Cultivation techniques of longan

Longan, also known as longan, is a valuable specialty in southern China, rich in nutrition and a precious tonic. The pulp contains 12.38% sugar 22.55%, reducing sugar 3.85% 10.16%, converted sugar 9.59% 13.59%, acid 0.096% 0.109%, sustaining C43.12~163.70mg/100g pulp. There are also vitamin K and inorganic salts. It has high medicinal value, tonifying the heart and tonifying the heart, nourishing blood and calming the nerve. it can treat weakness, anemia and yellowing, neurasthenia, postpartum blood deficiency and other diseases. In addition to fresh food, longan can also be dried, canned, longan ointment and so on. It is approved to make wine.

Selection of improved varieties

The varieties in Fujian are Fuyan, Wuqiuben, Banana Eye, Red Shell, Wulongling, Youtanben, Pumingelection, Dongbi, Egg Longan, Red Kernel, etc., while the varieties in Guangdong, Guangxi and Sichuan are Shixia and Wuyuan. Caopu species, Kaohe, Daguang, Guangyan, button button, Luyuanqiang, Luyuan 6, Luyuan 106, August fresh, Fuling yellow shell longan and so on.

Raising seedlings

1. Seedlings: choose hillside land with wind and frost protection, good drainage and irrigation, deep soil layer, loose and fertile texture as seedling land. Ploughing 20~33cm deep, applying turf soil 5000kg, then ploughing and harrowing, applying barnyard manure 2000~2500kg, and then building a border, the border height is 20-25cm, the width is 1m, and the furrow depth is 33~40cm. The ratio of longan nursery to transplant nursery should be 1:6 or 1:7. Longan seeds must be sown as they are picked. The seeds taken out were immediately mixed with sand in the proportion of 1 to 2 to 3 to accumulate and germinate. The optimum germination temperature was 25 ℃, and the water content of fine sand was about 5%. When the germ elongates 0.5~1cm, it can be sown in the seedbed. Can be sown, grain spacing 8 × 10cm, sowing rate 115-250kg per mu, 2500~3000kg after sowing cover burning soil or sand, covered with straw, then irrigated by water diversion, and then drained after wet. After emergence, it is necessary to strengthen management, such as watering and removing straw. Fertilizing to ensure the robust growth of seedlings. Transplant during spring plum rain. When transplanting, apply good fertilizer, plant row spacing 20 × 30 ~ 33cm, planting 7000000 plants per mu. Timely management after relocation.

2. Grafting propagation: the seedlings of 5-6 years after planting were used as rootstocks, and the grafting method was used. The scion with 2-year-old strong branches, thick 1cm and long 4-12cm can also be used by leaning grafting, and the best time is from March to April, and the grafting propagation can also be carried out by tongue grafting and bud patch grafting.

3. High pressure propagation: the method is to select 3-year-old and 4-year-old 3cm with 3 branches with 2 Mel branches on the robust plants over 15 years old. The girdling was carried out at the place away from the branch 10~20cm, the width was about 40~50cm, and the cortex was scraped off. When the tumor appeared in 10-20 days, it could be wrapped with grass mud, filled with a bowl or covered with plastic film as the hairy root matrix.

4. Cut the twigs of longan that year, cut them into 15~17cm branches and insert them into the hotbed of 27Mel 29 ℃ to cover the sun and water at ordinary times. Before cutting, the bottom of the selected branch was peeled around first, and after 1 / 2 days, it was coated with 300g mixed coating of 100 parts of straw ash, 10 parts of red mud and 0.18 parts of salt, then bandaged, and then cut off the mother branch after two and a half months.

Planting

It can be planted in 2-3 months in spring and in late October in winter. Planting density, available row spacing 16m, plant spacing 4.5m, planting 1920 trees per mu. The planting hole with a depth of 1m was dug first and the river mud was applied below. Soil, burning soil, composting, calcium superphosphate and plant ash should be mixed with topsoil. After planting, it must be fully irrigated first, then covered with fine soil, and then irrigated once or twice a day. The depth of planting, the root and neck should be level with the ground.

Shaping and pruning

The natural flat circle shaping was adopted and dried at 1.2m to 1.3m in 2 ~ 3 years after planting, and the main branches were cultivated into 5 ~ 7 main branches in 3 ~ 4 years. Pruning 3 times a year, pruning at the first flowering stage, mainly cutting off diseased ears, shade branches and stumps. In the second pruning, the short fruiting branches, long branches, diseased branches, dead branches and shade branches were mainly cut off. The third time in winter, shade branches, withered branches and diseased branches were mainly cut off.

Fertilizer application

Base fertilizer is applied once a year, and topdressing is applied 3 or 4 times a year. The first topdressing was from February to March, when dung and ammonium sulfate were applied. The second topdressing is in the young fruit stage after flowering, about 4 ~ 5 months, mainly applying nitrogen fertilizer and proper application of phosphorus and potassium fertilizer. The third topdressing was from late June to early July, mainly phosphorus and potassium fertilizer, followed by nitrogen fertilizer. The fourth forced fertilizer was still dominated by nitrogen fertilizer when the fruit was close to maturity. The method of fertilization is to open a trench at the 30cm away from the trunk. Fertilization can be combined with ploughing, weeding, soil cultivation, drainage and irrigation.