Submitted to: South Carolina Entomological Society
Publication Type: Abstract only
Publication Acceptance Date: 11/13/2002
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Collard plants were monocropped in bare plots and intercropped with white clover at the Coastal Research and Education Center, Charleston, SC during 2002. Yield of collards interplanted in clover was significantly less than that of collards grown in bare plots. The competition between clover and collard, as well as possible allelopathic activity, resulted in the reduced yield in clover plots. Major weeds included corn spurry and Bahiagrass, which were more dense in the bare plots. Imported cabbageworm (ICW) larval populations peaked on 23 April at 8.9 and 4.9 per 5 plants in clover and bare plots, respectively. The increased insect pressure by ICW early in the season might have contributed to reduced yield in clover plots. Larvae were significantly reduced by insecticides in the bare plots. Furthermore, ICW damage in bare plots during May was significantly less in the treated (Confirm and Spintor) plots than in the untreated control. There were no clear trends for damage in the clover plots and no significant differences among treatments for oviposition of ICW eggs (reaching 70 per 5 plants). Cabbage looper larval density reached 1.5 per five plants on 9 May in bare control plots and were not detected in the other treatments. Mean numbers of diamondback moth larvae were significantly higher in the bare plots that were not treated with insecticide than in each of the clover treatments. White clover may be helpful in reducing weed density in collards; however, further investigations are needed to determine level of competition with collards and possible allelopathic activity.