When Is the Blooming Season of Jujube Trees? A Detailed Guide to Key Management Techniques

Bud-stage management of jujube trees is an important part of production. It affects the growth vigor of the branches and leaves of jujube trees in that year, the maintenance of tree shape and tree vigor, the rational distribution of stored nutrients, and the robust formation and development of flower buds, and is the guarantee for achieving high yield, high quality, and high efficiency. Only when all measures are fully implemented can the stable yield and improved quality of jujube trees truly be achieved. So when is the blooming season of jujube trees? What are the key management techniques?

1. When is the blooming season of jujube trees?

Jujube trees bloom from May to June. The cymes are axillary, the flowers are small and yellow-green, and the flowering period lasts about one month. Legend has it that during the Mid-Autumn Festival, the Yellow Emperor led his ministers and guards out to hunt in the wild. When they reached a valley, they were thirsty, hungry, and exhausted. Suddenly, they saw several large trees halfway up the mountain, bearing tempting fruit. Everyone hurried over and rushed to pick them. The fruit tasted sour with a hint of sweetness, quenched their thirst especially well, and made them forget their fatigue. Everyone repeatedly said it was good, but no one knew its name, so they asked the Yellow Emperor to name it. The Yellow Emperor said: “This fruit relieved our hunger and fatigue, and it was not easy to find along the way, so let us call it zhao (find)!)” Later, when Cangjie created characters, based on the characteristic that the tree has thorns, he stacked the thorn radical and created the character ”zao“ (jujube).

2. What are the key management techniques during the blooming season of jujube trees?

1. Topdressing during the blooming season

This is generally carried out in late May. The topdressing is mainly quick-acting nitrogen fertilizer with 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 fertilizing, water promptly to promote flowering, and loosen the soil to preserve moisture.

2. Girdling

This is generally carried out at full bloom (early to mid-June), that is, when the amount of open flowers accounts for 30% to 50% of the total flower buds. Girdling is recommended for young and vigorous trees. For trees being girdled for the first time, the operation is performed on the trunk at 20-30 cm above the ground. After that, 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 girdle opening is generally 0.3-0.6 cm. For strong trees, the girdle width should be wider, and for weak trees, narrower. During rainy weather at the blooming stage, 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 girdle opening. About every 1 week, apply one application of a 100-200 times diluted insecticide such as Lorsban to the opening. For openings that heal slowly, smear them flat with mud, which both prevents insects and preserves moisture, helping the opening heal. Girdling can also be used together with the new technique of using Flower Promoter No. 2. The timing 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.

3. Pinching new shoots

From mid-May to late June, timely pinch the primary and secondary branches of new jujube heads that are not 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, and 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 early from the base, and overly dense perennial branches inside the canopy should be thinned out, so as to save nutrients and facilitate ventilation and light penetration.

4. Three sprays during the blooming season

Fertilizer spraying. Fertilizer spraying is carried out during the full blooming stage of jujube. Every half month, continuously spray the leaves 2-3 times with a mixed aqueous solution of 0.3% urea, 0.1%-0.3% monopotassium phosphate, and 0.2%-0.3% borax. Choose to spray on clear mornings or evenings, especially in the evening. Spray just enough to moisten the leaf surface. If rain occurs after spraying, promptly spray again.

Water spraying. Choose to carry out this step when 60% of the flowers have opened at full bloom. The best time is in the evening. Use a sprayer to evenly spray clean water onto the jujube flowers, just enough to wet the leaves thoroughly. 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 severely dry years, spray 3-5 times.

Spraying plant growth regulators. This is carried out from the initial blooming stage to the full blooming stage of jujube trees. Choose clear mornings or evenings to spray 15-20 mg/L gibberellin solution, or 15-20 mg/L naphthaleneacetic acid or sodium naphthaleneacetate dilution, or 5-10 mg/L 2,4-D 1-2 times. During the young fruit stage, spray 30-60 mg/L naphthaleneacetic acid or 30 mg/L 2,4-D 2 times (with an interval of 20 days), which can effectively prevent flower and fruit drop.