What should be paid attention to during the fruitful period of fruit and vegetables in greenhouses?
September 15 02:12:27, 2025
After the low-temperature period, vegetables grown in protected areas enter a productive phase, marking the peak time for water and nutrient absorption. Therefore, it is essential to fully understand the specific needs of these crops during this stage to ensure proper and scientific management.
1. Pay attention to balanced fertilization. The nutrient uptake ratio of nitrogen, phosphorus, and potassium changes during the fruiting stage compared to earlier growth phases. At this point, more potash (potassium) is needed, while the demand for phosphorus remains stable, and nitrogen requirements increase but should be lower than that of potassium. Many farmers mistakenly believe that applying more urea or ammonium bicarbonate will boost fruit production, leading to excessive nitrogen use, over-application of phosphorus, and insufficient potassium. This imbalance can degrade soil quality, cause nutritional deficiencies in plants, and make them more prone to diseases. For example, excess nitrogen may result in large, dark green, thick leaves with twisted shapes, reduced fruit size, or distorted melon strips. Too much phosphorus can lead to chlorotic symptoms like zinc, iron, or magnesium deficiency, as phosphate binds with these elements in the soil, reducing their availability. A lack of potassium causes the older leaves to develop burnt edges, fruits to crack easily, sugar content to drop, flavor to deteriorate, and the plant to age prematurely.
To avoid such issues, fertilization during the fruiting stage should follow the principle of fewer applications and focus on potassium. If trace elements are needed, foliar spraying is an effective method.
2. Manage greenhouse temperature and moisture carefully. As temperatures rise, symptoms like cucumber browning or tomato umbilical rot may occur, often due to iron deficiency. Rapid temperature increases can affect water absorption and calcium transport within the plant, causing calcium deficiency at the top. To prevent this, adjust greenhouse temperatures gradually, water regularly, and apply calcium foliar sprays when necessary.
3. Monitor and control pests like aphids, whiteflies, and viral diseases. With rising outside temperatures, the population of virus-carrying pests increases, making pest control critical to reduce disease outbreaks. Several effective measures include:
1. Installing fine mesh nets on all ventilation openings to block pests.
2. Setting up a disinfectant pool at the entrance, using quicklime for foot disinfection.
3. Preparing a 0.1% potassium permanganate or 10% trisodium phosphate solution for disinfection before entering the greenhouse.
4. Controlling aphids and whiteflies by spraying 25% Actara at a dilution of 7,500–10,000 times, which not only controls pests but also helps prevent viral infections.
By following these practices, farmers can ensure healthier crops, better yields, and sustainable agricultural production.