Key Technical Points for Fruit Retention and Fruit Enlargement in Lychee, Longan and Mango
At present, most lychee and longan trees in Guangdong Province are at the stage from flower panicle emergence to flower bud stage. Affected by the weather since the beginning of spring, with relatively high temperatures and suitable humidity, the flower panicles of lychee and longan have emerged early, pests and diseases have occurred early, and the base of pest and disease sources after winter is relatively high. It is expected that the main pests and diseases during the flowering period of lychee and longan will occur at a moderate level, with some areas being relatively severe. Lychee stink bug...
I. Targeted foliar spraying of endogenous hormones and biomolecular plant organic nutrients.The essence of fruit retention and fruit enlargement in woody fruit trees such as lychee, longan and mango is: through the implementation of appropriate cultivation and management measures, ensure that young fruits obtain timely and sufficient nutrients required for their growth and development, so that they develop well and do not drop. In recent years, research and production practice have proven that, by utilizing the absorption and conduction function of leaves, the goal of fruit retention and fruit enlargement can be achieved through the following methods.
1. Foliar spraying of endogenous hormone (regulator) substances to mobilize the nutrients originally stored in the tree body (in the fruiting mother branches) to supply the young fruits, thereby achieving the goal of fruit retention and fruit enlargement -- when the fruiting mother branches are thick and healthy and the light conditions, water and fertilizer conditions during the young fruit stage are good, this is a relatively cost-saving method; however, when the fruiting mother branches are not robust enough (insufficient internally stored nutrients) or the light conditions, water and fertilizer conditions (such as drought) during the young fruit stage are poor, the effect of this method is not good. Because prematurely mobilizing the nutrients stored in the mother branches is unfavorable for later fruit development, it is generally only sprayed during the fruit expansion stage and used with caution during the young fruit stage.
2. Foliar spraying of organic foliar fertilizer rich in biomolecular nutrients, such as organic liquid fertilizer foliar tablets rich in multiple amino acids, vitamins, polysaccharides and trace elements, directly supplementing nutrients to young fruits and leaves from the leaf surface and young fruit peel, and improving leaf photosynthetic capacity so as to achieve the goal of fruit retention and fruit enlargement (for example, spraying Shengzhifeng liquid fertilizer, nucleotides, etc. on lychee, longan and mango during the young fruit stage and fruit expansion stage has relatively obvious effects).
3. Combined use of the above two types of substances: alternate spraying or mixed spraying.
II. Basic strategy for fruit retention and fruit enlargement in lychee, longan and mango this year.
Because lychee and longan bore many fruits last year, tree nutrient consumption was large, and in addition last winter was dry, nutrient storage in fruiting mother branches this year has been affected. Therefore, the basic strategy for fruit retention and fruit enlargement this year is: spray biomolecular nutrient-type liquid fertilizer, conduct timely and early fruit thinning and pest and disease control, and by no means use only hormone-type foliar fertilizers as in the past.