Tomatoes are thermophilic crops that are sensitive to temperature. Too high or too low temperatures can cause poor tomato growth and can even cause death or death when severe.
1. Tomato in different stages of growth, the temperature requirements are also slightly different (1) germination tomato seed germination requires a higher temperature of 25-30 °C, the fastest germination at 28 °C, and the temperature is lower At 11°C, seeds germinate slowly after sowing.
(2) The optimum temperature for tomato vegetative growth at seedling stage is 20-25°C. Excessive temperatures are liable to make seedlings long; at temperatures above 35°C, plant growth stagnates. At seedling stage, tomatoes can tolerate prolonged low temperatures of 6-7°C and short periods of 0--3°C. Above 40°C, stems and leaves stopped growing; necrosis above 45°C; growth retardation at 8°C; growth at 5°C; freezing at -1-2°C. Seedling stage often through artificial low-temperature exercise, can enhance the cold resistance of the seedlings, conducive to controlling leggy, nurturing strong seedlings, low temperature exercise to 10 °C is appropriate. Plants at the seedling stage can tolerate low temperatures of 5-6°C for a longer period of time, and early maturing varieties can tolerate short-term low temperatures of 0°C.
(3) During flowering period, tomato plants are sensitive to temperature during the flowering period, and the optimum temperature is 20-25 °C during the day and 15-20 °C during the night. At lower temperatures, especially at night temperatures of 15-20°C, flower buds tend to differentiate earlier, while the number of flowers per inflorescence is higher and the number of first-inflorescence nodes is lower. If the night temperature is lower than 15 °C or higher than 32 °C, flower bud differentiation is delayed, the number of flowers in each inflorescence is less, the flowers are also smaller, and it is easy to fall off. The optimum temperature for flower bud differentiation and flowering and seeding requires that the night temperature be 5-10°C lower than the daily temperature. If the night temperature is higher than the daily temperature, it is not good for the differentiation of tomato flower buds.
(4) The minimum temperature for tomato fruit development during fruit development is 5°C, the maximum temperature is 35°C, and the optimum temperature is 20-25°C. When the temperature is relatively high and the climate is relatively dry, the fruit color turns faster and matures within about 30 days after flowering. At temperatures below 10°C, the synthesis of lycopene is severely disturbed and destroyed. Even if given temperatures are appropriate, the fruit will not turn to normal red. When the temperature exceeds 32°C, although the speed of fruit development is accelerated, the number of fruit set is significantly reduced, that is, the fruit drop rate is increased, and the formation of lycopene is also inhibited, and the fruit is not bright, thus affecting the value of the commodity. When the night temperature is higher than the daily temperature, it will affect the nutrient accumulation of the tomato fruit, the increase of the fruit is blocked, and the empty fruit is easily formed.
2. Different organs have different temperature requirements. (1) Temperature requirements of root growth The optimum soil temperature for root growth is 20-22°C. The appropriate soil temperature not only promotes the development of roots, but also promotes the nutrients in the soil. Conversion, increasing the content of nitrate nitrogen, is conducive to the absorption of nitrogen by the root system. The root function declines at 13°C; when the temperature is lower than 8°C or higher than 36%, the root hairs stop growing; when the temperature is lower than 6°C or higher than 38°C, the root elongation stops; when it falls to 5°C, the root absorbs nutrients and moisture Obstruction. In the cultivation of tomato, the actual soil temperature limit is 13-14°C, and the high temperature limit is about 33°C.
(2) The temperature requirement of stem and leaf growth The minimum temperature for stem and leaf growth is 8°C, the optimum temperature is 26-28°C, and the maximum temperature is 38°C.
(3) The relationship between flower bud differentiation and temperature Temperature and seedling development have a great relationship. After sowing tomato, if the temperature is suitable, 25-30 days can be achieved: 30 cm in plant height, 2 mm in stem, 2 leaves in true leaves, weight in stem and leaf. 0.4-1.0 g, that is, flower bud differentiation of the first inflorescence. From sowing to flower bud differentiation of the first flower head, the approximate accumulated temperature was 600°C; the flower buds of the second flowering bud differentiated, and the accumulated temperature was 850-970°C; the accumulated temperature from flower bud differentiation to flowering was approximately 1 000°C. The period of flower bud differentiation can be predicted by the effective accumulated temperature and the temperature at the time of raising the seedlings. Although flower bud differentiation under high temperature conditions is earlier, the quality of flowers is affected. However, under low temperature conditions, although the seedling age is slightly longer, the number of flower bud differentiation is larger, the flower is larger, and the flowering rate is also high. high. The temperature difference between day and night also affects the flower buds. The most suitable temperature is 24°C during the day, 17°C at night, and the night temperature above 30°C makes it easy to develop flower buds and cause malformed flowers.
(4) Relationship between pollination, fertilization and fruit development and temperature During the flowering stage, tomato is sensitive to temperature, especially 5-9 days before flowering. On the day of flowering and 2-3 days after flowering, the temperature requirement is more stringent. The suitable temperature during the day is 20-30 °C, and the temperature is lower than 15 °C or higher than 35 °C, which is not conducive to the normal development and flowering of flowers, and the floral organs are affected, and it is easy to form malformed fruits.
Each flower is exposed to flowering from the corolla. It takes 4-5 days at an outside temperature of 22-25°C. The time of flowering is usually between 4-8am in the morning and rarely after 2pm. When the temperature is lower than 15°C, it stops. Flowering, easy to drop when above 35°C. When the petals are open to full bloom, the flower is mature, loose powder and pistil secrete a lot of mucus to accept pollen. The optimum temperature for pollen germination is 21°C. If the temperature is too high or too low, it will cause physiological disorders and cause flowers to fall. The minimum temperature for pollen development is around 13-15°C. If you suddenly encounter a large temperature drop during the flowering period or if it is at a low temperature for a long time, it will cause flowering. Falling flowers caused by high temperature mainly destroyed the normal function of pollen, reduced the fertilization ability of the pistil, the transpiration of the leaves was strong, the respiration was enhanced, the nutrient consumption was increased, and the plants were in a physiological imbalance.
Tomato can produce a parthenogenetic result under the action of growth stimulants, and the unisexual result is without seeds. Greenhouse tomatoes use growth stimulators or flower sprays during the early flowering period, and the majority of their results are unfruitful.
In the flowering stage, the temperature should be below 35°C, preferably below 30°C. For the fruit to develop well, the daytime temperature must be a photosynthesis temperature that maintains a strong, that is, the highest 28 °C, the most suitable 25 °C, night temperature between 12-17 °C. In the result period, the temperature is low and the growth rate of the fruit is slow. When the temperature in the daytime increases to 30-35°C, the fruit grows faster, but the number of fruit set is less, the night temperature is too high is not conducive to the accumulation of nutrients, and the fruit is not stunted. . When the fruit enters mature coloring, if the temperature is higher than 30°C, it will inhibit the formation of lycopene and other pigments and affect the normal coloration of the fruit.
1. Tomato in different stages of growth, the temperature requirements are also slightly different (1) germination tomato seed germination requires a higher temperature of 25-30 °C, the fastest germination at 28 °C, and the temperature is lower At 11°C, seeds germinate slowly after sowing.
(2) The optimum temperature for tomato vegetative growth at seedling stage is 20-25°C. Excessive temperatures are liable to make seedlings long; at temperatures above 35°C, plant growth stagnates. At seedling stage, tomatoes can tolerate prolonged low temperatures of 6-7°C and short periods of 0--3°C. Above 40°C, stems and leaves stopped growing; necrosis above 45°C; growth retardation at 8°C; growth at 5°C; freezing at -1-2°C. Seedling stage often through artificial low-temperature exercise, can enhance the cold resistance of the seedlings, conducive to controlling leggy, nurturing strong seedlings, low temperature exercise to 10 °C is appropriate. Plants at the seedling stage can tolerate low temperatures of 5-6°C for a longer period of time, and early maturing varieties can tolerate short-term low temperatures of 0°C.
(3) During flowering period, tomato plants are sensitive to temperature during the flowering period, and the optimum temperature is 20-25 °C during the day and 15-20 °C during the night. At lower temperatures, especially at night temperatures of 15-20°C, flower buds tend to differentiate earlier, while the number of flowers per inflorescence is higher and the number of first-inflorescence nodes is lower. If the night temperature is lower than 15 °C or higher than 32 °C, flower bud differentiation is delayed, the number of flowers in each inflorescence is less, the flowers are also smaller, and it is easy to fall off. The optimum temperature for flower bud differentiation and flowering and seeding requires that the night temperature be 5-10°C lower than the daily temperature. If the night temperature is higher than the daily temperature, it is not good for the differentiation of tomato flower buds.
(4) The minimum temperature for tomato fruit development during fruit development is 5°C, the maximum temperature is 35°C, and the optimum temperature is 20-25°C. When the temperature is relatively high and the climate is relatively dry, the fruit color turns faster and matures within about 30 days after flowering. At temperatures below 10°C, the synthesis of lycopene is severely disturbed and destroyed. Even if given temperatures are appropriate, the fruit will not turn to normal red. When the temperature exceeds 32°C, although the speed of fruit development is accelerated, the number of fruit set is significantly reduced, that is, the fruit drop rate is increased, and the formation of lycopene is also inhibited, and the fruit is not bright, thus affecting the value of the commodity. When the night temperature is higher than the daily temperature, it will affect the nutrient accumulation of the tomato fruit, the increase of the fruit is blocked, and the empty fruit is easily formed.
2. Different organs have different temperature requirements. (1) Temperature requirements of root growth The optimum soil temperature for root growth is 20-22°C. The appropriate soil temperature not only promotes the development of roots, but also promotes the nutrients in the soil. Conversion, increasing the content of nitrate nitrogen, is conducive to the absorption of nitrogen by the root system. The root function declines at 13°C; when the temperature is lower than 8°C or higher than 36%, the root hairs stop growing; when the temperature is lower than 6°C or higher than 38°C, the root elongation stops; when it falls to 5°C, the root absorbs nutrients and moisture Obstruction. In the cultivation of tomato, the actual soil temperature limit is 13-14°C, and the high temperature limit is about 33°C.
(2) The temperature requirement of stem and leaf growth The minimum temperature for stem and leaf growth is 8°C, the optimum temperature is 26-28°C, and the maximum temperature is 38°C.
(3) The relationship between flower bud differentiation and temperature Temperature and seedling development have a great relationship. After sowing tomato, if the temperature is suitable, 25-30 days can be achieved: 30 cm in plant height, 2 mm in stem, 2 leaves in true leaves, weight in stem and leaf. 0.4-1.0 g, that is, flower bud differentiation of the first inflorescence. From sowing to flower bud differentiation of the first flower head, the approximate accumulated temperature was 600°C; the flower buds of the second flowering bud differentiated, and the accumulated temperature was 850-970°C; the accumulated temperature from flower bud differentiation to flowering was approximately 1 000°C. The period of flower bud differentiation can be predicted by the effective accumulated temperature and the temperature at the time of raising the seedlings. Although flower bud differentiation under high temperature conditions is earlier, the quality of flowers is affected. However, under low temperature conditions, although the seedling age is slightly longer, the number of flower bud differentiation is larger, the flower is larger, and the flowering rate is also high. high. The temperature difference between day and night also affects the flower buds. The most suitable temperature is 24°C during the day, 17°C at night, and the night temperature above 30°C makes it easy to develop flower buds and cause malformed flowers.
(4) Relationship between pollination, fertilization and fruit development and temperature During the flowering stage, tomato is sensitive to temperature, especially 5-9 days before flowering. On the day of flowering and 2-3 days after flowering, the temperature requirement is more stringent. The suitable temperature during the day is 20-30 °C, and the temperature is lower than 15 °C or higher than 35 °C, which is not conducive to the normal development and flowering of flowers, and the floral organs are affected, and it is easy to form malformed fruits.
Each flower is exposed to flowering from the corolla. It takes 4-5 days at an outside temperature of 22-25°C. The time of flowering is usually between 4-8am in the morning and rarely after 2pm. When the temperature is lower than 15°C, it stops. Flowering, easy to drop when above 35°C. When the petals are open to full bloom, the flower is mature, loose powder and pistil secrete a lot of mucus to accept pollen. The optimum temperature for pollen germination is 21°C. If the temperature is too high or too low, it will cause physiological disorders and cause flowers to fall. The minimum temperature for pollen development is around 13-15°C. If you suddenly encounter a large temperature drop during the flowering period or if it is at a low temperature for a long time, it will cause flowering. Falling flowers caused by high temperature mainly destroyed the normal function of pollen, reduced the fertilization ability of the pistil, the transpiration of the leaves was strong, the respiration was enhanced, the nutrient consumption was increased, and the plants were in a physiological imbalance.
Tomato can produce a parthenogenetic result under the action of growth stimulants, and the unisexual result is without seeds. Greenhouse tomatoes use growth stimulators or flower sprays during the early flowering period, and the majority of their results are unfruitful.
In the flowering stage, the temperature should be below 35°C, preferably below 30°C. For the fruit to develop well, the daytime temperature must be a photosynthesis temperature that maintains a strong, that is, the highest 28 °C, the most suitable 25 °C, night temperature between 12-17 °C. In the result period, the temperature is low and the growth rate of the fruit is slow. When the temperature in the daytime increases to 30-35°C, the fruit grows faster, but the number of fruit set is less, the night temperature is too high is not conducive to the accumulation of nutrients, and the fruit is not stunted. . When the fruit enters mature coloring, if the temperature is higher than 30°C, it will inhibit the formation of lycopene and other pigments and affect the normal coloration of the fruit.
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