Adaptability Of Rice Varieties Research And Integration Technology Application Of Direct Seeding After Harvesting Rapeseed/Wheat In Northeast Sichuan Hilly Region

In Sichuan Basin,the area of direct seeding rice increased year by year.Compared with seedling raising and transplanting,the sowing date of the cultivation mode that direct seeding after harvesting rapeseed/wheat was delayed,and the whole growth period was relatively shortened,resulting in lower yield.At present,there are few studies on variety selection and Cultivation Techniques of the cultivation mode that direct seeding after harvesting rapeseed/wheat.In this study,several rice varieties were used as experimental materials to study the growth characteristics and yield performance of different varieties under the cultivation mode that direct seeding after harvesting rapeseed/wheat,in order to screen out suitable rice varieties for the cultivation mode that direct seeding after harvesting rapeseed/wheat.Through production investigation,the key technologies of the cultivation mode that direct seeding after harvesting rapeseed/wheat were integrated,and the application effect of the cultivation mode that direct seeding after harvesting rapeseed/wheat in Northeast Sichuan hilly region was analyzed.This study provided a theoretical and technical basis for the selection and the cultivation mode that direct seeding after harvesting rapeseed/wheat in the hilly region of Northeast Sichuan.The main results are as follows:(1)The average growth period of 50 rice varieties was 142 days.The growth period of 20varieties was longer than the average growth period.The growth period of 30 varieties was shorter than the average growth period.The average yield of the tested varieties was 8096.1 kg/hm2.There were 11 varieties with yield above 9000 kg/hm2,such as Longyou 8,and 28 varieties with yield lower than the average yield,such as qyou 5.Correlation analysis showed that there was no significant correlation between growth period and yield traits under direct seeding,and all tested varieties could mature normally.Grain number per panicle and 1000 grain weight had significant positive correlation with yield,which indicated that grain number per panicle and 1000 grain weight were two key factors affecting yield of the cultivation mode that direct seeding after harvesting rapeseed/wheat.Selection of large panicle varieties is a key to high yield.(2)37 rice varieties were selected to investigate the growth period,diseases and insect pests and lodging of the tested varieties under the cultivation mode that direct seeding after harvesting rapeseed/wheat.The growth period of the tested varieties ranged from 118 to 135 days,and they could mature normally except Luliangyou 2840.According to the results of principal component analysis,six varieties,such as Yixiangyou 2115,are suitable for the cultivation mode that direct seeding after harvesting rapeseed/wheat;six varieties,such as fyou 498,and yuehesi seedling are suitable for the cultivation mode that direct seeding after harvesting rapeseed/wheat.(3)Comparative test in the same field was carried out at three test sites.The results showed that the rice yield was slightly increased under the cultivation mode that direct seeding after harvesting rapeseed/wheat compared with the conventional artificial seedling transplanting.Taking Youxian experimental site as an example,the cost of conventional artificial seedling transplanting by21.1%compared with the cultivation mode that direct seeding after harvesting rapeseed/wheat,Compared with conventional seedling transplanting,the cultivation mode that direct seeding after harvesting rapeseed/wheat increased yield by 1.3%,increased output value by 304.8 yuan/hm~2,reduced cost by 4225 yuan/hm~2,and increased net income by 4529.8 yuan/hm~2.To sum up,this study screened out f you 498,Guang 8 you 589,Yue He Si Miao and other varieties suitable for the cultivation mode that direct seeding after harvesting rapeseed/wheat,combined with relevant direct seeding cultivation techniques,which can effectively reduce the production cost of rice and improve economic benefits.