Main technical measures for cultivating thick and strong seedlings of Carya cathayensis

Carya cathayensis is one of the main economic specialties in Lin'an. In order to help farmers solve the problems existing in the process of raising Carya cathayensis seedlings, continuously improve the quality of Carya cathayensis seedlings and speed up the development of Carya cathayensis, according to the successful experience of Carya cathayensis seedlings accumulated for a long time, the techniques of cultivating thick and strong seedlings of Carya cathayensis were summarized. ⒈ selected the mother tree and selected the sunny hillside, disease-free and pest-free, big fruit, full fruit, thin shell, unobvious size and high yield of Carya cathayensis as the seed collection mother tree. The seed collection season is in the early and middle of September (after White Dew), and the fully mature and self-falling fruit is the best. Spring sowing seeds, after picking and removing cattail, float the empty seeds and non-full seeds with water and spread them in an indoor ventilated place for 3-4 days, then they can be stored, if the exocarp of autumn-sown seeds does not need to fall off. ⒉ spring sowing and timely storage of spring sowing seeds should be stored through the winter. There are three storage methods: dry storage, sand storage and cattail storage, and sand storage is better. Specific method of sand storage: the dry seeds are stored in layers with wet sand (coarse sand), the water content of the sand is 30.4%, the sand should not stick to the hand, a layer of seeds (about 5~10cm), covered with a layer of sand (thick 4~5cm), pile up to 30~40cm, 1m wide, unlimited length, large number of seeds should be put into bamboo basket or straw bag for ventilation, turn the pile every half a month. About 30 days before sowing in the next spring, increase the temperature of the sand (water content 5.5-7.0%) to accelerate germination before sowing, and check in time. If seeds are found to crack and germinate, they should be sown in batches in time. Before ⒊ sowing in autumn, Carya cathayensis will germinate when the temperature is more than 10 ℃. The collected seeds are made of 250kg, covered with straw and covered with plastic film. The seeds can also be packed in a snakeskin bag and covered with hickory cattail (exocarp). After about 4-5 days, the seeds will crack and germinate and sow in batches (uncracked germinated seeds continue to germinate). It should be noted that the germ should not be pushed too long (generally not more than 1cm), otherwise it will affect the unearthed. According to the ecological habits of Carya cathayensis seedlings afraid of strong sunlight and stagnant water, the nursery site should be selected by ⒋. The best nursery site is sandy loam soil with high elevation of 200m, 500m, Yinpo Mountain, good drainage, convenient irrigation and fertile soil, and avoid choosing the old base of cultivating mu for many years. The main root of one-year-old seedlings of Carya cathayensis in ⒌ seedbed is longer, so the nursery needs deep ploughing before sowing. The width of the seedling bed is about 1m, and the height of 25cm is good, which is convenient for the management of drainage, weeding, fertilization, prevention and control of diseases and insect pests, building shade shed and so on. Carya cathayensis sown in time by ⒍ can be divided into autumn sowing, winter sowing and spring sowing, and autumn sowing is better. Carya cathayensis has a thick shell and is difficult to germinate. Carya cathayensis seeds can be germinated and unearthed when they are sown in September, and the height of seedlings can reach more than 10 cm in this year. Winter sowing from December to January of the following year did not sprout and generally did not take root in the same year. Both autumn and winter sowing should be covered with grass and plastic film (arch), and pay attention to the "four defenses": anti-freezing, drought, rotting roots and rodent damage. Spring sowing should be from February to March, no later than the end of March, and the seeds should sprout before sowing. Carya cathayensis was sown by strip sowing, strip spacing 20cm, plant spacing 5~10cm, overlying soil 3~4cm, horizontal seed placement, sowing amount of 500kg per mu (about wet seed 150kg). Straw should be covered in time after sowing to prevent the soil from hardening so as to maintain humidity and facilitate the emergence of seedlings. The careful management of Carya cathayensis seedlings by ⒎ has to go through three hurdles: unearthed clearance, rainy season pass and summer pass. When the seedlings are unearthed, they are most afraid of soil consolidation, summer and seedling injury. When weeding, pull the grass by hand at the root as far as possible, the hot season is carried out in the morning and evening, and the rainy season should be drained in time to prevent rotting roots. From July to September, we should build a shade shed to protect against the sun (30%-50%). In order to raise seedlings at higher elevations, a small amount of corn should be planted around the seedbed instead of shade. ⒏ scientific fertilization is mainly based on base fertilizer (organic fertilizer). 100 piculs of rotten manure (fermented) or 10 loads of human manure and compound fertilizer 50kg per mu are applied to the overlying soil in the sowing ditch. The amount of topdressing should be less and more. 0.5% of human manure or chemical fertilizer can be used for flushing application, and the roots can be applied 2-3 times a month during drought. Nitrogen fertilizer is the main fertilizer in the early stage, phosphorus and potassium fertilizer is the main fertilizer in the middle and later stage.