After White Dew, manage autumn-winter vegetable planting and care well
September 7 is the White Dew solar term. Dew is formed when water vapor condenses on the ground or on near-ground objects as temperatures drop, so White Dew means the weather has already turned cool. As the saying goes: "One autumn rain, one spell of cold; ten autumn rains, and you wear cotton." During the White Dew solar term, rainfall gradually decreases, there are many sunny days, sunlight is abundant, the climate is mild, and the temperature difference between day and night is large, making it very suitable for the growth of various vegetable crops. Seize the favorable opportunity to plant and manage open-field autumn crops and protected autumn-winter vegetables well, and also do a good job of raising seedlings for overwintering protected vegetables.
Pay attention to disease and pest prevention for autumn-sown Chinese cabbage
Autumn-sown Chinese cabbage is at the rosette stage, and early-sown market cabbage has reached the heading stage. For Chinese cabbage, do a good job of intertillage loosening soil and weed control. After the seedling-restraint stage ends, begin watering and topdressing. Topdressing can be done by making holes or furrows, applying 300 kg of bio-organic fertilizer or 20 kg of nitrogen-phosphorus-potassium compound fertilizer per mu each time; topdressing with irrigation water can also be used, applying 8-10 kg of liquid fertilizer with complete nitrogen, phosphorus, and potassium per mu. For market cabbage, focus on watering and topdressing to promote heading and growth. The watering interval should be controlled according to soil texture, weather conditions, and plant growth, but the amount of water per irrigation should not be too much; small amounts of frequent watering are preferable. The rosette stage is a period when diseases and pests occur more frequently, with key control targets including viral disease, downy mildew, black rot, and pests such as aphids and green caterpillars. Strengthen field inspections for diseases and promptly control when central diseased plants are found. Green caterpillars are mostly noctuid pests; they hide during the day and come out at night to cause damage. If pesticides are sprayed during the day, they often have no effect; applying pesticides at night or in the early morning when dew has not yet dried is effective. In recent years, dry heart rot has occurred more in some plots. Control the amount of nitrogen fertilizer, increase phosphorus and potassium fertilizer, water reasonably, and especially do not let the soil lack water from the rosette stage to the early heading stage.
Radish and carrot: focus on water management
Various radishes successively move from the leaf growth stage to the root-splitting stage and the fleshy root growth stage. Water management differs between these two stages. During the leaf growth stage, watering should mainly be controlled; watering too early will promote excessive leaf growth and affect root growth. At the root-splitting stage, this indicates a shift to the root growth stage, so water timely and keep the soil often moist so the root can grow well. If sufficient base fertilizer was applied, topdressing is generally unnecessary; at the same time, do a good job of intertillage, weed control, and timely control of pests such as aphids and cabbage caterpillars. Carrots are still in the leaf growth stage, so control watering. If there has been no rain for many days, the soil is dry, and plant growth is slow, a small amount of water can be given. Mainly do a good job of intertillage, weed control, and aphid control.
Autumn-winter greenhouse crops: ensure transplanting quality
Solar greenhouses with good heat retention can still transplant heat-loving crops such as tomato, eggplant, and sweet pepper. Install the greenhouse film in advance, do a good job of disinfecting the greenhouse and soil, and apply sufficient organic fertilizer as base fertilizer, applying more than 5,000 kg of fully decomposed, finely crushed high-quality organic fertilizer per mu; apply fertilizer and finely prepare the soil 10-15 days in advance, achieving thorough tillage, leveling, and no visible or hidden clods; make high beds or tile-ridge high beds 15-20 cm above the ground. Tile-ridge high beds are suitable for greenhouses without drip irrigation facilities; dig a V-shaped watering ditch in the middle of the bed, convenient for winter watering by subsurface irrigation under film. Ensure transplanting quality: select strong seedlings that are uniform in growth and size for transplanting, requiring appropriate depth and reasonable density. Generally, ordinary tomato varieties are about 3,000 plants per mu, cherry tomato varieties 2,200 plants, and plant 2-4 extra plants per bed for gap filling. Because the temperature is relatively high, transplanting on a sunny afternoon is better, and water thoroughly in time.
In sandy loam greenhouse soil, water once more 3-5 days after transplanting to help seedling recovery, and promptly intertill and loosen the soil to promote seedling recovery.
Overwintering heat-loving crops: do a good job of seedling raising
For overwintering cultivation in solar greenhouses with good heat retention, crops such as tomato, pepper, and eggplant are raised as seedlings in early to mid-September. Cucumber and zucchini in greenhouses with medium heat retention are raised as seedlings in early September; cucumber and zucchini in greenhouses with good heat retention are raised as seedlings in late September. Choose excellent varieties with good cold tolerance, tolerance to low temperature and weak light, and strong ability to continuously set fruit under low-temperature and low-light conditions. For cucumber, "Zhongnong 26" can be selected; for eggplant, "Zaoshu Jingqie No. 6"; for zucchini, "Jinghu 12" or "Jinghu 36" can be selected. Use 50-cell or 72-cell plastic plug trays for seedling raising, with a substrate made of peat, vermiculite, and perlite, or purchase prepared special substrate. Do a good job of seed treatment and prevention of tomato yellow leaf curl virus disease. For cucumber, use grafted seedling methods; it is best to use "Beinong Liangzhen" brown-seeded pumpkin, which has removed wax powder and good flavor, as the grafting rootstock.
Open-field fast-growing leafy vegetables: sow successively
Fast-growing vegetable crops such as rapeseed, spinach, garland chrysanthemum, cilantro, leaf lettuce, fennel, cherry radish, and small water radish can be sown successively, and harvested and marketed from late September to early October to meet market demand around National Day. Prepare the soil finely, sow evenly, cover with soil at an appropriate depth, and ensure the soil moisture needed for emergence.
Autumn greenhouse vegetables: manage well and harvest
Autumn greenhouse cucumbers have already been harvested, tomatoes are at the fruit-setting and fruit-enlarging stage, and eggplants and peppers grown through the summer are also at the fruit harvest stage. Field management should be strengthened to encourage the plants to bear more fruit with a high commercial rate. Cao Hua, Municipal Agricultural Technology Extension Station
◆Adjust suitable temperature, light, and humidity. The suitable temperature for heat-loving vegetables such as tomato is 23°C-28°C during the day and 15°C-18°C at night; the suitable daytime temperature for cool-loving vegetables such as celery is 20°C-22°C and 10°C-12°C at night; shade nets no longer need to be covered, so crops can receive as much light as possible; adjust indoor air humidity according to different crops: sweet pepper, cucumber, and leafy vegetables at 60%-85%; tomato and eggplant at 45%-55%.
◆Pruning and removing side shoots. Timely remove old leaves, yellow leaves, and side branches to facilitate ventilation, light penetration, and fruit setting. When tomato grows to the predetermined fruit cluster, pinch the growing tip early, generally leaving 3-4 fruit clusters. Cucumber, pumpkin, etc. should be trained around the trellis and lowered to extend plant growth so they bear more fruit.
◆Fruit management. Tomato and eggplant can use bumblebees or vibrating pollinators to assist pollination and increase fruit set; when using regulators to spray or dip flowers, choose products such as "Fengchanji No. 2" and "Guomeining" that are safe for crops and unlikely to cause deformed fruit. Also promptly thin out excess fruit.
◆Scientific watering and topdressing. Water and topdress according to weather conditions, soil conditions, and plant growth to meet the needs of growth and development. Vigorously promote integrated water and fertilizer technology, and it is advisable to apply fully nutritious, reasonably proportioned quick-soluble fertilizers such as "Christmas Tree" with drip irrigation. Fertilizer proportions should differ for different crops. During the fruit-enlarging stage of tomato, apply quick-soluble fertilizer with a nitrogen-phosphorus-potassium content of 16:8:34 and high potassium content at 5-8 kg per mu.