A Detailed Guide to the Latest Control Methods for Citrus Sunburn

Citrus sunburn, also called sun scald, is a disease that affects citrus fruit as it nears maturity. The main cause is that during the hot summer and autumn seasons, the fruit is exposed to intense direct sunlight, causing the fruit surface temperature to reach above 40 degrees, resulting in sunburn damage. It causes brown lesions to appear on the fruit, which gradually expand, and eventually the rind becomes hard and the flesh becomes lignified, losing its edible value and affecting growers' income. So how should sunburn be prevented and controlled? Let's take a look together.

1. Irrigation to lower temperature

When high temperatures arrive, irrigate and spray the plants promptly. This replenishes the plant's nutrients in time, preventing symptoms of water deficiency caused by excessive transpiration, which would worsen sunburn. At the same time, spraying can lower the surface temperature of the fruit, leaves and branches, preventing drought stress in the tree and allowing it to grow normally.

2. Deep plowing of the orchard soil

Deeply plow the orchard soil beside the plants to a depth of more than 30 cm. This promotes robust root growth in the citrus plants, thereby improving the roots' absorption capacity and range, balancing above-ground and below-ground consumption. This helps nutrients meet the plant's growth needs and reduces the harm caused by sunburn.

3. Spraying lime water or whitewashing

We all know that whitewashing fruit trees in winter helps protect against cold and freezing, but whitewashing citrus plants is also a good method here. The whitewashing should be applied to the middle and upper part of the canopy where sunburn is most likely to occur. For orchards with severe sunburn, you can spray the fruit and canopy surface with 1%-2% lime water to reflect strong light, but be careful with the lime water concentration to avoid phytotoxicity.

4. Bagging or applying paper

Currently in the fruit-growing industry, bagging technology is widely used. It protects fruit from pests and diseases as well as intense light, and improves fruit quality, so bagging young fruit can effectively reduce the harm of sunburn. In addition, there is an even simpler method: applying paper. White paper is mainly used, and generally at the early stage of sunburn occurrence, you just stick the paper on the sun-facing side of the fruit.

5. Growth regulators

When sunburn occurs, you can spray a low concentration of the highly effective plant growth regulator Aiduosho at 5000 times dilution + Huaguosu at 1500 times dilution. This can effectively reduce the severity of sunburn, with good results.

The above is an introduction to the control methods for citrus sunburn. We hope it helps you. If you want to learn more related knowledge, please stay tuned to us.