Why Do Navel Oranges Crack? Detailed Explanation of Causes and Control Methods

Navel orange fruit cracking is a phenomenon in the navel orange cultivation process, mainly occurring during the fruit expansion period. Fruit cracking affects the appearance of navel oranges and, in severe cases, can also affect yield, being directly related to the income of fruit growers. So what are the causes of navel orange fruit cracking? Let's take a look.

I. Causes of Fruit Cracking

1. Climatic Causes

During the high-temperature period in summer and autumn, strong sunlight exposure damages the peel tissue and cells of the fruit. If rain or irrigation then occurs in the soil, the fruit rapidly expands and bursts the peel, resulting in fruit cracking.

2. Thin Peel

Somewhat similar to the climate of prolonged drought followed by rain, when the fruit approaches maturity, the peel becomes thinner and softer. As the sugar content in the flesh increases, the fruit absorbs water and rapidly swells, which can also cause fruit cracking.

3. Improper Fertilization and Watering

If too much phosphorus fertilizer is applied during fertilization, or if there is excessive soil moisture, both can lead to fruit cracking in navel oranges.

4. Variety and Nutrition

There are many varieties of navel orange, and different varieties have different characteristics. Some varieties bloom heavily but have more severe fruit cracking; leaf-only single-fruit varieties are prone to cracking; varieties with a higher proportion of leafless flowers are prone to cracking; varieties with flat fruit shape are prone to cracking, while long-shaped fruit is not prone to cracking; varieties with thinner peel are prone to cracking.

II. Control Measures

1. Select Good Varieties

When planting, choose varieties with a small navel or closed navel, thicker peel, and high round fruit shape, which can reduce fruit cracking.

2. Strengthen Fertilization and Water Management

Apply more organic fertilizer to strengthen tree vigor. During the fruit development period, apply more potassium fertilizer as a fruit-strengthening fertilizer so that the fruit tissue grows robustly. During the navel orange cracking period, spray a nutrient solution containing elements such as nitrogen, phosphorus, potassium, and calcium. In addition, do a good job with drainage and irrigation measures: water promptly during drought, but avoid flood irrigation; drain promptly during the rainy season.

3. Thin Flowers and Fruits

During the flowering and fruiting period, first thin out leafless flowers and fruits, leaf-bearing single fruits, and flat-shaped fruits, then during summer fruit cracking apply gibberellin to coat the fruit. Bagging technology can also be used to control fruit cracking.

The above is an introduction to the causes of navel orange fruit cracking and control methods. We hope it can help you. To learn more related knowledge, please follow us.