What causes tree seedling leaves to turn yellow

Tree seedlings, also called nursery stock, are the general term for all kinds of fruit tree seedlings, tree saplings and shrub seedlings. Nowadays, whether people are planting fruit trees or planting landscape trees, they generally buy seedlings to plant. So, what causes tree seedling leaves to turn yellow? How to solve it?

Cause one: soil that is too acidic or too alkaline. The pH of the soil can affect the solubility of minerals. If the soil is too acidic, iron, aluminum, manganese and others dissolve in excessive amounts, and the seedlings can be poisoned by absorbing too much; if the soil is too alkaline, iron, calcium, phosphorus, magnesium, zinc and others easily form soluble compounds, which reduces the seedlings' absorption of these elements and causes yellow leaf disease.

Solution: control the acidity and alkalinity of the soil and adjust the soil pH. For soil that is too acidic, apply more nitrate salts; for soil that is too alkaline, apply more ammonium salts.

Cause two: insufficient light. Seedlings need sufficient light to carry out photosynthesis. If light is insufficient, plant cells cannot differentiate smoothly, the stems and branches of the seedlings become thin and weak, and the leaves turn yellow.

Solution: increase light.

Cause three: temperature too low. If the temperature is too low, the seedlings will suffer from cold, which reduces the respiration rate and slows the absorption of water and mineral elements, causing young shoots and young leaves to turn yellow and wilt.

Solution: pay attention to cold protection.

Cause four: too much water. Too much water causes a lack of oxygen in the soil, making it difficult for the roots to breathe and hindering the roots from absorbing water and fertilizer, which causes the new shoots and top leaves of the seedlings to turn pale yellow and the old leaves to turn dark yellow; in severe cases the plant will wither and die.

Solution: loosen the soil and drain in time, and control the amount of watering.

Cause five: insufficient water. If water is insufficient, the seedlings wilt as they grow, and the new leaves take water from the old leaves, causing the old leaves to turn yellow and fall off.

Solution: water in time, and water thoroughly.

Cause six: too little fertilizer. Too little fertilizer leaves the seedlings lacking nutrients, which causes the leaves to lose their green color and turn yellow.

Solution: apply organic fertilizer.

Cause seven: fertilizer too concentrated or too much. Fertilizer that is too concentrated or too much causes fertilizer burn, which makes the new leaves thick and wrinkled rather than spread out, and the old leaves gradually turn yellow without falling off.

Solution: fertilize reasonably, or apply organic fertilizer.

Cause eight: damage from pests and diseases. If seedlings develop diseases such as damping-off, rust and leaf spot blight, or are damaged by pests, the leaves will shrink and curl, and spots and yellowing will appear on the leaves.

Solution: prevent early, and once pests or diseases are found, control them in time.

Cause nine: improper pesticide application. In the process of preventing and controlling diseases and pests, improper spraying of chemicals or too high a concentration can cause pesticide damage to the seedlings, making the leaves turn yellow and fall off.

Solution: spray chemicals strictly according to the instructions; if pesticide damage occurs, rinse with clean water as soon as possible to reduce the effect of the chemical.