Preliminary Study On Screening And Evaluation Method Of Double Cropping Rice Varieties Suitable For Mechanical Transplanting In Southern Hunan

In order to screen the early and late rice varieties suitable for mechanical transplanting in southern Hunan,the evaluation method of rice varieties suitable for mechanical transplanting was explored,and the rapid screening index was established to realize the rapid screening of rice varieties suitable for mechanical transplanting.To 12 early rice varieties with 17 late rice varieties(including with super rice between inbred rice and hybrid rice)studied the early and late rice varieties’ growth period,seedling quality(root entwining force,snapping resistance and root-developing ability),green period and root damage flow intensity,sword leaf SPAD value,dry matter accumulation at each growth and development stage and yield and yield components of indicators,preliminary explore the indexes and the correlation between varieties appropriate machine.The main research results are as follows:(1)By referring to literature,relevant analysis and consulting experts,the five key indexes of suitable intercalation screening and evaluation were selected,including root-developing ability,root-shoot ratio and snapping resistance at seedling stage,the greening period after transplanting and the daily yield of varieties.The comprehensive index method was used to evaluate the early and late rice varieties.(2)According to the comprehensive evaluation results,the early rice varieties Lingliangyou 1309 and Xiangyou 616 got the highest scores(0.79 and 0.73,respectively).The late rice varieties Shenyou 610,Hengliangyoujinlongsimiao and Hengxiang 1 got the highest scores(0.84,0.74 and 0.72 respectively),which were more in line with the requirements of mechanical transplanting.(3)In the comprehensive evaluation,the weight coefficients of root-developing ability and root-shoot ratio in seedling stage are higher and less influenced by the environment.Using them as a preliminary screening basis can ensure the effectiveness of the screening results.(4)Early rice and second rice production in southern hunan on collocation,suggest that early rice seeding Lingliangyou 1309 or Xiangyou 616,collocation of late rice Shenyou610,Hengxiang 1,Jiuliangyouyuzhan and Zhongyou 9918 in mid to late march sowing rice,if the late rice is matched with Hengliangyoujinlongsimiao,it is suggested to sow early rice appropriately in advance,so as to ensure the smooth connection of late rice stubble and safe panicle.