Key Management Techniques of Greenhouse Tomato Fruiting Period in Autumn and Winter

When the autumn and winter greenhouse tomatoes begin to bloom and bear fruit, it is the period when the external environment changes greatly, the external temperature gradually decreases, and the sunshine time gradually shortens. If the management is improper, it is easy to cause weak plant growth, slow fruit expansion and uneven fruit coloring. and other phenomena, affecting yield and efficiency. The following key technologies should be mastered in the management of tomato fruiting period in autumn and winter:

1. Temperature control

Temperature regulation is the top priority of tomato fruiting period management in autumn and winter. Tomato is a temperature-loving crop, the suitable temperature is 25-28 ℃ during the day and 15-18 ℃ at night. If the temperature is too high during the day or too low at night, it is easy to cause tomato flower drop or deformed fruit, which will affect the fruit quality. Before the frost comes, the straw and paper quilt should be covered at night. In the first few days when the straw and paper quilt are covered, the cover should be removed early and late. Later, as the temperature decreases, it will gradually transition to the normal time of uncovering. That is to open the straw one hour after sunrise, and put down the straw 30 minutes before sunset.

An important measure for temperature regulation of tomato in autumn and winter is to increase light. Especially on sunny days in winter, after the sun comes out, it is necessary to open the thatch as soon as possible to increase the temperature in the shed. Even if it is cloudy and snowy, you must remove the thatch, and you can use the method of "separating one piece and uncovering one piece" to strive for more scattered light. After the weather is clear, the snow on the shed film should be cleaned immediately, and the shed film should not be scratched as much as possible. In addition, it should be noted that every morning after the thatch is uncovered, the dust and grass clippings on the shed film should be wiped off to keep the shed film clean, and the accumulated water on the shed film should be scraped off frequently to ensure that the light transmittance of the shed film is better. it is good. In addition, pay attention to preventing cold currents, and do a good job of thermal insulation and cold protection before the arrival of cold currents to prevent frost damage.

2. Strengthen water and fertilizer management

The suitable soil humidity during the tomato fruiting period is 60-80%, and the relative air humidity is 45-50%. Drip irrigation or under-film dark irrigation can be used for watering during the fruiting period to avoid excessive humidity in the shed and cause pests and diseases. As a result, in the early days, the outside temperature was high during the day. Generally, water every 7 days. As the weather turns cold, it is necessary to water the seedlings properly. When watering, choose to do it in the morning on a sunny day, and open the air vent at noon to ventilate and reduce humidity.

The top dressing in the fruiting period is mainly nitrogen and potassium fertilizers, and an adequate supply of potassium fertilizers must be ensured. Specifically, when the first ear of fruit grows to the size of a walnut, topdressing with expanding fruit fertilizer is carried out in conjunction with watering. Generally, 10-15kg of urea and 15kg of potassium sulfate are applied per mu. In the future, when each ear of fruit grows to the size of walnut, it should be topdressed once, and the amount of topdressing is the same as the first time. Stop top dressing 30 days before pulling the seedlings.

3. Plant adjustment

Generally, only one trunk is retained per plant, and all lateral branches are removed. In order to maintain a good plant shape, it is necessary to prune and fork in time. The time for pruning and fork should not be too early or too late. Generally, when the axillary buds grow to 3cm, pruning and fork should be carried out. When pruning, no piles are left, and excessive skin on the trunk is not taken away, and the wound surface is minimized as much as possible. Pruning and forking are generally carried out between 10 am and 3 pm on sunny days. At this time, the temperature is high, which is conducive to wound healing and reduces the probability of disease occurrence. Remember not to prune and fork on cloudy days or when the humidity in the shed is too high.

The pruning should be combined with the work of tying the vines and hitting the old leaves, so as to facilitate the ventilation and light transmission of the plants, reduce the ineffective consumption of nutrients, and prevent the spread of diseases. That is, when the first ear of fruit is green and ripe, remove the old leaves under the first ear of fruit, when the second ear of fruit is green and ripe, remove the old leaves under the second ear of fruit, and so on.

4. Flower thinning and fruit thinning

Reasonable flower and fruit thinning can promote development, increase single fruit weight, and improve fruit uniformity. The first flower of each inflorescence is prone to deformed fruit and should be removed before dipping the flower. Excessive number of flowers per ear will affect the quality of the fruit. Small and deformed flowers should be removed, and the method of "pinch the head, remove the tail and leave the middle" should be adopted to keep the size of the remaining fruit consistent. Generally speaking, 3-4 fruits should be left in each panicle of large-fruited varieties, 4-5 fruits should be reserved for medium-fruited varieties, and more than 5 fruits should be reserved for small-fruited varieties.