How should mango trees be fertilized to resolve the conflict between vegetative and reproductive growth?

    Fertilizing fruit-bearing mango trees should follow the principle of balancing the conflict between vegetative and reproductive growth. It is necessary both to promote flowering and fruiting in the current year and to control excessive summer shoot growth, while also promoting the emergence and robust growth of autumn shoots to lay a good foundation for a bumper mango harvest the following year. The types of fertilizer applied should still be mainly nitrogen, phosphorus and potassium, with particular emphasis on increasing the application of potassium and calcium, along with small amounts of manganese, boron, zinc, copper, iron and other nutrients.

Mango

    1. Fertilizer before and after harvest:Mango trees bear many fruits and high yields, but after fruiting the nutrient level of the mango tree is at its lowest point of the year. If fertilizer is not applied promptly, the tree vigor weakens and it becomes difficult to restore growth, which affects the cultivation of bearing mother branches and the fruiting and yield of the mango the following year. The key focus of fertilization throughout the year is the fertilizer applied before and after harvest, and the amount applied during this period accounts for 60%-80% of the annual total.

    Before mango harvest, fertilization should mainly be foliar topdressing. 30-45 days before harvest, some foliar fertilizer containing high phosphorus and potassium can be mixed in for spraying while treating diseases. In addition, 60 days before harvest, spraying fruit tree harvest spirit can inhibit photorespiration consumption in mango trees, increase the accumulation of photosynthetic products, and improve mango quality and yield.

    After mango harvest, fertilization is divided into two applications: the first application is completed in mid-to-late August with quick-acting fertilizer, in order to help the mango tree recover as early as possible and sprout and produce autumn shoots. Apply 0.5-1 kg of compound fertilizer and 0.3-0.5 kg of urea per mango tree. Dig a ring-shaped trench just inside the drip line of the canopy and apply shallowly. If the weather is dry, irrigate after fertilizing. The second application is combined with deep plowing and soil improvement, applying farmyard manure from mid-November to December. Apply 20-30 kg of decomposed farmyard manure, 1 kg of lime, 0.5-1 kg of compound fertilizer, and 0.3-0.5 kg of potassium fertilizer per mango tree, plus an additional 10-15 kg of burnt soil, which can promote panicle emergence and flowering in mango trees.

    2. Flower-strengthening fertilizer:In early spring, before or when the flower buds of the mango tree emerge in large numbers, quick-acting fertilizer should be applied to promote flower development, improve flower quality and the proportion of bisexual flowers, strengthen the mango tree's ability to resist adverse weather such as low temperatures and continuous rain, and increase the fruit-setting rate. Apply 0.2-0.3 kg of compound fertilizer per mango tree, or 0.2 kg of peanut bran, 0.2 kg of potassium chloride or potassium sulfate, and 0.1-0.15 kg of urea. Before and during full bloom, spray 500 times diluted boric acid once each time, which can be combined with pest and disease control by mixing it into the pesticide and spraying on the foliage.

    3. Fruit-strengthening fertilizer:From April to mid-June after fruit set, mango enters a period of rapid enlargement, which is also the period when summer shoots emerge. Fertilization during this period directly supplies nitrogen and potassium and coordinates the conflict in nutrient allocation between branches and shoots and the mango fruit. Fertilization is the only way to meet the nutritional requirements of mango development, but it must also be based on tree vigor, fruit load, and leaf color. For mango trees with strong vigor and few fruits, apply less or not at all, otherwise the emergence of summer shoots will intensify fruit drop. For trees with weak vigor and many fruits, apply quick-acting fertilizer as a topdressing, with 0.2-0.3 kg of compound fertilizer and 0.15-0.2 kg of potassium fertilizer per tree, and spray foliar fertilizer 2-3 times. Generally, Lyuwang series foliar fertilizer or 0.2% monopotassium phosphate is used and can be sprayed in combination with pest control.