Study On Fruit Drop Regultion During Mid-late Period Of Fruit Development And Experiment On Fruit Retention Of Litchi Cv,Jizui

In this study,20-year-old trees of litchi cv. Jizui were taken as materials to study the following 4 aspects. (1) study on the fruit drop regulation during the mid-late development of Jizui litchi. (2) study on the effects of different treatments(folia spraying with GA3, CCC and PP333) on the fruit retention of Litchi cv. Jizui, (3)study on the effects of girdling time on the fruit retention of Litchi cv.Jizui.(4)study on the effects of mulching and drip fertigation on the fruit retention of Litchi cv. Jizui. The results of the study indicated that:Experimental findings show that litchi cv. Jizui in fruit drop have three main peaks:in about 25 days after flower fruit drop occurs once the larger peak the number of fruit drop; occur about 45 days after flower a fruit drop peak, before picking 5-10 days once another fruit drop peak,the two fruit drop compared to the previous peak have a smaller number drop.With the testing concentrations, the effects of GA3, CCC and PP333 on the fruit setting rate, fruit fresh and dry weight, the fruit length, edible portion and TSS were not significant. Bud all treatments increased the fruit width and fruit panicle weight markedly. Treatment with GA3 increased the yield greatly bud CCC and PP333 had no effects.Girdling on truck decreased the fruit drop of Jizui litchi significantly. Twice girdling showed the better result in fruit retention. Girdling could markedly increased the fruit weight and fruit panicle weight, and twice girdling showed the better result. Girdling also had obvious effects on the fruit length and width and the yield/tree, bud girdling 40 days after flowering had no effects on the fruit width. There were not any effects on the edible portion and TSS. Girdling increased the content of N、P、K in the leaves of Jizui litchi and promoted the transmit of the N.P.K. Twice girdling also showed the best result.All treatment of mulching and fertigation with K fertilizer had some effects on fruit retention of Jizui, bud mulching with sugarcane bagasse can reduced the fruit drop markedly. Mulching and fertigation with K fertilizer increased the single fruit weight, yield /tree and TSS. There were great different among the effects of different treatments on fruit length and fruit width. Mulching and fertigation with K fertilizer increased the fruit size significantly. Except for treatment of mulching and fertigation with K fertilizer, other treatments had no effects on the fruit number on a panicle. Mulching and fertigation with K fertilizer had marked effects on the K content in the leaves; bud had no markedly effects on the content of N and P.Mulching with white plastic film can slow down the content of soil available nitrogen. Bud mulching and fertigation with K fertilizer had no significant effects on the content of soil available nitrogen. All mulching and fertigation treatment had no marked effects on the content of P, bud they had significant greater effects on the content of soil available K. mulching and fertigation with K fertilizer increased the soil available K markedly. Mulching with white plastic film reduced the content of soil organic matter, bud fertigation had no effects on the soil organic matter.Mulching with white plastic film can reduced the decreasing of soil pH, while mulching and fertigation with K fertilizer reduced the pH of the soil and lead to acid soil. There was no significant different between fertigation with K fertilizer.