Unlike other fruit trees, citrus trees have no obvious dormancy period, and the picking season is in winter, and winter is the period of citrus flower bud differentiation. The number of flower bud differentiation and quality are directly related to the next year’s fruit yield and quality. Fertilization management in the field in winter is a very important part of the management throughout the year, directly related to the tree vigor and yield in the following year.

1 pruning

The pruning of citrus trees should be based on factors such as the season, variety characteristics, tree age, and other factors. When pruning takes the main branch as a unit, from bottom to top, from the inside to the outside, first cut the big branches, then cut the small branches, cut the dry and dead branches first, the branches with heavy diseases and insects, the overlapping hidden branches, the large branches with few leaves, and the decline results after the cut Branch groups and twigs, after pruning, make the crown of the tree staggered, the inside of the crown is full of light, and the inside and outside, up and down can bear fruit.

2 fertilizing

Fertilization after citrus fruit picking is also called overwintering fertilizer, base fertilizer, yang fertilizer, and confinement fertilizer. The best time to apply basal fertilizer is from late autumn to early winter. In the process of citrus fertilization management, it is necessary to apply fertilizer scientifically in combination with specific varieties. For early-maturing varieties, winter fertilizer needs to be applied after fruit picking, while late-maturing varieties need to apply winter fertilizer within a week before harvesting. The advantage of early application is that it can effectively prevent the citrus fruit from turning green. In the process of winter fertilizer application, the low temperature will affect the fertilizer absorption capacity of citrus fruit trees. Therefore, to analyze the composition of winter fertilizer, it should include phosphate fertilizer, organic fertilizer, nitrogen fertilizer, potash fertilizer, etc., and mainly phosphate fertilizer and organic fertilizer. The application amount of organic fertilizer should be more than half of the total amount. Decomposed pig manure or commercial organic fertilizer can be used, while the application amount of phosphate fertilizer and potash fertilizer should be 35% of the total amount. The amount of nitrogen fertilizer should be 30% of the total amount.

It is recommended that for orchards with a yield of more than 3000kg per mu, the base fertilizer should be no less than 4000kg of decomposed organic fertilizer before and after fruit picking in November to December, with a compound fertilizer (such as Huaqiang MAINPAR 13-8-24S or YANGJIA15-15-15, etc.) 40-50kg ; For orchards with a yield of 1500~3000kg per mu, 3000~4000kg per mu of decomposed organic fertilizer shall be applied before and after fruit picking from November to December, together with high-nitrogen or general-purpose compound fertilizers (such as Huaqiang MAINPAR13-8-24S or YAGNJIA15-15-15) Etc.) 30~40kg.

3 Clear Garden

  It is more important to clear the garden in winter, because the sources of diseases and insects that harm citrus are all overwintering in litter, weeds, and fruit drops. Therefore, it is necessary to carry out a complete orchard clearing, promptly remove all diseased branches, dry branches, fallen leaves, fallen fruits, and weeds out of the orchard, burn them or bury them deeply, spray bactericidal insecticides on the canopy and ground surface, and turn the soil deeply. , Freezing to death or being pecked by birds, reducing the number of pests in the coming year.

4 Drought and frost resistance

The freezing damage of citrus is the "dry death" of cells due to physiological water loss, so the wilting, litter and other behaviors after freezing are similar to drought damage. The clearing after freezing will aggravate the occurrence of freezing damage, which will have a great impact on the citrus tree body and the next year's yield. It is recommended to take the following measures to prevent:

First, we must deepen the soil, expand the hole and bury the fertilizer, and cultivate a deep and long developed root system. This is also the key to improving cold resistance, and strengthening the prevention and control of plant diseases and insect pests to control shoot shoots in late autumn.

Second, cultivate the soil to thicken the soil layer and increase the soil temperature. Cultivate soil before winter to cover the part above the root neck, and plow and plow in spring. For irrigation before freezing, the latent heat of the water can be used to increase the soil temperature by 2~4 ℃.

Third, the branches are painted white. The whitening agent is usually prepared with lime 5 kg, sulfur powder 0.5 kg (or lime sulfur mixture), table salt 0.1 kg, animal and vegetable oils 0.1 to 0.2 kg, and water 15 to 20 kg. For young trees that have been planted for 1~2 years, the whole plant can be used for scaffolding, and the straws can be used for wrapping. The south side is open for light to prevent falling leaves, and the straws are opened in spring.

Fourth, smoke. Using smoke to create clouds can effectively reduce radiation heat and reduce frost. For every 667 m2, 4~5 piles of weeds, branches, leaves, straws, etc. can be used, and smoke will be produced in the early morning.

Fifth, shake the snow in time after heavy snowfall to prevent the snow from crushing the broken branches and damaging the tree crown. If there is icing, gently shake the tree with a stick, which may damage the tree and cause broken branches and leaves.