关键词: 油菜, 植物生长调节物质, 倒伏, 产量, 株高, 抽苔期

Abstract: The effect of palcobutrazol (PP₃₃₃) applied at the bolting stage o the oilseed raPe and its. combinative effect with nitrogen level and gibberellin (GA3) on plant height and lodging resistance were studied. The results showed as follows, pp₃₃₃ applied at the bolting stage of the oilseed rape signifficantly decreased plant height, lowered primary branching height, and thickened root collar, as a result, increased lodging resistance. The higher the concentration of PP₃₃₃, the stronger the effect, The effect of PP₃₃₃ on the rapeseed yield was showed on two sides, PP₃₃₃ decreased the yield by inhibiting growth too much under low nifrogen level, especially under high concentration of PP₃₃₃, but it might increase the yield indirectly by incresing lodging resistance and reducing yield loss of lodging under high nitrogen level. 40ppm GA3 applied 26 days affter applying PP₃₃₃ at the bolting stage promoting growing and flowering. Both effect of increasing lodging resistance and rapeseed yield were showed in this case.

Key words: BRASSICA, SPP, PLANT GROWTH REGULATING SUBSTANCES LODGING, YIELD, PLANT HEIGHT, BOITING STAGE