Planting time of tomato

Tomato likes temperature, and the suitable temperature is 25: 28 ℃ in daytime and 16: 18 ℃ at night. Below 15 ℃, tomato seed germination, pollination and fertilization and tomato turning red were affected: below 10 ℃, the growth was slow, the reproductive development was inhibited, the stem and leaf stopped growing at 5 ℃, 2 ℃ was chilled, and 0 ℃ was frozen to death. The reproductive development was affected when it was higher than 35 ℃, and died of heat due to physiological disorder above 40 ℃. Sufficient light and suitable temperature difference are beneficial to the accumulation and maturity of nutrients, promote the healthy development of plants, prevent overgrowth, enhance the disease resistance and stress resistance of tomato, and increase the yield.

Planting time of tomato

In general, according to the different planting and harvest time, tomatoes are divided into spring tomato, autumn and winter stubble, winter and spring stubble and overwintering stubble. Let's take a look at their planting time.

1. Planting time of spring tomato

The suitable seedling age for spring tomato cultivation in open field is 50ml 70 days, that is, it should be sowed 70 days before planting. For example, in Shenyang, located at latitude 41 north, spring tomatoes were planted in the protected field in February and planted in the open field after the late frost in early May.

Spring tomatoes are generally planted immediately after the local late frost period, when the soil temperature of the plough layer 5 Mel 10 cm deep stably passes through 12 ℃. For example, the average late frost period in Shenyang is May 2, and the suitable planting period is generally May 6-10. The Yangtze River basin is generally around the Qingming Festival, North China before and after Grain Rain, and the northeast region before and after the Beginning of Summer. The sandy land with Phoenix barrier, plastic film cover, and leeward and sunny terrain can be planted early. Planting should also be determined according to the weather conditions. In case of cloudy, rainy and Phoenix weather, planting should be postponed appropriately. In the suitable planting period, Shaanxi tomatoes should be planted early, mainly according to the time on the market, there are mainly two seasons a year, one is delayed cultivation after autumn, the seedlings start after July and August, and can be put on the market one after another in November. One is cultivated in early spring, raising seedlings in November and February and listing in May and June.

2. Planting time in autumn and winter.

The autumn and winter stubble is generally sown and raised seedlings from mid-July to early-middle August, and planted from mid-late August to early September. The plastic film was buckled from mid-late September to early October and harvested from late November to early February of the following year.

3. Planting time in winter and spring.

The winter and spring stubble was sown from early November to early December, planted from mid-late January to early February, and harvested from early-mid-March to June the following year.

4. Planting time of overwintering stubble

Overwintering stubble belongs to a large stubble cultivation. Generally, seedlings are raised from mid-late September to early October, planted in November, and harvested in January of the following year.

Tomato seed treatment

1. Soak the seeds with warm soup

Soaking seeds with warm soup is an effective measure to break seed dormancy, promote seed germination, sterilize and prevent disease, and enhance seed resistance.

① soaked the seeds in clean water for 1-2 hours.

② remove and put the seeds in warm water of 55 degrees Celsius, keep the water temperature and soak for 15 minutes, then soak the seeds for 3-4 hours, and then accelerate germination. When soaking seeds in warm soup, usually one seed and two parts of water. At the same time, stir constantly and quickly so that the seeds are heated evenly to prevent scalding the seeds.

③ should keep heating water to keep the temperature of 55 degrees Celsius. This disinfection method can prevent the occurrence of tomato leaf mold, canker, early blight and other diseases.

2. Disinfection with medicament

Soak the seeds with ① trisodium phosphate: first soak the seeds in clean water for 3-4 hours, remove them and drain them, then soak them in 10% trisodium phosphate solution for 20 minutes, rinse with clean water and accelerate germination. This method has obvious effect on tomato virus disease.

Soak seeds in ② formalin solution: soak the swollen seeds in 1% formalin solution for 15-20 minutes, seal the container so as not to volatilize the liquid when soaking the seeds, then wrap them in a closed container with a wet cloth for 2-3 hours, rinse with clean water repeatedly, and then soak the seeds to accelerate germination, this method can reduce or control the occurrence of tomato early blight.

③ soaked seeds with 0.1% potassium permanganate solution for 15 minutes, which could effectively reduce the occurrence of tomato mosaic virus and early blight.

④ put the pre-soaked tomato seeds in 1000mg/kg agricultural streptomycin solution for 30 minutes, which had a good effect on the control of bacterial wilt.

Tomato Seedling raising technique

1. Determine the sowing amount

General tomato seeds contain about 300 seeds per gram, according to the planting density, generally 20-30 grams per 667 square meters of field seeds. Each square meter of seeding bed can sow 10-15 grams. If the seed germination rate is less than 85%, the sowing rate should be increased appropriately. The seeds should be soaked in warm water for 6-8 hours to fully expand, and then sprout at 25-28 degrees Celsius for 2-3 days. On the other hand, the seeds soaked with chemicals only need to rinse the seeds with clean water and then sprout directly. In the process of sprouting, it is necessary to provide appropriate temperature, moisture and air, so that the seeds should be checked and turned frequently to make the seeds loose, and rinse with clean water 1-2 times a day to update the air and maintain humidity. It is best to use a thermostat to promote budding. After accelerating the germination of the seeds, the seedlings emerge quickly and neatly after sowing, which is conducive to the cultivation of robust seedlings.

2. Seed bed preparation

Before sowing tomatoes, adequate seeding beds should be prepared according to the planting plan. In order to prevent the harm of bacteria, the seedling bed should be disinfected before sowing. In most areas of China, especially in the north, sufficient bottom water should be irrigated in the sowing bed before sowing, and the appropriate amount of irrigation is that the water content of the bed soil is 8-10 cm deep to reach saturation. Generally, the seedlings are no longer irrigated before transplanting. In the south or areas with high groundwater level, only a small trench is opened on the bed before sowing, small water is watered with a kettle, and then sown after the water seeps, and then a proper amount of water is sprayed with a spray can according to the growth of the seedlings to prevent soil consolidation. After the bottom water seeps, sprinkle a thin layer of sifted soil on the bed surface. The sowing bed is divided into cold bed and hotbed. The cold bed is the nursery bed or the nursery bed set up in the plastic greenhouse. It is a way to raise seedlings by using sunlight heating. On the basis of the cold bed, the hotbed is a way of raising seedlings by using artificial heating equipment to increase the temperature of the seedling bed.

3. Determine the sowing date

The suitable sowing date was determined according to the planting season, climatic conditions, cultivation methods, seedling facilities and other factors. For example, in open field cultivation in spring, seedlings are usually sown in Beijing from mid-February to early March. The effect of open field cultivation in autumn is the best in places such as Shanghai and Nanjing to the south of the Yangtze River from late July to early August, while the yield of sowing in eastern Sichuan is higher in early July. The output is also higher. In some areas where tomato diseases are serious, the sowing date can be postponed for 1-2 months, and then higher yield can be obtained through close planting, early coring, increasing fertilizer and water and other measures.

4. Sowing method

There are usually broadcast, broadcast and on-demand. The soil should be covered immediately after sowing, and sifted fine soil should be used for covering. The thickness of the covered soil is about 0.8-1.0 cm, and the thickness should be consistent. After sowing, 8 grams of carbendazim 50% wettable powder mixed with fine soil is scattered evenly on the bed surface after sowing, which can prevent the occurrence of seedling quenching disease. The surface of the seedling bed should also be covered with plastic film in winter and spring. The surface of the seedling bed should be covered with sunshade net or straw in summer and autumn, and the mulch should be removed when there is 70% seedling top soil.

5. Management during seedling emergence

In general, the temperature of the nursery bed is high, the heat preservation condition is good, and the seeds are accelerated first, and the seedlings can emerge 2-3 days after sowing, on the contrary, it will take 5 days or more to emerge.

6. Seedling stage management

The seedling management of tomato planting is mainly the control of temperature and light.

Seedbed management from sowing to emergence of ①: this period refers to the period from sowing to full expansion of two cotyledons. The nursery period of tomato cultivated in open field in spring is arranged in the cold season, and the bed temperature must be controlled at 25-28 degrees Celsius during the day and 15-18 degrees Celsius at night. If a cold bed or hotbed is used to raise seedlings, solar energy should be fully utilized to increase the bed temperature and mulch should be used to maintain a higher bed temperature. Generally do not uncover the film and open the window before emergence. When the young buds begin to emerge from the top soil, if the cover soil is too thin and the top shell phenomenon is found, it should be covered with soil again immediately. The temperature management in winter and spring nursery period is shown in the table below.

② seedling bed management from emergence to pre-seedling division: this period is mainly to adjust the temperature and humidity of the seedling bed, timely interseedling and soil mulching, improve light conditions, control seedling diseases and so on. After the two cotyledons of the seedlings are fully expanded, the bed temperature should be reduced appropriately, which can be controlled at 20-25 degrees Celsius during the day and 10-15 degrees Celsius at night to prevent excessive growth. 4-5 days before seedling separation, in order to adapt to the lower temperature of the seedling bed, improve the survival rate after transplantation, and promote slow seedling, the bed temperature can be further reduced by 2-3 degrees Celsius. Raising seedlings in cold beds, especially in hotbeds and greenhouses, should gradually increase ventilation vents during the day, prolong ventilation time, and gradually uncover grass or thin mats early and late to prolong light time. The disease of standing blight or quenching which is easy to occur in the seedling stage is often caused by the gradual increase of air humidity in the seedbed without proper ventilation and covering with grass grass and thin film for a long time in bad weather. During this period, special attention should be paid to protecting cotyledons, improving light conditions, harmful time seedlings, water and fertilizer management, and reasonable soil mulching.

Control of Tomato Diseases and insect pests

1. Tomato flower peel

Tomato flower skin is a physiological disease, also known as tendon rot or stripe rot or with rot, which mainly harms the fruit. Here are two common types:

Browning type: it began to occur in the young fruit stage, mainly harming 1-2 ear fruit, local browning appeared on the fruit surface during the fruit expansion period, the fruit surface was uneven, some fruits showed tea-brown hardening or necrotic spots, and the diseased fruit was dissected. It can be found that the vascular bundles in the pericarp showed tea-brown strip necrosis, hardening of the core or browning of the flesh, losing commercial value.

White metamorphosis: it mainly occurs in the period when the green ripe fruit turns red, the disease is that the fruit coloring is uneven, the light fruit shape does not change much, the heavy part near the fruit stalk appears green protuberance, the red part is slightly sunken, and the bright face is red and green uneven.

[symptoms] Tomato tendon rot is generally not seen on the stems and leaves, but the stem 70 cm away from the root shows brown pathological changes in the conducting tissue of the stem, which has been destroyed, resulting in the above-mentioned disease in the fruit, which is different from the virus disease.

[etiology] because it is a physiological disease, the degree of damage depends on the variety (big fruit red tomato Wanda is not easy to be infected), sunshine hours, light intensity and the proportion of nitrogen, phosphorus and potassium in the soil.

[prevention and control methods] the main work is to make efforts in management, appropriately increase light to scientifically determine the date of sowing and planting, and adopt formula fertilization. Those who have the above symptoms can be sprayed with multi-element fertilizer.

2. Tomato fruit is hollow.

Tomato hollow fruit refers to the fruit with holes between the pericarp and the pulp jelly. Although the hollow fruit has little effect on the yield of tomato, it will seriously affect its commerciality and reduce the economic benefit, which can not be ignored in the production.

Tomato hollow fruit is a physiological disease, which is easy to occur in varieties with a small number of ventricles. There are many reasons for the formation of tomato hollow fruit, such as improper spraying time of hormone, lack of light, insufficient watering in peak period, too much fruit left, lack of nutrition supply and so on. The growth trend of each tomato variety is different, so it should be pinched in time according to the characteristics of each variety, so that the vegetative growth and reproductive growth of the plant can be developed in a balanced way.

3. Bacterial spot of tomato

Tomato bacterial spot disease is also called bacterial leaf spot disease, bacterial leaf spot disease. In general, the output is reduced by 1030%, and in severe cases, it can reach more than 50%.

[damage characteristics] Tomato bacterial spot is mainly harmful to leaves, stems, flowers, petioles and fruits.

① leaves are susceptible: produce dark brown to black irregular spots, 2mm in diameter, with or without yellow halos around the spots.

② petiole and stem: the symptoms are similar, producing black spots, but there is no yellow halo around the spot. The disease spot is easy to connect into patches, and in severe cases, it can blacken a section of stem.

③ bud damage: many black spots are formed on the sepals, which, when connected, make the sepals dry up and fail to bloom normally.

④ young fruit: the small spots are slightly raised in the early stage, and the spots around the disease spots tend to remain green for a long time when the fruit is nearly mature. The flesh near the spot is slightly sunken, the spot is black around, and the middle color is light and slightly sunken.

[occurrence regularity] the pathogen of tomato bacterial spot disease is Pseudomonas clove. The pathogen can overwinter on tomato plants, seeds, disease residues, soil and weeds, can survive on dry seeds for 20 years, and can spread over a long distance with seeds. After sowing infected seeds, the seedlings can get sick, and the seedlings can be transmitted to the field after the disease, and spread through Rain Water, insects, and agricultural operations, resulting in an epidemic. As long as 10% of the plants in the field are sick, it can be transmitted to the whole land. It is beneficial to the occurrence of the disease when the temperature is below 25 ℃ and the relative humidity is more than 80%.

[prevention and control methods]

① agricultural prevention and control: strengthen quarantine, prevent infected seeds from being introduced into non-epidemic areas, select disease-resistant and disease-tolerant varieties, establish disease-free seed fields, adopt disease-free seedlings, carry out rotation with non-eggplant vegetables for more than 3 years, pay attention to avoid the spread of diseases in agricultural operations such as pruning, branching and harvesting, and adopt drip irrigation or furrow irrigation in arid areas to avoid sprinkler irrigation as far as possible.

② seed treatment: soak the seeds in 55 ℃ warm water for 30 minutes, or soak the seeds in 0.6% acetic acid solution for 24 hours, or soak the seeds with 5% hydrochloric acid for 10 hours, or soak the seeds with 1.05% sodium chlorate for 20 minutes for 40 minutes. Rinse off the solution with clean water after soaking the seeds, dry slightly before sprouting.

③ medicament prevention and treatment: in the early stage of the disease, 77% Keshou wettable powder 400% 500 times, 53.8% can kill 2000 dry suspensions, 20% thiabendazole (Longke bacteria) suspension 500x, 14% complex ammonia copper solution or 0.3% 0.5% copper hydroxide solution for prevention and treatment, spray every 10 days or so for 3 times.

4. Green back fruit

[harmful symptoms] after the fruit turned red, green areas or patches remained on the shoulder or near the pedicel of the fruit, which did not turn red all the time. The fruit was red and green, the flesh in the green area was hard, the fruit tasted sour and the taste was poor.

[cause of the disease] excessive growth of tomato plants occurred when nitrogen fertilizer was applied, especially when there was more nitrogen fertilizer, less potassium fertilizer, boron deficiency and dry soil.

[control methods] during the fruit expansion period, potassium should be supplemented in time and compound micro-fertilizer containing potassium and boron should be sprayed.

5. Brown fruit

[harmful symptoms] the fruit turns red after ripening, but the red is exposed brown so that the fruit is tea-brown, the appearance of the fruit is dirty, the radiance is poor, and the commerciality is obviously low.

[cause of the disease] High temperature and weak light are the root genes that produce brown fruit. when the fruit ripening temperature is lower than 24 ℃, chlorophyll will increase and delay the composition of lycopene, resulting in the appearance of brown fruit, partial or excessive application of nitrogen fertilizer and lack of potassium and boron. In the greenhouse of rotation and soil salt evolution, it is easy to cause brown fruit if excessive fertilization is applied.

[control methods] punishment for accelerated ripening and disposal of fruits should be held to prevent sudden dryness, dampness, or over-drying and over-wetting. Or excessive application of nitrogen fertilizer to stop vegetative growth.

6. Umbilical rotten fruit

[harmful symptoms] the disease occurs in the young fruit stage from ping-pong to the size of eggs, at the beginning of the fruit top (navel) is flooded dark green or dark gray, and soon becomes dark black, the pulp is dehydrated, the top is flat or sunken, and the disease spot sometimes has concentric wheel markings, the peel and pulp are flexible, generally do not decay, when the atmosphere is moist, the diseased fruit is rotten.

[cause of disease] the direct cause is caused by calcium deficiency. Fourth, the punished fruits treated with growth regulators are prone to navel rot.

[prevention and control methods] while ① stops excessive nitrogen and potassium fertilizers, a large number of quick-acting fertilizers are applied at one time, ② prevents soil boredom and increases the amount of irrigation. After ③ enters the fruiting period, 0.1%-0.3% calcium chloride aqueous solution is sprayed every 7 days, and calcium fertilizers such as Lufenwei No. 3 can also be sprayed successively.

7. Sunburn fruit

[harmful symptoms] the burned part of the fruit showed large chlorotic white spots, the appearance was bright and leathery, sunken. In the later stage, the disease turned yellow, the appearance sometimes appeared wrinkles, dried and hardened, the flesh was necrotic and became brown and massive.

[control methods] reasonable close planting, excessive pruning and branching, when selecting inflorescences and pruning and binding vines, the inflorescences should be arranged on the inside of the bracket, shaded by their own leaves, and 2 leaves should be left on the top of the last ear when hitting the top, so as to protect the ear from light, timely ventilation, low room temperature, and sunshade net to stop strong light.

[cause of the disease] the fruit is burned because of the high temperature in the direct sunlight department.