Labor-saving cultivation techniques of fragrant walnut

Labor-saving cultivation techniques of fragrant walnut

The labor-saving cultivation of fruit trees is based on intensive cultivation, through the use of orchard grass growing, water-saving irrigation, mechanized operation, comprehensive control of diseases and insect pests, bagless cultivation and other techniques to reduce orchard labor intensity, save labor time, reduce production costs and improve efficiency. Relying on the national science and technology project, forestry workers in Pingshan County focused on the labor-saving cultivation of walnut, starting with fragrant walnut. A number of experimental studies were carried out, such as tree shape selection, branch pruning, artificial pollination, scientific fertilization, grass management, pest control and so on, to explore the high efficiency and labor-saving cultivation techniques of walnut in dry sloping land, which reduced the cost, improved the benefit and realized the high yield and harvest of walnut in dry sloping land of Taihang mountain area.

1 labor-saving land preparation

The labor-saving land preparation is changed from manual land preparation to mechanical land preparation. According to local conditions, we should popularize land preparation methods such as mechanical land preparation of terraced fields in hilly areas, mechanical land preparation of low mountains and rivers, and horizontal steps of middle and high mountains, so as to ensure the normal growth of young trees. Excavators are used to level up a large piece of terraced land and dig a large pit of 1m × 1m × 1m. According to the investigation and comparison, the mechanized big pit has low cost and high efficiency. One excavator can dig 480 pits a day, which is equivalent to 22 labor forces. the cost of each pit of the excavator is 2.2 yuan, which is 3.3 yuan less than manual labor. By digging 56 pits per 666.7m2, the cost of land preparation can be saved by 184.8 yuan. There are many hills and mountains in Pingshan County, and the land is barren. Mechanical trenching and soil preparation can deeply turn the soil layer, speed up the afforestation progress, reduce the afforestation cost, and lay a good foundation for the growth of walnut young trees.

(2) labor-saving soil, fertilizer and water management

2.1 Natural grass

The natural grass is to retain the natural 1-2-year-old weeds between the rows of fruit trees and to remove perennial weeds and weeds in the 60cm area around the trunk. Cut weeds with a lawn mower when the 50cm is high. In addition, low-stalk crops such as peanuts and potatoes can be intercropped between rows, reducing fertilizer input in orchards, saving the cost of weeding, improving soil structure, increasing organic matter content and water content, reducing surface evaporation and reducing the incidence of freezing injury. Natural weeding costs 114RMB per 666.7m2 per year, while manual weeding by clear tillage requires 4.29workers with a cost of 429RMB. Natural weeding can save 315RMB per year (Table 1). Large funnel-shaped tree plates are used in walnut orchards without irrigation in arid mountainous areas, which are covered with plant straw or weeds to store water and preserve soil moisture.

Table 1 comparison of the cost of natural weeding and artificial weeding

2.2 Integration of water and fertilizer

The labor-saving water and fertilizer management is to change the traditional ditch fertilization into simple integrated water and fertilizer fertilization. The simple integrated fertilization of fertilizer and water is a fertilization method which uses the mechanical devices of orchard spraying, such as medicine storage tank, pressure pump, high-pressure pipe, tricycle and so on, to change the spraying gun into the topdressing gun and dissolve the fertilizer in the water. After being pressurized by the fertilizer pump, the topdressing gun is applied to the concentrated distribution area of the root system of fruit trees. After repeated experiments, the compound fertilizer which is soluble in water and less impurities is finally selected, such as Leili seaweed organic fertilizer, Baiquan urea sulfate water-soluble compound fertilizer and so on. Basal fertilizer was applied after the autumn shoot of walnut stopped growing, pre-flowering fertilizer was applied from late March to early April, fruit fertilizer was applied after the spring shoot of walnut stopped growing from late May to June, and 2000kg was applied with topdressing gun with water each time (Fig. 1). Fertilizing deep 25~35cm. According to the tree size, each tree had 4-16 topdressing holes, each hole was fertilized for 10-15 seconds, and each tree was topdressing with fertilizer and water 20~25kg. Through investigation, it was found that the total cost of using this technology in 17.3hm2 walnut demonstration orchard was 441000 yuan per year, which was 95250 yuan lower than that of ditching fertilization, and the average fertilization cost per 666.7m2 was reduced by 158.7 yuan.

Fig. 1 Integrated fertilization method of water and fertilizer

3 labor-saving shaping and pruning technology

The labor-saving shaping and pruning technique is to cultivate the spindle tree and popularize the pruning technique of pulling branches all the year round.

3.1 spindle tree

The spindle shape has a strong central trunk, and there are 10 to 13 main branches in the central trunk, and there are no lateral branches on the main branches, directly bearing fruit branches. The spindle-shaped backbone branches have few grades, small amount of pruning, ventilation and light transmission, and early fruiting, so they are suitable for close planting (figure 2).

Fig. 2 spindle-shaped tree shape of walnut

3.2 pruning techniques throughout the year

Pruning techniques throughout the year are adopted to pull branches as an important measure to control prosperity and promote fruit, to flatten or droop branches, ease the growth of branches, promote the germination of branches, increase the number of medium and short branches, and promote the early formation of flower buds. The central stem maintained absolute dominance, and the thickness of the main branch did not exceed 1 / 2 of the thickness of the central stem, exceeding the thinning. After years of experiments, branch drawing up to 90 °can significantly increase the germination rate, flower formation rate and yield per plant, reaching the effect of 3% in the second year, 35% in the third year and 100% in the fifth year after grafting (Table 2).

4 labor-saving and efficient flower and fruit management technology

The labor-saving and efficient flower and fruit management technology is artificial male thinning and artificial pollination to improve the fruit setting rate.

4.1 artificial male thinning

"Walnut thinning male is better than fertilization", male thinning can reduce the nutrient consumption of trees and make more nutrients for female flower development and flowering and fruiting. The male thinning of fragrant walnut for 4 consecutive years from 2012 to 2015 showed that the male thinning amount was 80%-90%, and the effect of increasing yield was obvious. Compared with the control, the male-thinning could increase the yield by 15.91%-19.16%. The time of male thinning is from March to early April, which can be carried out from flower bud germination to male inflorescence extension, and male inflorescence 1~2cm is the most suitable. When thinning males, pull down the branches with a hook rod of 1 × 1.5m long, manually break off the male inflorescences, leave 5% 10% male inflorescences in different parts of the crown, and remove the rest to save tree nutrition.

Table 2 flowering effect of fragrant walnut after 3-5 years of branch treatment

4.2 artificial pollination

Using the pollination method of nylon socks, the pollen and corn flour were mixed into nylon stockings (1 / 2 layers) according to the ratio of 1 ∶ 5. Tie the socks tightly, tie them to the bamboo pole, and then shake gently above the crown. Artificial pollination could increase the yield of each walnut by an average of 0.4 kg per plant and increase 22kg by 666.7 m2, which was 8.2% higher than that of the control.

4.3 spraying foliar fertilizer

Fuman foliar fertilizer was sprayed during flowering and fruit setting stage and fruit expansion stage, and 0.4% potassium dihydrogen phosphate was sprayed at hard core stage, which increased yield by 25% compared with the control treatment, and the fruit was large, with few diseased and rotten fruits.

5 labor-saving management techniques of diseases and insect pests

The labor-saving management technology of diseases and insect pests is to strengthen prediction and forecast, implement biological, physical and artificial control, reduce the number of drug use, and effectively control the occurrence of diseases and insect pests. The prevention and control of diseases and insect pests should be based on biological and physical control, supplemented by chemical control, strengthen the forecast of pest situation and reduce the number of medication. Walnut limb moth is a common walnut pest. Three pesticides are needed for routine control of walnut limb moth. Studies have confirmed that spraying 1000-1500 times diflubenzuron 3 at the initial stage of larval hatching during the peak period of adult occurrence (late July to early July) can achieve the purpose of prevention and control, with a good fruit rate of 86%, reducing the cost of control and reducing pesticide pollution. Installing black light in the walnut orchard and raising chickens in the garden can effectively control the occurrence of beetles.

6 labor-saving post-mining treatment technology

The peeling, cleaning and drying of walnut after harvest are all mechanized.

From late August to early and middle September (around White Dew), the green skin of walnut turned yellowish green or light yellow, the top cracks of some fruits or the natural shedding of individual fruits were the best harvest time for walnut. After harvest, soak the green fruit with 3000~5000mg/kg ethephon solution for half a minute, remove and control clean water, stack high 30~50cm indoors, cover with hay about 10cm, peel off in 2 days, the peeling rate can reach 94%, and the shell surface is clean. The efficiency can be greatly improved by using the peeling machine. The green walnut peeling machine can peel and clean 250kg per hour. 1.04 workers are used for mechanical peeling, cleaning and drying per 666.7m2, which is 3.13 less than manual peeling, cleaning and drying, and the cost is saved by 313 yuan. A drying room was established and a walnut grader was purchased to facilitate walnut drying, storage and classification. Save labor, improve efficiency and increase efficiency.