How to manage walnut trees in spring? Latest techniques and methods tutorial
Spring is the period of walnut flower bud differentiation. Management before walnut budbreak is the most important part of the walnut year. Grasping this stage well is one of the effective measures to ensure walnut budbreak, flowering and fruiting, and a high yield. So how should walnut trees be managed in spring? Let's find out together with the editor.
1. Soil, fertilizer and water management
First is soil. Soil is the foundation of walnut growth. Strengthening soil management can be carried out by combining orchard clean cultivation, orchard grass growing, and orchard intercropping. Next is fertilization. For young trees under 3 years old, the ring-shaped trenching method is generally used, digging pits 30cm from the trunk to apply fertilizer, while for mature trees it is best to use concentrated fertilization mainly by digging pit-shaped holes, digging four pits in the vertical direction of the canopy. The amount of fertilizer should also be controlled. Generally, each young tree is applied with 5-15 kg of farmyard manure and 0.3-0.6 kg of urea; while for 3-5 year old fruiting trees, each tree can be applied with 30-50 kg of farmyard manure and 0.5-1 kg of urea. The application amount of chemical fertilizer should increase with tree age. In March to April, before walnut budbreak, when there is insufficient rain and the climate is dry, water once with budbreak water to promote new branch growth. After transplanting, also pay attention to watering to improve the survival rate.
2. Pruning
Spring pruning is generally done 20-30 days before budbreak. At this time, combine pruning with collecting scions for short-term storage, and by late March to late April use branch grafting for top grafting to replace superior varieties or to propagate grafted walnut seedlings. For trees beginning to bear fruit, branch bending can balance the branch vigor of main branches and fruiting branch groups and promote flower bud formation; for full-bearing trees, adjusting the angle and direction of branches can noticeably improve ventilation and light penetration, promote the formation of medium and short branches, reduce bare lower parts of branches, and increase effective fruiting positions; for young trees, promote canopy formation so they bear fruit as early as possible.
3. Pest and disease prevention and control
In spring, the main diseases to prevent are walnut black spot disease, canker disease, and rot disease. Lime sulfur mixture can be sprayed before budbreak. When the temperature rises above 18°C, spray the whole orchard's plants and ground once with 3-5 degrees Baume lime sulfur mixture, then spray again with 0.3-0.5 degrees Baume lime sulfur mixture after budbreak during the leaf expansion stage. In orchards with severe black spot disease, spray once more with 0.3-0.5 degrees Baume lime sulfur mixture after 7-10 days, which can effectively prevent and control black spot disease. For canker disease and rot disease, the control method is to scrape off the diseased spots to the xylem, then apply control agents.
4. Frost prevention
Spring temperatures are unstable, and many areas experience a late spring cold spell, which causes relatively severe frost damage to walnuts and dampens the enthusiasm of some fruit growers, so frost prevention should also be done well. First, choose frost-resistant varieties. These varieties bud about 1 week later than other varieties, which can effectively avoid frost. In addition, pay timely attention to weather forecasts. When the nighttime temperature drops to 0-2°C, smoke the orchard for protection. Smoke-producing materials can be crop straw, weeds, fallen leaves, corn cobs and other flammable materials that can produce large amounts of smoke. Dig pits on site, pile the grass in the pits, and cover the outside with a layer of wet grass or wet soil, so the smoke is abundant and lasts a long time.
The above is an introduction to spring walnut management techniques. We hope it helps you. To learn more related knowledge, please follow us.