Study On The Regulation Technology Of Secondary Bearing Of Castanea Mollissima Bl.

Some varieties of Castanea mollissima Bl. possesse the character of double blossoming and fruiting in one year. The fact that it is colder in the north than in the south has great adverse influence upon the growth of Secondary bearing Chinese chestnut in the north, and the secondary fruit cannot normal mature.Therefore, the study of internal mechanism and regulation of floral bud differentiation and secomdary-flowering period in order to make secondary-fruit normal matrue has important economic value and practical significance.This article mainly deals with the exeriment in which we make certain physiolosical differentiation of floral bud of Castanea mollissima Bl.by the method of band girdle and leaf and study the relation between the content of endogenous hormone in floral bud and foral bud differentiation .It is the basis of hormone regulator .In addition ,this article study on the effect of plant growth regulator and fertilizer measures to flora bud differentiation, secondary floral period and scondary fruit of Castanea mollissima Bl.The main results:1. The phase the secondary differentiation of bud is from 2,June to 7,July, and it is 1-6 weeks after the ceasing of growth.2. The concentration of ZT and ABA in peak bud increased gradually in period of floral bud differentiation of Castane mollissima Bl.. On the other hand,the concentration of GA₃ and IAA is decreased little by little .What it proves is the higher concentration of ZT and ABA and the lower concentration of GA₃ and IAA contribut to floral bud differential of Castane mollissima Bl..3. The higher ratio of ZT/GA₃,ZT/IAA, ABA/GA₃ and ABA/IAA contribute to the process of floral bud differential of Castane mollissima Bl.. 4. P can significantly increase the amount of female flower, regulate the sex ratio, enhance the width of branches, and gain more fruits; N, K can greatly increase more fruits; The ideal compounding of N,P and K is 0.3kg of carbamide per individual plant, 0.6kg or 1.2kg calcium phosphate per individual plant, and 0.6kg of potassium chloride per individual plant.5. Every disposal of PP333 can regulate the time of differentiation of bud significantly. 500mg/L,1000 mg/L advance 5,9 days respectively; 1500 mg/L, 2000 mg/L both advance 13 days .In addition ,with the increasing of PP333 concentration from 500mg/L,1000 mg/L to 1500 mg/L,the secondary fruit also increased. The concentration of 1500 mg/L is optimal to regulate secondary flower an fruit of Castanea mollissima Bl.6. Every disposal of GA₃ can delay the time of differentiation of bud significantly .With the decreasing of GA₃ concentration from 50mg/L,100 mg/L , 1500mg/L to 200 mg/L the secondary fruit also decreased .Therefore,the regulator of GA₃ is not benefit to secondary flower an fruit of Castanea mollissima Bl.