can negate the positive effects of strip-tillage.}, number={1}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={Hummel, RL and Walgenbach, JF and Barbercheck, ME and Kennedy, GG and Hoyt, GD and Arellano, C}, year={2002}, month={Feb}, pages={84–91} }
 @article{hummel_walgenbach_hoyt_kennedy_2002, title={Effects of production system on vegetable arthropods and their natural enemies}, volume={93}, ISSN={["0167-8809"]}, DOI={10.1016/S0167-8809(01)00345-0}, abstractNote={Populations of foliar insect pests and natural enemies were monitored in vegetable production systems incorporating varying degrees of sustainable practices in Fletcher, NC, USA. Two types of tillage (conventional plow and disk, strip-tillage), two input approaches (chemically-based, biologically-based) and two cropping schedules (continuous tomato (Lycopersicon esculentum Mill.), 3-year rotation of corn (Zea mays L.), cucumber (Cucumis sativus L.) and tomato) were employed from 1995 to 1998. Tomato pest pressure was relatively low in all years, resulting in a limited impact of production systems on potato aphid, Macrosiphum euphorbiae (Thomas) (Homoptera: Aphididae), and its associated parasitoids and predators. Thrips (Frankliniella spp. (Thysanoptera)) populations were significantly higher in the biological input treatments in 3 of 4 years. Lepidopterous (primarily Helicoverpa zea Boddie (Lepidoptera: Noctuidae)) damage on tomato was significantly higher in biological treatments in all years, damage by thrips and pentatomids (Hemiptera: Pentatomidae) increasing each year in the continuous tomato crop schedule. Most insect populations were significantly influenced by type of insecticide input or ground cover. Few population measurements were affected by tillage type. Foliar insect problems in commercial vegetable production may be associated predominantly with insecticide input (i.e. more damage with biologically based insecticides) and use of intercropping (i.e. more damage in systems with living mulch); however, the long term effects of tillage and crop rotation remain to be seen.}, number={1-3}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Hummel, RL and Walgenbach, JF and Hoyt, GD and Kennedy, GG}, year={2002}, month={Dec}, pages={165–176} }
 @article{hummel_walgenbach_hoyt_kennedy_2002, title={Effects of vegetable production system on epigeal arthropod populations}, volume={93}, ISSN={["0167-8809"]}, DOI={10.1016/S0167-8809(01)00346-2}, abstractNote={Populations of epigeal arthropods were monitored in vegetable production systems under varying degrees of sustainable agricultural practices in Fletcher, NC (USA). Two tillage types (conventional plow and disk, strip-tillage (ST)), two input approaches (chemically based, biologically based) and two cropping schedules (continuous tomato Lycopersicon esculentum Mill.], 3-year rotation of sweet corn [Zea mays L.]/cabbage [Brassica oleracea L.], cucumber [Cucumis sativus L.]/cabbage and tomato) were employed from 1995–1998. A second study with tomatoes was performed in 1997–1998 to separate effects of pesticide use, intercropping and herbicide application. Pitfall traps (48-h sample period) were used at ∼25-day intervals to monitor relative activity of carabid beetles (Coleoptera: Carabidae), staphylinid (Coleoptera: Staphylinidae) beetles and lycosid spiders (Araneidae: Lycosidae). Carabids and lycosids appeared to be more active in systems with ground cover. Trap catches of carabid species were not significantly affected by insecticide input, but trap catches of lycosids were lower in plots with conventional insecticide use. No consistent effect of tillage was found over time, although Scarites spp. were more active in minimally disturbed habitats in 1998. Two distinct patterns of seasonal activity were observed for carabid beetles and lycosid spiders. Ground cover generally enhanced abundance of carabids and lycosids, while tillage type, pesticide use and crop rotation had different effects.}, number={1-3}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Hummel, RL and Walgenbach, JF and Hoyt, GD and Kennedy, GG}, year={2002}, month={Dec}, pages={177–188} }