الفهرس | Only 14 pages are availabe for public view |
Abstract Weed species under investigation differed in their competing abilities against sugar beet plant, and consequently in their impairment on aerial and root growth criteria. It is possible to produce tentative ranking of competitive abilities of the seven weed species under investigation as following: high competitive: wild beet, canarygrass, and bermuda-grass; medium competitive: dock weed and tooth pick and poorli competitive: lambsquarters and bindweed. Moreover, weed interference reduced to different extents T.S.S. %, sucrose % and nutrient (N, K and Na) concentrations in sugar beet roots than the control. Sugar beet exerted also a drastic reductions in growth indices of associated weed species. Aerial parts of bindweed followed by wild beet and sub-soil parts of dock weed, wild beet and lambsquarters were the most sensitive weed parts to the harmful impacts of such interference. Contrarily, canarygrass and tooth pick can withstand competition of sugar beet without any significant reduction in their growth. Weeds can also affect sugar beet plant through the production of teletoxic substances. Aqueous leachates of weed roots inhibited germination and seedling development of sugar beet seedlings. Decayed weed roots in soil decreased significantly growth, yield and quality parameters of sugar beet plant. Bermuda-grass. canarygrass and wild beet were the greatest dangerous weeds in weed interference trial. However the same weed species imposed also the strengther allelopathic effect on sugar beet plant. Meaningly, alielopathy constructed a significant component in weed-crop interference of sugar beet. Key |