In recent days, there are many problems in the management of early-matrix walnut in Anhui and Xingtai districts. In particular, in regard to pest control, the summer management experience summarized in actual production is summarized as follows and is for reference only.
Early walnut varieties entered in June, the walnut fruit size has been basically stereotypes, the main phenological period are: walnut flower bud differentiation period, the second branch rapid growth period, fruit hard nuclear stage, nucleolus enrichment period. At this stage, the walnut fruits are often exposed to high temperature and high humidity, resulting in serious pests and diseases. To ensure the high yield and quality of walnuts, the following management measures must be taken during production.
I. Pest control
Early-on-season walnuts were most likely to occur in June-August and were able to cause significant reductions in production: walnut black spot and walnut anthracnose. Insect pests include: walnut limb moths, American white moths, and moths.
As the infection of pathogens is often in the natural orifices of the tree tissues (the lenticels, flower buds) and the wound wormholes (the larvae of the walnut larvae are the main infestation pathways of walnut black spot pathogens). Prevention and control pests must be combined to achieve good control effect.
The prevention and control measures for the occurrence and characteristics of the above diseases and insect pests are as follows: Around June 5, the entire park sprayed 4.5% high-potassium hydroperoxide 1000 times solution + Guofukang (peracetic acid) 400 times solution + 72% agricultural use. Streptomycin 1500 to 2000 times. On the 15th of June, the whole park sprayed 4.5% of high-efficient hydropermethrin 1000 times solution and 80% of Dasong M-45 wettable powder 800 to 1000 times solution. Around July 10, the entire park sprayed a solution of 4.5% high-potassium hydroperoxide 1000 times and 70% thiophanate-methyl wettable powder 800 to 1000 times. From July to August, the Bordeaux mixture was sprayed twice with copper sulfate, lime, and water at a ratio of 1:1:200 for disease prevention.
In addition, there are two common diseases that can result in debilitating trees and even dead trees.
One is the main rot of walnut trees. The performance of the field is: black and white spots of different sizes appear in the trunk of the walnut trees. There are no bad signs in the branches and leaves of the trees. If they are not treated in time, the tree vigor can be weakened and the leaves can be yellowed. Affect fruit growth and development. The treatment method is: using a sharp knife vertical scratch lesions, deep to the xylem, the knife does not cross between the interval of 0.5 to 1 cm, both sides more than 1 cm above the lesion is appropriate. Brush the lesion with 1 to 3 times the fruit fukang liquid with a brush and blisters after application. After 1 minute, apply it again until no bubbling occurs after application. 7 to 10 days after the smear once for consolidation treatment, can be cured.
One is the root rot of walnut trees. The performance in the field is that the leaves on one or more branches of the tree are yellow, dry, and fall off; the green fruit stops growing, shrinks, and falls off; and no insect or diseased tissue can be seen on the tree. Since root rot pathogens belong to anaerobic bacteria, they are more severe in rainy season or after rain. Treatment: Open the tree tray, deep 10 ~ 15 cm, 100 ~ 120 cm square, exposed a small amount of roots, drying more than 12 hours. Then use the fulvic acid nutrient solution 100 times and add hymexazol 1000 times to mix and then irrigate the roots. The tree is 50 kilograms of medicinal liquid and the small tree is 30 kilograms of medicinal liquid. After filling, there is no need to backfill, and it can be cured by backfilling after a period of vigorous growth in autumn roots.
Second, top dressing
At the beginning of July, according to the amount of fruit in the walnut trees, radial fertilization method was applied, and top-dressing compound fertilizer with high phosphorus, high potassium, and low nitrogen was used for 1 to 2 kg/tree to promote plumpness and fullness of the kernels and increase yield.
Third, summer trim
The main purpose of summer pruning is to consolidate the effects of spring pruning, mainly by eradicating the clipped buds and selecting the remaining branches. The second is to improve the ventilation and light transmission conditions of the tree, mainly in the early June to eliminate the dense branches, thin branches of the internal malleolus, the secondary axillary shoots and secondary branches. Summer cut It is worth noting that the cut must be close to the base, and avoid leaving it, otherwise it will cause sprouting again.
Fourth, grafting improvement
At the beginning of June, the bud-shaped bud connection method was adopted, and the real-life trees and poor quality tree trees in the garden were changed. Grafting time is controlled before June 20th.
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