Orange Park has a high degree of close planting, partial application of nitrogen fertilizers, low topography of orange groves, easy accumulation of water, disease occurrence, etc. can easily lead to citrus fruit drop. Control methods: Planting branches and trees in the dense orange planting garden, and pruning branches to make large branches with large saws and large windows. Trim pests with dead branches, leggy branches, cross branches, overlapping branches, and dense branches. Orange trees that are too tall are to be divided. Gradually sparsely cut high branches and lower the height. Deep plowing will change soil to dig deep trenches of 50 to 70 centimeters in width and 60 to 80 centimeters in width along the canopy drip line. When the soil is back, the topsoil shall be placed on the bottom and the straw, weeds and organic fertilizer shall be applied in layers. Red soil added 50 kg of lime per acre to improve the soil. Take root properly and promote new roots. And do a good job in the drainage of the orangery, and strengthen the management of the orangery. Control the use of nitrogen fertilizers Make a reasonable mix of nitrogen, phosphorus, and potassium, apply special organic compound fertilizers for citrus, and apply organic fertilizers such as rapeseed cake, pig bark, chicken duck dung, and others. Pest and pest control Anthracnose Chemical control can be 80% mancozeb WP 400 to 500 times, or 5% pyraclostrobin + 55% MSC water 750 to 1500 times, or 50% The tebuconazole + 25% trifloxystrobin water dispersion granules 4000 to 6000 times liquid and other prevention. Citrus fruit flies in adult mating oviposition period, the use of homemade brown sugar, protein bait traps, etc.; or 0.02% more bactericidal bait spotting and killing adults.