What are the high-yield planting techniques for large-fruited tomatoes in greenhouses?

Due to factors such as temperature and humidity and improper management, greenhouse tomatoes are prone to developing stiff fruit, empty trusses and hollow fruit. To achieve high yield and high efficiency, besides raising strong seedlings, applying fertilizer reasonably and strengthening temperature and humidity management, some techniques are also needed.

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

Second, master the timing of flower pollination and the dosage of the treatment. Pollinating too early easily causes stiff fruit, while too late makes fruit set difficult or causes cracked fruit, both of which affect market quality. On each truss, starting from the second flower (the first flower having been removed), basically 2-3 flowers open on the same day each time, 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 a little stronger at low temperatures and a little weaker at high temperatures.

Third, during the fruit-swelling stage, fertilizer and water must be sufficient to meet the needs of fruit expansion and increase yield and efficiency. When the 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 and hollow fruit easily appear, affecting quality. On the basis of applying sufficient bio-organic fertilizer, apply a quick-acting plus long-lasting, fully balanced complete fertilizer as the base fertilizer. According to the number of fruit trusses retained, determine the amount and type of topdressing, focusing on topdressing to obtain yield. If a total of 6 trusses of fruit are retained, topdress 3 times when the 1st, 3rd and 5th trusses swell respectively; if a total of 4 trusses of fruit are retained, topdress 2 times when the 1st and 3rd trusses swell; when the fruit load is heavy, 1 additional topdressing may be added as appropriate. Topdressing should mainly be a potassium sulfate type quick-dissolving, quick-acting compound fertilizer, with a formula of medium nitrogen, low phosphorus and high potassium being best, at 20-30 kg per mu each time. In the later growth period, when the soil temperature is low, applying it together with fertilizers containing humic acid or amino acids is even better, to buffer the effect of pure chemical fertilizers on soil temperature and roots. At the same time, note that around 60 days after planting, add one more root-nourishing watering, and it is recommended to apply 10-15 kg per mu of a 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 an imported complete-nutrition 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 truss begins to color, to favor coloring and fruit swelling.

Fourth, note that leaf removal in the later stage must not be excessive. During the fruit coloring period, in order to promote coloring and increase light, many vegetable growers remove all the leaves below the fruit truss, and some also remove quite a few leaves above it. Too few leaves will seriously affect the photosynthetic accumulation of the leaves, leading to insufficient nutrition and the appearance of hollow fruit. Therefore, in the middle and late growth stages, shoot thinning and leaf removal should be moderate and must not be excessive.