化学疏花对荔枝果实品质及叶片全N含量的影响

【目的】观察喷施外源乙烯利及荔枝丰产素对荔枝花穗疏剪效果，并分析其对果实品质和叶片全N含量的影响，为科学合理运用乙烯利和荔枝丰产素进行荔枝疏花及优质高产栽培提供理论参考。【方法】采用单因素随机区组试验设计，桂味荔枝始花期树冠喷洒53 mg/L（T1）、106 mg/L（T2）和160 mg/L（T3）的乙烯利水溶液，以及荔枝丰产素水溶液（T4）和清水（T5，对照），测定脱落的花蕾、枝梗和果实数量，测定果实品质和叶片全N含量。【结果】5个处理的花蕾脱落数和枝梗脱落数排序为T3>T2>T1>T4>T5，果实脱落数总数排序为T5>T4>T3>T1>T2。5个处理对单穗重、果粒数、小横径、果形指数和可溶性固形物含量无显著影响（P>0.05，下同），且肉质、风味、香气、涩味、果肉内膜褐色也无明显差异，但对单果重、可食率和种子重有一定的影响，其中单果重排序为T2>T1>T4>T3>T5，T2处理的单果重（19.45 g）比T5处理（13.68 g）增重42%；T1、T2、T3和T4处理（即乙烯利和丰产素处理）可食率为78%~79%，焦核率为97%~99%，分别较T5处理（清水处理）提高30%~32%和31%~34%。5个处理下叶片全N含量无显著差异，全N含量排序为T2>T1>T4>T3>T5。单果重、果皮重、种子重、可食率、焦核率和可溶性固形物含量与叶片全N含量的相关系数分别为0.886、0.851、0.898、0.739、0.740和-0.947，其中单果重和种子重均与叶片全N含量呈显著正相关（P<0.05，下同）；可溶性固形物含量与叶片全N含量呈显著负相关。【结论】乙烯利和荔枝丰产素能对桂味荔枝进行花穗疏剪，且乙烯利一次性喷施浓度106 mg/L能起到最佳控花穗的效果，有效实现省工省力增产的目的，可用于实际生产。

Effects of chemical flower thinning on fruit quality and total N content in leaves of litchi

【Objective】To observe effects of spraying exogenous ethephon and litchi high yield reagent on litchi flower thinning and to analyze its influence on fruit quality and leaf total N content，so as to provide theoretical reference for scientific and appropriate use of ethephon and litchi high yield reagent in litchi flower thinning and high quality and high yield cultivation.【Method】A single-factor randomized group test design was adopted. Spraying 53 mg/L（T1），106 mg/L（T2），160 mg/L（T3）of ethephon solution and litchi high yield reagent solution（T4）and water（T5）as control on the Guiwei litchi tree crown at initial flowering stage，respectively. The amount of fallen flower branch stalks，flower buds，flowers，and fallen fruits was recorded. And the fruit quality and total N content of leaves were determined. 【Result】The order of the number of fallen buds and flower branch stalks in the 5 treatments was T3>T2>T1>T4>T5，and the order of the number of fallen fruits was T5>T4>T3>T1>T2. No significant effects of the 5 treatments on single panicle fruit weight，fruit number，small diameter，fruit shape index and soluble solid content（P>0.05，the same below） were found. Moreover，no significant difference between the treatment groups and the control was found in pulp texture， flavor，aroma，astringency and brown degree of pulp intine. But spraying exogenous ethephon and litchi high yield reagent could affect the single fruit weight，edible rate and seed weight. The order of single fruit weight was T2>T1>T4> T3>T5，the maximum single fruit weight was 19.45 g，which was 42% increased than the minimum of 13.68 g. In T1， T2，T3 and T4 treatment groups，the edible rate ranged from 78% to 79% which was 30%-32% higher than control；the wilted-seed rate ranged form 97% to 99% which was 31%-34% higher than T5（water treatment group）. The order of total N content of leaves was T2>T1>T4>T3>T5，however，there was not significant difference between the 5 treatment groups and control. The correlation coefficient of single fruit weight，peel weight，seed weight，edible rate，wilted-seed rate，soluble solid substance content and total N content was 0.886，0.851，0.898，0.739，0.740 and -0.947，respectively. The single fruit and seed weight was significantly positive correlated with total N content（P<0.05，the same below），and the soluble solid substance content was significantly negative correlated with total N content.【Conclusion】The application of ethephon and litchi high yield reagent can help Guiwei litchi flower thinning and the ethephon concentration of 106 mg/L has the best effect of controlling flower cluster，therefore，it can be used for litchi production，which is beneficial for saving labor and increasing production.