Calcium belongs to a group of secondary micro nutrients, along with magnesium and sulfur. This means that plants need large amounts of calcium. Calcium usually is sufficient represented in the soil. Smaller amounts of calcium occurs in soils that have acid reaction and in sandy soils. However, the emergence of a lack of calcium binds exclusively with smaller amounts of calcium in the soil, but also with his insolubility or unavailable to plants. The emergence of insoluble forms of calcium is common in soils rich with phosphorus, who creates insoluble calcium compounds. The availability of calcium is associated with abundant fertilization with potassium and magnesium fertilizers. If all this is linked with poor mobility of calcium in the plant, particularly in terms of lack of water or in circumstances where there is a strong increase of transpiration, it is clear that the lack of calcium can occur in conditions of soils that are well provided with this item. Calcium, which is adopted by the root is transported through xylem in the leaves and in the initial stages of development of the fruit. The transport of calcium in the fruit goes through phloem, in which calcium is slightly mobile. Therefore, deficiency symptoms of calcium appear on fruits which affects their appearance and quality and cause significant economic damage. That;s why in literature calcium is often associated with the quality of the fruit.
The lack of calcium causes various symptoms in different cultures. Here is the most common occurrence of lack of calcium in the tomatoes and peppers which causes rot at the top of the fruit, at the apples which causes bitter fruit stains, in cabbage cultures causes the chapter that is closed and non-compact , with lettuce, which results in rotting of the tops of the leaves and more. It is believed that the lack of calcium in apples is associated with the proportion with nitrogen, potassium and magnesium. During the harvest ratio of nitrogen to potassium should be 10: 1 and the ratio of potassium to calcium is not less than 2.25:1. A good indicator is the ratio of the sum of the potassium and magnesium against calcium which, if greater than 40 indicates the lack of calcium in the fruit of apples. Good availability of calcium in the fruit of apples (and other fruit species) is important prerequisite for successful storage in warehouses.
Due to damage to fruit which is caused by lack of calcium, it is necessary to take preventive measures to eliminate this phenomenon and to recognize the early symptoms of deficiency.
In general, the lack of calcium occurs in the parts of the plants that grow vigorously and which can not pass the required amounts of calcium. Therefore, the early symptoms of the deficiency of calcium occurring in younger parts of the plant such as chlorosis or soft appearance of necrotic tissue.
In case of lack of calcium is necessary to perform the treatment with calcium fertilizers through with tem-drip or foliar treatment in which calcium enters directly into leaves. It should be taken to include the young (top) parts of the plant where the lack of calcium is most strongly expressed. As best selection of calcium garbage recommended calcium nitrate. For its proper application, dose and concentration in different crops, contact an expert Advisory Team HORTICENTAR.