Tomato likes temperature, and the suitable temperature is 25 ~ 28℃ during the day and 16 ~ 18℃ at night. When the temperature is lower than 15℃, it will affect the germination, pollination and fertilization of tomato seeds and the tomato will turn red. When the temperature is lower than 15℃, the growth will be slow and the reproductive development will be inhibited. When the temperature is 5℃, the stem and leaf stop growing; When the temperature is 2℃, they suffer from chilling injury; When the temperature is 0℃, they will freeze to death. When the temperature is higher than 35℃, reproductive development will be affected, and when the temperature is higher than 40℃, physiological disorder will lead to thermal death. Adequate illumination and suitable temperature difference are beneficial to nutrient accumulation and maturity, promote healthy plant development, prevent overgrowth, enhance tomato's disease resistance and stress resistance, and increase yield.
Planting time of tomato
Generally speaking, according to the different planting and harvesting time, tomatoes are divided into spring tomatoes, autumn and winter crops, winter and spring crops and winter crops.
1, planting time of spring tomato
The suitable seedling age for open-field spring tomato cultivation is 50-70 days, that is, 50-70 days before sowing. For example, in Shenyang, located at 465,438+0 north latitude, spring-crop tomatoes were planted in protected fields in February and in the open field after frost in early May.
In spring, tomatoes are usually planted immediately after the local late frost period and when the ground temperature of the 5- 10 cm plough layer stably passes through 12℃. For example, the average late frost period in Shenyang over the years is May 2, and the suitable planting period is generally May 6-10. Generally, it is planted around Qingming in the Yangtze River valley, around Grain Rain in North China, and around long summer in Northeast China. It can be planted early in the sandy land with phoenix barrier, plastic film coverage and Gao Qian leeward and sunny terrain. Planting should be decided according to the weather. In case of rainy weather in Taihō, planting should be postponed appropriately. In the suitable planting period, Shaanxi tomatoes should be planted early, mainly depending on the time to market. There are two seasons in a year. One is delayed cultivation after autumn, and seedlings are raised after July and August.165438+1October can be listed one after another. One is early spring cultivation, 1 1,1February seedling raising, and may and June marketing.
2. Planting time in autumn and winter.
Crops in autumn and winter are generally planted from mid-late July to mid-August, and from mid-late August to early September. From the middle and late September to the beginning of 10, and harvesting from the end of 1 1 to the beginning of February of the following year.
3. Planting time in winter and spring
165438+1sow in winter and spring from early October to early February of 65438+,1sow from late October to early February of the following year, and harvest from early March to June.
4. Planting time of winter stubble
Overwintering stubble belongs to one big stubble cultivation. Generally, 10 is from the middle and late September to the early October of 10, and it is sown in June of10 and harvested in June of the following year.
Tomato seed treatment
1, soak seeds in warm soup
Soaking seeds in warm soup is an effective measure to break seed dormancy, promote seed germination, sterilize and prevent diseases and enhance seed stress resistance. Specific measures are as follows:
① Soak the seeds 1-2 hours with clear water.
(2) Take out the seeds and put them in warm water at 55 degrees Celsius, keep the water temperature and soak them evenly for 65,438+05 minutes, then continue soaking for 3-4 hours to accelerate germination. When soaking seeds in warm soup, it is usually one seed and two waters. At the same time, it is necessary to continuously and quickly stir the seeds so that they are evenly heated to prevent scalding.
(3) Keep the water heated, and keep the water temperature at 55 degrees Celsius. This disinfection method can prevent tomato leaf mold, canker and early blight.
2, drug disinfection
① Soak the seeds with trisodium phosphate: soak the seeds with clear water for 3-4 hours, take them out and drain them, then soak them with 10% trisodium phosphate solution for 20 minutes, and then rinse them with clear water to accelerate germination. This method has obvious effect on tomato virus disease.
(2) Soaking the seeds in formalin solution: soak the pre-soaked seeds in 1% formalin solution for 15-20 minutes. When soaking the seeds, seal the container to prevent the liquid medicine from volatilizing, then take it out, wrap it with wet cloth and put it in a closed container for 2-3 hours, rinse it repeatedly with clear water, and then soak it again to accelerate germination. This method can reduce or control the occurrence of tomato early blight.
③ Soaking seeds with 0. 1% potassium permanganate solution for 15-30 minutes can effectively reduce the occurrence of tomato mosaic virus disease and early blight.
④ Soaking seeds with 1000mg/kg agricultural streptomycin solution for 30 minutes has a good effect on controlling bacterial wilt.