What are the key measures for spring management of lychee?
From September last year to January this year, the weather remained warm and dry, with little rain, which promoted nutrient accumulation and flower bud differentiation in lychee and longan. Due to different varieties of lychee, tree conditions vary greatly, and corresponding measures should be taken according to specific situations for management: (1) Apply flower-strengthening fertilizer: after flower panicle formation...
From September last year to January this year, the weather remained warm and dry, with little rain, which promoted nutrient accumulation and flower bud differentiation in lychee and longan. Due to different varieties of lychee, tree conditions vary greatly, and corresponding measures should be taken according to specific situations for management:
(1) Apply flower-strengthening fertilizer: Apply from after flower panicle formation to 15 days before flowering. Old trees and weak trees should be fertilized earlier. Based on a fruit load of 50 kg per tree, apply 2-3 kg of compound fertilizer.
(2) Kill small leaves: For flower panicles bearing small leaves, from the beginning of small leaf development until before they turn red, choose Xiaoye Weisuo Su, Xiaoye Tuo or Zhuanghua Sha Xiaoye Su to spray and kill the small leaves, cultivating pure flower panicles.
(3) Pruning: Trees with dense canopies should be pruned by cutting off shaded branches, weak branches, and diseased and pest-infested branches to improve ventilation and light penetration conditions of the tree; trees that have not yet sprouted flower panicles should be pruned promptly to facilitate the sprouting and growth of flower panicles.
(4) Panicle control: For varieties with relatively long flower panicles, such as Feizixiao, Guiwei, Nuomici, and young Huaizhi Qing trees, spray half-dose Kongshao Ling when the flower panicle is 8-10 cm to control panicle elongation; manual flower thinning can also be done by cutting off 1/3-1/2 of the flower panicle; or when the flower panicle is 20 cm long, cut off half; at the same time, thin out overly dense or weaker lateral branches of the flower panicle, which helps the flower panicle become short and sturdy.
(5) Strengthen flowers: For weak flower panicles, spray 1-2 times with multi-element nucleotides + cytokinin + Wanfeng Lu to strengthen flowers, combined with foliar fertilizer application and pest control.
(6) Do a good job in lychee pollination work. ① Place bees during the flowering period to increase the pollination rate. ② During the flowering period, if drought occurs, spray water to prevent flower scorching. ③ During the flowering period, if rain occurs, shake off accumulated water on the flowers to prevent flower rotting.
(7) For Feizixiao, Guiwei, and Nuomici with good fertilizer and water management and strong tree vigor, if spiral girdling was carried out in autumn and winter last year to control winter shoots, check the girdling cuts and keep them open; for those without girdling or ringing, carry out girdling or ringing before and after flowering to retain fruit.
(8) Spray "Guodebao" once each at 10-12 days and 40 days after flower drop to retain fruit, and multi-element nucleotides and other foliar fertilizers can be added when spraying to improve fruit quality.