You are sure to encounter the problems of citrus planting!

Today, let's sort out the questions from the training session and share:

We put the questions on Youguo Master app, there are a lot of questions, especially suitable for citrus growers to check, communicate with each other and share experiences.

1. What is the reason for the mandarin sun fruit? How to solve?

Answer: the sun fruit is mainly due to the high temperature and water loss of the fruit surface caused by the sun, and if the plant moisture fails to keep up, it will be sunburned, which mainly occurs on the top fruit of the erect branch, and the occurrence degree has a great relationship with the variety. the specific reason is that different varieties have different physiological habits and pericarp structure. It can be alleviated by some cultivation methods, such as proper growing branches, proper drooping, keeping orchard humidity (grass, spraying water to cool, etc.), applying more organic fertilizer and so on. The most economical and effective means for fertile mandarin is to properly release late summer shoots to shade the fruit. Experiments have shown that bagging can not effectively reduce sunburn fruit, and it may be aggravated.

two。 The newly built land is 1446 meters above sea level. What planting suggestions are there?

A: from the picture, it should be at the peak. The mountain may be relatively barren, and you can't see the orientation. If you want to plant, you should pay attention to the selection of varieties to match the local climate. For example, fertile mandarins are not cold-tolerant and have already suffered once below zero.

3. Planted on dry slopes, when the summer shoots were sprinkled with 3-5 pairs of flue-cured tobacco high-nitrogen compound fertilizer, the leaves turned yellow. what is the reason? Lack of elements? Lack of fat?

A: first of all, the yellowing of the midrib may be caused by fat damage and rotten roots, and secondly, there is mottled yellowing, which is not just a simple root problem. There is a 60% chance of Huanglong disease.

4. What's going on?

Answer: if you look at the main vein yellowing from the picture alone, the probability of rotting the root is 80%. Dig it up to see the situation of the root.

5. Excuse me, what is the reason for the micro-curls of the leaf veins toward the center?

Answer: the whole plant rolls leaves, the probability caused by diseases and insect pests is relatively small, it should be physiological leaf curling, the tree does not have the phenomenon of root damage, too much fertilizer, pyrazole damage, uneven mixing when using medicine, may be the cause of leaf curling. Check the drip of this tree to see if it produces more water than the others.

6. After spreading fertilizer for a period of time, the citrus roots are covered with moss. What is the reason for this? Is there a problem with fat? Can I continue to use it?

Answer: Chlorella verticillata on the ground shows excess nutrition, and the soil environment is sour, and the leaves are not large and not very green and have no luster. It is suggested that half a jin of calcium and magnesium nitrate can be applied every year, because calcium and magnesium neutral fertilizers can not cause soil acidification and improve fertilizer use efficiency.

7. Macular symptom, what reason is this?

Answer: from the picture to see the burns on the back of the leaves, the possibility of drug damage is relatively large, it may be that the concentration of EC pesticides is too high before the leaves turn green. It depends on whether it happens in the whole garden, and if it is only a few, it may also be caused by other reasons.

8. What is the concentration of gibberellic acid for fruit protection? And how to control the timing and depth of ring cutting?

Answer: you did not specify the variety. In general, it is recommended that the concentration of 100 ml of 3% concentration should be mixed with 200-300 jin of water. The low concentration should be used for the first time, mainly to inhibit the formation of abscisic acid, and the second time to use high concentration.

First of all, it is necessary to make a clear distinction between ring cutting and ring peeling, which is called ring cutting with No. 0 knife and ring peeling with knife number 0 or above.

It is suggested that the time of ring cutting (or girdling) is about 30 days after Xiehua, when a small amount of early summer shoots germinate, when the big and small fruits are finished, and the summer shoots can be controlled while preserving the fruit. The depth of circumcision (or girdling) is that the cambium is cut without harming the xylem. When peeling, it is recommended not to close the ring, leaving about 1/10 of the life channel, so that it is not easy to cut the tree to death. Liu Daike teacher's practice is to cut the No. 0 knife ring twice, the distance is 5-8 cm, the fruit protection effect is good, and the safety is high, the knife number combination of the two knives can be properly adjusted according to the age of the tree. We must pay attention to the ring cutting according to the tree potential, we must look at the tree all cut, at the same time, the knife should be sharp, the knife should be flat, to prevent the bark from warping up.

9. How to deal with such a problem?

Answer: watermark disease caused by white cortex development disorder is more common in barren mountain soil, which generally occurs in the late stage of expansion to the period of color conversion. Apply more organic fertilizer to improve the ability of soil water and fertilizer conservation, supplement calcium and boron from May to August, supplement calcium and magnesium from August to October, irrigation in time for drought, and control the concentration of 920 in the early stage. The pericarp is green and the nitrogen is high.

10. Should the late summer shoots be cut off before the autumn shoots come out?

Answer: it is not necessary to cut off all of them. The purpose of cutting late summer shoots is to increase the number of last shoots. The number of summer shoots is determined according to the expected yield.

11. Excuse me, what kind of disease is this?

Answer: drug damage or fat spot macular disease is more like drug burns, drug damage is more likely.

twelve。 Why are some leaves of the same tree so different in shape?

Answer: part of the root injury, drug damage, when the leaves are not consistent with gibberellin, herbicide drift, etc., are possible. The drug damage relief scheme given by teacher Zhang is brassinolide + compound nitrophenol sodium, or brassinolide + amine fresh ester + amino acid.

13. Is this Huanglong disease?

Answer: the yellowing of leaf veins is generally a root problem, the first two are similar to herbicide damage, Huanglong disease is unlikely. But it can not be ruled out, the last two are a little dangerous, it is better to take them for PCR testing.

Citrus House Technology Industry Alliance

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