多效唑在杂交稻制种上推广应用

Applicafion of Paclobutrazol in Hybrid Rice Seed Production

多效唑用于杂交稻制种秧苗（２叶１心）期能矮化秧苗，增加单株分蘖，提高秧苗素质；用于调节花 期，能有效控制幼穗发育；用于成熟期能降低穗头芽谷率．

Paclobutrazol(also called PP333) has been widely used in hybrid rice seed production in recent years. In Taizhou prefecture of Zhejiang province, the successful experience of paclobutrazol application for years was summarized in the paper. (1)Used in seedling raising. With the leaf numhar 0. 2-0. 39 more, the tillers per plant 0. 3-3. 4 more and the plant height 2-6cm shorter, paclobutrazol improved the seedling quality and favoured the survival of seedlings after transplanting. (2)Used to adjust the heading stage of the male or the female parent. Applied at the late stage of secondary primordium differentiation of the female parent in the concentrations of 100, 200 and 300ppm, paclobutrazol delayed heading of 1, 3and 4 days respectively. (3) Used to control germinating of grains in panicle. Sprayed 25 days after heading in 200ppm. paclobutrazol lowered the percentage of germinated grains in panicle by 4. 9%.