What are the water management measures for greenhouse tomatoes?

First inflorescence flowering: on the basis of watering thoroughly at transplanting, watering should be controlled during and after the seedling recovery stage; do not water lightly before the first truss flowers, in order to prevent excessive vegetative growth and flower drop. Even in drought, water sparingly to promote flowering and fruit set and prevent flower drop.

From the flowering of the first inflorescence to the flowering of the third inflorescence, watering should be strictly controlled to promote root growth into deeper soil layers. Only if the growing point wilts at midday may a small amount of water be applied along the furrow. If there is too much water during this period, the plants tend to grow leggy and excessively, causing flower drop and making fruit set difficult.

After the third inflorescence flowers, the first truss of fruit enters the swelling stage; begin watering at this point. The amount of water should be sufficient, but do not flood-irrigate; water under the mulch film. Sufficient water not only ensures normal growth of stems and leaves but also promotes fruit development and helps the fruit swell.

Severe cold season (mid-to-late December to early February): during this stage temperatures are low and light is weak, and both plant growth and fruit growth are relatively slow, so watering must be appropriately controlled.

Warming stage after mid-February: temperatures gradually rise, plant and fruit growth accelerate, and water demand gradually increases. Choose sunny mornings to water, and gradually increase the frequency of watering. In spring, water about once every 15-20 days, but grasp the principle of "water the fruit, not the flowers" to prevent reducing the fruit set rate.