What are the key technical points for managing jujube trees during the flowering period?
How should jujube trees be managed during the flowering period? What methods can prevent flower and fruit drop during the flowering period of jujube trees? We also ask experienced netizens to help explain. Because the flowering period of jujube trees is long and the number of flowers is large, the consumption is very great. In addition, during this period flower bud differentiation, the sprouting of fruiting branches, and fruit setting proceed simultaneously, which leads to jujube trees blooming but not setting fruit, or a large amount of...
How should jujube trees be managed during the flowering period? What methods can prevent flower and fruit drop during the flowering period of jujube trees? We also ask experienced netizens to help explain.Because the flowering period of jujube trees is long and the number of flowers is large, the consumption is very great. In addition, during this period flower bud differentiation, the sprouting of fruiting branches, and fruit setting proceed simultaneously, which leads to jujube trees blooming but not setting fruit, or a large amount of flower and fruit drop. Therefore, Zhongdi Network has organized the management steps for the flowering period of jujube trees, listed step by step below for netizens' reference.
Step one, first, topdressing during the flowering period of jujube trees:This is generally carried out in late May. The topdressing is mainly quick-acting nitrogen fertilizer and an appropriate amount of phosphate fertilizer. Generally, each fruiting tree is applied with 0.5 kg of urea and 0.5 kg of ammonium dihydrogen phosphate. After fertilization, water promptly to promote flowering, and loosen the soil to preserve moisture.
Step two, girdling of jujube trees:This is generally carried out during the full flowering period of jujube trees (early to mid-June), that is, when the amount of opened flowers accounts for 30%-50% of the total number of flower buds. Girdling of young and vigorous trees is recommended. For trees being girdled for the first time, the trunk is girdled at 20-30 cm above the ground. Thereafter, the girdling position is moved upward by 5-10 cm each year. When it reaches the first main branch, repeat the above operation. The width of the girdling cut is generally preferably 0.3-0.6 cm.
For girdling width, vigorous trees should be girdled wider and weak trees narrower. During rainy weather in the flowering period, it may be appropriately widened by 0.1-0.2 cm, but the maximum width must not exceed 1 cm. After girdling, attention should be paid to protecting the girdling cut. About every 1 week, apply a 100-200 times dilution of insecticide such as Lorsban to the girdling cut once. For girdling cuts that heal slowly, smooth them over with mud, which both prevents insects and preserves moisture, helping the girdling cut heal. Girdling can also be used in combination with the new technique of Flower Promoter No. 2. The application period is to use it the first time when about 20% of jujube flowers have opened, and then use it a second time after 30-35 days.
Step three, pinching of new shoots of jujube trees:From mid-May to late June, promptly pinch the primary branches and secondary branches of new jujube heads that are not being kept as scaffold branches, to control the growth of vegetative branches, reduce nutrient consumption, and increase the fruit-setting rate.
Generally, for mature trees, when a new jujube head grows to 2-6 secondary branches, pinch off the terminal bud. Secondary branches are pinched as they grow. When the 3-4 secondary branches at the base of the jujube head grow to 5-7 nodes, pinch them. When the upper 1-4 secondary branches grow to 3-5 nodes, pinch them.
The degree of pinching depends on the growth vigor of the jujube head and the amount of space it occupies. Generally, weak branches are pinched heavily, vigorous branches lightly; when space is large, pinch lightly, and when space is small, pinch heavily. In addition to pinching during this period, newly sprouted jujube heads with no useful value should also be removed from the base as early as possible, and overly dense perennial branches inside the canopy should be thinned out, so as to save nutrients and facilitate ventilation and light penetration.
Step four, the three sprays during the flowering period of jujube trees:The first is fertilizer spraying. Fertilizer spraying is carried out during the full flowering period of jujube trees. Every half month, continuously spray the leaves 2-3 times with a mixed aqueous solution of 0.3% urea + 0.1%-0.3% potassium dihydrogen phosphate + 0.2%-0.3% borax. Choose to spray on a sunny morning or evening, especially in the evening. The spraying amount should be just enough to moisten the leaf surface. If rain occurs after spraying, promptly spray again.
The second is water spraying. Choose to carry it out when 60% of the flowers have opened during the full flowering period. The best time is in the evening. Use a sprayer to evenly spray clean water onto the jujube flowers, with the degree of wetting the leaves thoroughly as the standard. The number of water sprays depends on the degree of drought. In ordinary years, spray once every 3-5 days, for 2-3 consecutive sprays. In years of severe drought, it may be sprayed 3-5 times;
The third is spraying plant growth regulators. This is carried out from the initial flowering period to the full flowering period of jujube trees. Choose to spray on a sunny morning or evening with 15-20 mg/L gibberellin solution or 15-20 mg/L naphthaleneacetic acid or sodium naphthaleneacetate dilution, or 5-10 mg/L of 2,4-D 1-2 times. During the young fruit period, spray 30-60 mg/L naphthaleneacetic acid or 30 mg/L of 2,4-D twice (at an interval of 20 days), which can effectively prevent flower and fruit drop.
Step five, pest and disease control of jujube trees:The main pests and diseases harming jujube during the flowering period include green plant bug, girdling cut borer, red spider mite, peach fruit moth, jujube inchworm, jujube rust, etc. Around wheat harvest is the best period to control red spider mite. Spray 1% abamectin 5000 times dilution or 15% fenbutatin oxide emulsifiable concentrate 2500 times dilution.
Mid-May and mid-June are the key periods for controlling the second generation of green plant bug. Spray 1-2 times on weeds and crops on and under the trees with 20% fenpropathrin 2000 times dilution, or 20% fenvalerate 2000 times dilution + 10% imidacloprid 3000 times dilution. Black light lamps may also be hung to trap and kill adults.
In early to mid-June, hang peach fruit moth sex pheromone traps. 5-7 days after the peak of peach fruit moth sex-attractant moths, promptly spray fenvalerate 6000 times dilution.
In early to mid-July and mid-August, spray a fungicide once each time (200-240 times Bordeaux mixture with 50% carbendazim wettable powder 800 times dilution and 70% thiophanate-methyl wettable powder 1000 times dilution used alternately) to prevent jujube rust and fruit diseases.
Step six, bee release during the flowering period. The distance between beehives should preferably be about 300 m. During the bee release period, spraying pesticides harmful to bees such as carbaryl and pyrethroids is strictly prohibited in jujube orchards.
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