Investigation of four-step shaping technology and application effect of wine grape "factory" shape
Shi Jingjing et al
Funds: Key R&D Program of Ningxia Hui Autonomous Region (2021BEF02017) Ministry of Finance and Ministry of Agriculture and Rural Affairs: National Modern Agricultural Industrial Technology System Construction Project (CARS-29-zp-6)
In the northwestern part of the continent, the choice of vine shape for wine grapes is limited. Many studies have found that the "factory" shape is easier to bury in winter than the erect monosaurus tree shape, and it can also reduce the damage to the base of the plant. In addition, some studies have shown that the leaf area of the "factory" shape is higher than that of the Dulong vine tree, the leaf quality is improved, and the leaf area index, direct transmission coefficient, net photosynthetic rate and fruit quality are also higher than those of the Dulong vine tree, and the leaf curtain transmittance and fruit-to-fruit photosynthetic effective radiation of plants at different phenological stages are increased, the fruit spike is more loose, the fresh weight of the peel and seeds, the number of seeds are significantly increased, and the total amount of anthocyanins in the pericarp is significantly increased. The drought and lack of rainfall in the eastern foothills of Helan Mountain in Ningxia, and the lack of standardization of wine grape "factory" shape and shaping technology lead to slow growth of young trees, non-standard tree shape, and long forming time, which cannot give full play to the advantages of this tree shape. In view of such problems, combined with the actual cultivation experience, this paper summarizes and verifies the key technical parameters of the four-step shaping method of "factory" shape for reference.
1 Four-step plastic surgery key technology
One year strong seedlings: 1~2 new shoots are selected to grow freely after the seedlings sprout in the current year, and the new shoots are topped in early to mid-August, and the autumn is required
The diameter of the base of the annual branch (the base of the seedling) reached 9.0~12.0 mm, and the number of mature and full buds reached 7 or more. During winter pruning, one robust annual branch was selected and the length of 50~80 cm was retained for pruning.
Two-year strong vines: the branches will be unearthed before budding in the spring of the second year, and after the winter buds at the top of the main branch germinate, 2~3 buds will be retracted and pruned at the base for retraction and pruning (stubble), and 1~2 strong new shoots will be selected after elongation, close to the bamboo pole with a length of 2.0 m obliquely inserted into the new shoots, and the angle between the bamboo pole and the ground will be about 45 °, and the new shoots will be tied to the bamboo poles to make them grow upward, and the main shoots (length of more than 200 cm) will be truncated (topped), and 3~4 leaves will be left under the top of the main shoots for continuous topping, and the rest of the secondary shoots will be erased. At the end of autumn, the main vine should be fully mature, with a length of ≥ 200 cm, a base diameter of 12.0~15.0 mm, and a diameter of ≥ 6.0 mm at 180 cm of the main vine. When pruning in winter, keep the main vine 180~200 cm cut, and the diameter of the cut should be greater than 6 mm.
Three-year results: the grapes will be unearthed and put on the shelves before budding in the spring of the third year of planting, the base of the main vine is 20 cm and the ground is at an angle of 55~60°, the main vine is inclined in the same direction along the shelf surface and gradually rises to the second steel wire at the top of the previous plant for binding, and the 6~8 buds (length of about 50 cm) at the tip of the main vine are horizontally tied to the second steel wire as 1/ 2 horizontal vines, after germination, select 6~7 new shoots vertically clamped into the double steel wire on the frame surface, the tender shoots on the main vine under the second steel wire are all erased from the base, and the diameter of the base of the new shoots is required to be ≥ 8.0 mm at the end of autumn. During winter pruning, the long shoots (6~8 buds) at the top of the horizontal vine are cut off, and the rest of the new shoots are cut with double buds.
Four-year forming: The grapes are unearthed and put on the shelves before budding in the spring of the fourth year of planting, the main vine is tied to the second steel wire according to the inclination angle and position of the third year, and the annual branches at the top of the horizontal vine must be tied horizontally to the steel wire to form a complete horizontal vine. After germination, 12~15 new shoots were selected per meter of the frame surface of the fruiting mother branch on the horizontal vine, which were vertically and evenly clamped into the double steel wire on the frame surface, and the diameter of the base of the new shoots was required to be ≥ 8.0 mm in late autumn. During winter pruning, one fruiting branch group was arranged every 10 cm or so on the horizontal arm, and 1~2 fruiting mother branches were retained on each fruiting branch group for single bud or double bud pruning. After the fifth year, 14~18 new shoots are selected per meter of shelf surface, and the yield per mu is about 500~800 kg.
2 Materials and Methods
2.1 Investigation Materials
The data was collected from the wine vineyard of COFCO Great Wall Wine (Ningxia) Co., Ltd. in Yongning County, Yinchuan City, Ningxia Hui Autonomous Region in 2021. The survey materials showed that seven main wine grape varieties such as 'Cabernet Sauvignon' and 'Marselan' were planted in the young orchard in 2018 and the mature orchard in 2012, with a row spacing of 1.0 m × 3.2 m, and the cultivation mode of "factory" shape of the hedge.
2.2 Survey Methodology
2.2.1 Plant growth and development survey
In the first year of planting, the survival rate of seedlings was investigated by counting method, the average survival rate was calculated, and the number of mature buds was counted directly. Seedling survival rate (%) = number of surviving seedlings / total number of planted seedlings × 100
In the second year of planting, the diameter of the main vine was measured by digital display electronic vernier caliper, the maximum diameter at the base of the main vine was measured at 2~3 cm, the upper diameter was measured at the upper part of the main vine at 180 cm, and the length of the mature main vine was measured by a steel tape measure.
In the third year of planting and beyond: the main vine diameter measured the maximum diameter at 2~3 cm at the base of the plant, the density of new shoots was calculated by direct counting method (the average number of new shoots per meter of shelf surface was calculated), the diameter of new shoots was measured by the maximum diameter at 1 cm at the base of new shoots, and the loading was carried out by direct counting method (the average number of spikes per meter of shelf surface was calculated).
2.2.2 Determination of fruit ears and fruit traits
Physical traits: 30 ears were randomly collected and weighed on a scale to calculate the panicle weight (g), and 50 fruit grains were randomly weighed on a balance to calculate the grain weight (g). Repeat 3 times.
Physical and chemical quality: soluble solids were determined by the Japanese Atago portable digital sugar meter PAL-1 (0.0%~53.0%) refractometer method, and the total acid was determined by sodium hydroxide direct titration method (based on tartaric acid). The total phenols of the peel were determined by the forlin-shoka method, the tannins were determined by the methylcellulose precipitation method (MCP method), the total anthocyanins were determined by the pH index method, the total flavonoids were determined by the chromogenic method of marbutin methanol, and the total flavane-3-ol was determined by the p-DMACA-hydrochloric acid method.
3 Results and Analysis
3.1 One year of strong seedlings, two years of strong vines
3.1.1 Grow robust seedlings in the first year
The survey data (Table 1) showed that the diameter of the new shoots of the finished seedlings of 'Marselan' in the autumn of the first year exceeded 12 mm, and the diameter of the new shoots of the finished seedlings of 'Cabernet Sauvignon', Cabernet Franc, Syrah and Malbec reached more than 10 mm. Most of the tested varieties had more than 10 mature buds in autumn, including more than 13 mature buds of 'Syrah', and less than 10 mature buds of 'Cabernet Franc' and 'Xiaoweierduo'.
Table 1 Growth and development of grape seedlings (new shoots) in autumn of planting year
Note: Different lowercase letters in the same column indicate significant differences between different varieties (P <0.05), the same below
3.1.2 Cultivate a strong main vine in the second year of planting
The results (Table 2) showed that the mature main vine length of most of the tested plants in the second year of planting was ≥ 220 cm, and the proportion of the main vine length of each variety reaching 220 cm was more than 90%, and all the mature main vines of 'Merlot' exceeded 220 cm, but the diameter of 'Merlot' at the main vine length of 180 cm was smaller than that of other varieties. Except for 'Merlot', the average diameter of the base of the mature main vine of the other tested varieties ≥ 16 mm. In the second year of planting, 'Syrah', 'Xiaoweierduo' and 'Malbec' were not significantly different from those in the year of planting due to poor growth, so they were all treated with stubble.
Table 2 Growth and development of the main vine in the second year of planting
3.2 Three years to bear fruit, four years to form
3.2.1 Growth and fruiting in the third year of planting
Table 3 showed that the average diameter of the main vine base of the triennial plants of 'Cabernet Sauvignon' and 'Marselan' was 23.81 mm and 24.71 mm, which increased by 47.98% and 48.23% respectively compared with the two-year-old plants. The average diameter of the base of the new shoots was 9~10 mm, the average number of new shoots per meter of shelf surface (leaf curtain) was 8.58 and 10.17, and the number of fruit spikes was 9.71 and 11.05, respectively. The average yields per mu of 'Cabernet Sauvignon' and 'Marselan' were 208.75 kg and 252.10 kg, which reached 35.19% and 35.93% of those of mature trees (10-year-old), respectively. Other three-year-old and above varieties were not sampled for analysis.
Table 3 Growth and yield of grape plants of three years and above
3.2.2 Basically formed in the fourth year of planting
The study (Table 3) showed that the average diameter of the main vine base of the four-year-old plants of 'Cabernet Sauvignon' and 'Marselan' was 26.66 and 29.01 mm, which reached 51.70% and 58.62% of that of the mature trees (10.70% and 58.62% respectively), the diameter of the base of the new shoots was 10~11 mm, the average number of new shoots per meter of shelf surface (leaf curtain) was 13.53 and 13.25, and the number of fruit spikes was 18.13 and 26.15. The average yields per mu of 'Cabernet Sauvignon' and 'Marselan' were 463.83 kg and 480.83 kg, reaching 78.19% and 68.54% of the mature trees (10-year-old), respectively.
3.3 Fruit quality at different ages
3.3.1 Basic quality of fruits of different ages
As can be seen from Figure 1, the ear weight and grain weight of three-year-old grapes were significantly smaller than those of mature plants, and there was no significant difference between the ear weight and grain weight of four-year-old grapes and those of mature plants. The ears of 'Marselan' are significantly larger than 'Cabernet Sauvignon', while the fruit is significantly smaller than 'Cabernet Sauvignon'. Table 4 showed that the soluble solids content of grape fruit decreased significantly with the increase of tree age, the soluble solids content of 'Cabernet Sauvignon' and 'Marselan' mature trees decreased by 7.25% and 8.13% compared with the three-year-old plants, and the titratable acid content of 'Cabernet Sauvignon' and 'Marselan' increased significantly with the increase of tree age, and the titratable acid content of 'Cabernet Sauvignon' and 'Marselan' mature trees increased by 13.41% and 10.87% compared with that of three-year-old plants. The "drop and one liter" of sugar and acid content in the fruit is more conducive to maintaining the "sugar and acid balance" and the quality of winemaking.
Fig.1 Grape spikes and fruit sizes of different tree ages
Table 4 The contents of the main quality indexes of grape fruit at different ages
3.3.2 Phenolic substances in fruits of different ages
Fruit phenols are important components that make up the skeleton and flavor of wine, and anthocyanins determine the color of grapes and wines. In general, the phenolic content of fruit increased with the age of the tree. The total phenolic content of 10-year-old plants of 'Marselan' was significantly higher than that of 3-year-old and 4-year-old plants, while there was no significant difference between the trees of different ages of 'Cabernet Sauvignon'. The total tannin content of fruit also increased with the age of the tree, but there was no significant difference among different tree ages. The anthocyanins content of four-year-old and ten-year-old plants was significantly higher than that of three-year-old plants, and the anthocyanins of four-year-old and ten-year-old plants of 'Cabernet Sauvignon' increased by 22.06% and 13.74% compared with those of three-year-old plants, and the anthocyanins of four-year-old and ten-year-old plants of 'Marselan' increased by 12.69% and 17.21% compared with those of three-year-old plants. The contents of total flavanols and total flavonoids in the fruits of the three-year-old plant of 'Cabernet Sauvignon' were significantly lower than those of the ten-year-old plant, while there was no significant difference between the four-year-old total flavonoids and the ten-year-old plant. The total flavanool content of the three-year-old plants of 'Marselan' was significantly lower than that of the ten-year-old plants, and there was no significant difference between the four-year-old and ten-year-old plants, and although the flavonoid content of the fruit increased with the increase of tree age, there was no significant difference between the tree ages.
4 Conclusion
The four-step "factory" shaping method is suitable for the northwestern buried soil and cold-proof areas, and the grape plants cultivated with this technology are in good condition and the fruit quality is suitable for making high-quality wines. Although the yield of the four-year-old plants was only about 70% of that of the perennial plants, there was no significant difference in fruit quality between the four-year-old plants and the ten-year-old plants. This technology provides data support for the "factory" cultivation of wine grapes in the buried soil and cold-proof areas, which is convenient to ensure the quality of grapes and the mechanized management of wine grapes throughout the whole process.