Cultivation Techniques for High and Stable Yield of Loquat in South China

Planting techniques for High and stable yield of Loquat in South China

Loquat can grow normally when the annual average temperature is more than 12 ℃, but the annual average temperature should be 15-17 ℃ in economic cultivation, and there is no severe cold weather. When the temperature is-6 ℃, it will cause freezing damage to flowering and-3 ℃ to young fruit, and about 20 ℃ is the most suitable for pollen germination. Too high temperature is not suitable for loquat growth, more than 35 ℃ affects seedling growth, fruit development, but also prone to sunburn.

Loquat grows rapidly and bears early. Grafted seedlings begin to bear fruit 2-3 years after planting and seedlings begin to bear fruit 4-5 years. Loquat yields begin to flourish in 8-10 years, decline gradually after 30 years, and decay after 40-50 years. If it is well managed, its economic life can be greatly prolonged, and the old trees of more than 100 years can still be fruitful.

1 Garden site selection

Loquat likes the environment where the air is moist, the water is abundant, and the light is not too strong. The garden should choose the south and southeast gentle hillside, and the north slope is also suitable in the area without frost damage. If cultivated in flat land, it is necessary to prevent stagnant water rotting roots, pier or dig deep ditches before planting, to do a good job of drainage. Loquat is not strict in soil selection and can generally grow and bear fruit normally. The gravelly soil with deep soil layer, loose and fertile soil and rich in organic matter is the best.

2 planting

There are mainly two kinds of loquat seedlings: sowing and grafting. The method of sowing and raising seedlings is simple, but the result is late and the variability is large after planting. Promote the use of grafted seedlings in production (figure 1)

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2.1 planting distance

The row spacing of loquat planting is generally 3 m × 3.5 m, 64 plants per mu, sparse planting on flat land, 3 m × 4 m, 56 plants per mu.

2.2 planting time

Loquat can be planted in both spring and autumn, and it is better to plant in spring before spring shoots germinate, that is, from December to February of the following year, and after spring shoots are enriched, before summer shoots germinate, that is, 3mi can also be planted in April. It is suitable to plant in spring in the mountainous areas where there is a lack of water. Autumn is usually planted in October.

2.3 planting methods

2-3 months before planting, dig planting holes with a depth of 60 cm, mouth width of 80 cm and bottom width of 70 cm, and pile the topsoil and subsoil separately at the same time. The bottom layer of each planting pit is supplemented by a layer of green manure,

Fig. 1 Loquat tree after 2 years of grafting (planted in the base)

Straw; each hole in the middle layer was evenly filled with topsoil and 30 kg farm manure + 0.7 kg calcium, magnesium and phosphorus, and then all the original subsoil was backfilled. The backfilling work must be completed 2 months before planting so that the base fertilizer is fully mature and the fill is solid. After returning to the acupoint for 2 months, plant in cloudy days or sunny days after rain. Planting layer with ripe soil, planting seedlings need to take more whisker roots and attached soil, in order to survive, the root can not contact fertilizer, should not be planted deep, it is appropriate to cover the soil to the root neck, compaction soil, pier, trim the tree plate. Planting seedlings should cut off some leaves and twigs to reduce evaporation. Pour enough water to fix the root, and then cover a layer of fine soil after the water seeps down.

3Water and fertilizer management

3.1 Water management

Loquat most avoid stagnant water in the garden, especially in the fruit ripening period, if Rain Water is too much, it is easy to cause fruit cracking and rotten fruit, so it should be drained in time. If too dry, strong sun, it is easy to burn the fruit, at this time should be irrigated or sprayed. Proper drought in summer is beneficial to flower bud differentiation. On the other hand, the drought in autumn and winter is easy to cause defoliation, affect the tree potential, reduce the ear of flowers and blossom earlier, so we should pay attention to irrigation or cover the tree plate to moisturize.

3.2 fertilization

Loquat leaves grow in luxuriant flowers and grow in four seasons, and the growth peaks of root system and branch shoot are carried out alternately. Generally, the growth peak of root system is about 2 weeks earlier than that of branch shoot, and there are 3 or 4 growth peaks a year. It needs a lot of fertilizer. Fertilization should be carried out according to the characteristics of root and shoot growth.

3.2.1 Fertilizer amount and fertilization methods in young orchards, the principle of thin application should be adopted in young orchards, mainly nitrogen and phosphorus, to promote the vegetative growth of shoots and rapidly expand the crown.

The first fertilizer was applied from planting to sprouting 2cm, urea 411g, diammonium phosphate 6g, mature human feces 4kg / plant. Once every 15-20 days, promote spring and summer shoots. After applying fertilizer for 4 times, topdressing was suspended and water was controlled to promote flower bud differentiation. 9 Mel topdressing again in November. In the second year, topdressing was applied once in February, March, May, September and November, with 50 grams of urea per plant, 612 kilograms of feces and urine of mature acquaintances, 100 grams of superphosphate in February and November, and 60 grams of potassium sulfate in March. Fertilizing 4 times in the third year, fertilizing once in early March, late May, late September and late November respectively, applying 70 grams of urea per plant, 815 kilograms of feces and urine of mature people, 65 grams of potassium sulfate in early March and 110 grams of superphosphate in late November.

3.2.2 Fertilizer amount and methods in adulthood

Loquat shoots have four shoot peaks a year, mainly in spring, summer and autumn, while summer shoots and spring shoots are the main fruiting mother branches, so the cultivation of excellent summer and spring shoots is the key to high yield. Therefore, the adult orchard (after 3 years) can be fertilized three times a year.

The first application of spring shoot fertilizer was applied in the early and middle of February, when the root system was in the first growth peak, which was convenient for nutrient absorption, and fertilization could promote spring shoot and increase fruit. The second application of summer shoot fertilizer

It was applied after fruit harvest from mid-May to early June (late-maturing varieties were applied before fruit harvest), which was the second peak of root growth, which mainly promoted summer shoots and flower bud differentiation in August. The third application of autumn fertilizer (pre-flowering fertilizer), mostly from September to early October, after heading to before flowering, mainly promote good flowering, improve fruit setting, and increase the ability of cold prevention and overwintering.

(4) thinning flowers and fruits

Loquat has many flowers and fruits (Fig. 2 and Fig. 3). Thinning flowers and fruits can reduce nutrient consumption and adjust the ratio of vegetative branches to flowering branches, which is conducive to high yield, increase fruit, improve fruit quality and consistent ripening period.

Fig. 2 Loquat flower

Fig. 3 bagged mature loquat

4.1 Flower thinning

Generally speaking, the time of flower ear thinning in loquat is obviously visible, but it is the most suitable when it has not yet bloomed. If the flower is thinned too early, it is easy to have two flower ears and need to be thinned again. In areas with frost damage in winter, fruit thinning can be carried out at the same time in spring.

The number and method of thinning spikes vary according to tree age, tree potential and variety. First of all, the flowers and ears with few leaves, poor development and harmful diseases and insect pests should be thinned out, according to the principles of leaving the outside and staying inside, leaving late and staying early, and leaving the weak and the strong. In general, young trees and weak trees are more sparse, strong trees and full-fruiting trees are less sparse; 4 ears on one branch is 1 ear 2 ears, 5 ears 2 ears, and large fruit-shaped varieties are more sparse. In addition, we should leave more flowers on the central branch of early heading and less on the extended branch of late heading, so as to make the fruit mature in the same period.

4.2 thinning fruit

The fruit thinning time of loquat should usually be carried out when the inflorescences are exhausted and the young fruit is the size of broad bean. Areas with frost damage should be able to identify cold jelly fruit.

Fruit thinning method and quantity: first thinning part = dividing too many ears, and then thinning fruit grains, removing diseases and insect pests, frozen fruit, deformed fruit, small fruit, too dense fruit. The number of fruits per panicle depends on the variety, tree age, growth, and the number of leaves. Strong trees, strong branches and fruiting branches with a large number of leaves remain more, and vice versa. Generally, there are 7-8 big spikes and 4-5 spikelets, and the varieties of large fruits are appropriately reduced by 1 big 3. In addition, pay attention to the selection of young fruits of the same size and in the middle of the ear, the fruit should not be crowded between the fruit and the fruit, and the branches should not touch each other. The fruit hidden in the leaves as far as possible can prevent sunburn and facilitate bagging (figure 3) and harvest.

(5) Disease and pest control

5.1 Disease control

The common diseases of loquat are physiological diseases.

(mainly: sunburn, leaf tip scorch blight, fruit cracking, purple spot, etc.) and infectious diseases (mainly: trunk rot, flax color spot, leaf spot, white feather, anthrax, etc.).

5.1.1 physiological disease control measures physiological diseases can be prevented by breeding disease-resistant varieties, strengthening water and fertilizer management, bagging and other measures. Fruit cracking disease can also be extra-root topdressing, such as spraying 0.2% (mass fraction) of urea, borax or potassium dihydrogen phosphate, and spraying 0.1% ethephon [Yoshama Huayao] during the green period.

5.1.2 Control measures for infectious diseases

The main measures of infectious diseases are as follows: (1) strengthen the management of water, fertilizer and soil, enhance the tree potential and improve the disease resistance; (2) prune, clear the garden, cut off the diseased leaves in time, scrape the diseased skin, dig out the diseased plants, and reduce the source of the disease. (3) use medicine in time after the disease is found. The diseased skin of tree trunk rot should be scraped in time, then scrubbed with 1 ∶ 4 pure alkali water, and then coated with Bordeaux solution to heal the wound; flax color spot can be sprayed 2 times three times with 70% methyl topiramate 800 × 1000 times; leaf spot disease can be controlled with 50% carbendazim 800 × 1000 times; 320 grams of 70% methyl topiramate can be used around the trunk of each diseased tree to control white stripe feather; anthracnose can be controlled with methyl topiramate 1000 times.

5.2 Pest control

The main insect pests of loquat are: loquat yellow caterpillar, pear insectivorous insect, boat worm, leopard bark moth and so on. Control methods: in addition to manual hunting and trapping by insecticidal lamps, pesticides can also be used to control all kinds of insect pests. Control loquat yellow caterpillar with 40% dimethoate 1000 times or 80% dichlorvos 800 times, spray imidacloprid 800 times to kill pear carnivores in March, select 50% dichlorvos 800 times or 90% trichlorfon 1000 times to kill navicular caterpillars. 80% trichlorfon 10 ~ 30 times solution into the wormhole, external application of yellow mud to control leopard bark moth.