Response of Weeds and Rice to Certain Granular Herbicides

Abstract

The response of weeds and rice to 11 herbicide treatments evaluated at the Chiayi Agricultural Experiment Station , Chiayi, Taiwan in the second crop of 1971 are reported. Granular C-288 + 2, 4-D IPE and C-285 + 2, 4-D IPE provided the best control of weeds. Good initial control of weeds was also obtained with C-290 + 2, 4-D IPE and NTN5006/2, 4-D IPE , Granular 2, 4-D IPE , CP53619, and Bonthiocarb gave the poorest control of weeds, but weed control effect of CP53619 and Benthiocarb was considerably improved when combined with 2, 4-D BE and 2, 4-D IPE, respectively. Rice plants were not injured by the herbicide treatments but the growth of rice plants was indirectly affected by weed competition in the treatments with poor control of weeds. Poor weed control treatments also hastened the heading of rice and reduced the plant height as number of panicles per hill of adult plants. As a result , grain yields of these treatments decreased significantly. The handweeded control gave the highest yield which was followed by C-288 + 2, 4-D IPE, while C-285 + 2, 4-D IPE ranked third in its yield production. Difference in yield among these high yielding treatments failed to attain significance. 本文係報告民國60年第2期作嘉義農業試驗分所與國際稻米研究所合作舉辦第5次稻田除草劑試驗所得之結果。 C-288 + 2, 4-D IPE與C-285 + 2, 4-D IPE 粒劑之治草效果最佳。C-290 + 2, 4-D IPE與NTN 5006/2, 4-D IPE 粒劑之初期治草效果亦佳。2, 4-D IPE, CP53619與Benthiocarb粒劑之治草效果最差，惟後兩種除草劑若分別與2, 4-D BE及2, 4-D IPE 混合施用時，其治草效果即改觀。 本試驗供試除草劑對水稻均未構成嚴重藥害，惟在除草效果較差之處理，水稻之發育則遭受雜草競爭之間接為害。水稻在除草較差之處理多提早抽穗，其成熟期、株高及每株穗數亦見減少，而稻谷產量顯著低減。人工除草處理之稻谷產量最高，C-288 + 2, 4-D IPE 粒劑次之，C-285 + 2, 4-D IPE粒劑居第3，三者間之產量差異不顯著。