2. Pruning: Pears have strong branching and weak fruiting, and most of the fruiting trees are short. When pruning, you should pay attention to the following items:
(1) Cultivation and pruning of fruit branches: Rational distribution of fruit branches is the key to high and stable yield. For varieties that are easy to bloom, the method of cutting first and then releasing or cutting first and then shrinking can be adopted, and for varieties that are difficult to bloom, the fruiting branches can be cultivated after long releasing and shrinking. For the trees in the pre-fruiting stage and entering the fruiting stage, the fruiting branches should be finely pruned, the preparation skills should be kept in the same branch group, the fruits should be updated alternately, and the fruiting parts should be controlled to move outward. It is necessary to make full use of the retraction of light shears and short shears to regulate the regeneration, growth and fruiting within and between branches, so that the period can not only maintain vigorous fruiting ability, but also have proper nutritional growth.
(2) Pruning with auxiliary cultivation techniques: Because the branching ability of pear trees is weak, more auxiliary cultivation branches should be left between the backbone branches during pruning to enhance the tree potential and make use of the results. When it affects the growth of main branches, it should be retracted in time until it becomes thinner.
(3) Preventing the fruiting part from moving out: thinning the upper and peripheral strong branches can reduce the number of the upper and peripheral strong branches, thinning the upright strong branches, leaving mediocre branches, and slowly releasing them to make them blossom and bear fruit, weakening the growth potential. Leave more weak branches in the lower part and inner chamber and cut them properly to promote branching, rejuvenation and regeneration, and shrink the weak branches into strong branches and strong buds to enhance the tree potential. Branches extending between rows should be properly contracted to maintain an aisle of about 0.5 meters between rows.
(4) Pruning in winter should be strengthened during the full fruit period, and the inner chamber should be weakly regenerated and rejuvenated, so that after the inner chamber and the lower branches are fully cultivated, the fruits should be changed in turn, and at the same time, the fruit parts should be prevented from moving out to maintain the tree structure. Summer pruning, as an auxiliary pruning, mainly adopts techniques such as core removal, tip twisting and branch pulling to promote flower bud differentiation. 1, Measures to improve fruit quality:
(1) flower thinning and fruit thinning: generally used after entering the full fruit stage.
① flower thinning: thinning flowers for plants with too many flowers can improve the quality of flowers, thus improving the fruit setting rate. The suitable time for flower thinning is from inflorescence to early flowering. However, in areas with late frost hazards, it is safer to thin fruits after flowering. The amount of flower thinning depends on tree potential, variety, fertilizer and pollination conditions. Prosperous branches have few leaves, while weak branches have many leaves. First, the weak inflorescence is dense, the central flower is dense, and the marginal flower is reserved.
② Fruit thinning: Fruit thinning can increase the weight of single fruit and improve the quality of fruit, generally after the initial climax of fruit dropping, and it is advisable to do it about two weeks after flower dropping. Leave 1-2 fruits per inflorescence. First, remove the diseased and deformed fruits and keep the fruits with good shape and orientation.
③ Chemical flower thinning: At the end of flowering, when it is estimated that high yield can be obtained, it should be combined with pest control, and 0.5% Bordeaux mixture and Pomei 0.3 degree stone sulfur mixture or 40PPM sodium naphthylacetate can be sprayed (note: for safety and insurance, it is best not to use chemical agents to thin flowers and fruits).
(2) Increase the application of phosphorus and potassium fertilizer.
(3) Spraying 0.3% urea and 0.2% potassium dihydrogen phosphate.
2. Prevention measures of fruit cracking, rust and fruit drop before harvest:
(1) Apply sufficient phosphorus and potassium fertilizer in early and middle May, and cover the tree with weeds to prevent fruit cracking.
(2) spray 1 time 50PPMGA3 (920) or 1 0-100 ppm Cai acetic acid1month.
(3) Don't apply too much quick-acting nitrogen fertilizer at one time, so as to make the pulp and pericarp develop in a balanced way and reduce the rust spots formed by cutin cracking of fruit epidermis. At the same time, spray less Bordeaux mixture to reduce the occurrence of rust fruit and strengthen the prevention and control of pear rust.
3. Fruit bagging: According to the size of the fruit, it is better to choose domestic double-layer or single-layer paper bags for charging. Before fruit spots are formed on the fruit surface in mid-May, a wide range of fungicides and pesticides are sprayed on the fruit surface, and then bagged in time. The outer paper bag of the double paper bag is disassembled one month before the fruit is harvested, which is beneficial to the fruit to receive light. Single paper bag, take the bag when picking fruit. Pear scab (also known as scab) is one of the most important diseases of pear, which harms the fruit, spine, leaves, petioles and new shoots of pear trees. )
Preventive and control measures:
1 eliminate the pathogen: pay attention to the occurrence of diseased shoots from early spring to June, clear and burn them in time, clean up fallen leaves and fruits, and cut off diseased shoots.
2. Chemical control: ① spray 1:2:244 bordeaux solution or 1: 2: 200-244 bordeaux solution or 800 times "Sheng Da M" to protect inflorescences, shoots and new shoots; ② Spray 1 800 times DuPont Fuxing, 1200 times Domaine or 800 times Sheng Da M in mid-May, mid-June, mid-July and early August respectively.
Pear black spot (attacks pear leaves, new shoots, flowers and fruits, and young leaves are vulnerable. )
Preventive and control measures:
1 combined with the control of scab and other diseases.
Pay attention to the cleanliness of the countryside, strengthen management and enhance the tree potential. 3. Spray 1000 times of Eudragit solution for prevention and treatment. Pear moth
Preventive and control measures:
1 Combined with winter pruning, cut off insect buds, check damaged flower clusters (scales of damaged flower clusters fall off) after flowering and remove them in time. Before the end of May (before the emergence of adults), the control effect is remarkable.
2 Spraying 5000-7000 times of 10% efficient pesticide emulsifiable concentrate, 800 times of 4% sulfamic acid, 40% sulfamic acid or 40% omethoate during the germination and fruiting period of overwintering larvae.
Pear stem bee
Preventive and control measures:
1 combined with Qingyuan, the bark of Laoqiao was scraped and burned to eliminate overwintering nymphs.
2 In spring, before overwintering nymphs start to move to branches and live in groups in summer, 5000 times of 10% acetaminophen or 3000 times of 10% mirex and 800 times of 40% omethoate can be sprayed.
Golden Chrysopa
Prevention and control measures: clear branches and eggs in winter and check frequently in summer. Catch larvae in time.