How to prevent pomegranate cracking?

How to prevent pomegranate cracking?

Fruit cracking is a common problem in pomegranate production, which can occur from young fruit stage to mature stage, especially 10-15 days before fruit harvest. The cracking rate is generally 3% Mur9% in light years and as high as 30% Murray 75% in heavy years; fruits are perishable after cracking, cannot be kept fresh and stored, and commodity and edible value are reduced or lost, resulting in significant economic losses. The preventive measures are as follows:

1 reasonable pruning. The aim is to improve the ventilation and light transmission conditions in the garden, promote coloring and prevent fruit cracking through pruning. In winter pruning, thinning or retraction of some large cross branches and overlapping branches, adjusting the subordinate relationship of backbone branches at all levels, thinning and retraction of peripheral dense fruiting branches and weak drooping branches, summer pruning, mainly wiping buds, coring and pruning, etc. For those who do not use dense squeeze shoots as early as possible, and timely remove useless overgrown branches, the branches with space can be transformed into fruiting branches by coring and twisting.

2. Orchard cover. In the early stage of fruit growth, covering the tree plate with plastic film or crop straw is beneficial to maintain soil moisture, prevent garden hardening and reduce pomegranate fruit cracking. In addition, planting green manure, legumes or other dwarf cash crops in pomegranate orchards has the same effect.

3. Rational irrigation. Pomegranate irrigation should be based on the principles of small amount, balance, multiple times and proper control. In production, generally, in the period of rapid growth or expansion of young fruit, water is irrigated every 1o~15 day; near the rainy season, gradually increase the number of irrigation, and spray water to the crown every 7 ~ 10 days, in order to increase the air humidity in the garden, wet the pericarp, enhance the adaptability of the pericarp to continuous rain and high humidity, and prevent fruit cracking; before the fruit is about to mature, stop watering.

4. Rational fertilization. Pomegranate trees should be fertilized mainly with organic fertilizer, with sufficient phosphorus and potassium fertilizer and less nitrogen fertilizer as far as possible. During the fruit expansion period, foliar spraying with 0.3% potassium dihydrogen phosphate solution or 0.5% calcium chloride solution is helpful to enhance the pericarp toughness and prevent fruit cracking.

5. Reasonable chemical control. In the middle and later stage of pomegranate fruit development. Spraying the fruit surface with 25 mg / L gibberellin solution can reduce fruit cracking by 30%. In addition, at the calyx depression of pomegranate fruit, sticking a strip of rubber cloth soaked in 10% 30 mg / L gibberellin solution, or spraying 0.3% paclobutrazol solution and 2O~25 mg / kg ethephon solution can also reduce or prevent fruit cracking.

6. Fruit bagging. It is generally carried out in the young fruit stage, and it has the function of disease prevention, insect prevention and fruit cracking prevention. Bagging has a certain cushioning effect on the drastic changes of temperature and humidity, which can protect the pericarp, reduce the burn of the pericarp caused by sunlight during the dry period and the damage of persistent high humidity to the pericarp toughness, so as to prevent fruit cracking. In addition, it is necessary to control fruit borer pests in time.