Soil polarization for 98 days in 1985 resulted in a 91% reduction of weeds present in collard greens (Brassica oleracea acephafa L.) plots during 1986. Soil solarization was more effective in controlling weeds in collard green plots when compared to an application of Dacthal-75W herbicide in nonsolarized plots. Collard green plants grown in solarized soil showed an increase in yield and other growth responses. Soil samples from the rhizosphere of plants grown in solarized soil showed higher population levels of bacteria and thermotolerant fungi than from nonsolarized soil. There were significant negative responses in marketable yield and root growth of collard greens and in soil microflora in solarized soil in response to Dacthal-75W herbicide application. Chemical name used: dimethyltetrachloroterephthalate (Dacthal-75W).
Clauzell Stevens, Victor A. Khan, Theresa Okoronkwo, Ah-Yin Tang, Mack A. Wilson, John Lu, and James E. Brown
James E. Brown, James M. Dangler, Floyd M. Woods, Ken M. Tilt, Michael D. Henshaw, Wallace A. Griffey, and Mark S. West
Silver reflective plastic mulches were compared with conventional bare-ground culture of yellow crookneck summer squash (Cucurbita pepo L. var. melopepo Alef.) for reducing aphids and the following mosaic virus diseases: cucumber mosaic, watermelon mosaic I and II, zucchini yellows mosaic, and squash mosaic. Plants grown on silver plastic mulch produced higher marketable yields than those grown on bare ground. Other colors (white, yellow, and black with yellow edges) of plastic mulch were intermediate in their effects on aphid population and virus disease reduction. Silver reflective mulch alone and silver reflective mulch with insecticide were superior to other colors of plastic mulch in reducing aphid populations. Silver reflective plastic mulch, with or without insecticide, resulted in 10 to 13 days delay in the onset of the mosaic diseases noted.