Want high yields from greenhouse tomatoes? Mastering these little tips is key

Greenhouse tomatoes, affected by factors such as temperature, humidity and improper management, are prone to developing stiff fruit, empty clusters and hollow fruit. To achieve high yield and high efficiency, in addition to raising strong seedlings, rational fertilization and strengthening temperature and humidity management, some tips are also needed.

First, remove the first flower of each cluster, pollinate more flowers, thin fruit early and keep good fruit. The first flower should be removed in time; 6-8 flowers per cluster can be pollinated. When the tomatoes grow to the size of a pigeon egg, remove deformed fruit, damaged fruit, diseased fruit and fruit that is too large or too small, keeping 3-5 fruit per cluster is appropriate.

Second, master the timing of flower pollination and the dosage of the treatment. Pollinating too early easily leads to stiff fruit, while pollinating too late makes fruit set difficult or causes cracked fruit, both of which affect market quality. The flowers on each cluster start from the second flower (the first flower having been removed); each time basically 2-3 flowers open on the same day, and this is the best time to pollinate. The best time is in the morning when the flowers have just opened. As for the concentration of the pollination solution, it should be mixed at a higher concentration at low temperatures and slightly lower at high temperatures.

Third, fertilizer and water must be sufficient during the fruit-swelling stage. When tomatoes are the size of a walnut, they are in a period of vigorous nutrient demand; at this time fertilizer and water must be sufficient, otherwise stiff fruit, small fruit, hollow fruit and the like easily appear, affecting quality. On the basis of applying sufficient bio-organic fertilizer, apply a quick-acting plus long-lasting full-nutrient balanced compound fertilizer as base fertilizer. Determine the amount and type of topdressing according to the number of fruit clusters set, and focus on topdressing to secure yield. If a total of 6 fruit clusters are kept, topdress 3 times when the first, third and fifth fruit clusters swell; if a total of 4 fruit clusters are kept, topdress 2 times when the first and third fruit clusters swell; when the fruit load is large, topdressing can be appropriately increased by 1 time. Topdressing should be mainly potassium sulfate type quick-dissolving, quick-acting compound fertilizer, with a formula of medium nitrogen, low phosphorus and high potassium being best, at 20 kg per mu each time. In the later growth period, when the ground temperature is low, it is better to apply it together with fertilizers containing humic acid or amino acids, to buffer the effect of pure chemical fertilizers on ground temperature and roots. At the same time, note that about 60 days after planting, apply a root-nourishing fertilizer once more with irrigation water; it is recommended to apply 10-15 kg per mu of liquid fertilizer containing humic acid or amino acids. Avoid high-nitrogen fertilizer for topdressing, avoid drastic changes in soil moisture, and at the same time apply a full-nutrient foliar fertilizer to prevent nutrient deficiency symptoms in the plants. It is recommended to stop watering and fertilizing when the fruit of the second-to-last cluster begins to color, to facilitate coloring and fruit swelling.

Fourth, note that leaf removal in the later stage must not be excessive. During the fruit coloring period, many vegetable growers, in order to promote fruit coloring and increase light, remove all the leaves below the fruit clusters, and some also remove quite a few leaves above, but too few leaves seriously affects the photosynthetic accumulation of the leaves; insufficient nutrition leads to the appearance of hollow fruit. Therefore, in the middle and later stages of growth, pruning shoots and removing leaves should be done appropriately and not excessively.

Qin Zhiqing, Agricultural Committee of Changzhi County, Shanxi Province