Therefore, the minimum temperature for cultivating tomatoes in winter should not be lower than 7 degrees as far as possible.
tomato
I. Introduction
Tomato is also known as tomato and persimmon, and its ancient name is June persimmon, and it is good news for three yuan. In Peru and Mexico, it was originally called "Wolf Peach". Fruit is rich in nutrition and has a special flavor. Can be eaten raw, cooked, processed into tomato sauce, juice or whole fruit can. Tomato is one of the most widely cultivated fruits and vegetables in the world. The United States, the Soviet Union, Italy and China are the main producers. In Europe, America, China and Japan, there are large-scale greenhouses, plastic greenhouses and other protected facilities for cultivation. It is widely planted in all parts of China. The cultivation area continues to expand. The blue one may be poisoned if eaten.
Second, the characteristic taste
Cool, sweet, slightly sweet.
Third, the functional use
Clearing heat and quenching thirst, nourishing cool blood, promoting fluid production and quenching thirst. Tomatoes eaten raw can supplement vitamin C. After cooking, the content of lycopene and other antioxidants will increase significantly, which will reduce the risk of heart disease and resist aging.
Fourth, the requirements for environmental conditions
(1) Temperature: Tomato is a thermophilic vegetable. Under normal conditions, the optimum temperature for assimilation is 20 ~ 25℃, and the optimum soil temperature for root growth is 20 ~ 22℃. Increasing soil temperature can not only promote root system development, but also significantly increase the content of nitrate nitrogen in soil, accelerate growth and development, and increase yield.
(2) illumination: tomato is a light-loving crop with a light saturation point of 70000lx. The suitable light intensity of eggplant is 30000～50000lx. Tomato is a short-day plant. In the process of changing from vegetative growth to reproductive growth, short-day is basically required, but the requirements are not strict. Some varieties can bud in advance under short-day sunshine, while most varieties bloom earlier under the sunshine of113h, and the plants grow healthily.
(3) Moisture: Tomatoes need more water, but they don't need to be irrigated frequently. Generally, soil humidity is 60-80% and air humidity is 45-50%. High air humidity not only hinders normal pollination, but also causes serious diseases under high temperature and high humidity conditions.
(4) Soil and nutrition: tomatoes are not strict with soil conditions, but in order to obtain high yield and promote good root development, tomatoes need to absorb a lot of nutrients from the soil during their growth. According to Eigerstein, for every 5000kg of fruit, they need to absorb 33kg of potassium oxide, 5kg of nitrogen 10kg and 5 kg of phosphoric acid from the soil.
Five, food selection
When choosing tomatoes, you should choose the ones with pink and round colors and little white skin. It feels like there is a layer of light powder on the surface, so it is very pinched. The eggplant is soft. The part of the pedicle must be round, preferably with a hint of cyan. The seeds are khaki, red, sandy and juicy. Don't buy sharp, high-bottomed or angular tomatoes, and don't choose tomatoes that feel light. These are all ripening tomatoes.
Ripening tomatoes are all red, hard to handle and polyhedral in appearance. When opened, the seeds are green or have no seeds. Although this medicine has low toxicity, it is harmful to human body after long-term consumption.
If the harmful substances in tomatoes exceed the standard, there will be a convex part like a peach at the top, which is a sign of excessive hormones.
The harder tomatoes are, the more phytohormones are used. It is best not to buy them, or don't eat them immediately after you buy them. Leave it for two or three days to continue the ripening period until it naturally softens, because at this time, the unhealthy lycopene has also been released.