Apple

1. Nutritional characteristics

The growth period of new shoots (mid to late May) is the key period of apple annual cycle management. During this period, apple leaves develop rapidly and fruit begins to enter the first expansion period, which is also the critical period of water; Entering the flower bud differentiation stage (mid-June), new shoots and fruits grow slowly, roots grow rapidly, and carbohydrates accumulate rapidly in the tree, requiring the growth of new shoots in a rhythm. Cultivation should control the growth of trees and ensure the supply of nutrients. From mid-July to fruit maturity is the fruit expansion period, which is the key period for the formation of yield, requiring continuous supply of nutrients and water to maintain leaf function and ensure the nutrients and water required for fruit expansion.

2, need fertilizer characteristics

During the entire growth period of apples, the amount and proportion of nitrogen, phosphorus and potassium required vary according to soil, climate, varieties and planting methods. For every 1000 kg of apples, pure nitrogen (N) is 4 ~ 7 kg, phosphorus (P2O5) 2 ~ 3.5 kg, and potassium (K2O) 4 ~ 7 kg.

The main nutrients needed by young apple trees are nitrogen and phosphorus, especially phosphorus has a good effect on the growth and development of plant roots. The establishment of a good root structure is the premise of a good crown structure and robust growth of apple. The nutrient demand of adult fruit trees is mainly nitrogen and potassium, especially because the harvest of fruit takes away a lot of nitrogen and potassium and many other nutrients, if not timely supplement will seriously affect the growth and yield of apple trees in the next year.

There is demand for calcium, magnesium, boron, zinc and other medium and trace elements in the whole growth period of apple. For example, calcium supplement can improve fruit hardness, increase fruit weight and reduce physiological calcium deficiency. Magnesium supplementation can promote green leaves, reduce yellow leaf decay, and facilitate photosynthesis and fruit expansion. (Taken from the network, if there is infringement, please contact to delete.)

3. Fertilization technology

It is recommended to apply special formula fertilizer (15-18-10), and the application amount of young trees is 1 ~ 2 kg; The application amount of adult trees is 2 ~ 4 kg per plant. Winter fertilizer (or spring fertilizer) and strong fruit fertilizer are applied according to 60% and 40% of the total fertilizer.

Ditch or hole application along the drip line of the tree crown, the depth of fertilization is 20 ~ 40 cm, and the soil is covered. They can also spread and turn the soil.