Abstract:
ObjectiveThe aim of this experiment was to find out the effects on dry matter accumulation, distribution and yield composition of succeeding hybrid rice varieties under different winter planting patterns in Guizhou karst areas, and provide reference for selection of the green,efficient and cyclic compound cropping pattern.MethodUsing hybrid rice Zhongyou 808 as test material in 2015 and 2016,the test was conducted with five winter planting patterns including idleland-rice(treatment A,control),rape-rice(treatment B),vegetable-rice(treatment C),potato-rice(treatment D)and green manure-rice(treatment E). Leaf area index,dry matter accumulation,yield and yield composition of rice at different developmental stages were measured in all treatments.ResultAt jointing stage,the leaf area index of treatment C(3.30) was significantly higher than that of treatment A(2.31)(P<0.05,the same below),but there was no significant difference with treatment C and treatments B,D and E(P>0.05,the same below). The leaf area index of treatments B and E were the highest at booting stage and heading stage,and significantly higher than those in the other treatments. At maturity stage, the rank of dry matter accumulation and total biomass of rice under different winter planting patterns was:treatment C>treatment B>treatment E>treatment D>treatment A. In the treatments of winter planting crops and green manure,the dry matter accumulation of rice were higher than idleland control. From the perspective of yield components,effective pani-cles of treatment B was the highest(221.62×104 panicle/ha);grain number per panicle of treatment D(181.03 grain/pani-cle)was the largest;the setting rate of treatment C was the highest(90.58%). In the treatments of winter planting crops and green manure,the rice yields were higher than idleland control,the yield of treatment C was the highest(10480.23 kg/ha), followed by treatment D(10245.80 kg/ha)and treatment B(10069.99 kg/ha).ConclusionUnder the same amount of fer-tilizer,in winter,planting crops and green manure is conducive to increase dry matter accumulation of rice,and at certain extents increases rice yield. The three planting patterns,vegetable-rice,potato-rice and rape-rice,have obvious advantages in yield increase. They are compound planting patterns suitable for karst area in Guizhou.