珍汕97A(以下简称珍A)繁殖、制种,其结实率高低,在很大程度上取决于珍A柱头外露的多少。这是因为珍A柱头外露,延长了授粉时间,弥补了与父本花时相遇之不足,扩大了授粉面积,增加了授粉机率。两年来,笔者在实践中观察到,适时适量进行叶面喷施“九二○”,能显著提高珍A的柱头外露率和结实率。据调查,喷“九二○ Zhen Shan 97A (hereinafter referred to Jane A) breeding, seed production, the level of its seed set, largely depends on the number of Jane A stigma exposed. This is because Jane A stigma exposed to extend the pollination time to make up for lack of encounter with the parent flowers, expanding the pollination area and increase the chances of pollination. In the past two years, the author observed in practice that proper amount of foliar spray “920” can significantly improve the stigma exsertion rate and seed setting rate of Zhen A. According to the survey, spray "nine two ○