Key Technical Points for Autumn and Winter Management of Greenhouse Tomatoes

Tomatoes have a unique flavor and are rich in nutrients. They are grown all over China, and thanks to the development of greenhouse technology, we can now basically eat tomatoes all year round. Let's take a look below at the key technical points for autumn and winter management of greenhouse tomatoes.

1. Determine the number of fruit trusses according to density, and determine the size according to the number of fruit trusses. Whether early-maturing or late-maturing varieties, a single fruit can generally reach more than 100 grams, and some can reach more than 500 grams. Therefore, regardless of the variety, only 4--6 fruit trusses should be retained, not more, and each fruit truss should retain 3--4 fruits. Only in this way can it be conducive to promoting the growth of large fruits. For pruning, single-stem pruning and the plastic-string vine-hanging method are generally used.

2. Pay attention to seedling hardening after planting. From planting until the first inflorescence sets fruit, the main task is seedling hardening, which promotes deep rooting and encourages downward growth while controlling upward growth, laying a foundation for high yield. If the soil moisture content is above 20%, do not water at all. If special drought conditions are caused by soil, weather and other conditions, dissolve an appropriate amount of diammonium phosphate or compound fertilizer in water and splash-irrigate 1--1.5 jin per plant.

3. For those planted on ridges, do not cultivate on the ridges, but pay attention to timely loosening the soil in the wide rows to prevent compaction. For those where base fertilizer was broadcast and deeply plowed without ridging, multiple cultivations can be carried out to a depth of 10--15 cm. This can increase soil temperature and improve soil permeability. But be careful to cultivate deeply without damaging the roots.

4. Master the temperature and water the first water in time. When the first truss fruits are walnut-sized, the second truss fruits are broad-bean-sized, and the third truss flower buds have just opened, end seedling hardening and begin irrigation, once every 10--15 days, combined with topdressing urea, 15--20 jin per mu each time. Also pay attention to frequently increasing carbon dioxide. If excessive vegetative growth occurs, appropriately spray chlormequat or mepiquat chloride. Before and after watering, keep the soil temperature above 20°C, and note that the ventilation rate should not be too large, so as not to affect root growth.

5. Prevent fruit drop and deformed fruit

There are many factors that cause flower and fruit drop. The main reasons include: temperature too high or too low; insufficient light, lack of water, and malnutrition caused by root damage, etc. If it is caused by the temperature factor, plant growth regulators can be used, usually 2,4--D applied to the flower stalk, with a concentration of 10--20 PPM. Flowers that open on the same day are best, from 9 a.m. to before 3 p.m. In addition, 1 milliliter of 25% fruit-setting hormone can be mixed with 1 jin of water and sprayed on the flowers. If it is caused by other conditions, then pay attention to improving light, regulating soil moisture, carrying out foliar topdressing, and increasing carbon dioxide, among other factors. For applying 2,4--D to the flower stalk, a brush is best; when applying, it must not be too heavy or done too many times, and be sure to pay attention to the appropriate concentration to prevent deformed fruit.

6. Do a good job at the fruit harvest and storage stage

The main purpose of autumn and winter tomato cultivation is to obtain greater economic benefits through off-season market sales, so at harvest, delay harvesting as much as possible, which can fetch a better price. Generally, do not use ethephon for ripening. Harvest 3 months after sowing, and complete the fruit harvest all at once before the Spring Festival. For fruits that are still at the green-ripe stage at harvest, they can be placed in baskets and stored in the greenhouse, and brought to market successively after ripening.