When do plum trees usually be planted? What technical points need to be mastered?

Plum sweet and sour delicious, eat raw appetizer, steamed to eat sugar soft waxy sweet, many friends like to eat. We often see plum trees full of branches when they bear fruit. The growth of plum trees is also slightly shade-tolerant, cold-resistant and adaptable, and the warm and humid climate and sandy loam with good drainage are the most favorable. When do plum trees usually be planted? What technical points need to be mastered?

When do plum trees usually be planted?

The survival rate of plum trees was the highest when plum trees were transplanted about a week after defoliation in autumn (early and middle November) or about half a month before spring germination (mid-late March).

The grafting of plum trees should be carried out in late June. In the 7-10 days before grafting, the peripheral branches with strong growth should be selected to promote the early maturity of the scion. In addition to selecting full buds during grafting, the grafting site should be 5-8 cm on the ground, which is beneficial to the early germination of grafted buds.

II. Key points of plum planting techniques

(1) fertilization technology

1. Fertilization technology in young plum orchard (before hanging fruit).

In the first year, clear manure water containing 2 ‰ urea (50kg + 0.1kg urea) was applied every half month from May to August, and farm manure matured by 3.5kg-5kg was applied in September. Clear fecal water containing 3 ‰ urea (50kg clear fecal water + 0.15kg urea) was applied every half month from March to August in the second year, and 7.5kg-10kg mature farm manure was applied in September.

2. Fertilization technology in plum orchard.

① base fertilizer

Base fertilizer accounts for 60% of the total amount of fertilizer applied in the whole year, and it is applied from fruit harvest to autumn defoliation (September-October). For each tree producing 50kg, each tree was treated with mature livestock and poultry fertilizer 25kg-35kg, mixed with mature cake fertilizer (peanut bran or rapeseed bran) 2kg-4kg, combined with 1kg superphosphate, mainly in ditch application, combined with hole application. Open ring ditch or parallel ditch, deep 20cm-45cm, wide 30cm-40cm, fertilization position at the outer edge of tree crown dripping water, cover soil with fertilizer and apply fertilizer water 100kg, the ratio of retting fertilizer water is peanut bran (rapeseed bran): pig manure: water = 1: 20: 100. The base fertilizer was misplaced into the soil year by year.

② topdressing

Topdressing accounts for 40% of the total amount of fertilizer applied in the whole year, of which sprout fertilizer (pre-anthesis fertilizer) accounts for about 15%. Trees that produce 50kg are applied in mid or late February, and each tree is treated with rotten chicken manure or pig manure 7-10kg plus peanut bran (rapeseed bran) 1kg plus superphosphate 1kg, mixed pile and compost, and the soil should be kept moist after application. Strong fruit fertilizer accounts for 25%, 30-45 days before fruit ripening, trees that produce 50kg are applied to each tree with clear fecal water 50kg and potassium sulfate (high potassium) compound fertilizer 0.5kg-0.8kg, which is applied by multi-point and multi-hole method.

③ foliar spraying

According to the tree phase indexes of different growth periods and the actual requirements of production, nitrogen, phosphorus, potassium and nutritious liquid fertilizer were properly applied outside the root. At the same time, foliar spraying of trace and medium element fertilizers such as calcium, magnesium, manganese, iron, zinc and boron was carried out according to the symptoms of element deficiency in plum orchards. Foliar spraying should not exceed 3 times during the whole growing period.

(2) shaping and pruning

1. Plastic surgery

The happy shape of three main branches was adopted. In one year, the seedlings had full buds about 15cm-25cm above the ground, and three main branches were selected in the distribution of 5cm-8cm at the interval of the trunk. The branching angle of the main branches was 45 °- 65 °, and 3-5 lateral branches were left on each main branch, which were arranged in the space of 70 °- 80 °. The total height of the tree is controlled within 3.5m.

2. Pruning

① young tree

The focus of the young trees within three years of planting is to cultivate the main and side branches, adjust the angle, restrain the strong and help the weak, and balance the tree potential. Mainly pruning in summer, pruning methods such as pulling branches, wiping buds, coring and so on are mostly used. Properly cut and lengthen the branches in winter, quickly form a skeleton and expand the crown, and remove the inner branches, dense branches and improperly positioned branches.

② result tree

According to the characteristics of the variety. The cutting intensity and renewal mode of fruiting mother branch were determined by tree age and yield. Gradually aggravate the short cut and regulate the balance between reproduction and vegetative growth. Remove the inner branches, dense twigs and withered branches of diseases and insect pests, so that the branches are evenly distributed, do not shade each other, and the trees are ventilated and transparent. Timely update the pruning to prevent the result part from moving out and the size of the result. Combined with summer scissors, mainly winter scissors.

③ senescent tree

The trunk branches were retracted to the position of about 5 years, and the latent buds were stimulated to sprout and cultivate into a new crown. At the same time, the overgrown branches from the senescent trees were pulled or cut properly to promote branches and form fruiting branches, so as to fill the crown, restore tree potential and fruiting ability, and delay the fruiting years.

(3) Flower and fruit management period

1. Protect flowers and fruits

In case of adverse climate at flowering stage, the seed setting rate can be improved by releasing bees at flowering stage and spraying compound nutrient solution on leaves. The proportion of nutrient solution is 15L water + 15g borax + 30g urea + 15g potassium dihydrogen phosphate.

2. Thinning flowers and fruits

① principle

Plums bear strong fruit, and the yield is controlled by shaping, pruning, fruit thinning and other measures. In principle, each 666.7m2 is controlled between 1000kg-2000kg.

② flower thinning

Combined with winter pruning, cut off too many flower buds, weak flowers, spring inflorescence separation period for pre-flowering re-cutting, cut off too many flower branches and inflorescences.

③ fruit thinning

According to the leaf-fruit ratio of 30-40:1, excessive young fruits were thinned (usually 2-5 times) at 4-8 weeks after flowering. Strong tree leaves more strong branches, weak branches less, according to the first inside and then outside, first up and then down, thinning weak small fruit, deformed fruit, disease and insect fruit, poor pollination and fertilization fruit; no matter long or short fruit branches, leave one fruit at intervals of 2cm-3cm, and leave one fruit with bouquet-like fruit.