Cultivation Technology Consturction Of Reducing Herbicide With Allelopathic Rice In Rice Production

The purpose of this study was to provide the basis for constucting cultivation technology system of the allelopathic rice with herbicide reduction.This study designed two consecutive years(2015~2016)of early and late field experiment in Daze town,using five allelopathic rices(Allelopathic rice 3,Xinliangyou 3,Huazhenyou 3,Nongzhenyou 3,Hualiangyou 3)and three common conventionalrices(Wuxinsimiao,Yuxiangyouzhan,Baixiangzhan)as materials.Theallelopathic index,occurrence of paddy weeds,the yield and quality of rice under different herbicide reduced doses had been analysised.The main results were as follows:(1)Theplant height of allelopathic rices could increase under herbicide reduction of 50%,where the common conventionalrices,were decreased under herbicide reduction.The 50% of herbicide reduction in early and late season would slow down the tiller speed of allelopathic rice 3 and common conventional rices,and the effect decreased gradually with rices growing.Reduction of 50%~75% could increase the number of allelopathic hybrid rice tillers.(2)The herbicide reduction had no effect on allelopathic index of allelopathic rice 3,and its AI had been at a high level(AI>0.45)all the time,the reduction of 50%~75% could increase the AI of allelopathic hybrid rice before closure line,and the allelopathic index of allelopathic hybrid rice was higher than 0.45 under 50%~75% reduction all along.Herbicide reduction had no effect on the AI of common conventional rice,and its allelopathic index had been a low level always(AI<0.45).All tested varieties could effectively control the occurrence of weeds before the closure lines under 50% reduction in early and late seaso n.The high herbicidal effect of allelopathic rice 3 could be sustained until the late closure,and the weeds of hybrid rice at 50% could be effectively controlled after closure.The weed control effects of the tested varieties in the milk stage were poor.The occurrence of weeds in the continuous cropping paddy field was significantly less than that in the previous crop.(3)There was no effect on the yieldof all tested varieties through reducing 50% herbicide both in early and late season.Herbicide reduction by 50%~75%had no effect on the quality of allelopathic rice and Wuxingsimiao in early season,however,it improved the quality of Yuxiangyouzhan.Both when the Huagandao 3,Xinliangyou 3,Huazhenyou 3 and Wuxingsimiao treated by 50% herbicide reduction,and Nongzhenyou 3 was 75% herbicide reduction in early season,all their milling qualities were lower.But the above treatments ameliorated their exterior qualities.The quality of Hualiangyou 78 and Baixiangzhan were little effected by herbicide reduction.(4)In early season,there was a significant positive correlation between allelopathic index of Huagandao 3 and dicotyledonous weeds before closure,while the allelopathic index of Huazhenyou 3,Wuxingsimiao and Yuxiangyouzhan had no significant correlation with the weeds and their yield in the corresponding period.The allelopathic index of Xinliangyou 3 and Nongzhenyou 3 showed a significant negative correlations with weeds,which were significantly positively correlated with yield,and the difference among cultivars was significant.In late season,the correlation was different and unstable in different years.