What to Do About Yellow Leaves on Fruit Trees? Cause Analysis and Treatment Methods

AbstractImproving soil: In the orchard, leguminous crops can be intercropped and a suitable amount of organic fertilizer can be added to improve the soil, which can effectively control yellow leaf disease in fruit trees. Choose disease-resistant rootstocks: Choose rootstocks with strong adaptability, resistance to yellowing, and tolerance to saline-alkali conditions. Reasonable irrigation: Saline-alkali plots and sandy beach orchards should be covered with film or grass, and flood irrigation can be changed to seepage irrigation or furrow irrigation. Supplemental iron fertilizer: Combined with deep plowing, apply ferric citrate or ferrous sulfate to improve the soil, or spray iron fertilizer on the leaves or inject iron elements.

1. Improve the soil

In the orchard, leguminous crops can be intercropped and an appropriate amount of organic fertilizer can be added, which helps improve the soil and the environment for iron fertilizer supply. In particular, planting deep-rooted sweet clover, sainfoin, alfalfa, and similar plants has a good effect on controlling yellow leaf disease in fruit trees.

2. Choose disease-resistant rootstocks

In saline-alkali plots, it is necessary to plant rootstocks with strong adaptability, resistance to yellowing, and tolerance to saline-alkali conditions. For apple rootstocks, the main choices are Malus prunifolia, Malus halliana, and Malus sieversii; for pear rootstocks, the main choices are Mo pear, Pyrus betulifolia, and Hongxiao pear.

3. Reasonable irrigation

In saline-alkali plots and sandy beach orchards, it is necessary to combine orchard film mulching and grass mulching, and appropriately reduce the number of irrigations and the amount of irrigation water. Flood irrigation can be changed to seepage irrigation or furrow irrigation, which helps prevent yellow leaf disease in fruit trees.

This is especially true in areas with high groundwater salinity. If irrigation is frequent and the water contains excessive salt, it will destroy the acidified environment around the fruit tree roots, raise the rhizosphere pH, and reduce the availability of iron, so the roots cannot fully absorb iron ions.

4. Apply iron fertilizer to the soil

During this period, combined with deep plowing to improve the soil, apply 0.5 kg of ferric citrate or ferrous sulfate, mixed with 50 kg of cow manure or 5 kg of cottonseed cake, and then open a furrow and apply it into the soil. The effective period can last about 1 year. Generally, for fruit trees about 10 years old, 0.5-1 kg of ferrous sulfate can be applied.

5. Spray iron fertilizer on the leaves

During the growth of fruit trees, 0.3%-0.5% ferric citrate or ferrous sulfate can be sprayed on the fruit trees, once every about 10 days, for 3-4 consecutive sprays. Continuous spraying multiple times is necessary for control effectiveness, but it is relatively time-consuming and labor-intensive, so other new types of iron fertilizer can also be used for control, such as amino acid iron and Kehuangling.

6. Inject iron elements into the trunk

When soil application is not suitable in alkaline soil, trunk injection is an effective method to control iron deficiency. Generally, during the growth period of fruit trees, a 0.2%-0.5% ferrous sulfate solution can be injected into the trunk with a syringe, with each dose being 0.25 kg.

A discarded medical infusion set can also be used for injection. After inserting the needle into the trunk, the suspended medicine bottle needs to maintain a certain height difference from the injection site. One bottle of ferrous sulfate solution can be hung until finished in about 10 days. During this period, it can be hung once every 30 days, for 3-4 consecutive times.