PENGARUH DOSIS HERBISIDA GLIFOSAT DAN 2,4 - D TERHADAP PERGESERAN GULMA DAN TANAMAN KEDELAI TANPA OLAH TANAH EFFECTS OF GLYPHOSATE AND 2,4-D DOSAGES ON WEED SUCCESSION AND NO-TILLAGE SOYBEAN

The objective of this study was to determine the pattern of weed succession and yield of soybean under no tillage management. The experiment was arranged factorially in a randomized complete block design with three replications. Glyphosate was applied at 0,0, 1,00 , 2,00 and 3,00 L ha -1 whilst 2,4-D was applied at 0,0 1,00, 1,25, and 1,50 L ha -1 . Results of the study indicated that the weed composition was changed at the end of the experiment. Prior to herbicide application, Widelia sp (SDR=40,67%) was the most dominant species followed by Imperata cylindrica (SDR=39,00). At the end of the experiment, however, Imperata cylindrica take place the domination and some new other species appeared, i.e. Corton hirtus, Mimosa pudica and Eleusin indica. The largest weed dry weight was obtained on no herbicide application and 2,4 D at 1,50 L ha -1 , i.e 1,52 g at 14 dap. 2,4-D at 1,5 L ha- 1 had resulted the largest leaf area and leaf area index, i.e. 402,67 and 0,531 respectively. The tallest plant (77,66 cm ) was obtained from the application of 2,4 -D at 1,5 L ha -1 . Application of glyphosate at 3,00 L ha -1 had resulted the highest soybean dry weight at 28 dap.