Summary of one year of cultivation and management experience in pomelo growing
February to March: ① Apply a bud-promoting fertilizer as topdressing, per plant apply 50-100 kg of human and livestock manure water and 0.15-0.25 kg of urea, or 1 kg of bio-organic fertilizer and 0.15 kg of urea. ② Spray 1500-2000 times diluted Nissorun plus 0.3%-0.5% urea to control red and yellow spider mites and increase foliar nutrition.
April: ① Clear and dredge irrigation and drainage canals, weirs and ditches. ② Sow leguminous green manure. ③ For trees with an especially heavy flower load, thin out some fruiting mother branches to balance vegetative growth and reproductive growth; for trees with a light flower load, 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 cuts, apply 100 times diluted thiophanate-methyl or carbendazim to control it. ⑤ Handpick swallowtail butterfly larvae, or spray 1500 times diluted 25% fenvalerate to control them.
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 laundry detergent, 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 longhorn beetle adults. ③ Spray 1000-2000 times diluted 48% chlorpyrifos to control scale insects, citrus spiny whitefly, red and yellow spider mites, rust mites and other pests. ④ Spray 500 times diluted 25% bisultap or 1000-1500 times diluted 1% imidacloprid to control citrus leafminer.
July to August: ① In late July, heavily apply a shoot-promoting and fruit-strengthening fertilizer, per plant apply 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. ② Mulch the tree plate with green grass, branches and leaves, rice straw and wheat straw to keep the soil loose, lower temperature, conserve water and prevent rain erosion. ③ Use a thin wire to clear insect holes, insert waste paper or cotton dipped in undiluted dichlorvos or dimethoate into the holes, then seal the holes with mud kneaded into balls by hand 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, injure as few large roots over 1 cm in diameter as possible, and apply decomposed organic fertilizer or residue fertilizer at the same time. In drought, irrigate in good time to prevent tree death. ② Spray 0.5-0.8 degrees Baumé lime sulfur mixture to control red and yellow spider mites and rust mites, adjusting the solution concentration according to temperature.
October to November: ① Where autumn drought is severe, 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, apply a recovery fertilizer in good time, per plant apply 50-100 kg of human and livestock manure water and 0.15-0.2 kg of urea.
December to January of the following year: ① Winter pruning, taking care to retain leafless fruiting branches and drooping branches to favor fruiting; for dense 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 transmission inside the canopy. ② Deeply plow the soil 50-60 cm. ③ Pruned branches and diseased branches should be burned in a centralized manner to reduce overwintering pest sources. ④ Spray 1-1.5 degrees Baumé lime sulfur mixture or 8-10 times diluted pine resin mixture to clean the orchard.