First, the biological characteristics of tomato
Root system: the root system is relatively strong, widely distributed and deep. At the full fruit stage, the taproot penetrated into the soil for more than 1.5 meters, and the root spread could reach 2.5 meters. Most root groups are located in 30-50 cm topsoil. Roots have strong regeneration ability, and adventitious roots are easy to produce on stem nodes, so cutting propagation is easy to survive.
Stems: Semi-erect stolons. Seedlings can stand upright, and sheds need to be built in the middle and late stages. A few varieties are erect stems. The branches of the stems are very strong, so they need pruning and branching. According to the growth of stem, it can be divided into self-capping type and infinite growth type.
Leaves: molecular leaves and true leaves. True leaves have fluff on the surface and large cracks, so they are drought-tolerant leaves. Early-maturing varieties have small leaves, late-maturing varieties have large leaves, deep leaves cultivated in the field and small protective leaves. At low temperature, the leaves are purple, and at high temperature, the leaves are rolled lobules, with hairs and secretory glands on the leaves and stems, which can secrete juice with special odor and fewer pests.
Flowers: bisexual flowers, the number of flowers per inflorescence is generally 5~8, up to more than 20, self-pollination. In bad environment, especially at low temperature, it is easy to form deformed flowers, deformed fruits or fall off. Individual varieties or some varieties can cross-pollinate under certain conditions, and the natural hybridization rate is 4~ 10%.
Fruit: Fruit has various shapes, such as round, flat, pear and rectangle. Fruits are varied in color, including red, pink, orange red, yellow, green and white.
Seed: kidney-shaped, 1,000-grain weight 3-3.3g, life span 4-5 years, and new seeds used in production for 1-2 years.
Second, the growth cycle of tomato
Tomato is a perennial herb in tropical regions, but it is cultivated as 1 year in frost regions in temperate regions. Its growth and development process has certain stages and periodicity, which can be roughly divided into four different stages: germination stage, seedling stage, flowering and fruiting stage and fruiting stage.
Germination period: it takes 6-9 days from sowing to the appearance of the first true leaf at room temperature, and the nutrients needed for its growth are supplied by the seeds themselves.
Seedling stage: it refers to 45-50 days from the appearance of the first true leaf to the appearance of the first inflorescence, and there is no seedling division at room temperature. This stage is the turning point of tomato from vegetative growth to reproductive growth and vegetative growth, which is directly related to the formation and yield of product organs.
Flowering and fruit-setting period: it takes about 15~30 days from the first inflorescence to the first fruit formation. In this period, fruits and seedlings grow at the same time, so it is a key task to solve the contradiction between vegetative growth and reproductive growth.
Fruiting period: about 40-60 days from the first flowering to the end of harvesting. During this period, the plant not only continued to differentiate and develop flower buds and leaf buds, but also grew vigorously in nutrition, and the phenomenon of plant height increase and leaf growth appeared. Therefore, at this stage, it is necessary to adjust the relationship between vegetative growth and reproductive growth, not only to make vegetative growth full, leaves stout, stems stout and deep-rooted, but also to avoid virtual growth, prevent flowering and delay flowering and fruiting.
Third, the demand of tomatoes for the environment
temperature
Tomato is a kind of temperate vegetable. Generally speaking, it can adapt to the growth of tomato in the temperature range of 15~35℃, and the most suitable temperature for the growth period is 20~30℃. The optimum ground temperature for tomato growth is 20~23℃. When the ground temperature drops to 6℃, the root system stops growing.
Seedling stage: the optimum temperature is 20~25℃ during the day and 10~ 15℃ at night. Too high or too low temperature at seedling stage will easily lead to weak seedling growth, poor flower bud differentiation and development, and poor flower quality, which will easily lead to falling flowers and fruits during flowering and fruiting.
Flowering: sensitive to temperature, the optimum temperature is 20~30℃ during the day and 15~20℃ at night. When the flowering period encounters low temperature or high temperature above 30℃, pollen grains germinate, pollen tube elongation is poor, fertilization is poor, and it is easy to drop flowers and fruits.
Results: The optimum temperature was 24~26℃ during the day and 12~ 17℃ at night.
Fruit coloring period: the optimum temperature is 20~25℃, and coloring is not good above 30℃.
illuminate
Tomato is a kind of crop that likes light and short sunshine, but most varieties are not strict with sunshine and do not need a specific photoperiod.
Germination stage: no light is needed.
Seedling stage: strict requirements for light, insufficient light delayed flower bud differentiation, resulting in an increase in flowering nodes, a decrease in the number of flowers and a decline in flower bud quality.
Flowering period: insufficient light can easily lead to falling flowers and fruits.
Fruiting period: under strong light, there are many fruits and large single fruit. In weak light, the fruit setting rate is low, the weight of single fruit is reduced, and empty fruit and rotten fruit are easy to appear.
moisture
Tomato has lush stems and leaves on the ground, and its transpiration is relatively strong. The transpiration coefficient is about 800, so it needs more water. However, tomato has developed roots, strong water absorption capacity, semi-drought-tolerant water demand, and the suitable air relative humidity is 45~50%.
Seedling stage: rapid growth. In order to avoid excessive growth and diseases, soil moisture should not be too high, and irrigation should be controlled properly.
Before the first inflorescence fruit setting: Too much soil moisture can easily lead to excessive plant growth, poor root development and flowering.
After the fruit of the first inflorescence expands, the water demand increases obviously.
Fruit expansion period: the daily water absorption of each tomato is 1~2 liters. According to soil transpiration, water properly, and water less frequently. Watering interval is 5~7 days in full fruit period.
land
Tomatoes have low requirements for soil, so it is best to choose fertile loam with deep soil layer, good drainage and rich organic matter.
Four. Key points of tomato cultivation techniques
seed treatment
Disinfection: Choose the appropriate disinfection method according to local common diseases. There are two main methods in common use. ① Soak the seeds in warm soup, put the seeds in warm water at 55℃ and keep the water temperature to soak the seeds for about 15 minutes. Through this treatment, diseases such as canker and leaf mold can be effectively controlled. (2) Soaking the seeds with trisodium phosphate: firstly, soak the seeds in clean water at room temperature for 3-4 hours, then add an appropriate amount of trisodium phosphate solution into the clean water to continue soaking for about 20 minutes (the concentration is 10%), and finally take out the seeds for cleaning. Through this treatment, viral diseases can be effectively prevented.
Accelerating germination: soak the sterilized seeds for 6-8 hours, then take them out and wash them, and put them in an environment of 25℃ to accelerate germination, keeping proper temperature and humidity.
Preparatory work/about to start work
Nursery facilities: Choose suitable nursery facilities according to local seasons and climatic conditions. Commonly used facilities mainly include: sunlight greenhouse, plastic greenhouse, multi-span greenhouse and hotbed. In addition, in summer and autumn, corresponding pest control facilities and sunshade facilities should be provided.
Preparation of nutrient soil: according to the basic principle of adjusting measures to local conditions, planting elements, such as field type, fertilizer, peat, chaff ash, etc. , according to the design proportion, to meet the requirements of subsequent use.
sow seeds
Sowing date: according to the local season and climate conditions and the selected strong seedling index, determine the best sowing date.
Sowing method: more than 70% of the seeds with accelerated germination appear white, and the seedlings in summer and autumn can be directly sowed with sterilized seeds.
Before sowing, pour enough bottom water until the depth of bed soil exceeds10cm. Sow a layer of nutrient soil after water is completely soaked, level the bed surface, then sow evenly, and then cover with a layer of nutrient soil after sowing.
In order to prevent damping-off, carbendazim and fine soil should be sown on the seedbed. Cover the seedbed with a plastic film in winter and Spring Festival, and cover the seedbed with straw in summer and autumn.
Seedling management
Environmental control: ① temperature, shading and cooling should be carried out in summer and autumn, and appropriate management methods should be adopted according to the actual situation in winter and spring; (2) Lighting should be strengthened in winter and spring, and shaded in summer and autumn; (3) Moisturize, fully water the seedlings, and water them according to the season and other factors.
Seedling separation: after the two cotyledons of the seedlings are completely unfolded, they are moved into a nutrition bowl. The scheme of soil for nutrition bowl is to mix live soil with decomposed ring fertilizer in a ratio of 7:3, and add diammonium phosphate, plant ash and carbendazim appropriately.
Increase the nutrient area: when the number of leaves of seedlings reaches 3~4, increase the seedling spacing, fill the gap in the container with fine mud, and do a good job of moisturizing and heat preservation.
Fertilizer and water management: the main work at seedling stage is to control water and fertilizer. When the number of seedlings leaves reaches 3~4, biological stimulators can be sprayed according to the actual situation.
Hardening: the temperature of early spring seedlings is strictly controlled between 15~20℃ during the day and 5~ 10℃ at night. Sunshade facilities should be gradually dismantled in summer and autumn to effectively control humidity.
Strong seedling index: the seedlings cultivated in spring and summer have a plant height of 25cm, a stem diameter of 0.6cm and large buds. Summer and autumn seedlings, plant height 15cm, stem diameter 0.4cm, developed and formed within 25 days.
Field planting
Soil preparation and fertilization: the base fertilizer is mainly decomposed high-quality organic fertilizer, with an amount of 2500~3000kg per mu. According to the maturity and cultivation period of tomato varieties, a proper amount of chemical fertilizer is added.
● For early-maturing varieties, 25-30kg of calcium superphosphate, 0/5-20kg of potassium sulfate and 0/0kg of urea are applied per mu.
● For late-maturing varieties, the amount of nitrogen fertilizer should be properly controlled.
Generally speaking, the distribution of nitrogen fertilizer and chemical fertilizer in plastic film tomato cultivation is suitable for spreading base fertilizer and topdressing.
In addition to phosphate fertilizer, full-layer fertilization can also be implemented, so that fertilizer and topsoil can be evenly mixed, and soil and fertilizer can be blended. Calcium superphosphate and organic fertilizer are fully mixed and applied to planting holes to reduce the fixation of phosphorus in soil. After tomato seedlings are put into planting holes, biological stimulators are sprayed immediately to stabilize the seedlings. In addition, in order to make tomato roots grow normally and increase sugar, a small amount of boron fertilizer can be applied when sowing.
Planting time: 25 days after sowing, when the number of seedlings leaves is 5, it is the suitable planting period.
Field water and fertilizer management
Water and fertilizer management is the most important part of tomato growth. After 7~ 10 days of planting, combined with watering, the fruit-promoting fertilizer was applied at one time, and the dosage was 500 kg per mu.
When the first ear begins to swell, apply urea 10~ 15kg with water. The first ear of fruit is about to be harvested, and when the second and third ears of fruit expand, the plant enters a prosperous period. It is better to apply about 1000kg of manure or available nitrogen fertilizer per mu, and it is better to apply manure and nitrogen fertilizer alternately for three consecutive times, which can achieve the purpose of strengthening seedlings, preventing premature aging and improving fruit quality.
In addition, in the middle and late stage of tomato growth, the growth of stems and leaves began to slow down. In order to strive for the yield in the middle and late stage and prevent premature aging, foliar fertilizer spraying on leaves has a good effect on promoting fruit development.
Plastic trimming
Tomato has a strong growth potential. Every node of the stem will split into axillary buds, and each axillary bud can sprout branches, blossom and bear fruit. If it is allowed to grow, it will lead to excessive growth of branches and leaves, disorder of plant shape, easy consumption of a large number of nutrients, resulting in falling flowers and fruits, small deformation of fruits, and decline in yield and quality. Therefore, in the process of tomato growth, pruning, harrowing and leaf thinning should be carried out continuously to adjust the growth.
_ For specific methods, please refer to: tomato shaping and pruning technology.
Eliminate pests and diseases
Common tomato diseases include early blight, late blight, cotton wilt, gray mold, leaf mold, bacterial spot disease, virus disease, root-knot nematode disease and so on. Pests mainly include liriomyza sativae, whitefly, aphid, cotton bollworm and so on. Attention should be paid to timely medication, prevention first and comprehensive treatment.