Growth characteristics of stem auxiliary buds on ratoon rice

In order to improve yield of the ratoon rice,differentiation and growth of the stem auxiliary buds on different nodes,development traits of the ear grain and morphology of the stem organs were studied.The results indicated that(a) the differentiation of rachis primordial of the stem auxiliary buds began from bottom up before the mother stem heading;(b) after the mother stem heading,the differentiation of primary or secondary rachis branch occurred in a top down order;(c) under the apical dominance,the stem auxiliary buds began to germinate 3d before the mother stem ripened;and(d) the panicle bearing tiller rate decreased and the grains per spike reduced to one-third of the mother stem,as the node moving downward due to congenital deficiencies.Thus,boosting germination rate of the stem auxiliary buds in the lower nodes while retaining upper buds at initial harvest could improve the yield.By forming 1.70-2.00 folds spikes more than the initial rice,the yield could be increased.The converse 3rd pulvinus was 8-16 cm higher than converse second buds,and its height could be used as a quick morphological index for optimum stubble height of the mother stem.