Performance Of Different Rice Varieties Under Direct Seeding Cultivation In Gannan And Selection Of Suitable Varieties

Direct seeding of rice can save a lot of labor and alleviate the contradiction caused by seasonal labor tension.It has important research significance for the realization of light simplification,specialization,and large-scale rice production.Therefore,direct seeding of rice has a wide range of application prospects in my country.In this study,18 early rice varieties and 41 second rice varieties were used as materials to study the growth period,yield,yield component factors,and lodging resistance evaluation of different varieties under direct seeding and transplanting methods.The aim is to screen out excellent rice varieties suitable for direct sowing in the water and soil environment and climatic conditions in Gannan,and provide guidance for rice production.The following conclusions are drawn through research:(1)Performance of most rice varieties under the direct seeding method was lower than that under the transplanting method.Among the 18 early rice varieties tested,7varieties had no significant yield reduction,11 varieties had a significant reduction in yield,and 18 early rice varieties had an average yield reduction of 16.75%.Among the41 second rice varieties tested,only 2 cultivars had a slightly higher yield than the transplanting method,but the difference was not significant.The yield of the remaining39 varieties was lower than the transplanting method,with an average yield reduction of17.20%.The yield of 18 varieties in direct sowing mode was not significantly lower than that in transplanting mode,and the rest reached a significant level.(2)Fifteen of the 18 early rice varieties had an increase in the whole growth period under the direct seeding method compared with the whole growth period in the transplanting method,and the average growth period was extended by 2.39 days.This may be due to the low temperature in early spring and slower seedling emergence in the field.The whole growth period of most second rice varieties under the direct seeding method was significantly shorter than that of the transplanting method,with an average of 14.63 days.(3)The lodging resistance of rice under the direct seeding cultivation mode was weaker than that of the cultivation method.The second rice varieties tested have relatively better lodging resistance.Most varieties with higher yield under the direct seeding method did not show lodging,which showed that lodging affects direct seeding rice was one of the key factors of yield.(4)Divide the tested varieties into three types: high-yield,medium-yield,and low-yield according to actual output,and analyze the traits of different yield types.The results showed that the total grains per panicle and the seed setting rate of the high-yield types of early rice varieties were significantly higher than those of the middle-yield and low-yield types The effective ears per unit area of the high-yield and middle-yield types are significantly higher than those of the low-yield types.Path analysis also shows that the total number of grains per ear contributes the most to the yield among the yield factors,followed by the number of effective ears.Therefore,based on a certain effective ear On the other hand,increasing the total number of grains per panicle will help direct sowing early rice with high yield.The number of effective panicles,total grains per panicle,and seed setting rate of second rice varieties for high-yield types were significantly higher than those of middle-and low-yield varieties.Path analysis showed that among the yield factors,the thousand-grain weight contributed the most to the yield,followed by the total grains per panicle.Therefore,for second rice,on the basis of ensuring a certain number of effective panicles,increasing the thousand-grain weight and the total number of grains per panicle will contribute to the high yield of direct sowing second rice.(5)Based on the yield,growth period and lodging resistance performance of each variety,’Hongyouzao No.1’,’Xiangzaoxian45’,’Xiangzaoxian No.24’,’Zhongjiazao17’,’Zhon gzao35’,’Zhuliangyou30’ and’Zhuliangyou829’ had a moderate growth period,more effective panicles,large panicles,high seed setting rate and high yield,and can be planted as direct seeding early rice varieties;’Changyou Huazhan’,’Jiuliang Youhuang Huazhan’,’Longxiang Youhuazhan’,Taifengyou208’,Taiyou398’,Taoyouxiangzh-an’,Tianyou Huazhan’,’Wanxiang You Shuangzhan’,’Wuyou 308 ’,’Wuyou325’,’Zhongjia No.8’,’Taiyou553’,’Changnongjing No.12’ had a moderate growth period,many effective ears,large ears,and high yields,and can be planted as direct seeding second rice.(6)According to the stubble arrangement of double-season direct seeding rice in southern Jiangxi,taking full advantage of light and temperature conditions,it is recommended that the varieties match mode:early-season direct seeding rice chooses’ Xiangzaoxian45’ and’Xiangzaoxian No.24’,and late-season direct seeding can Choose’Changyou Huazhan’,’Jiuliangyou Huanghuazhan’,’Longxiangyou Huazhan’,’Tianyou Huazhan’and ’Zhongjia No.8’;choose’Hong Youzao No 1’,’Zhongzao35’,’Zhuliangyou30’for early-season direct seeding rice and late-season direct seeding rice can choose Taoyouxiangzhan’,’Wanxiang Youshuangzhan’,’Wuyou308’,’Wuyou325’and’Taiyou553’;For early season choose’Zhongjiazao17’ and’Zhuliangyou 829’,and for late season choose Taiyou398’,Taifengyou208’,’Changnongjing No.12’.