Analysis of the Causes of Citrus Fruit Cracking and Its Prevention and Control Techniques

China is a major citrus-growing country, and whenever citrus ripens for harvest, fruit cracking is extremely prone to occur, with the cracking rate reaching over 40% in severe cases, seriously affecting the economic returns of fruit growers. So what causes citrus fruit cracking? How should it be prevented and controlled? Let's take a look at the detailed introduction below.

1. Variety-related causes

The fruit cracking rate varies greatly among citrus varieties, and it is closely related to how tightly the peel wraps the fruit, the thickness of the peel, and the fruit shape. Generally, varieties whose peel wraps tightly, whose peel is thicker, and whose fruit shape is oblong are not prone to cracking; conversely, varieties whose peel wraps loosely, whose peel is thinner, and whose fruit shape is flat and elongated are prone to cracking, and the flatter the fruit shape, the more prone it is to cracking. Therefore, when planting, be sure to choose varieties with a low cracking rate to cultivate and plant, so as to reduce the cracking rate and increase returns.

2. Climatic effects

Fruit cracking is also a gradual process: at first the outer layer of the peel cracks, then the cells gradually deform and rupture from the outside inward, and finally the peel splits open. It generally occurs during the fruit's expansion stage and ripening stage. If the climate at this time features a long drought followed by rain, it will cause the flesh to grow faster than the peel during fruit expansion, directly bursting the peel open. In addition, during fruit growth and development, the fruit is affected by water content; in hot, dry weather, the peel's cellular tissue stops growing, and once heavy rain or heavy irrigation occurs, it causes turgor pressure in the flesh tissue and results in fruit cracking. Therefore, pay attention to climate changes: water frequently during droughts to keep the soil moist, so as to avoid cracking caused by a long drought followed by rain; and under rainy-season conditions with abundant rainfall, take good drainage measures to avoid cracking caused by the fruit absorbing too much water.

3. Nutrient deficiency

During the early development of the fruit, due to insufficient nutrients, the peel cells divide and water is lost, which causes the peel to continuously expand and become thinner during fruit expansion, making it highly prone to cracking. If planting lacks nutrients such as calcium and boron, the peel's toughness will be reduced, so that during fruit expansion it cannot withstand the turgor pressure and cracking occurs. In addition, during fruit expansion, applying excessive nitrogen fertilizer will cause the fruit to absorb too much fertilizer and water in a short period, causing the flesh to expand rapidly and resulting in a large amount of fruit cracking.

4. Pests and diseases

There are many pests and diseases of citrus, and the diseases that can cause fruit cracking include sunscald, citrus canker, stink bugs, mites, and so on; when they occur, they aggravate fruit cracking. Therefore, attention must be paid to the prevention and control of pests and diseases: apply more organic fertilizer to enhance the plant's disease resistance, and when pests and diseases are found, control them promptly to prevent the condition from worsening.

The above is an introduction to the causes of citrus fruit cracking and prevention and control techniques. I hope it can help you. To learn more related knowledge, please follow us.