Primary study on the development of special seed coating agents and their application in rice (Oryza sativa L.) cultivated by direct seeding
直播稻专用种衣剂的研制和应用效果初探

Physical properties of five basic seed coating agents were examined in the experiment. The most desirable basic coating agent was selected out for cultivation of rice by direct seeding, followed by addition of different active compounds and various formulae were proposed. The influence of film coating based on these formulae on germination, seedling quality, field growth and development of the directly seeded rice plants were studied. The results indicated that basic coating agent No. 5, which was safe for seed germination of the directly seeded rice, was relatively more ideal than the other agents used. The treatments with coating agent formula No.4 or No.5 showed no inhibitory effect on seed germination. They substantially promoted root growth, reduced shoot height in cultivars Jiayu 948 and Zhongzu No.1,and led to significantly increase in proline content and peroxidase (POD) activity in the seedlings. Coating with agent of the formula No.5 also significantly increased the chlorophyll content of the seedlings. Field experiment showed that the seedling establishments were improved, damage due to rice thrips were remarkably reduced and yields were raised by 27.48% and 23.52% as compared to un-coated controls after cultivar Zhongzu No.1 was treated by coating agent formula No.4 and No.5 respectively. The two-plot field experiments in the following year showed that the treatments with coating agent formula No.4 improved the seedling establishment in Jiayu 948 and Zhongzu No.1 and significantly raised the yield in Zhongzu No.1.