Effect of Bending on Shoot Growth, Flowering and Fruiting of Xianjinfeng Litchi

Abstract

【Objective】Xianjinfeng litchi is a new variety introduced in recent years. It is characterized by high quality and late ripening and has significant economic and social benefits in the middle and late ripening litchi producing areas, however, its efficient and high-yield cultivation technology needs to be studied. Shoot bending is an important shaping and pruning method in orchard management, which can effectively reduce the apex dominance and facilitate flowering and fruiting. Here, the effects of different bending treatments on Xianjinfeng litchi were explored in order to provide references for the application of shoot bending technology as well as the establishment of technology for stable and high yield.【Method】Xianjinfeng litchi grafted for four years was used as the test material, and three bending treatments were set: vertical (0°, CK), horizontal (90 °) and drooping (110 °). After treatments, the indicators including growth, flowering rate, and fruit setting rate were counted.【Result】Compared with the vertical treatment (CK), drooping and horizontal treatments had limited effects on the vegetative growth of the first and second shoots, but delayed the germination of the third shoot (the last autumn shoot) for more than seven days, and dramatically reduced germination number of shoots at the same time. In addition, drooping treatment had the strongest inhibitory effect. When the leaves of the last autumn shoot were mature, the branch diameter under bending treatments was slightly lower than that under CK, however, and there were no significant difference among all treatments. Both drooping and horizontal bending treatments could effectively control the length of the last autumn shoot to about 15 cm, promote the growth of short and medium shoots, which was conducive to flowering and fruiting. In the coming spring, the flowering rate and fruit setting rate of drooping and horizontal treatments were notably higher than those of vertical treatment (CK). The flowering rate of droop treatment reached 100%, and all of them were pure flowers with high quality, while vertical treatment (CK) produced more panicles with leaves in comparison with the other two treatments. There was no significant difference in the length of panicle among different treatments, however, the base diameter of panicle were observably reduced and vigorous growth of panicles were inhibited by bending treatments. Fifty days after blooming of pistillate flowers, the fruit setting rates under drooping and horizontal treatments were 9.81% and 7.61%, respectively, markedly higher than that under vertical treatment (CK, 5.54%).【Conclusion】For Xianjinfeng litchi, drooping and horizontal branch bending can effectively control the excessive growth of parent branches, improve the quality of flowers, and significantly increase fruit setting rate. The best results are obtained under drooping treatment (110°).

Keywords

• xianjinfeng
• litchi (litchi chinensis sonn.)
• shoot bending
• flowering rate
• fruit setting rate
• control shoot length and promote flower quality