Effects Of The Growth,Development And Yield Of “Two-super” Rice With Three Transplanting Patterns In Double Rice-Cropping Systems

In order to explore the high-efficiency technology model of high yield and cost saving in the double-cropping rice areas in central and Eastern Hunan.Taking the early rice Zhuliangyou 819 and late rice H You 518 as materials,effects of three different transplanting patterns(manual throwing,conventional machine transplanting,and less seedling machine transplanting)on growth and development dynamics,yield and yield composition,yield formation,and cost-effectiveness were compared by randomized block design.The following results and conclusions were obtained:1)The quality of rice seedlings of early-rice and late-rice by less seedling machine transplanting is the best,followed by manual throwing,and finally by conventional machine transplanting.In early rice transplanting,the basic seedlings of conventional machine transplanting were significantly higher than those of small seedling machine transplanting and manual throwing,the seedling machine transplanting was 54.2%higher and 60.3%higher than that of manual throwing,but the tillering force and earing rate of conventional machine transplanting were significantly lower than those of small seedling machine transplanting.The tillering force and panicle rate of Late Rice Transplanted by small seedling machine were significantly higher than those by manual seedling throwing and conventional machine transplanting.The growth period by conventional machine transplanting is the shortest,followed by manual throwing,and finally by less seedling machine transplanting.2)Compared with the three planting modes,the vegetative growth stage of the less seedling machine transplanting is the longest and has obvious advantages,which are mainly embodied in the total dry matter accumulation,harvest index and leaf area index.The harvest index of early rice was 61.6%by conventional transplanting,65.4%by less seedling transplanting,51.4%by manual throwing.The harvest index of late rice was 56.6%by conventional transplanting,57.3%by less seedling transplanting and 54.4%by manual throwing.The results showed that increasing dry matter accumulation was beneficial to high yield,and the source,flow and sink of less seedling transplantation were significantly improved,and ultimately the yield could be increased.3)The effects of three planting methods on effective panicle,grain number per panicle,theoretical yield and actual yield of early and late rice were significantly different,showing that the effective panicle,grain number per panicle,theoretical yield and actual yield of less seedling machine transplanting were significantly higher than those of conventional machine transplanting and artificial throwing.The measured yield of early rice was 692 kg/hm~2higher than that of conventional transplantation,718 kg/hm~2 higher than that of manual transplantation,and that of late rice was 646 kg/hm~2 higher than that of conventional transplantation,885 kg/hm~2 higher than that of manual transplantation.4)The economic benefits of early and late rice were significantly affected by the three planting methods.The cost of small seedling transplanting machine is the least,followed by conventional machine transplanting,and the cost of manual seedling throwing is the highest.The total cost of seedling quantity transplanted by small seedling machine for early and late rice is half less than that of conventional machine transplantation,while the other costs are basically the same.The total cost of seedling quantity,seedling raising,transplanting and topdressing for early and Late Rice Transplanted by small seedling machine are lower than that of manual seedling throwing.The economic benefit of small seedling machine transplanting is the highest,followed by artificial throwing seedling,and the lowest of conventional machine transplanting.