汕优组合制种大面积亩产过270kg的技术总结

汕优系统组合制种，由于珍汕９７Ａ花期长，花时迟，加之开颖角度小，柱头双边外露少．长期处于制种低产．针对这种状态，采取相应技术措施，使制种大面积亩产过２７０ｋｇ。

Technical Summary of High Yield over 4.05t/ha in Hybrid Seed Production of Shanyou Combinations

To raise the seed yield of Shanyou combinations which has not been very high due to the CMS line Zhengshan 97A with long and scattering cowering period, late anthesis time and low stigma exsertion rate the corresponding cultural techniques were adopted, resulting in a high yield over 4. 05t/ha of hybrid seeds obtained under a large area. The main practices were: (1)two - step seedling raising to raise healthy seedlings with enough tillers to increase productive panicles; (2)with the principle of the female parent mainly on transplanted seedlings and the male parent mainly on tillers after transplanting to form panicles, determine the proper number of basic seedlings for the male and the female to centralize and shorten the flowering period of the female but prolong that of the male; (3)strengthen the management of the sensitive stage of stigma exsertion from 15 days before to 5 days after heading. More attention should be paid to the application of flowering fertilizer,water management and pest control ; (4)skillfully applying GA3 to promote anthesis , lengthen the stigma and strengthen the stigma vigor, which are favourable to cross pollination and increase of outcrossing rate.