부산대학교 도서관

The life history of broadleaf dock (Rumex obtusifolius L.), an aggressive weed in parmanent grasslands, was investigated in order to find out the effective method for controlling this weed. Seedlings of broadleaf dock sown in the current spring were cultivated in 1/2000 a wagner pots under individual plant condition. Chronological changes including plant length, leaf number, stem or sprout number, leaf area and dry weight were examined at two-week intervals from June to November in 1987. Above ground parts of all experimental plants were cut on 13 August at fullripe stage, and after that, process of regrowth was examined. As for top growth, it was observed that plant length, leaf number and top dry weight increased in accordance with growth of plant after budding, and reached the maximum values in blooming stage. While, stem or sprout number increased in both periods from budding to ripening stage and regrowth stage. Number of seed production was estimated about 15,000 per plant. The maximum values of leaf area per plant was attained at blooming stage and period before wintering. Individual leaf area at different leaf position increased remarkably after 3rd leaf, especially as high a leaf area value as 100 cm^2 was maintained by the radical leaves such as 6th to 13th leaves. After that position, leaf area decreased rapidly. As for root growth, dry weight and diameter of tap roots increased gradually with the progression of growth, but the dry weight of lateral roots showed variation by growth stage. These results suggest that the top growth of broadleaf dock is changing remarkably with growth stage, but the root growth increase nearly from spring to autumn.