How to grow citrus?

In the long-term production practice, through continuous accumulation and improvement, a set of very practical traditional citrus cultivation techniques has been formed. With the development of the times, the cultivation technology of citrus also keeps pace with the times, especially the large-scale development of citrus in mountainous areas, which has injected new content into the cultivation technology of citrus.

1. Soil, fertilizer and water management

(1) Soil management The main soil management work of Ogan Orchard in the plain area includes intertillage weeding, interplanting, tree covering and exotic soil. The main soil management work of mountain orange orchard includes: intertillage weeding, interplanting green manure, orchard covering, deep ploughing and soil improvement. Intertillage weeding is generally combined with fertilization, and the principle of "deep in winter and shallow in spring and scraping in summer" should be followed in plain citrus orchards, that is to say, intertillage should be shallow in spring and summer (5 ~ 10 cm) to prevent excessive root damage, and intertillage can be deeper in winter (10 ~15 cm). When weeding in intertillage in plain Ougan Orchard, furrow should be dug to cultivate soil. After intertillage weeding, the orchard should be covered to reduce soil moisture evaporation. The covering materials can be local materials, weeds and green manure, and the covering thickness is 10 ~ 15 cm, which is about 5 cm away from the trunk. In the future, every time fertilization is combined with tillage, the plastic film is removed first, and then covered after the operation is completed; In winter, the plastic film is buried in the soil, combined with deep tillage. Intercropping dwarf crops in young citrus orchard can not only increase income, but also improve soil fertility. It is best to interplant Indian cowpea, alfalfa, arrowroot pea and other green manure in mountain orchards, and interplant vegetables and green manure in plain orchards. In the rainy season of spring and early summer, plain citrus orchards are generally not covered with trees to prevent roots from rotting due to excessive soil moisture. However, in summer drought and autumn drought, the tree tray should be covered with local materials, such as weeds, crop straws, water lilies, green duckweed, manure and so on. , the thickness is about 1o ~ 15cm, and the distance from the trunk is about 5cm. Plain Ogan Orchard has a good habit of digging pond mud (river mud) to fertilize the orchard in winter, which should be adhered to every year.

(2) Citrus fertilization is generally combined with intertillage, with organic fertilizer as the main factor and chemical fertilizer as the supplement. Shallow furrow fertilization is used in growing season and deep furrow fertilization is used in winter. Young trees should apply thin fertilizer frequently, mainly nitrogen fertilizer, with phosphorus and potassium fertilizer; Apply 1 time every time before new shoots germinate/kloc-0 ~ 1 5 days, apply 1 time again when leaves turn green, apply1time in winter, and apply fertilizer to soil for 7 times throughout the year; At the same time, combined with pest control, topdressing outside the roots. The amount of fertilizer applied to each young tree at one time is 2-3kg of 30% decomposed dilute human excrement and urine, 25-75g of urea or 50-100g of ternary compound fertilizer. Results Fertilization was carried out 4 ~ 5 times a year, and topdressing outside the roots was combined with pest control. From late February to mid-March, apply spring fertilizer (germination fertilizer) in shallow ditch, and apply 25 kg of 30% decomposed rare human manure, 0.25-0.5 kg of urea or 0.25-0.5 kg of ternary compound fertilizer to each plant; From late May to late June, apply summer fertilizer (fruit-strengthening fertilizer) in shallow ditch, and apply 25 kg of 20% ~ 30% decomposed human manure to each plant, and add 0.25 ~ 0.5 kg of urea or 0.25 ~ 0.5 kg of ternary compound fertilizer; Autumn fertilizer combined with drought-resistant watering 10 from the first ten days of August to the first ten days of October 1 time per month, with 30% ~ 40% decomposed dilute human manure 10 kg per plant and 0.25 kg urea or 0.25 kg ternary compound fertilizer each time; Top dressing should be done in deep furrow within 0/5 days after fruit harvesting. Each plant should be applied with 50% decomposed human manure15 ~ 20kg, high-quality decomposed manure10kg, decomposed cake fertilizer 3kg and ternary compound fertilizer 0.25 ~ 0.5kg..

Topdressing outside citrus roots can be sprayed alone or combined with pesticides to control pests and diseases. The total concentration should not exceed 0.3%. Fertilizers include borax, boric acid, zinc sulfate, urea, potassium dihydrogen phosphate, etc.

(3) Water management The citrus orchards in mountainous areas should be irrigated in time in dry season and bud stage. Water accumulation should be eliminated in time in rainy season, and irrigation should be done well in summer drought and autumn drought.

prune

Citrus can branch in spring, summer and autumn three times a year, and all of them can develop into fruiting branches. In the natural growth state, the fruiting mother branches of summer shoots account for 54%, most of which are clustered, with an average length of 465,438 0.3 cm, generally between 40 and 50 cm, and the length can reach more than 90 cm; The fruiting branches of spring shoots accounted for 46%, and those of autumn shoots accounted for 46%, with an average length of 15 cm. No matter spring shoots, autumn shoots or summer shoots can bear fruit, and the fruit mainly grows on the upper part of the fruiting mother. According to the investigation, the proportion of the upper part of the branch is 77.8%, the middle part is 18.5%, and the lower part is 3.7%. Due to overgrowth, the average number of mother branches is 65,438 0.9, and its new shoots are short and slender, with an average length of 5.3 cm, and the leaves become smaller, and the proportion of weak branches accounts for 22.8% of the total new shoots. Weak branches are mainly concentrated in the middle and lower parts, with 3.6% in the upper part, 765,438+0.4% in the middle part and 25% in the lower part. There is a phenomenon that the top fruiting branches and fruits are concentrated, the middle and lower parts are empty, and the fruiting part moves outward. If only pruning methods such as thinning weak branches, dead branches, pests and diseases are used, the yield and fruit quality are not bad at first, but after 3 ~ 4 years, the fruiting parts move outward and the inner cavity is empty, and the annual fruiting rate is 27%.

In view of the characteristics of Mandarin orange, such as many summer shoots, many mother branches, good early fruiting, high yield, easy empty fruiting chamber, fast outward movement of fruiting parts and obvious fruiting in different years, the pruning principles of Mandarin orange are as follows: young mandarin orange trees use the characteristics of large growth of summer shoots, select 3-4 summer shoots with reasonable branching angle and position, slowly release them first, and then cut them lightly and cut them short to cultivate them into main branches; Erase the erect shoots as soon as possible, so as not to grow branches in the future and disturb the tree shape; Too dense spring shoots, summer shoots and autumn shoots should also be smoothed as soon as they sprout; For other spring shoots, summer shoots and autumn shoots with reasonable planting positions, coring should be carried out. Generally, when the stem tip is 10 ~ 15 cm, it should be cultivated into fruiting branches; When the length of the main branch is 1.5 m, select 1 oblique summer shoot on the main branch and cultivate it into the first auxiliary branch; According to the planting density, the second main branch can be planted on the opposite side of the first main branch; When the whole tree has 150 robust top branches, it can bear fruit for the first time. After the citrus bears fruit, the main task of pruning is to continue to expand the crown, reach the highest production capacity as soon as possible, and prevent the fruiting parts from moving out, the inner cavity is empty, and the phenomenon of small-year fruiting occurs; The main pruning methods are budding, coring, short cutting and thinning.

3. Sparse flowers and protect fruits

Citrus is easy to blossom, with a large amount of flowers, and long branches can also differentiate into fruiting mother branches. Small trees also have many flowers. If it doesn't bear fruit, it should be completely thinned in bud stage to reduce the consumption of nutrients. For citrus fruit trees with excessive flowers, moderate pruning at bud stage and cutting off excessive buds will play a certain role in reducing nutrient consumption, promoting new shoots and maintaining tree vigor.

For fruit trees with too strong growth potential, measures can be taken to protect the fruit, such as controlling new shoots, cutting large and medium-sized fruit branches, spraying borax (or boric acid) before flowering, and spraying 50 ppm gibberellin when two-thirds of the flowers wither. For fruit trees with weak growth potential, spraying mixed solution of 0. 1% potassium dihydrogen phosphate, 0. 1% urea and 0. 1% borax before flowering, and spraying 50 ppm gibberellin when two thirds of the flowers wither can effectively improve the fruit setting rate. For citrus orchards that are seriously damaged by red spiders and aphids, thorough control 1 ~ 2 times before flowering and 1 ~ 2 times after flowering can effectively prevent abnormal flower and fruit drop caused by insect pests.

4. Pest control

There are many diseases and insect pests in citrus, and the main diseases are scab, anthracnose, resin disease, Huanglongbing and so on. The main pests are red spider, rust tick, leaf miner, leaf curl moth, butterfly, longicorn beetle, whitefly, scarab, aphid, scale insect and so on.