How to Grow Ice Wine Grapes? Cultivation Techniques Explained

Since 2003, the 70th Regiment began growing ice wine grapes, and to date the area has grown to 67 hectares, with the main varieties planted being Cabernet Gernischt, Merlot and others. Ice wine grapes are grapes picked when the cell water in the berries freezes at a temperature of about -10°C and the sugar naturally separates out; they are the main raw material for making ice red and ice white wines.

I. Planting Principles 1. Strictly limit yield, generally below 800 kg per 667 sq m. Winter pruning leaves the canes; summer shoot thinning, shoot positioning, flower thinning and cluster thinning result in a yield of 2.5-3 kg per plant. 2. Delay the harvest period; watering and spraying of any pesticide are prohibited; netting is hung to prevent birds from pecking the fruit. 3. The picking temperature is about -10°C, carried out when sugar accumulation reaches 350 g/L. Harvest in late November, generally picking before 12 noon, and stop picking after the temperature rises. Clear diseased berries, green berries and rotten berries from the vines 3 months before picking; no debris is allowed at picking. 4. Remove leaves at the end of August so that the grape clusters are fully exposed to light, accelerating sugar accumulation and increasing sugar content. 5. Dig soil pits in advance, and prune and bury the canes with soil while picking. 6. When the temperature is below -10°C, press slowly with a press. II. Cultivation Techniques 1. Inter-row cultivation and loosening Carry out inter-row cultivation, soil loosening and weeding to keep the soil loose and free of weeds. 2. Irrigation frequency Implement “promote early, control late” for watering, mainly by furrow irrigation. ① Irrigate once with bud-break water before and after grape bud break to promote uniform sprouting and favor rapid early growth of new shoots. ② Irrigate once with pre-flowering water to promote rapid growth of new shoots and leaves. ③ Irrigate once with post-flowering water. ④ During the rapid berry enlargement period, irrigate once every 15-20 days, requiring 2-3 irrigations, to favor rapid berry enlargement. ⑤ Irrigate with winter sealing water before winter begins, to help the root system and plants overwinter safely. Irrigation is prohibited during the flowering period and the 3 months before harvest. 3. Fertilization requirements ① Base fertilizer For 1-3 year old vines, apply in holes: dig pits of 30×30×40 cm between plants, apply 1-1.5 cubic meters of decomposed organic fertilizer per 667 sq m, add 25 kg of diammonium phosphate, and apply from after grape harvest to before soil burial; for 4-year-old mature vines, apply in trenches: dig a trench 30 cm wide and 40 cm deep 50 cm from the vine and apply into it, using 2-3 cubic meters of decomposed organic fertilizer per 667 sq m. ② Topdressing Before bud break, apply 15 kg of urea per 667 sq m; before flowering, apply 20 kg of diammonium phosphate per 667 sq m; during the berry enlargement period, apply 25-30 kg of diammonium phosphate and 10-15 kg of potassium fertilizer per 667 sq m. After berry harvest, together with the base fertilizer, apply an additional 25 kg of diammonium phosphate per 667 sq m. Dig shallow pits 15-20 cm deep 30-50 cm from the grape plants and apply into them, then irrigate immediately after application. Use Qilishi, 0.5% monopotassium phosphate and 0.3% urea, spraying 3-4 times at intervals of 10-15 days. 4. Training and pruning Use a trunkless multi-main-cane regular fan shape for training, selecting and retaining 3 main canes, with fruit-bearing branch groups growing directly on the main canes; according to variety characteristics, equip 6-9 fruit-bearing branch groups, leave 15-30 new shoots per sq m of trellis surface, and leave 15-20 fruit-bearing canes per plant. ① Renewal of main canes For 6-8 year old vines, select and retain thick, well-directed new shoots from suckers and train them into main canes according to the young vine training method, while gradually renewing the main canes, cutting out the main canes within 1-2 years to complete the renewal work. ② Pruning techniques Carry out winter pruning immediately after harvest is complete. Long-cane pruning: leave 7-12 buds. Medium-cane pruning: leave 4-6 buds. Short-cane pruning: leave 2-3 buds. According to the requirements of the trellis-trained trunkless three-main-cane regular fan shape, the fruiting mother canes are pruned with long, medium and short canes so that they are evenly distributed; extension canes are left long, lateral canes are left short; vigorous ones are left long, weak ones are left short; thick canes are left long, thin and weak canes are left short; young trees are left long, older trees are left short; trees with few canes are left long, those with many are left short. Remove canes below 30 cm from the ground, and select and retain fruiting mother canes on the main canes at 25-30 cm intervals. ③ Summer pruning After the vines are uncovered, tie the main canes and fruiting canes evenly and at an angle to the wire trellis surface; the height of the canes must not exceed the second wire (from top to bottom). After new shoots sprout, remove canes below 30 cm, excess buds and new shoots, leave 1 strong new shoot per bud eye, leave 15-30 new shoots per sq m of trellis surface, and leave 15-20 fruit-bearing canes per plant. When new shoots grow to 30-40 cm, tie them evenly to the wire without crossing or overlapping, and promptly remove tendrils. Pinch the growing tips of vegetative canes after leaving 8-12 leaves, and repeatedly pinch secondary shoots after leaving 1-2 leaves. 5. Grape harvest Once the grapes reach the harvest standard, they can be harvested. Handle them gently at picking to avoid losses from berry shatter. 6. Soil burial and uncovering ① Soil burial Bury with soil while pruning; when burying, lay all grape canes in one direction and cover all canes with soil to a thickness of 25-30 cm. ② Rodent control Scatter pesticide in the grape trenches to prevent rodent damage.

③ Uncovering When the sap begins to flow the next year and before bud break, in early to mid-April, clear the trenches promptly after uncovering to ensure irrigation. 7. Pest and disease control ① Do a good job of year-round orchard cleaning, promptly pruning out and thoroughly destroying leaves, canes, fruits, etc. where pests and diseases lurk. Thoroughly eliminate overwintering pests and diseases; the commonly used eradicant is lime sulfur plus 0.3% sodium pentachlorophenate. Spray protective agents early before diseases occur. ② Strengthen management and cultivate a robust tree vigor. Base it mainly on organic fertilizer, supplemented by chemical fertilizer, increase the application of phosphorus, potassium, calcium fertilizers and trace elements, and control the amount of nitrogen fertilizer. Promptly thin out branches and leaves to enhance ventilation and air permeability, prevent grape diseases, and promote evaporation of water within the berries. ③ According to the occurrence patterns of the control targets, rationally select pesticides, spraying times and methods, and use mixed and alternating applications to avoid resistance, thereby improving pesticide use efficiency.    ④ Achieve “four unifications” in spraying, namely unified pesticide, unified spray concentration, unified spray time and unified spray method, to improve control effectiveness.