Experience Sharing on Protected Cultivation of Ruby Seedless Grapes

Ruby Seedless grapes have a high fruit-setting rate and a high fruit-setting rate, with uniform berries, easy coloring, firm and crisp flesh, good flavor, early maturity and high yield, and strong adaptability. In 2000, we carried out continuous cultivation trials in a solar greenhouse. The fruit matured on May 5, 62 days earlier than in the open field, with an average yield of 4.5 kg per plant and 3000 kg per mu; in 2002, the average yield was 4.8 kg per plant and the yield per mu reached 3500 kg, with obvious economic benefits and easy cultivation and management.

1. Basic situation. The planting trial site was set up in the vineyard of Huiguokou Village in our district. The local frost-free period is 232 days, the annual rainfall is 650 mm, the average annual temperature is 13.1°C, the terrain is flat, the soil is slightly alkaline, and the soil layer is deep and fertile. In spring 2000, cuttings were used to establish the orchard directly, with a plant-row spacing of 1 m × 1 m. 2. Greenhouse structure. The greenhouse runs east-west, 50 m long, 7.5 m wide, with a ridge height of 3.3 m and a front foot height of 1 m. At the front bottom corner, a cold-proof ditch 50 cm wide was dug and filled with straw or wheat straw. The east and west walls and the back wall are 50 cm hollow walls filled with perlite. A row of cement columns is set inside the shed, with a column height of 2.4 m. Iron arch frames rest on top, covered with green drip-free film, and there are insulating cattail grass curtains. Simple flue coal-stove heating equipment is installed in the shed. 3. Cultivation techniques. 1) Planting and fertilizer and water management. Before planting, dig planting holes 30-40 cm deep, apply 5000 kg of organic fertilizer, 50 kg of diammonium phosphate and 10 kg of potassium sulfate per mu, mix evenly with soil and fill into the planting holes, then plant the seedlings. After planting, water thoroughly and cover with film to preserve moisture. From bud break to before flowering, apply 50 g of compound fertilizer per plant; when the new shoots grow to 40 cm, apply another 100 g of compound fertilizer; when they reach 1 m, spray 400-fold paclobutrazol; stop fertilizer and water in mid-July; after fruit set until berry coloring, spray 0.3% monopotassium phosphate; after harvest, continue to apply 5000 kg of decomposed organic chicken manure. In early October, irrigate thoroughly; in late November, cover the shed to raise the temperature and irrigate to promote bud break. 2) Training and pruning. After the seedlings are planted, use a single-cordon pruning system, with each plant having one main cane, on which 4-6 fruiting branches are retained, and no fruiting branch groups are retained. When they grow to 30 cm, set up a trellis and tie them up, and remove the secondary shoots in the leaf axils. On the main cane, when the new shoots grow to 1 m, spray paclobutrazol; when they grow to 2.5 m, pinch the tips, leaving 2-3 secondary shoots at the top, and pinch each shoot promptly after leaving 2-3 leaves. Before covering the shed, cut back to 60-80 cm. After raising the temperature, keep 5 new shoots per plant among those that sprout, and remove all the rest. When a new shoot first grows to 20 cm, twist the shoot to control growth; after 10-15 days, when the later-growing shoots reach 20 cm, pinch the tips. When they grow to 30-40 cm, use string to pull vigorously growing new shoots to areas with fewer canes, so that the fruiting branches are evenly distributed. For secondary shoots about to emerge, keep only 1-2 at the top, with 2-4 leaves per shoot. 3) Temperature and humidity control. Cover the film on October 19-20. During the day, cover with grass curtains so that the interior receives no light; at night, open the vents for ventilation to lower the temperature to the outdoor air temperature, and pre-cool for 30 days. Use calcium cyanamide solution to wipe the mother canes so that dormancy is broken earlier. In mid-to-late November, uncover the curtains during the day to raise the temperature. From bud break to before flowering, maintain 18°C at night and 25-28°C during the day; during flowering, control nighttime at 15-18°C and daytime not above 30°C. The suitable temperature is 25-28°C. During the young fruit swelling stage, the nighttime temperature is 20°C, and afterward it is controlled at 18-20°C, with daytime at 25-28°C. During the coloring stage, daytime is 25-28°C and nighttime is 16-18°C. Always pay attention to the temperature inside the shed; when it is too low, turn on the heating equipment to maintain the temperature in the shed. Humidity can be higher during the bud break stage, with relative humidity at 85-90%; before flowering, control it at 60-70%; during flowering, 60%; during fruit swelling, 50-60%; during coloring, 60-70%. Uncover the grass curtains early and cover them late to increase light duration. On cloudy and snowy days, use lights for supplemental lighting, and hang reflective curtains inside. Remove dust and debris from the shed film at any time to increase light. When carbon dioxide content decreases, apply solid carbon dioxide fertilizer. 4) Flower and fruit management. Do not retain clusters on weak branches; retain one cluster on strong branches, remove secondary clusters, pinch off the cluster tips, retain 5 clusters per plant, and thin out small and densely packed berries. During berry coloring, spray 0.3% monopotassium phosphate. 5) Pest and disease control. Before covering the shed, spray 5 degrees Baumé lime sulfur mixture. In the early stage of new shoot growth, which coincides with the lowest temperature period of the year, the plants are prone to gray mold and downy mildew, so ecological variable-temperature management should be adopted and regulated well according to the temperature and humidity requirements of each stage. For chemical control, use smoke methods and dust methods in rotation, once a week. Pay attention to the control of whiteflies; 25% cyhalothrin EC can be sprayed. During fruit growth, prevent downy mildew and powdery mildew, which are diseases very likely to occur in sheds; chlorothalonil smoke agents and 16% propamocarb dust can be used, fumigating once every 7-10 days. A 2000-fold solution of 46% triethylphosphonate aluminum plus 15% triadimefon can also be used. After harvest, spray 200-fold Bordeaux mixture at double strength, once every half month, to protect the leaves.