How to manage fruit trees in summer? Key technical points explained in one article

    Summer management of fruit trees is an important part of the year's fruit tree management work and has a great impact on the yield of fruit trees in that year. For this reason, the following technical points are hereby proposed.

    I. Fruit management

    1. Use hormones to retain fruit. When 2/3 of the flowers have fallen, spray the tree canopy with a mixture of 10PPM "2.4-D" or 50PPM "920" + 0.5% urea + 0.2-0.3% "monopotassium phosphate" to retain fruit, and spray again after 15 days. For navel oranges, use "Guodaduo" 3 times to retain fruit, or use 12PPM "E T-2" or "Lüsaite" to prevent navel yellowing, and "Yihuangzhi" can also be applied to the top of the fruit.

    2. Fruit thinning and bagging. Shatian pomelo and summer orange are thinned and set in mid-to-late June, removing diseased fruit, deformed fruit, small fruit, and clustered fruit. The amount of fruit retained can be determined according to the leaf-to-fruit ratio: for sweet orange-type citrus varieties, 40-50 leaves retain one fruit, and for Shatian pomelo, 100-150 leaves retain one fruit. On the basis of fruit thinning and fruit setting, spray once with an insecticide and fungicide: use "Lüjing" 1000-fold solution + 50% "carbendazim" 600-800-fold solution or "Dasan M-45" 1000-fold solution. Bag promptly after the liquid dries.

    II. Apply fruit-stabilizing fertilizer and fruit-sizing fertilizer well

    1. Fruit-stabilizing fertilizer. In mid-May, fertilize according to the tree condition. For trees with weak vigor and a large number of flowers, especially adult Shatian pomelo trees, soil application should be used once, with phosphorus and potassium as the main nutrients, to reduce physiological fruit drop.

    2. Fruit-sizing fertilizer. In early-to-mid July (for deciduous fruit trees in early-to-mid May, and for Shatian pomelo in late June), apply the first fruit-sizing fertilizer well. Generally, apply 40-60 kg of human and animal manure, 0.3 kg of urea, 0.5 kg of superphosphate, and 2-3 kg of plant ash (or 0.5 kg of potassium sulfate) per fruiting tree, and irrigate with 100-200 kg of water at the same time. After the Beginning of Autumn, apply the second fruit-sizing fertilizer to promote fruit expansion. The fruit industry station recommends the application of "Kaifeng" special compound fertilizer for fruit trees, which has a significant effect on improving fruit quality and yield.

    3. Irrigation. After entering the summer drought period in July, irrigate once whenever there are 7 consecutive sunny days, with 100-200 kg per tree each time, to ensure the water needed for fruit expansion.

    III. Seize the key periods and prevent and control pests and diseases

    1. Control of citrus red mites and yellow mites: While carrying out spring control, continue to do a good job in controlling red and yellow mites. On the basis of forecasting, carry out effective control. Effective pesticides include "Nisuolang", "Guosheng", "Saomanjing", "Jinbaman", "Juemieda", etc. The use of "Lüjing" biological pesticide has a particularly good effect.

    2. Scale insects: Scale insects occur commonly and rather seriously, so observation and control should be emphasized. For the pesticide, it is best to choose "Guosheng" 800-1000-fold solution and spray again after an interval of 7-10 days; "Lüjing" biological pesticide can also be chosen. At the same time, it can also control mites.

    3. Longhorn beetles: From mid-May to early June, manually capture adult longhorn beetles, and from early June begin hooking and killing longhorn beetle eggs and larvae.

    4. Citrus rust mites: From June to September, begin control whenever leaves show a rust color, once every 10 days, for 2-3 consecutive times. For the pesticide, 65% "zineb" 800-fold solution or "Guosheng" 1000-fold solution can be chosen.

    5. Leafminers: Leafminers mainly damage tender shoots and mostly occur from June to July. Control should be combined with bud removal and shoot release. When buds grow to 2-3 mm, spray immediately for control, once every 7 days, spraying 2-3 consecutive times. Pyrethroid pesticides are mainly chosen, and "Lüjing" biological pesticide has a particularly good effect.

    6. Pear weevils, pear fruit borers (large and small), pear lace bugs, pear black heart disease, etc.: 90% "trichlorfon" 800-1000-fold solution + 65% "Tuzimet" (or "carbendazim") 600-fold solution can be chosen for control.

    IV. Do a good job in summer pruning of fruit trees

    Summer pruning of fruit trees is divided into pruning before the flowering period and after the flowering period. Pruning before the flowering period is aimed at regulating the amount of flowers to protect flowers and fruit; summer pruning from May to July is aimed at improving light and promoting high-quality autumn shoots; summer pruning from August to October is aimed at promoting flower bud differentiation.

Pruning of young trees is mainly for shaping

    Main summer pruning operations for citrus from May to July:

    1. For summer shoots, fruiting trees should remove them completely, and young trees should be pinched in time. Removing summer shoots should be early rather than late, mainly removing summer buds; for vigorous trees, leave 2-3 leaves on summer shoots and pinch the tips.

    2. In July, cut off unreasonable large branches and shoots in the tree canopy to improve ventilation and light penetration. At the same time, in combination with fruit thinning, partially cut back flower-drop and fruit-drop branches and fruit-thinning branches to promote high-quality autumn shoots and lay the foundation for a bumper harvest the following year.

    3. Summer is the best period for branch pulling, top pruning (opening the skylight), and shaping of young Shatian pomelo trees, so as to improve canopy ventilation and light penetration; at the same time, prepare for using hormones to promote flowering at the end of August.

    V. Other work

    1. Orchard weeding. To prevent soil erosion and maintain soil fertility, pulling weeds and no-tillage are advocated. Low-growing weeds are retained to improve the orchard ecological environment and lower soil temperature in summer; tall weeds can be pulled out or cut in the middle to improve orchard ventilation and light penetration conditions.

    2. Do a good job in "top grafting and variety replacement" for old and inferior fruit trees, as well as sprout removal, branch support, and tip pinching for top-grafted and variety-replaced trees.