Calcium plays a role in balancing physiological functions in the body during the growth of fruit trees. It can improve the growth and development of fruit trees, achieve good flowering and fruit setting, and effectively prevent various physiological diseases such as black spot caused by calcium deficiency.
In the absence of calcium, the root growth of fruit trees is significantly inhibited. The roots are short and numerous, grayish-yellow in color, with sticky cell walls, and the cells at the root extensions are damaged or even partially rotted. The tips of young leaves become hook-shaped and dark green, and the new leaves die quickly. Flowers shrink, and stone fruit trees are prone to gum disease and root cancer.
Calcium does not flow easily within the tree, and old leaves contain more calcium than new leaves. Sometimes the leaves are not deficient in calcium, but the fruits are.
There are three peak periods for calcium absorption by fruit trees:
- The first time, about 20-30 days after the flowers fall, about 30% of calcium can be accumulated during this period;
- The second time is the fruit expansion stage, which can absorb about 50% of the total calcium;
- The third time is about 20-30 days before picking the fruit. The calcium absorbed during this period can meet the calcium needs of the fruit tree growth in the next spring as much as possible.
While adding sufficient organic fertilizer to orchards to promote the absorption and utilization of calcium by fruit trees, it is recommended to supplement calcium outside the roots during the three peak periods of calcium absorption to improve calcium concentration and application quality.
Why are fruit trees deficient in calcium? The main reasons are:
- With the expansion of commercial crop planting area, the demand for calcium by crops increases. For example, the average calcium demand of fruit and vegetable crops is generally about 5 times that of wheat. The amount of calcium absorbed exceeds the demand for phosphorus. Some crops even exceed the demand for nitrogen, ranking among the top three.
- For a long time, heavy nitrogen, phosphorus, and potassium fertilizers were used, and pay no attention to supplementing calcium fertilizers, and the available calcium content of the soil decreased. In some soils, due to improper management, such as soil acidification, the availability of calcium decreases, resulting in a decrease in calcium content.
- Unreasonable fertilization measures affect the absorption of calcium by crops.
How to effectively supplement calcium for fruit trees?
Calcium is an essential nutrient for fruit trees. Lack of calcium nutrition will lead to reduced resistance and poor growth of fruit trees. In severe cases, some special physiological problems may even occur, resulting in reduced yield and quality of fruit trees. Therefore, it is necessary to supplement calcium to fruit trees as early as possible.
The correct method of calcium fertilizers supplementation
The correct method of calcium supplementation is a combination of soil application of calcium fertilizer and foliar spraying of calcium fertilizers. Applying calcium fertilizer to the soil is the most important and important measure for calcium supplementation.
There are many types of calcium fertilizers for soil, such as superphosphate, gypsum, calcium magnesium phosphate fertilizer, etc. In addition to adjusting the acidity of the soil, applying quicklime to acidic soil also has the function of supplementing calcium. Significantly increases the content of available calcium in the soil, and also has the effect of improving acidic soil and compacted soil. Generally, applying 40-60 kilograms per acre can improve the soil and provide long-term calcium supplementation.
When supplementing foliar calcium fertilizers(calcium ammonium nitrate, calcium nitrate, calcium magensium nitrate), pay attention to selecting varieties with good absorption effects and a reasonable fertilization period. Fruit trees have a very high demand for calcium during the flowering and fruiting stage. It is the most critical period for calcium supplementation. Therefore, the spraying of calcium fertilizers start before flowering, and should be replenished in time from the young fruit stage to the picking stage, and sprayed 3-5 times continuously.
Since the mobility of calcium in plants is very poor, when spraying calcium fertilizer on the leaves, pay attention to spraying the calcium fertilizer on the fruits and leaves adjacent to the fruits. The choice of calcium fertilizer is mainly based on chelated calcium nutrition(EDTA-Ca).
How to achieve the best calcium fertilizers supplement effect？
In addition to supplementing calcium during the three important periods of fruit trees, pay the following points to achieve the best calcium supplement effect.
- Control and adjust soil pH to maintain it between 5-7. Because the pH value between 5-7 is the optimal pH value for crops to absorb nutrients.
- Combine soil calcium fertilizer with foliar calcium spray. When applying base fertilizer, use dcalcium fertilizer. It is beneficial to tree storage and greatly reduces the symptoms of calcium deficiency in fruit trees in the coming year. During the foliar spraying of calcium, spray three times continuously after flowering to achieve the ideal calcium supplementation effect.
Fruit tree management is very important. After bagging, if it is cloudy and rainy for 3 to 5 consecutive days, ventilate in time and spray calcium once to reduce the symptoms of calcium deficiency caused by continuous calcium application and large consumption of calcium fertilizers in fruit trees. Cloudy and rainy days. The amount of nitrogen fertilizer must be reasonable, as too much nitrogen fertilizer can lead to severe calcium deficiency. In particular, it is forbidden to apply nitrogen fertilizer 20 days before picking, which will greatly improve the quality of the fruit.
