Key Points of Tomato Seedling Planting Methods and Detailed Explanation of Yellowing Causes

Tomato, also called fanqie, usually ripens and comes to market in summer and autumn. With the development of cultivation techniques, it can now basically be eaten all year round. Tomatoes are brightly colored, have a distinctive taste, and are rich in certain nutrients, making them deeply loved by consumers. Tomatoes are cultivated in many parts of our country, so what are the key points of tomato seedling planting methods? Why does yellowing occur?

1. What are the key points of tomato seedling planting methods?

Tomato seedlings bought back must go through a proper hardening-off period. First water them with a certain amount of water and keep them in a cool place. Once the temperature reaches around 20°C, they can be transplanted. When transplanting tomato seedlings, the soil should be deeply plowed, and organic fertilizer or nitrogen-phosphorus-potassium fertilizer can be added appropriately.

Plant the tomato seedlings at a spacing of about 40 cm. When planting, pay attention to the depth at which the roots are transplanted into the new planting hole; the depth of the planting hole should be kept at about 10 cm. After the tomato seedlings have been transplanted, water them thoroughly for the first time. Note that during subsequent management, the soil should be kept moist but tending toward dry, and waterlogging should not occur, otherwise it will seriously affect plant growth.

During the transplanting period of tomato seedlings, pay attention to temperature changes. If the temperature is too high, the seedlings are easily sunburned, so it is best to find a breathable cloth for covering; otherwise they can easily be smothered to death.

2. Why do tomato seedlings show yellowing?

If tomato seedlings show yellowing, it is very likely caused by a lack of trace elements. Which specific one is lacking must be analyzed according to the yellowing site and symptoms of the tomato seedlings.

If yellowing occurs due to iron deficiency, the top leaves generally show yellowing first, then it gradually develops downward, with mild tissue necrosis appearing.

If tomato seedlings turn yellow due to boron deficiency, the typical phenomenon is that the small leaves lose their green color and turn yellow or orange-red, then gradually turn black. In severe cases, the leaves of the whole plant wither and die. In addition, boron deficiency can also cause leaf curling, poor growth, deformed fruit, and so on.

If tomato seedlings turn yellow due to zinc deficiency, it starts with the top leaves becoming thinner and the veins fading. Older leaves will not lose their green color, but will have brown spots. Generally, when zinc deficiency occurs, the tomato seedling leaves will wither and fall off within a few days.

When tomato seedlings are deficient in molybdenum, the older leaves generally lose their green color first. Yellow spots appear on the leaf margins and in the mesophyll between the veins, the leaf edges curl upward, and the leaf tips show scorched wilting, gradually moving inward. In mild cases, it affects the number and quality of flowers and fruit; in severe cases, the whole plant dies. For growers, the impact is very great, so everyone must pay attention.