Mechanization has become the important development direction of rice production with the rapidly development of economy and the transfer of rural labor force in recently years. In order to screening suitable rice cultivars for machine transplanting in Hunan Province, field experiments were carried out to study the grain yield and growth period using 11 late rice cultivars including H-you 518 and so on. The results indicated that enough effective panicles and safety full heading are preconditions of high yield of late rice. So the machine transplanting late rice cultivar should have the charact...