Detailed Explanation of Daily Technical Points for Pomelo Cultivation and Management
1. Strengthen spring shoots and promote their turning green and vigorous growth. When spring shoots are 4-7 cm long, spray 15% paclobutrazol at 600 times dilution to make the spring shoots short and sturdy and the flower clusters robust. During the leaf expansion stage of spring shoots, spray the tree canopy with Lufenwei to promote leaf greening. 2. Plastic film mulching to retain moisture and lower temperature. In summer and autumn, temperatures are high and soil moisture evaporation is great, so between orchard rows...
April: 1) Clear irrigation and drainage canals, weirs, and ditches. 2) Sow leguminous green manure. 3) For trees with particularly abundant flowers, thin out some fruiting mother branches to regulate the balance between vegetative growth and reproductive growth; for trees with few flowers, spray 0.2% boron fertilizer, 0.3% urea, and 0.1% monopotassium phosphate to retain fruit. 4) For trees with gummosis, after shallow scraping and deep longitudinal cutting, apply 100 times dilution of thiophanate-methyl or carbendazim for control. 5) Handpick swallowtail butterfly larvae, or spray 25% fenvalerate at 1500 times dilution for control.
May: 1) After petal fall, spray 0.5% urea, 0.2% boron fertilizer, and 0.1% monopotassium phosphate solution to retain fruit. 2) Spray washing soda mixture (150 g washing powder, 150 g soda ash, plus 100-200 g No. 0 diesel oil and 50 kg water) or pine-soda mixture (1 kg rosin, 0.75 kg soda ash, plus 7.5 kg water) at 15-20 times dilution to control scale insects, mites, and whitefly pests.
June: 1) Summer pruning and renewal pruning of aging trees (heading back, renewal pruning). 2) Handpick adult longhorn beetles. 3) Spray 48% chlorpyrifos at 1000-2000 times dilution to control scale insects, citrus spiny whitefly, red and yellow spider mites, rust mites, and other pests. 4) Spray 25% dimehypo at 500 times dilution or 1% imidacloprid at 1000-1500 times dilution to control citrus leafminer.
July to August: 1) In late July, heavily apply a fertilizer to promote shoots and strengthen fruit, applying 50-100 kg of decomposed human and livestock manure water, 1-1.5 kg of superphosphate, 0.1-0.15 kg of potassium sulfate, and 0.15-0.25 kg of urea per tree. 2) Mulch the tree plate with green grass, branches and leaves, rice straw, and wheat straw to keep the soil loose, lower temperature, retain water, and prevent rain erosion. 3) Use a thin wire to clear insect holes, insert waste paper or cotton soaked in dichlorvos or dimethoate stock solution into the insect holes, then seal the holes with hand-kneaded mud to poison longhorn beetle larvae. 4) Continue controlling citrus spiny whitefly, red and yellow spider mites, and rust mites.
September: 1) When renewing the root system of old orchards, damage as few large roots over 1 cm in diameter as possible, and apply decomposed organic fertilizer or residue fertilizer at the same time. In case of drought, irrigate promptly to prevent tree death. 2) Spray 0.5-0.8 degrees Baume lime-sulfur mixture to control red and yellow spider mites and rust mites, adjusting the solution concentration according to temperature.
October to November: 1) In cases of severe autumn drought, irrigate to prevent drought and ensure normal tree growth and fruit development and ripening. 2) Control damage to fruit by fruit-piercing noctuid moths, red and yellow spider mites, and rust mites. 3) 7-10 days before harvest or after harvest, promptly apply a rejuvenating fertilizer as a top dressing, applying 50-100 kg of human and livestock manure water and 0.15-0.2 kg of urea per tree.
December to January of the following year: 1) Winter pruning. Be careful to retain leafless fruiting branches and drooping branches to favor fruiting. For densely growing branches, follow the principle of "remove one of three, remove two of five" when thinning. For closed canopies, open a skylight to increase ventilation and light penetration inside the canopy. 2) Deeply plow the soil 50-60 cm. 3) Pruned branches and diseased branches should be gathered and burned to reduce overwintering pest sources. 4) Spray 1-1.5 degrees Baume lime-sulfur mixture or 8-10 times dilution rosin mixture to clean the orchard.