1. Cultivate strong seedlings
Strong seedlings are the basis for disease resistance and high yields. Strong tomato seedlings have thick stems and short nodes, large and thick leaves, and 7-8 leaves with large flower buds. The seedlings are 50-60 days old in winter and spring, and 20-30 days old in summer. The temperature and moisture in the seedling stage should not be too large to prevent the seedlings from growing too long. Generally, the temperature during the day is about 25°C, and the temperature at night is about 15°C. If the temperature is too low, deformed fruits may appear.
It is recommended to use nutrient formula soil for seedling soil. Mix peat and vermiculite in the ratio of 4:1 for sowing soil; add 10kg of decomposed chicken manure and 1.5~2kg of NPK compound fertilizer per m3 of seedling soil to fully mix evenly. In winter and spring, the seedling division is emphasized, and the seedling division is carried out at the 3 true leaf stage. Dividing seedlings is conducive to promoting new roots and cultivating strong seedlings. In summer, seedlings should be raised under a plastic roof and shade net to prevent strong light, high temperature and rain. Conditional insect nets can be added to avoid aphids and disease.
Open field cultivation in Beijing can be sown in early February~early March in Yang Qi or greenhouse, and planted in late April after the last frost; spring greenhouse can be sown in late December and planted in early February; spring greenhouse can be sown in mid-to-late January and planted in mid-March Planting in late June; autumn greenhouses can be direct seeded in late June or seedling pots, and planted in mid-to-late July; autumn greenhouses can be sown in late July and early August, and planted in late August and early September.
2. Reasonable close planting
Tomatoes are reasonably densely planted according to different cultivation and topping methods. In spring, the plant spacing in the open field is 50~60×30~35cm, and about 3,500 plants are planted per mu. About 3,000 plants can be planted in the spring greenhouse, and about 4,000 plants can be planted in the spring and autumn greenhouse if 2 ears of fruit are left for topping. If more than 5 ears of fruit are left in the Spring and Autumn Greenhouse, 1600 to 2000 plants can be planted per mu.
3. Fertilizer and water management
Large fruit-type high-yielding varieties require sufficient fertilizer and water. The base fertilizer should be applied with about 5000kg of organic fertilizer per mu. When planting, 100kg of hemp cake fertilizer and 30kg of compound fertilizer should be applied in the trench. When the first ear of walnuts is large, water it, follow up with thin manure or compound fertilizer, and do not lack water in the future. When each ear of walnuts is big, topdressing can be done once, and topping with 4 ears can be topdressed 3 to 4 times. Do not water too much in the greenhouse to prevent excessive air humidity and prevent the spread of late blight, botrytis, and leaf mold.
Micro (cherry) tomatoes should be planted with large seedlings, the base fertilizer is less than that of large fruit types, and the top dressing should be later to prevent the fruit from becoming larger.
4. Topping at the right time to protect flowers and fruits
Tomatoes can adopt different topping methods according to the cultivation method and variety habit. The self-capping type generally leaves a side branch under the first panicle to form a double-stem cap; the infinite-growing type generally prunes a single stem. According to the needs, it is advisable to leave 3 to 4 ears in greenhouses and open fields in spring and autumn; 2 ears and 3 ears can be reserved for early maturity; 4 to 5 ears in the open field in spring; 4 to 6 ears in solar greenhouses; 8 ears or even 10 ears in large greenhouses above the spike. Topping should be done in time. When the ear is about to show buds, leave 2 leaves on the upper part of the inflorescence to pin the heart to ensure the development of the upper fruit and prevent sunburn. Tomatoes are dipped in auxin 2, 4D10~20ppm, 2.5% water-soluble anti-falling element 30~50ppm when the flowers first bloom, which can prevent the flowers from falling off and promote fruit enlargement. When the temperature is high, the concentration should be appropriately reduced. If the concentration is too high or repeated dipping, it is easy to form deformed fruit and empty fruit. 2. Do not spray 4D on young shoots and young leaves. It is especially important to protect the flowers in the ground.
5. prevention-based integrated pest management
The current varieties are basically resistant to viral diseases, and some are resistant to leaf mold and fusarium wilt. But disease resistance in any variety is relative. Cultivation and disease prevention are extremely important. Such as appropriate early planting and planting in spring, coupled with good cultivation management can reduce the occurrence of virus diseases. The diseased strains infected with viral diseases should be removed in time. Before the arrival of the rainy season and in protected areas, attention should be paid to the prevention and control of late blight, botrytis and leaf mold, and timely spraying should be done before and in the early stage of the disease. Late blight can be treated with 72% glu WP 500 times, 25% metalaxyl manganese zinc WP 500~600 times, 75% chlorothalonil WP 500 times, 40% ethylphosphonium aluminum 250 times liquid, etc. and spray evenly. Disease-resistant varieties should be selected for the control of leaf mold. To control Botrytis cinerea, add 50% carbendazim 500 times to the auxin spray. It is better if the residual petals and stigma can be removed. 50% carbendazim 500 times solution can be sprayed once before planting, after slow seedling and flowering period to prevent botrytis as early as possible, and 55% chlorothalonil smoke tablets are used in protected fields with good effect. The main pests of tomato are cotton bollworm, aphids, greenhouse whitefly, Liriomyza sativa, and yellow tea mites.
6. Comprehensive control of tomato physiological diseases
Physiological diseases such as deformed fruit, cracked fruit, tendon rot and poor coloration will also occur in tomato in case of bad environmental conditions and improper cultivation.
(1) Tomato deformed fruit: the fruit surface has folds that reach the pulp, the style is long and narrow, the number of ventricles is many and disordered, the whole fruit is oval, oblate or oblong, and some are irregular or double-fruited. (called multi-heart fruit); some have fingers and nodules next to the fruit carpel or on the top of the fruit (called abruptio-shaped fruit); some crack into holes next to the carpel, the seeds are exposed, or the style scars are severely cracked After the enlargement, it is a messy heart-shaped fruit (called a hole fruit or a heart-turning fruit); some have a reduced number of carpels, and the fruit shape is slender and pointed (called a pointed fruit). The above-mentioned deformed fruits mostly originate from the flower bud differentiation stage, the early stage of stamen and pistil differentiation. During this period, the temperature is too low, the nitrogen fertilizer is too high, the humidity is too high, and the sunlight is insufficient, so that the nutrients are concentrated and transported to the flower buds that are being differentiated, and the differentiation time of each flower bud changes. Excessive division of long cells, increased number of carpel differentiation, uneven carpel development after flowering. Improper use of auxin can also cause deformed young fruit to crack. Therefore, in the seedling stage, it is necessary to prevent excessive low temperature, long seedling age and high temperature. This is important to prevent the types of deformities mentioned above. Of course, under the same conditions, it is also restricted by the characteristics of the variety, and it is necessary to choose a variety that is not prone to deformed fruit under low temperature conditions. The small fruit type varieties with 2~3 ventricles basically do not have deformed fruit.
(2) Tomato cracking: There are four common types of tomato cracking: longitudinal crack, ring crack, chapped crack and irregular cracking of ripe fruit surface. Longitudinal fissure of the fruit appears earliest, and some radial fissures appear on the shoulder during the green ripening stage of the fruit. As the fruit expands, the fissure widens, deepens, lengthens, and reaches the pulp. The cracks turn black and the shoulders of the fruit harden, seriously reducing the appearance and quality of the fruit. Ring dehiscence occurs in the middle to maturity of fruit expansion. Concentric cracking occurs around the fruit depression on the shoulder of the fruit, which widens and lengthens as the fruit expands and matures, and the depth is generally shallower than that of the longitudinal crack, which also seriously affects the appearance and quality of the fruit. Chapped cracks are the cracks that occur in the shoulder and middle of the fruit. The depth is limited to the peel, which is small and numerous. The fruit is black and mesh-shaped. Irregular cracks on the fruit surface are mostly found in mature fruits. Due to the thin peel and poor toughness, after the fruit is wetted by rain or high humidity, the moisture inside the fruit increases sharply, and the internal pressure increases. The pulp is cracked. Such dehiscence can also occur when the fruit is harvested overripe. Cultivation and management can not be too dry and too wet, especially to prevent rapid irrigation after prolonged drought. The fruit should be harvested in time. The fruit of autumn canopy tomato swells under high humidity, and the peel is thin and tight. After low humidity and high water in the later stage, the cracking of the fruit will increase. Special attention should be paid to the uniformity of water, and irrigation should be appropriately reduced as the humidity decreases to prevent fruit cracking. Insufficient calcium and boron, and the harm of tea yellow mites are also easy to cause premature aging of the peel, and improper water management is more likely to crack the fruit. The cracked fruit is related to the variety. Generally, the large fruit-shaped pink fruit and the thin-skinned variety are easy to crack the fruit, while the small fruit-shaped, red fruit, thick skin, and larger peel toughness are lighter. Therefore, to prevent fruit cracking, comprehensive management should be carried out from the aspects of variety selection, fertilization and irrigation, temperature management, and pest control.
(3) tendon rot fruit: it occurs from the early stage of fruit expansion until it affects fruit ripening. The vascular bundles in the pulp near the peel and in the pulp next to the ventricle turn brown and necrotic. From the top of the fruit to the depression, the fruit appears black streaks. In severe cases, the inner wall of the pulp becomes (called black rib), with many backlit surfaces and accompanying coloration. Poor, uneven coloring, and some peels appear white stripes (called white tendons). Tendon rot is caused by excessive nitrogen fertilizer, especially excessive ammonia nitrogen and nitrite nitrogen, relatively insufficient potassium, excessive water and other adverse soil conditions and insufficient sunshine, excessive night temperature and other adverse light and temperature conditions and excessive branches and leaves, fruit. caused by malnutrition. Viral infection is also a type of tendon rot. The soil conditions for planting tomatoes can be improved, such as good drainage, increased soil aeration, less nitrogen fertilizer, more phosphorus and potassium fertilizer, improved temperature and sunshine conditions, timely pruning, ventilation and light transmission, enhanced photosynthesis, respiration, and nutrition. Substances are fully distributed to the fruit. Different tomato varieties have different resistances to tendon rot. The selection of virus-resistant and less prone to tendon rot varieties can effectively prevent tendon rot from occurring.
(4) Poor fruit coloring: Tomato fruits cannot be colored normally, uniformly and brightly. Its occurrence types and influencing factors are very complex, and are related to varieties, temperature, sunshine, gas hazards, soil nutrients including the amount of certain trace elements, and pest and disease hazards. During the green ripening stage of tomato, the content of chloroplasts is more and carotene is less. With the ripening of the fruit, lycopene and carotenoids increase sharply, and chlorophyll decreases. Lycopene is most easily formed at 19~24°C, and when the temperature drops to 13~14°C, lycopene cannot be formed normally, while carotene can still be formed, so the color of tomato turns yellow at low temperature or high humidity , fades. Tomatoes in winter with insufficient sunlight and in protected fields are not as bright as open fields. When there is too much nitrogen, when the plant is strong and the water is insufficient, uneven coloring of the green shoulder occurs. Nitrogen deficiency, poor fruit coloration, yellow shoulder. Potassium deficiency, yellow-green shoulders, lignification of vascular bundles in the heart. Boron deficiency, green residue on the shoulder and necrotic spots, etc. Poor coloration of the fruit should be diagnosed according to the shape, and targeted measures should be taken to prevent it. The vascular bundles in the pulp of fruit tendon rot turn brown, and the appearance of the fruit will also be uneven and poor. It is a physiological disease mainly caused by poor environmental conditions.
(Note: This article is reproduced for reference only)