Tomato Green Cultivation Technology of Reducing Fertilizer and Pesticide Input and Increasing Fertilizer Efficiency

Yongxun MAO, Chun LI, Lanxiang MA, Yuanjing XU, Tao WEI

1. Zaozhuang Academy of Agricultural Sciences, Zaozhuang 277399, China; 2. Zaozhuang Agricultural Machinery Technology Extension Center, Zaozhuang 277101, China

Abstract According to the technical approach of green production and yield increase pattern, green, pollution-free, quality and efficiency improvement can be achieved by reducing nitrogen, controlling phosphorus and stabilizing potassium, replenishing sulfur, zinc, iron, manganese and boron from the aspects of controlling fertilizer, drug and water. The main measures include combination use of organic and inorganic fertilizer, effective control of the amount of nitrogen and phosphate fertilizer, reduction of the application amount of chemical fertilizers and pesticides, and rational crop rotation to reduce the occurrence of diseases and insect pests, which can improve the yield and quality of tomato.

Key words Tomato; Intensive technology; Pollution-free; Quality and efficiency improvement

1 Introduction

With the development of agricultural science and technology, the improvement of people’s quality of life and the enhanced awareness of environmental protection, human beings are more and more strict about food that affects physical and mental health. Nutritious, safe, green and healthy vegetables are the inevitable requirements of agricultural economic development. Mastering the growth and development rules of tomato, creating suitable environmental conditions, controlling or promoting vegetative growth or reproductive growth purposefully play a vital role in improving the yield and quality of tomato.

2 Requirements on environment

Tomato prefers warmth and light and is afraid of rain and heat, so it has good growth and high yield in spring and autumn with warm climate and strong light, but has weak growth, heavy disease and low yield in summer with high temperature and heavy rainfall and in winter with low temperature and sparse sunlight.

2.1 Environment of producing areaPollution-free tomato production base should be far away from the pollution of "three wastes" and choose the area with good ecological conditions. The environment of producing area should comply with atmospheric environment quality standard and water quality of pollution-free agricultural products base and the quality standard of farmland soil environment issued by the Ministry of Agriculture. The terrain in the base should be flat, with convenient and separate irrigation and drainage system. Therefore, the producing area must be selected in agricultural production areas with good ecological environment, without or with indirect acceptance of industrial "three wastes", as well as agricultural, urban life, medical waste pollution. There are no pollution sources threatening the environment of producing area in the producing area, upwind direction and upstream of irrigation source. The producing area must avoid the main trunk highway.

2.2 Requirements for temperatureThe optimum temperature for tomato growth is 20-25 ℃ during the daytime and 15-18 ℃ at night. When the temperature exceeds 33 ℃ and reaches 40 ℃, the tomato plants will stop growing. When the temperature exceeds 40 ℃ and reaches 45 ℃, high temperature harm occurs, even if the time is very short. When the temperature drops below 10 ℃, plants grow slowly, which will stop growing below 5 ℃. The growth and development of tomato requires a certain temperature difference between day and night. Appropriately increasing the temperature during the daytime is beneficial to photosynthesis, which increases the production of photosynthetic products. Appropriately lowering the temperature at night can effectively reduce respiratory consumption and promote the growth of roots, stems, leaves and fruits, thus improving the yield and quality.

2.3 Requirements for lightPlenty of light should be ensured during the growth period. Weak light will result in slender stem, thin leaves, light color and bad quality.

2.4 Requirements for waterThe water requirements of tomato vary with different growth stages. During the seedling period, plants need little water and water should be properly controlled. The moisture before and after fruit setting of the first inflorescence can not be too large, and water should be controlled, otherwise there will be falling flowers and fruits. Branches and leaves grow rapidly after the expansion of the first inflorescence fruits, and water consumption is increased, so it is necessary to strengthen water supply. Plenty of water should be supplied during the fruiting period, but heavy fertilizer and water is undesirable.

2.5 Requirements for soil and nutritionTomato prefers the neutral and acidic soil with good air permeability. Due to long growth period, organic fertilizer should be increased. Due to large absorption of potassium, potassium fertilizer should be increased appropriately.

2.6 Requirements for CO2In the early stage of tomato growth, the concentration of CO2is deficient due to low temperature and little ventilation in greenhouse. The lack of CO2will directly affect the growth and yield of tomato. CO2fertilization is a very important measure to increase production, in addition to the clever ventilation to make indoor CO2supplement. This work begins after tomato planting. The practice has proved that the yield of tomato is the highest when the concentration of CO2is increased by 1 000-1 500 mg/kg in the protected area.

3 Seedling cultivation

The environmental conditions vary greatly in different planting seasons, and there are great differences in facilities and management of seedling cultivation. Scientific management should be performed according to different stubble characteristics. Heat preservation should be attached importance in low temperature season, while high temperature, heavy rainfall, diseases and insect pests should be paid attention in high temperature season. High furrow can be made, and sunshade net and rainproof shed can be installed to prevent insects and rainfall. Industrialized trays should be adopted for seedling cultivation. But no matter which stubble it is, there are basically the following processes and techniques.

3.1 Preparation of nutrient soil1/3 of Rotten barnyard manure and 2/3 of disease-free mellow soil are pressed, sieved and mixed completely. The nutrition soil is added with 1 kg/m3superphosphate or 2 kg/m3of NPK compound fertilizer (15∶15∶15) and 80 g/m3of 50% carbendazim WP, and mixed uniformly. It is necessary to use substrate in seedling cultivation with trays.

3.2 Seed treatment

3.2.1Seed soaking and germination acceleration. Seed soaking or dressing with medicament, or seed treatment with boiling soup or hot water can obtain good results.

3.2.2Germination acceleration. In the process of germination acceleration, seeds are turned over every day, rinsed with water for 1-2 times. When 60% of the seeds have "broken mouth", that is, when the radicle is exposed, seeds can be sown.

3.3 SowingThe coated seeds can be sown directly. The sowing bed is watered adequately with basal water. The water temperature of 30 ℃ is appropriate in winter sowing. When the soil temperature is relatively low, the water temperature can be higher. A layer of fine soil can be scattered on the bed after water infiltration. The seeds are evenly broadcasted on seed bed, 7-8 g seeds/m2, and the seed bed is covered with 1-1.2 cm of sieved fine soil.

3.4 Seedbed managementShading measure should be adopted in the daytime with high temperature, and the seed bed temperature should not exceed 30 ℃. Thin film is covered in rainy days for the protection against rain. During seedling cultivation, night temperature should not be too high. In order to prevent the seedlings from excessive growth, 1 000 mg/kg mepiquat can be sprayed during 2 true leaf stage. Seedlings are separated at 2-3 true leaf stage. The seedlings are moved to the seedbeds prepared with nutritive soil in advance, with the row spacing of 12 cm and the plant spacing of 12 cm. The seedlings can also be moved to the nutritional bowl with a diameter of 10-12 cm. During the rejuvenation period, the seed bed should be shaded appropriately at noon. When the bed temperature is 25-30 ℃ during the daytime, it should be controlled at 18-20 ℃ for rejuvenation at night; if the bed temperature is about 25 ℃ during the daytime, it should be controlled at 15-18 ℃ at night. The seed bed temperature is lowered appropriately for seedling hardening before transplanting. Mepiquat is sprayed once again at 4-5 true leaf stage.

4 Transplanting

4.1 Preparation before transplantingDue to the long growth period of tomato, the basal fertilizer should be dominated by high quality and long-term farmyard manure, and cooperated with other fertilizers. 45 t/hm2Rotten high-quality barnyard manure or 230 t/hm2chicken manure can be piled and fermented with equal amount of crop straw, and then 750-900 kg of NPK (15∶15∶15) compound fertilizer, 120 kg of superphosphate or not less than 3 000 kg of cake fertilizer, and 750-1 125 kg diammonium phosphate are applied.

Fertilization adopts the method of spreading and ditching; 2/3 of the total amount of farmyard manure are broadcasted on the ground, and then plowed twice, ensuring that the fertilizer is fully mixed with the soil. After raking, ditches are opened, with the width of 30 cm and the depth of 30 cm. The remaining basal fertilizer is then scattered to the ditch and mixed evenly, and then watered along the ditch. The soil is turned into the ditch if the condition is appropriate. Fertilization and land preparation should be done 10-15 d prior to transplanting in order to allow fertilizer to be evenly saturated by soil moisture and to stabilize fertilizer efficiency. The greenhouse should be covered with PVC drip-free film or EVA multifunctional composite film. Straw mat is usually covered in middle October. During the late winter, straw mat is covered with a layer of old film or polyethylene film to prevent straw mat from getting wet by rain and snow.

4.2 TransplantingSeedlings are transplanted in the way of large and small row and small high furrow. The large spacing is 100 cm and the small spacing is 60 cm. Level furrow is first made, two furrows each row, with the plant spacing of 38-40 cm and the density of 30×103-33×103plant/hm2. After seedling transplanting, the field is watered permeably, and is watered 2-3 times from shallow to deep if the ground is dry. After 7-10 d, the plants are planted with soil to form small ridges, and mulching film is not covered temporarily.

5 Field management

5.1 Seedling managementThe cultivation in low temperature season is selected as the standard, and that in high temperature season shall be as close to the standard as possible.

5.1.1Temperature and humidity management. Before rejuvenation, the room temperature is 28-30 ℃ during the daytime and 17-20 ℃ at night, and the ground temperature should not be lower than 20 ℃ to promote the rejuvenation of seedlings. After rejuvenation, the temperature should be slightly lower, which is 22-26 ℃ during the daytime and 15-18 ℃ at night. In order to prevent falling flowers and fruits caused by low or high temperature before and after fruit setting of the first inflorescence, PCPA can be sprayed on flowers. After fruit setting, flowers and fruits are appropriately thinned, with 3-4 fruits per ear. In winter, the indoor temperature is 20-30 ℃ during the daytime and 13-15 ℃ at night, and the minimum night temperature is not less than 8 ℃. When the noon temperature reaches 30 ℃ in sunny days, windows are opened for ventilation. Windows can be closed if the temperature is lower than 30 ℃, implementing "raising fruits with high temperature". If the weather is very good, the indoor temperature is too high and the humidity is large, straw mat can be uncovered, and the greenhouse is immediately ventilated for 30-40 min, and then the ventilation openings are covered strictly.

5.1.2Opaque covering management. Straw mat should be uncovered at appropriate time, ensuring that the indoor temperature will not drop significantly. When the sun shines on the southern roof, straw mats should be uncovered in time. The film should be cleaned to maintain a high light transmittance. In the afternoon when the room temperature drops to 20 ℃, straw mats should be covered. In the late winter season, straw mats can be properly uncovered late and covered early. In general rainy and snowy days, as long as the indoor temperature does not drop, straw mats should be uncovered. In heavy snow days, it can be opened for a short time at noon after snow clearing. In continuous cloudy days, straw mats can be uncovered before noon, and covered early after noon. When there is sudden clear after long cloudy days, straw mats should be uncovered at intervals, which can not be all opened suddenly, so as to avoid leaf burns. If leaves are wilted after straw mat uncovering, straw mat should be covered again, which should be uncovered at intervals when plants are restored to normal. Shading net is covered in high temperature season, which is generally covered at about 10:00 in sunny days, and generally does not cover in cloudy days. It depends flexibly on temperature and illumination.

5.1.3Fertilizer and water management. Watering should be controlled after seedling rejuvenation and before fruit setting, and multiple intertillages are conducted to promote root growth and prevent overgrowth of stems and leaves. When the first inflorescence is as big as walnut, ditches are opened on both sides, and NPK (15∶15∶15) compound fertilizer is applied at the dose of 450-600 kg/hm2. After covering soil, a layer of mulching film is covered, and the soil is watered under the film as thoroughly as possible. Few amount of water can be irrigated in late winter. During the wintering period, if plants show signs of water deficiency, it can be irrigated at noon on sunny days under the middle membrane of high furrow, and irrigated with potassium chloride at the dose of 10 kg/667 m2, or irrigated with fermented bean cake water.

5.1.4Fertilization. During the wintering period, there is low volume of ventilation, and CO2deficit will occur if the application of organic fertilizer is insufficient. Therefore, CO2fertilization can be carried out from 9:00 to 10:00 on sunny morning, and the appropriate concentration is 1 000-1 500 mg/L.

5.2 Fruiting period managementThe cultivation in low temperature season is selected as the standard, and that in high temperature season shall be as close to the standard as possible.

5.2.1Temperature and light management. After the middle of February, with the increase of sunshine, straw mats are appropriately uncovered early and covered late, to prolong the light duration. The thin film should be kept clean. Meantime, ventilation should be noticed; the temperature is maintained at 25-28 ℃ at noon during the daytime and 13-15 ℃ at night, 25-20 ℃ in the afternoon, 15-20 ℃ before midnight and 15-10 ℃ after midnight. The temperature is maintained at 25-20 ℃ during the daytime and 15-10 ℃ at night in rainy days.

5.2.2Fertilizer and water management. In case of irrigation after seedling rejuvenation, it can not be watered until the fruit setting of the first layer. However, if the water is insufficient, small amount of water can be irrigated in ditches according to the specific situation, and ventilation and humidity elimination should be strengthened after watering. Watering should be performed during the fruit expansion of the first layer, and 150-225 kg/hm2urea and 150 kg/hm2diammonium phosphate are topdressed together, avoiding water shortage in management. Watering is performed against during the fruit expansion of the second layer, and fertilizers are applied at the same dose. Due to low temperature, early watering should be carried out under the film. From mid-February to mid-March, the field should be watered once every 15 d, and 750-1 050 kg/hm2fermented bean cake water or 300 kg/hm2NPK (15∶15∶15) compound fertilizer can be applied as well. After the middle of March, the field is watered once every 7-10 d. Fertilizer is applied once every two watering, and 225-300 kg/hm2diammonium phosphate is applied each time.

5.2.3CO2fertilization. In the early growth stage of tomato, the concentration of CO2is deficient due to low temperature and little ventilation in greenhouse. The lack of CO2will directly affect the growth and yield of tomato. CO2fertilization is a very important measure to increase production, in addition to the clever ventilation to make indoor CO2supplement. This work begins after tomato planting.

5.2.4Pruning. Single stem is pruned, and old leaves are removed timely. Topping is conducted as early as possible after enough ears are retained. Continuous heart pruning can also be adopted for pruning.

5.3 Disease and pest control

5.3.1Agricultural and physical measures. Aiming at the major diseases in the local area, the varieties with high resistance against a variety of diseases should be selected. Strong seedlings of appropriate age are cultivated, and indoor temperature and humidity is controlled properly. The compost organic fertilizer can be increased, and the vent of solar greenhouse is strictly sealed with insect-proof net.

5.3.2Biological agent. In the early incidence period of virus disease, 2% junkeduke (ningnanmycin) 200-250 times dilution or weilike 1 000-1 500 times dilution can be sprayed. 1% wuyiencin AS 150-200 times dilution can be sprayed for controlling gray mold and anthrax. Previcur 500-800 times dilution can be sprayed for controlling leaf mildew and gray mold.

5.3.3Chemical agent. Before transplanting, the solar greenhouse should be sealed and fumigated with 45% chlorothalonil FK at the dose of 15 kg/hm2, or 75% chlorothalonil 500 times dilution can be evenly sprayed on the internal walls, ground, bamboo poles and pillars of the facility and then sealed.

In the early incidence period of virus disease, 1.5% urea peroxide 1 000 times dilution or 20% virus A WP 500 times dilution, or 5% junduqing AS 200-300 times dilution, or potassium permanganate 1 000 times dilution mixed with atonik 6 000 times dilution can be sprayed.

In the early incidence period of gray mold, 50% iprodione WP 1 000-1 500 times dilution, or 28% cyprodinil·pyrimethanil WP 500 times dilution, or 50% diethofencarb WP 800 times dilution can be sprayed. 0.1% of 50% procymidone WP or 28% cyprodinil·pyrimethanil WP can be added to the liquid for flower dipping. The occurrence of gray mold can be reduced by removing corolla in time after flower withers.

In the early incidence period of leaf mold, 40% flutolanil EC 8 000-10 000 times dilution, or 10% difenoconazole WDG 1 500-2 000 times dilution, or 47% kasumin+bordeaux WP 800 times dilution, or 60% carbendazim UP 500 times dilution, or 70% thiophanate-methyl WP 800 times dilution can be sprayed.

For the prevention and control of late blight, 72% cymoxanil WP 600-800 times dilution or 69% acrobat WP 800 times dilution or 58% metalaxyl mancozeb WP 800-100 times dilution can be sprayed in the early incidence period. 5% chlorothalonil-cymoxanil DPC or 55% propamocarb DPC can also be sprayed at the dose of 15 kg/hm2.

For the prevention and control of early blight, 80% procymidone 600 times dilution, or 10% difenoconazole WDG 1 500-2 000 times dilution, or 50% iprodione WP 1 000-1 500 times dilution, or 70% mancozeb WP 600 times dilution can be sprayed.

In the early incidence period of bacterial disease such as bacterial wilt, 3% zhongshengmycin WP 800 times dilution, or 50% copper succinate WP 500 times dilution, or 77% kocide WP 500 times dilution can be sprayed or used to irrigate roots.

5.3.4Standard for safe use of chemical prevention and control. Since tomato is a continuously harvested vegetable crop and raw tomato is often eaten, pesticides should be used in strict accordance with GB4285, GB/T8321, NY/T5007 and DB3T/T 328, in order to ensure the edible safety, green and pollution-free products. Pesticides should not be sprayed during harvesting period, and fruits should be harvested before pesticide application. Chemical pesticides are strictly prohibited 7 d prior to harvest. Different types of pesticides should be used alternatively as much as possible to control the diseases. The product shall pass pesticide residue test.

6 Harvest

Fruits for long distance transportation can be harvested from fruit color turning stage to half-ripe stage. The varieties tolerant to storage and transportation can also be harvested from fruit half-ripe stage to firm ripe stage.

7 Conclusions

Selection of good varieties is the basis for high yield and high quality; reasonable dense planting, flower and fruit protection, and increasing fruit setting rate are the keys for high yield and high quality; pest control is an important link, and cultivation and management measures are the guarantee for high yield and high quality. Mastering the growth and development rules of tomato, creating suitable environmental conditions, controlling or promoting vegetative growth or reproductive growth purposefully play an important role in improving the yield and quality of tomato.