Detailed Explanation of Key Points for Open-Field Cucumber Cultivation Techniques

AbstractSelect high-quality seedlings with a seedling age of about 35 days, well-developed root systems, and no pests or diseases for transplanting. For the base fertilizer, diammonium phosphate, urea, boron fertilizer, potassium sulfate, etc. can be applied. When the seedlings grow to 20-30cm, supports need to be set up for vine tying, and then diseased and old leaves should be pruned in time. For later topdressing, organic fertilizer and chemical fertilizer can be applied alternately. 4-5 days after cucumber transplanting, water once to help the seedlings recover. When the soil surface is slightly dry, carry out intertillage and loosening of the soil. During the fruiting period, large amounts of water and fertilizer are needed.

I. Select Excellent Varieties

1. Varieties with high yield, low-temperature tolerance, weak-light tolerance, strong disease resistance, and good market quality can be selected for planting. Varieties suitable for open-field cultivation in spring include Bomei No. 4, Jinchun No. 4, Zhongnong No. 12, etc.

2. Seedlings with a seedling age of about 35 days, intact cotyledons, a seedling height of 8-10cm, 3-5 true leaves, relatively short internodes, an angle of 45° between the petiole and the main vine, dark green leaf color, thick leaves, well-developed root systems, and no pests or diseases can be selected for transplanting.

II. Transplanting Management

1. On the basis of autumn plowing and winter irrigation, spring irrigation can be carried out from late March to early April to press down salt and alkali and store sufficient soil moisture. Before plowing the plot, apply 6000 jin of fully decomposed high-quality farmyard manure per mu, or 400 jin of highly concentrated refined organic fertilizer and 100 jin of nitrogen-phosphorus-potassium special fertilizer for vegetables, or 50 jin of diammonium phosphate, 30 jin of urea, 30 jin of potassium sulfate, and 2 jin of boron fertilizer.

2. After land preparation, according to a ridge bottom width of 70cm, ditch bottom width of 50cm, and ridge height of 20cm, open ditches and form ridges, then cover with plastic film. Open-field spring cucumbers are usually transplanted in mid-April when the ground temperature remains above 12°C and the weather is clear. Generally, a planting pattern of (50 cm + 70 cm) × 50 cm is used, with the ridge surface covered with plastic film for planting. The suitable planting density per mu is 2222 plants.

3. When the seedlings grow to 20-30cm, insert 1 branch pole of 1.7-2m per plant at a distance of 8-10cm from the seedlings, build them into a herringbone frame, and then tie the vines using the “8” method to prevent abrasion of the stems and vines and prevent the stems and vines from drooping.

4. When tying vines, choose to tie once every 2-3 nodes, and it can be done in the afternoon. In the morning, the stems and vines are easily broken. At the same time, remove tendrils and lower side branches, which is beneficial for fruit setting on the main vine. When cucumbers cover the frame, promptly remove diseased and old leaves to improve ventilation and reduce the incidence of diseases.

III. Water and Fertilizer Management

1. 4-5 days after cucumber transplanting, water once to help the seedlings recover. Wait until the soil surface is slightly dry, then carry out intertillage and loosening of the soil. Then control watering for seedling hardening. When the first cucumber begins to grow and the color of the cucumber base becomes darker, watering can be resumed. Before watering, carry out intertillage and weeding once, and sun-dry for 1-2 days to prevent weeds from reviving after watering.

2. During the fruiting period, large amounts of water and fertilizer are needed. Fertilize once and water once every 6-7 days. Watering can be done in the morning or evening. On the basis of sufficient base fertilizer, after transplanting, fertilizer can be applied together with watering. Apply 20-30 jin per mu of special organic compound fertilizer for cucumber, or 10 jin of urea and 20 jin of potassium sulfate. Organic fertilizer and chemical fertilizer can be applied alternately, so that the nutrition is comprehensive and the fertilizer effect is higher.

IV. Timely Harvesting

Picking cucumbers early is beneficial for increasing yield. In the early stage of cucumber fruiting, harvest once every 3-4 days. During the peak fruiting period, harvest every day or every other day. This helps ensure cucumber quality, promotes rapid expansion of young cucumbers, and increases the fruit-setting rate.

V. Pest and Disease Control

1. Common pests and diseases of cucumber include aphids, powdery mildew, fusarium wilt, downy mildew, angular leaf spot, etc.

2. Agricultural control methods: select disease-resistant varieties, carry out crop rotation, cultivate healthy seedlings of suitable age with no pests or diseases, strengthen water and fertilizer management, and cultivate with deep ditches and high ridges.

3. Physical control methods: hang yellow boards to trap and kill pests. The yellow board specification is 20×30cm, and the hanging density per mu is 40-60 pieces.

4. Chemical control methods for diseases

(1) Downy mildew: 72% DuPont Curzate 800-fold solution, or 80% fosetyl-aluminum wettable powder 600-fold solution, or 72% Previcur SL 1000-fold solution can be selected for spray control.

(2) Powdery mildew: in the early stage of disease, 75% chlorothalonil wettable powder 600-fold solution, or 15% triadimefon 1500-fold solution can be used, sprayed once every 5-7 days, for 2-3 consecutive sprays.

(3) Fusarium wilt: in the early stage of disease, 800-fold solution of Lvbang 98 wettable powder, or 600-fold solution of 37% Kusuo Like wettable powder can be used for root drenching, once every 10 days, for 2-3 consecutive root drenchings.

(4) Angular leaf spot: in the early stage of disease, 10-20g of agricultural streptomycin per mu, or 150-200g of 77% copper hydroxide, or 125-160g of 20% thiodiazole-copper suspension concentrate can be used for control, sprayed once every 7-10 days, for 3-4 consecutive sprays.

5. Chemical control methods for insect pests

Aphids: 10% acetamiprid wettable powder 600-fold solution, or 10% imidacloprid wettable powder 3000-fold solution can be used for spray control, sprayed once every 5-7 days, for 3-4 consecutive sprays.