Seedling cultivation of papaya

Papaya is the dry and nearly mature fruit of Chaenomelesspeciosa (Sweet) Nakai, also known as wrinkled papaya. It mainly produces Shandong, Anhui, Sichuan, Hubei, Yunnan, Shaanxi and other provinces. It has the functions of relieving cough and relieving spasm, clearing summer heat and diuresis, relaxing muscles and activating collaterals, and stomach dampness. In recent years, a series of products such as papaya beverage, papaya wine, preserved fruit, canned fruit and cosmetics have been developed. Domestic and foreign markets are in short supply. The prospect of developing papaya industry is very broad. The techniques of seedling breeding and propagation of papaya are introduced as follows:

I. seed collection and seed treatment

Select the fruit trees without diseases and insect pests in the full fruit period around the middle of September every year, when most of the outer skin of papaya fruit turns yellow, take out the seeds, select empty and shrunken seeds, then soak them in 0.1-0.3% potassium permanganate aqueous solution for about 1 hour, rinse clean with clean water, sow directly or sow in the spring of the following year, the sand storage method is to mix seeds and net sand at 1:3. The sand in the open air is stored in a cool and dry place in the leeward. The pit depth is about 50cm. If there are too many seeds, bamboo sticks or cornstalks should be used as "exhaust holes". The humidity of the sand should be held by hand instead of dripping water, and the sand should be covered with about 30cm. The storage process should be checked 2-3 times a month. If mildew or fever occurs, it should be stored in a kiln in time. Around the middle of March in the following spring, when the seed has 2/3 cleft mouth, it can begin to sow.

Second, nursery site selection and pre-sowing preparation

The nursery should choose brown soil or yellow loam land with convenient transportation, adequate water source, good drainage and irrigation, loose and fertile brown soil or yellow loam. Fine soil preparation should be done before sowing, and 10 kg of imported carbofuran, 5 kg of carbendazim and 15 kg of compound fertilizer should be applied per mu.

Third, sowing seeds

Papaya usually adopts flat bed strip sowing method, with sowing rate of 30-40kg per mu, bed width of 120-150cm, row spacing of 20cm, ditch depth of 8-10cm, soil thickness of 3-4cm, aisle of 20-25cm, and sufficient bottom water after sowing.

IV. Field management

The field management of papaya seedlings is mainly loosening soil, weeding, watering and fertilizing. As long as the seeds and soil are disinfected and the seeds are fully mature, there is generally no need for pest control. Weeding should be done to "remove early, small, except", avoid drought, loosen the soil regularly, fertilize the seedlings about one month after emergence, and use the ditch fertilizer method, once every half a month, applying about 15 kilograms of urea per mu for a total of 4-5 times, stop fertilizing after the beginning of autumn and promote the Lignification of seedlings.

5. Grafting of seedlings

Traditional planting seedlings often plant real seedlings, not only hang fruit late (usually five-six years to hang fruit) low yield, and variety degradation, low economic benefits, now most planting grafted seedlings, the third year began to hang fruit, Shandong in recent years selected Changjun, Guohua, Luyu and other varieties have strong adaptability, high yield (high yield can reach more than 5000kg per mu after high yield, income of nearly 10,000 yuan), excellent varieties, can be developed and promoted in a large area. The grafting time is generally from late August to early September, usually using the method of ventral grafting of single bud, not exposing buds, checking complete healing in the spring of the following year, cutting off 2-3cm from the place of grafting, wiping buds and removing tillers in time, and strengthening management, the seedlings can grow to about 1.5m in that year, and the same method is used for a small number of those who have not survived in spring.