大棚番茄整枝疏果提质增产栽培技术

Greenhouse tomatoes grow in a closed environment with sufficient water and fertilizer and stable temperature, which is prone to excessive plant growth, dense branches and leaves, and numerous invalid lateral branches. Without timely pruning and fruit thinning, a large amount of nutrients will be consumed in the growth of branches and leaves and the development of inferior flowers and fruits, resulting in poor field ventilation and light transmission, increased field humidity, frequent diseases and pests, as well as uneven fruit size, many malformed fruits, poor coloring and low single fruit weight, which seriously reduce the commercial value and overall yield of tomatoes. As the core key technology to regulate plant type and balance vegetative and reproductive growth in greenhouse tomato cultivation, pruning and fruit thinning can concentrate plant nutrients on the development of high-quality fruits, optimize the field microenvironment, reduce pest breeding, significantly improve the appearance, sweetness and uniformity of tomato fruits, and extend the harvesting period, which is an essential management link for high-quality and efficient greenhouse tomato planting. Combined with the growth characteristics of greenhouse tomatoes, this paper systematically introduces the pruning methods, flower and fruit thinning standards, leaf canopy management and supporting growth control technologies adapted to the facility environment, providing technical references for standardized quality and yield improvement planting of greenhouse tomatoes.

Greenhouse tomatoes mainly adopt single-stem pruning, which adapts to the planting characteristics of dense planting and limited space in greenhouses and is the optimal plant type management method for stable yield and quality improvement. In the whole process of single-stem pruning, only the main stem of the plant is retained as the main fruiting branch, and all lateral branches, axillary buds and secondary shoots germinating at the leaf axils of the main stem are completely removed to prevent nutrient consumption caused by excessive lateral branch growth. After seedling recovery, the plant enters a rapid growth period with fast lateral bud germination. It is necessary to adhere to the principles of early bud removal and frequent branch removal. Lateral branches with a length of 5-8 cm before lignification are removed in a timely manner to avoid large plant wounds and pathogen infection caused by removing thick branches. Pruning is carried out on sunny mornings with low greenhouse humidity and fast wound healing to effectively reduce the risk of disease infection; pruning is prohibited on rainy days to prevent wound water accumulation and infection of gray mold, early blight and other diseases. For weakly growing seedlings, branch removal can be appropriately delayed, and a small number of thin lateral branches can be retained to assist photosynthesis, and then completely removed after the plant growth recovers to avoid premature aging caused by excessive pruning.

The continuous pinching and head replacement pruning technology is suitable for long-season overwintering greenhouse tomato planting, which can effectively solve the problems of declining plant growth vigor and small upper fruits in the later stage and extend the fruiting cycle. Traditional single-stem pruning has limited fruiting layers. In the later stage, the top of the plant is far away from the root system with long nutrient transportation distance, which easily leads to weak top flowers and fruits, small fruits and declining quality. After the plant bears 4-5 clusters of fruits, continuous head replacement pruning retains the top lateral branch as the new main fruiting branch and removes the original top of the main stem to realize nutrient redistribution, continuously maintain strong plant growth vigor, ensure uniform expansion of fruits in the middle and later stages, effectively improve the total yield of long-stubble planting, and adapt to the cultivation mode of autumn-winter stubble and overwintering stubble greenhouse tomatoes.

Flower and fruit thinning is the core means to improve the commercial fruit rate and uniform quality of tomatoes. Greenhouse tomatoes have a large amount of flower bud differentiation and dense fruiting. Retaining all flowers and fruits will lead to scattered nutrients and crowded fruit development, easily resulting in malformed fruits, hollow fruits and small fruits, as well as excessive plant load, premature aging and leaf and fruit drop. Flower and fruit thinning follows the principles of retaining superior and removing inferior, uniform fruit retention and reasonable load. After each cluster of flowers blooms and young fruits set, sorting and thinning are carried out in a timely manner. Malformed, weak and diseased flowers are removed first, and robust and full normal flowers are retained. In the early stage of young fruit expansion, malformed, cracked, diseased, stiff and undersized weak fruits are removed in a timely manner. The number of retained fruits is standardized according to variety characteristics: 3-4 uniform strong fruits per cluster for large-fruited hard powder tomatoes, 4-5 fruits per cluster for medium-fruited varieties, and appropriate more fruits for small-fruited cherry tomatoes to ensure uniform cluster arrangement and sufficient nutrient supply. Excessive fruit retention leading to plant overdraw and premature aging and insufficient fruit retention causing production waste are strictly avoided.

Scientific leaf picking and growth control to optimize the field leaf canopy structure can significantly improve ventilation and light transmission conditions. Old, yellow, diseased and residual leaves at the lower part of tomato plants have weak photosynthetic capacity, which not only fail to produce nutrients, but also continuously consume plant nutrients, block light, close the field and increase humidity, inducing pest breeding. After each cluster of fruits enters the expansion and color turning stage, aging leaves at the lower part of the fruit cluster can be gradually removed, and upper functional green leaves are retained to ensure photosynthesis. Leaf picking follows the principles of small amount in batches and gradual progress. Excessive leaf picking at a single time is prohibited to avoid declining plant growth and blocked fruit color turning caused by sudden reduction of photosynthetic area. Middle and upper leaves of the plant are retained as much as possible to maintain a reasonable leaf-fruit ratio and ensure sugar accumulation and normal development of fruits. For plants with overly dense branches and leaves, overlapping and dense leaves are appropriately thinned to open up field ventilation and light transmission channels, reduce greenhouse humidity, decrease disease occurrence, and promote uniform fruit coloring and sweetening.

Timely topping and pinching accurately regulate plant growth vigor and lock the fruiting layers. The topping time is reasonably determined according to greenhouse planting stubbles and growth period length. For short-term planting tomatoes in early spring and late autumn stubbles, topping is carried out in a timely manner after retaining 6-7 clusters of fruits to remove the top growth point, terminate unlimited vegetative growth, and concentrate all nutrients on the expansion and maturation of retained fruits. For long-season overwintering cultivation tomatoes, topping can be delayed combined with head replacement pruning to extend the fruiting cycle and improve the overall yield. 1-2 functional leaves at the top are retained during topping to protect fruit clusters from strong light burn, maintain weak photosynthesis, ensure nutrient supply for fruit development, and avoid plant premature aging and declining fruit quality caused by bare topping.

Supporting field management after pruning and fruit thinning can further strengthen the effect of quality and yield improvement. Wounds caused by pruning are the main channels for pathogen infection. Protective biological agents or low-toxic fungicides can be sprayed in a timely manner after operation to seal wounds and prevent diseases. Pruning is coordinated with precise water and fertilizer management: nitrogen fertilizer application is reduced and potassium fertilizer and medium and trace elements are increased during growth control period to balance plant growth and avoid excessive growth; water and fertilizer supply is strengthened during fruit expansion stage to ensure the rapid expansion and development of retained fruits after thinning. Meanwhile, residual branches, weak flowers and inferior fruits trimmed in the field are cleaned up and treated centrally outside the greenhouse to keep the greenhouse clean and prevent pest breeding, creating a good environment for high-quality and high-yield tomato production.

In conclusion, the scientific and standardized pruning and fruit thinning technology for greenhouse tomatoes can effectively solve the pain points of excessive branch growth, disordered fruiting, uneven quality and frequent diseases and pests in facility planting. By optimizing plant type structure, regulating nutrient distribution and reasonably controlling load, it realizes balanced plant growth, uniform fruit development and excellent field environment, greatly improves the tomato commercial rate, single fruit weight and overall yield, reduces pesticide and fertilizer input, lowers planting costs, and is an indispensable core technology for green, high-quality and efficient cultivation of greenhouse tomatoes, suitable for the large-scale production and promotion of various facility tomatoes.