How to effectively control citrus yellow fruit fall?

In the early stage of citrus yellow peduncle fruit, the fruit peduncle yellowing phenomenon first appears, and then spreads throughout the whole fruit, and in severe cases, the fruit loses green and falls off. How to prevent citrus yellow peduncle fruit fall, let's take a look at it.

First, the six major factors that lead to the fall of citrus yellow fruit

1, summer shoots twitch too much, fruit tree nutrition can not keep up. Summer rain is abundant, and summer shoots germinate vigorously. If the pruning of the early summer shoots and the suppression of the late stages are not done, it will lead to excessive growth of the summer shoots and the consumption of too many nutrients of the plant.

2. Root growth is hindered or the absorption capacity is reduced. In summer, there is a lot of rain, and the orchard is not drained in time, resulting in water and roots, unable to absorb nutrients.

3. Insufficient fertilizer supply or partial application of nitrogen fertilizer. Single fertilization leads to a lack of nutrients in the fruit trees. The application of uncorrupted organic fertilizer can easily burn the roots and cause damage to the root system, which will also lead to fruit fall. For hanging fruit trees, partial nitrogen fertilizer is likely to lead to unbalanced vegetative growth and reproductive growth. If nitrogen fertilizer is applied too much, it is easy to cause nutrients to be transferred from the fruit to the shoots, and the fruit trees will emerge quickly, causing the yellow peduncle to fall fruit.

4. Anthrax, brown spot disease and other diseases cause fruit fall. Tikhu anthrax and brown spot disease tend to cause fruit drop, which is more common in citrus varieties with slender stalks. The soil is heavy and the probability of these diseases is higher in orchards that are not well managed

big. Fruit drop caused by tibial anthrax, with a dark brown color around the stalk, is a more obvious feature. High temperature and high humidity weather, prone to outbreak of acute anthrax caused by tree fruit fall.

5. Endogenous hormone imbalance, insufficient auxin and gibberellin in the young fruit stage. Some seedless citrus varieties are prone to increased levels of ethylene and abscisic acid in the stalk, resulting in the emergence of fruit fall at the fruit stem. In addition, if exogenous hormones such as abscisic acid are added to some foliar fertilizers, it will also cause endogenous hormone imbalance in the tree, resulting in fruit fall. Therefore, when choosing foliar fertilizer, we must pay attention to the composition of foliar fertilizer.

6. Climatic factors. Every summer, it is either exposed to the sun or rainstorm. Excessive precipitation, waterlogging leads to roots, the root system can not absorb nutrients, often causing a large number of citrus fruit fall. When there is too much rain, we must find ways to drain the water in time, and we must pay attention to the drainage work when building parks in low-lying areas.

2. Prevention and control measures

1. Balance tree nutrition and apply fertilizer scientifically. In the use of fertilizer, attention should be paid to balanced fertilization, while paying attention to the appropriate control of nitrogen fertilizer application, and how to grasp the specific fruit farmers should determine according to the soil conditions of their own orchards and the growth status of citrus. From July to September of each year, do a good job of fertilization of autumn shoots, apply fertilizer once 7 days before the release of the shoots, and supplement large, medium and trace elements to maintain an adequate supply of nutrients.

2. Do a good job in summer and autumn management. Summer shoots should be handled well before the arrival of autumn shoots, the pruning should be pruned, the inhibition should be suppressed, and the fruit trees that put the late summer shoots should do a good job of promoting the old ripening of the shoots, so as to improve the fruit set rate. Autumn shoots should grasp the time to promote the germination of the shoots, and do not affect the old ripeness of the autumn shoots later because of improper operation and other factors.

3. Do a good job in disaster prevention. When facing flooding in the summer, it is necessary to check whether the drainage system of their orchards is good in time, whether they need to re-open ditches and drain water, etc., and do a good job in draining the orchards in time. When facing drought, it is necessary to water in a timely manner according to the situation of the orchard, at this time, try to use small water flood irrigation to prevent the occurrence of fruit splitting, and it is best to ensure that the orchard with conditions is watered once a week.

4. Maintain the root system. Damaged roots can be sprayed with humic acid-containing fertilizer to help the roots recover growth, promote new roots, and enhance fertilizer water absorption capacity. The whole expansion period should strengthen the management of water, pay attention to drought and flood prevention, provide a good environment for root system and fruit tree growth, promote fruit expansion, and prevent fruit splitting and fruit fall.

5. Prevent diseases. Strengthen the pruning of orchards, for closed orchards to do a good job of pruning and shaping work in time, so that the ventilation and light transmittance of fruit trees remain good, reduce the probability of disease; do a good job in the prevention of anthrax and brown spot disease, the available preventive agents are pyrazole ether bacteriolate, daisen manganese zinc, etc., therapeutic agents such as phenoxymethazole, imidaminamide, pentanzool, etc.