What are the pollution-free cultivation technical measures for cherry tomatoes?

I. Cultivation season

In the northern region, sowing is from mid-September to early January of the following year, and harvesting is from late December to mid-May of the following year; in the southern region, sowing is from late August to mid-December, and harvesting is from late November to April of the following year.

II. Variety selection

Select varieties that are disease-resistant, heat-tolerant, high-quality, high-yielding, tolerant of storage and transport, good in marketability, and adapted to the market. Recommended varieties: AVRDC No. 6, Cuihong, Longnu, Red Queen.

III. Seedling-raising techniques

1. Preparation before seedling raising

(1) Seedling-raising facilities: According to different climatic conditions, choose seedling-raising facilities such as small plastic tunnels or ordinary cold beds, promote the use of plug seedling technology, and disinfect the seedling-raising facilities to create environmental conditions suitable for the growth and development of seedlings. Small plastic tunnel: ridge height 0.5 m—0.6 cm, span 1.2—1.5 m, length unlimited. Seedling plug tray: 72—100 cells, tray length, width, and height of 55 cm×35 cm×7 cm.

(2) Nutrient soil: According to local conditions, use field soil free of disease and insect sources, rice husk ash or coconut coir, fully decomposed farmyard manure, and sandy soil in a 6:3:1 ratio to prepare nutrient soil. Requirements: porosity of about 60%, available phosphorus above 100 mg/kg, available potassium above 100 mg/kg, available nitrogen above 150 mg/kg, pH 6—7. Loose, fertilizer-retentive, water-retentive, and complete in nutrients. Spread the prepared nutrient soil evenly on the sowing bed at a thickness of 10 cm, and fill it into the seedling plug trays.

(3) Sowing bed: Prepare enough sowing beds according to the planting plan. Spray the bed soil with a 1000-fold dilution of soil fungicide to disinfect the sowing bed. The sowing bed is generally 150 cm wide, 25-30 cm high, and unlimited in length.

2. Seed treatment

(1) Disinfection treatment

Select the following disinfection methods according to the main local diseases.

a) Hot water seed soaking: Put the seeds into 55°C warm water, maintain a uniform water temperature and soak for 15 minutes, then soak in warm water for 5—6 hours. Mainly controls leaf mold, canker, and early blight.

b) Trisodium phosphate seed soaking: First soak the seeds in clean water for 4—5 hours, then place them in a 10% trisodium phosphate solution and soak for 20 minutes, remove and wash clean. Mainly controls viral diseases.

(2) Germination

Remove the disinfected seeds and wash them clean, then place them under conditions of 25°C—28°C with heat and moisture retention for germination.

3. Sowing

(1) Sowing period: Select the appropriate specific sowing period according to the cultivation season, climatic conditions, seedling-raising methods, and strong-seedling indicators.

(2) Seed quality: Meets the requirements of grade 2 or above in GBI6715.3-1999. The specific requirements are: seed purity ≥95%, cleanliness ≥98%, moisture ≤7.0%.

(3) Sowing rate: According to seed size and planting density, generally 3—4 grams of seed are used per mu of field.

(4) Sowing method: Sow when more than 70% of the germinated seeds have broken through the seed coat, or sow directly after disinfection. Before sowing, water thoroughly to moisten the bed soil to a depth of 10 cm, available phosphorus 100 cm. After the water seeps down, thinly scatter a layer of nutrient soil, level the bed surface, and sow the seeds evenly. For each square meter of seedling bed, use 8 grams of 50% carbendazim wettable powder or 8 grams of 70% quintozene wettable powder mixed with dry fine soil and scatter it thinly and evenly on the bed surface to control damping-off. After sowing, cover with nutrient soil 0.8—1.0 cm. For plug seedling raising, first water the substrate thoroughly, and sow at a depth of 0.8—1.0 cm. According to climatic conditions, cover with plastic film, shade net, or rice straw, and remove when 70% of the seedlings emerge from the soil.

4. Seedling-stage management

(1) Environmental regulation

a) Temperature: High temperatures are mainly reduced by shade nets. Low temperatures are managed by using plastic tunnels. The optimum daytime temperature is 25°C—28°C, and the optimum nighttime temperature is 17°C—20°C.

b) Water and fertilizer: After emergence, appropriately control moisture. After the seedlings have 2 true leaves and 1 heart leaf, apply 2—3 times of seedling-promoting fertilizer according to seedling condition. Mainly use 0.1%—0.3% NPK compound fertilizer.

(2) Strong-seedling indicators

4 leaves and 1 heart leaf, plant height 15 cm, stem diameter about 0.4 cm, seedling age about 25 days. Leaf color dark green, free of diseases and insect pests.

IV. Field planting

1. Preparation before field planting

(1) Land preparation and base fertilizer application. Generally, the amount of base fertilizer applied: phosphate fertilizer more than 80% of the total fertilizer application, nitrogen fertilizer and potassium fertilizer 20%—30% of the total fertilizer application. Apply 1500—2000 kg of high-quality organic fertilizer (organic matter content above 9%) per mu. When nutrients are insufficient, supplement with chemical fertilizers; scatter 50—75 kg of quicklime per mu, 30—40 kg of high-quality cake fertilizer, and 30—40 kg of high-quality phosphate fertilizer. These fertilizers must be fully decomposed and fermented, of which 2/3 is scattered during land preparation with deep plowing of 25—30 cm, and the remaining 1/3 is applied into the planting furrows (holes). Make beds according to local planting habits. Generally, the bed width is 160—180 cm (including furrows).

(2) Mulching with plastic film: Choose plastic film according to the width of the bed. Generally choose black plastic film with a thickness of 0.02 mm and a width of 120—130 cm. Lay the plastic film flat on the bed, and press the edges tightly with dry fine soil to prevent the wind from lifting the film.

2. Field planting method and density

According to the bed specifications, use wide and narrow rows or single-row planting. Determine the plant spacing according to variety characteristics, pruning method, soil characteristics, climatic conditions, and cultivation habits; generally plant 1200—1600 plants per mu. Field planting should be shallow, with attention to carrying more nutrient soil, promptly watering the roots, and sealing the planting holes in the plastic film tightly.

V. Field management

1. Fertilizer and water management

(1) Fertilizer and water management methods

Drip irrigation under film or dark irrigation is preferable. If traditional irrigation methods are used, irrigation is preferable in the early stage, and furrow irrigation may be used in the middle and late stages, but water should not submerge the beds, and irrigation and drainage should be rapid. During the fruiting period, soil moisture should be maintained at 60%—80% of the maximum water-holding capacity of the soil. Apply topdressing promptly according to soil fertility, the length of the plant growth period, and growth conditions; the conventional cultivation fertilizer application amounts are shown in Table 3. After deducting the base fertilizer portion, apply it in multiple split applications with water (calculated at the low-fertility standard; the specific topdressing amount is 5 kg NPK compound fertilizer, 2.5 kg urea, 2.5 kg potassium fertilizer/667 sq m·time). In areas where soil trace elements are deficient, trace element fertilizers should also be applied as topdressing according to the deficiency conditions.

(2) Fertilizers not permitted for use

In production, urban waste, sludge, industrial waste residue, and organic fertilizer that has not undergone harmless treatment should not be used.

2. Vine tying and pruning

(1) Trellis and vine tying: A straight-line trellis is preferable, using thick bamboo poles and iron wire to fix the main frame, then using thin bamboo poles as auxiliary support, and tying the vines promptly.

(2) Pruning methods: There are three pruning methods for cherry tomatoes: two-stem pruning, three-stem half pruning, and two-stem two-half pruning; select the appropriate pruning method according to planting density and purpose. Two-stem two-half pruning is recommended.