Cultivation points of Xinsheng No.3 Ponkan

1. Suitable rootstock and strong seedlings, reasonable close planting

It is appropriate to use Fructus Aurantii as rootstock, early fruiting, high yield, short crown and compact crown; Guangdong and Guangxi use sour orange as rootstock to show early fruiting and early high yield.

Xinsheng No. 3 Ponkan is erect, especially young trees. In order to make full use of land resources, close planting or planned close planting can be carried out. It is usually appropriate to plant 74 × 89 plants per mu, that is, the row spacing is 3 m × 3 m ~ 3 m × 2.5 m, and the planned dense planting is 3 m × 2 m, that is, 112 plants per mu. After 5-6 years, thinning or interplanting was carried out among plants, and 56 plants were planted per mu.

2. Scientific fertilization and timely irrigation

(1) fertilization

Fertilization for unfruited young trees should adhere to the principle of a small amount of fertilizer for many times, usually applied once before the leaves turn green in spring, summer and autumn, respectively, the fertilizer is mainly available nitrogen and potassium, and properly combined with phosphorus fertilizer; overwintering fertilizer is applied in late autumn or winter, fertilizer is mainly organic fertilizer (livestock manure, compost, green manure, etc.), acid red-yellow loam should also be mixed with lime to reduce soil acidity. Fertilizer application amount: 30 grams of urea (or potassium sulfate) is applied to one-year-old trees, 50 grams to two-year-old trees, 75g to 100 grams for three-year-old trees, and compound fertilizers with N, P2O5 and K2O amounts above 15% can also be applied to one-year-old trees. In order to promote the plant to form a crown and put into production as soon as possible, combined with pest control, 0.3% 0.5% urea or 0.3% potassium dihydrogen phosphate can also be sprayed on the leaves, 3 or 4 times a year, and the effect is good before the leaves turn green.

Results the adult trees were fertilized 4-5 times a year. Spring shoot fertilizer was applied in February, mainly available nitrogen fertilizer, which was used to promote spring shoot growth. Stable fruit fertilizer was applied in May, mainly with comprehensive organic and chemical fertilizers of nitrogen, phosphorus and potassium, and trees with weak tree potential were combined with pest control. 0.3% urea or 0.3% potassium dihydrogen phosphate was sprayed on the leaves to improve the rate of fruit stability. In July, combined with drought resistance and strong fruit fertilizer, organic fertilizer was applied mainly to promote fruit expansion and early autumn shoot emergence, to prepare excellent fruiting mother branches for the following year, and to apply flower bud fertilizer in September, mainly phosphorus and potassium, to promote flower bud differentiation, root growth and improve fruit quality. Winter fertilizer and organic fertilizer were applied mainly in November to benefit trees to survive the winter. fertilization varied with unit yield, such as 74 8-year-old trees per mu, 3000 kg per mu, 1.5kg of pure nitrogen, 1.0kg of pure phosphorus and 1.2kg of pure potassium per year.

(2) Irrigation and drainage

Irrigation in case of drought and drainage in case of waterlogging are important conditions for Ponkan to obtain yield and high yield. It is usually irrigated in the following four periods. First, the first young fruit stage (April to June), when drought occurs, timely irrigation; second, the fruit expansion period (July to August), when the fruit expansion period, drought irrigation is very important; third, the late fruit expansion stage (late August to November), according to the drought, appropriate irrigation. However, attention should be paid to water control before maturity and should not be irrigated more; fourth, during the growth standstill period (from postharvest to March of the following year), irrigation is generally not used, but excessive drought will lead to appropriate irrigation when leaves fall.

Drainage and waterlogging prevention should be carried out in time, especially in the garden where the groundwater level is high and it is not easy to drain, plant in deep trenches and high beds, lower the groundwater level, and remove stagnant water in time to facilitate root growth.

3. Shaping and pruning to promote fruit thinning

In order to promote early fruiting and early high yield, attention should be paid to the shaping of young trees and the cultivation of low trunk and high yield crowns. After that, with the increase of tree age, the branches showed an obvious trend of strong and weak differentiation, the middle and upper branches were strong, and the lower branches were weak, so pruning should be strengthened to maintain a high yield crown for a long time.

Increasing branching angle and short stem pruning were adopted to promote flower bud differentiation and fruiting of young trees. After entering the fruiting stage, especially after the full fruiting period, in order to prevent or reduce the size of the year and improve the appearance and endoplasm of the fruit, it is appropriate to carry out branch thinning, flower thinning and fruit thinning, so as to make the yield moderate and stable, and increase the commercial fruit rate and the first-class fruit rate.

4. Integrated control of diseases and insect pests

There are a lot of diseases and insect pests in Ponkan No. 3, but there are differences in different places. Epidemic areas should do a good job in the prevention and control of Huanglong disease, canker disease and large fruit flies; non-epidemic areas should strictly carry out quarantine and strictly prohibit the introduction of quarantine venereal diseases and insect pests. In addition to quarantine diseases and insect pests, the main diseases and insect pests of Cenozoic No. 3 Ponkan include split skin disease, anthracnose, scab, soot, green mold and so on; the main pests are red spider, yellow spider, leaf moth, leaf roll moth, Phoenix butterfly, aphid, shell beetle, longicorn beetle and so on. Attention should be paid to prevention and control.

The prevention and control of diseases and insect pests should be accurate, timely and thoughtful, use as few chemical pesticides as possible, prohibit highly toxic pesticides, and adopt biological pesticides and comprehensive control, so as to facilitate the production of high-quality and safe mandarins.