What are the spring management measures for lychee? Detailed explanation of planting key points
The generally dry climate in China promotes nutrient accumulation and flower bud differentiation in lychee and longan. It is currently spring, and lychee management at this time of year is a key link affecting the quality of growth and development for the year. Based on the current growth and development of lychee and longan, the following technical work recommendations for spring management are specially proposed. Because lychee varieties differ, tree conditions vary greatly, and corresponding measures should be taken for management according to specific circumstances:
(1) Apply flower-strengthening fertilizer: apply from after the flower spike forms to 15 days before flowering; old trees and weak trees should be fertilized earlier. For each tree, based on a fruit load of 50 kg, apply 2-3 kg of compound fertilizer.
(2) Kill small leaves: for flower spikes with small leaves, from when the small leaves begin to develop 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 spikes.
(3) Pruning: trees with a shaded canopy should be pruned, cutting off shaded branches, weak branches and diseased and pest-infested branches to improve ventilation and light penetration in the tree; trees that have not yet sprouted flower spikes should be pruned promptly, which is beneficial for the sprouting and growth of flower spikes.
(4) Spike control: for varieties with relatively long flower spikes, such as Feizixiao, Guiwei, Nuomici and young Huaizhi Qing trees, when the flower spike is 8-10 cm, spray half the amount of Kongshao Ling to control flower spike elongation; manual flower thinning may also be used, cutting off 1/3-1/2 of the flower spike; or when the flower spike is 20 cm long, cut off half; at the same time, thin out overly dense or weaker lateral branches of the flower spike, which helps the flower spike become short and sturdy.
(5) Strengthen flowers: for weak flower spikes, spray 1-2 times with multivitamin nucleotides + cytokinin + Wanfeng Lu to strengthen flowers, in combination with foliar topdressing and pest removal.
(6) Prevent and control diseases and pests: the flower spike development period is the occurrence period of downy blight and lychee stink bug, so insecticidal and fungicidal agents should be sprayed once every half month, and insecticidal and fungicidal agents should be used in rotation. Spray lychee fruit-setting agent once 15 days before female flowers open. Strictly prohibit spraying insecticides 10 days before and after flowering to avoid harming bees and pollinating insects.
(7) Do a good job of lychee pollination. ① Place bees during the flowering period to increase the pollination rate. ② During droughty weather at flowering, spray water to prevent flower damage. ③ During rainy weather at flowering, shake off accumulated water on the flowers to prevent flower rotting.
(8) For Feizixiao, Guiwei and Nuomici with good fertilizer and water management and strong tree vigor, if spiral girdling was used in last autumn and winter to control winter shoots, check the girdling incision and keep the girdling incision open; for those without girdling or ring cutting, carry out girdling or ring cutting before and after flowering to retain fruit.
(9) Spray “Guodebao” once each 10-12 days and 40 days after flower drop to retain fruit, and when spraying, add foliar fertilizers such as multivitamin nucleotides to improve fruit quality.