How old can tomato seedlings be transplanted, planted and fertilized? When will it blossom

Transplanting time: when the seedling age is 20-25 days and the seedling has 3-4 leaves, it is transplanted and planted. Land preparation and planting: the planting bed was made into a ridge with a width of 50cm, with 4500 plants per mu. Temperature management: the temperature is controlled at 25-30 ℃ in daytime and 15-17 ℃ at night. Fertilizer and water management: when the ear grows to the size of walnut, diammonium phosphate 25kg is applied per mu, and then appropriate amount of foliar fertilizer is sprayed during the ear expansion period. Flowering time: about 20 days after planting.

Transplanting time

The main results are as follows: 1. Sowing can be carried out in the first and middle of July, early sowing is easy to get virus disease, and if sowing late, the temperature is low, which will affect the fruit maturity and yield, and avoid the harm of rain, sun exposure and virus disease in the seedling stage, so it is necessary to set up the seedling bed in a high dry place. at the same time, make a high bed, build a shade shed, and raise seedlings with nutrition paper bags or bowls.

2. When the seedling age is 20-25 days and the seedlings have 3-4 leaves, they should be transplanted and planted. If overgrowth occurs in the seedling stage, it should be sprayed 1-2 times (1000) × 10-6 in time.

II. Land preparation and planting

Autumn tomatoes in the greenhouse are planted relatively early, and the external temperature is high. Before planting, it is necessary to buckle the shade type greenhouse film, open the surrounding greenhouse film, leave only the upper part of the greenhouse film to prevent rain and strong light, buckle the greenhouse film, and make the planting border into a 100cm wide high flat border, or 50cm wide ridge, combined with the border to apply basic fertilizer, irrigation is full of soil moisture, in the future, when leaving 2 ears of fruit, the planting distance is 25cm, and when 3 ears are left, the fixed plant spacing is 30cm, planting about 4500 plants per mu.

III. Temperature management

After planting, the ventilation was carried out day and night, and the bottom wind was closed around the greenhouse, only in the middle and upper parts. When the external temperature dropped below 15 ℃, the ventilation was stopped at night, and the temperature was controlled at 25-30 ℃ during the day and 15-17 ℃ at night. After the whole shed was fastened in late October, the roof was ventilated and dehumidified at noon.

IV. Fertilizer and water management

The main results are as follows: 1. 2-3 days after planting, when the soil moisture is suitable, it is necessary to plough and loosen the soil in time, combine with loosening soil to cultivate ridges, water once after slowing down the seedlings, and less water is needed to prevent overgrowth in the later stage, until the emergence of large buds, watering once, then shallow ploughing, squatting seedlings.

2. Topdressing and watering when the ear is the size of walnut, applying diammonium phosphate 25kg per mu. After the middle of October, in order to reduce the humidity in the greenhouse, it is necessary to stop watering, and then spray appropriate amount of foliar fertilizer during the ear expansion period.

5. Flowering time

Tomato flowering for summer and autumn, usually about 20 days after planting, the growth period needs to be single dry pruning, each ear to retain 3-4 fruits with correct shape, small fruit varieties can retain 4-5 fruits, excluding the rest of the fruit, the flowering period with 2R4murD tomato spirit treatment, conducive to flower and fruit protection, due to the high flowering temperature, the concentration needs to be lower than spring tomatoes.

VI. Prevention and control of diseases and insect pests

1. Planting autumn tomatoes needs to prevent virus diseases and late blight, and pay attention to the prevention and control of virus diseases at the initial stage. In addition to selecting disease-resistant varieties, sowing at the right time, raising seedlings in nutrient bowls, and selecting disease-free seedlings, it is also necessary to buckle the shed in advance. The number of aphids can be significantly reduced, and if diseased plants are found, they need to be pulled out in time.

2. After replanting after washing hands with soapy water, we should pay attention to the prevention and control of late blight in the middle and later stage, strengthen ventilation and reduce temperature after planting, remove diseased leaves and fruits in time, and spray Dysen zinc and chlorothalonil in an all-round way.