What causes citrus fruit to turn green again during the color-change period? How to prevent it

It is now the season when citrus fruits ripen and hit the market, but at this time a phenomenon that gives fruit growers a headache appears——citrus fruit turning green again. Citrus fruit turning green again seriously affects the quality of the fruit, not only damaging its appearance but also reducing its sweetness, which has a fairly big impact on growers' income. So what causes citrus fruit to turn green again at harvest? Let's find out together.

I. Causes of citrus fruit turning green again

1. Weather

Low temperatures help the accumulation of sugars and anthocyanins in the fruit, thereby promoting color change, but if abnormal warming weather occurs during the color-change period, the not-yet-fully-ripened peel will resume synthesizing chlorophyll, resulting in the phenomenon of turning green again.

2. Poor tree vigor

For fruit trees with poor vigor, the nutrients synthesized through leaf photosynthesis are limited, and the minerals absorbed by the roots are also insufficient, unable to meet the needs of fruit growth, so the fruit changes color early and shows false ripening. After nutrients are supplemented later through root fertilization and foliar spraying, the fruit will briefly turn green again.

3. Excessive nitrogen fertilizer

When foliar fertilizer with too high a nitrogen content is sprayed during the citrus color-change period, the excess nitrogen reacts with the sugars in the fruit to form organic nitrogen, thereby reducing the sugar content in the fruit, causing vigorous growth of branches and leaves that competes with fruit growth and development for nutrients, leading to a decline in citrus fruit quality; the anthocyanin content in the peel also decreases, resulting in the phenomenon of turning green again.

II. How to prevent citrus fruit from turning green again?

1. Adjust tree vigor

Proper pruning should be used to strengthen tree vigor and avoid decline in tree vigor and leaf yellowing, which cause the fruit to remain unripe. Many fruit growers spray paclobutrazol during the color-change period, which generally does not cause the fruit to turn green again, but if a large amount of high-concentration paclobutrazol is sprayed when tree vigor is weak, it will make tree vigor even weaker and thus cause the fruit to turn green again.

2. Fertilizer use

When fertilizing during the fruit color-change period, unless tree vigor is too poor and leaf color has faded severely, root fertilization is generally not advisable. It is recommended to start by supplementing nutrients through the leaves to promote fruit coloring, fruit enlargement and sweetness; you can spray Ziguohong or Gaoweilu K400 foliar fertilizer, which increases sweetness, improves coloring and enlarges fruit, and enhances the storage tolerance of the fruit.

3. Timely picking

To avoid overripe fruit losing sugar and turning green again, citrus fruit should be picked promptly and at the right time. In addition, in winter with many rainy days, long-term insufficient light and excessive consumption of tree nutrients, a large fruit load and delayed harvest of citrus can easily cause decline in tree vigor, and fruit drop and turning green again may both occur. Growers are best advised to pick in batches in a timely manner.

  The above is an introduction to the causes of citrus fruit turning green again during the color-change period and preventive measures. We hope it helps you. To learn more related knowledge, please stay tuned to us.