EFFECT OF NO-TILLAGE AND RYE MULCH ON OCCURRENCE OF WEEDS AND APHIDS AND ON YIELDS OF CABBAGE, CARROT AND RED BEET

In 1999 cucumber, lettuce and snap bean were grown on experimental field for the first time using no-tillage method and rye as cover crop and in the year 2000 cabbage, carrot and red beet were grown on the same field using the same cultivation method. Rye was sown in the middle of September and at the beginning of May it was desiccated with glyphosate. Two weeks later seeds of carrot (Daucus carota) and of red beet (Beta vulgaris) and transplants of cabbage (Brassica oleracea var. capitata f. alba) were planted into no-tilled field covered with rye mulch and on field cultivated conventionally. Three weeks after planting number and fresh weight of weeds grown in no-tilled plots were reduced by 99% in comparison to those in conventional tillage treatment. Four weeks later the differences in weed infestation between compared treatments were considerably smaller but still significant. At the beginning of July about 10% of carrot plants cultivated conventionally and 5% under no-tillage cultivation were invaded by Semiaphis dauci. Similarly cabbage plants were less invaded by Brevicoryne brassicae on no-tilled then on conventionally tilled plots. Method of cultivation did not influence significantly total and marketable yield of vegetables however on no-tilled plots cabbage grew slower and was harvested three weeks later.