Detailed Explanation of Grape Cultivation Techniques and Management Methods

Grape (scientific name: Vitis vinifera L.) is a woody vine of the genus Vitis in the family Vitaceae, with cylindrical branchlets bearing longitudinal ridge lines, glabrous or sparsely pubescent, ovate leaves, dense or loose panicles with well-developed basal branching, and spherical or oval fruits, flowering from April to May and fruiting from August to September.

1 Grape Cultivation

When planting grapes, varieties suited to the regional climate should be selected, and sandy soil should be chosen for planting whenever possible. The planting soil should be in an area with flat terrain, good drainage, and a good water source for irrigation. Due to the climatic characteristics of the north, planting is best carried out in autumn, and organic fertilizer should be applied before planting in order to lay the foundation for the growth of the grape root system. The temperature at planting should be maintained at around 10°C, and the soil temperature at a depth of 30 cm should reach around 8°C. Grapes are fond of light, and light can promote the development of grape branches and improve grape yield and quality, so an area with good light should be chosen when establishing the vineyard. Grapes have relatively high water requirements during growth, and water is the carrier through which the grape plant absorbs nutrients via its root system, so water during the growing process should be appropriate.

2 Grape Management Models

2.1 Branch Management

In the first year after planting grapes, a post needs to be erected beside the planted seedling to complete the design of the climbing trellis for the grape vines. After the grape seedlings emerge, following the principle of keeping the upper and not the lower, and keeping the strong and not the weak, the topmost two grape buds are kept and the other buds are removed. When the grape seedlings grow to about 17 cm, the relatively weaker retained branch is removed, leaving one stronger branch to grow upward, in order to prevent damage to the new grape branches from severe weather. When the thin seedlings grow to about 45 cm in height, nitrogen fertilizer is needed for topdressing, and at the same time the tender branches are trellised by tying the new shoots of the tender branches to the trellis, and when the new shoots grow to about 1 m they should be pinched. Pinching should be carried out repeatedly until the grape grows to about 2 m in height, when it stops. In the second year, pruning of the grape branches should keep the grape height no more than 1.5 m, with no less than 0.5 m being optimal, to ensure the growth capacity of the grape branches and the yield in the second year. In the second year after planting, vine tying should be carried out, tying the grape, pruned to a height of about 1.5 m, horizontally to a wire so that two grape plants are connected. Then bud removal and shoot fixing are carried out, mainly leaving one upright-growing branch at the bend of the grape as the fruiting branch for the next year, but this branch mainly grows upright in the second year without bearing fruit, and is pinched when it grows to 1.2 m in the second year. The new shoots that grow after the grape vines are tied need to be retained; these new shoots have inflorescences and can bear fruit. One new shoot is retained per inflorescence, with a spacing of about 16 cm between new shoots. When the new shoots grow to about 65 cm, pinching is carried out, and after pinching, the new shoots are pinched again when they grow to about 65 cm. In order for grapes to achieve high yield and good quality, cluster trimming and berry thinning are needed, in order to make the cluster shape uniform, but small berries and excessively dense berries should be avoided. In the winter of the second year, single-branch pruning of the grapes is needed: the single branch left at the previous bend is cut at 1 m as the fruiting branch for the next year, and all other branches are cut off.

2.2 Soil Management

Soil management mainly consists of hoeing weeds, deep plowing, etc. in the vineyard, and intercropping can also be carried out to ensure sufficient nutrients during the grape growing process.

2.3 Fertilizer Management

Fertilizer is an indispensable nutrient component in the grape growing process, and different types of fertilizer are applied at different stages of grape growth to ensure adequate nutrition for the grape plant. First, base fertilizer. Applying fertilizer to the vineyard in late autumn is very necessary; at this time mainly base fertilizer is applied, in order to make the fertilizer penetrate deep into the grape root growth zone. The base fertilizer can decompose in the soil to meet the needs of grape growth in the second year. In autumn, the grape root system enters a period of vigorous growth, and at this time a large amount of fertilizer is needed to ensure the regenerative capacity of broken roots. When applying fertilizer, if organic fertilizer is chosen, an appropriate amount of nitrogen-rich human and animal manure and urine should be added to help regulate the carbon-to-nitrogen ratio and make the fertilizer easy to decompose. The application of base fertilizer in autumn can be carried out simultaneously with deep plowing of the soil, to achieve the organic integration of soil and fertilizer; second, topdressing. Topdressing is mainly carried out before budding, mainly with urea and ammonium bicarbonate; at this time the grape enters the bleeding period, the root system's fertilizer absorption rate increases, and topdressing can increase the budding rate and raise yield; third, topdressing at the flowering stage. Topdressing at the flowering stage is mainly with nitrogen fertilizer and phosphate fertilizer, together with a certain amount of potassium fertilizer; the purpose of topdressing is to promote grape flowering, pollination and fruiting; fourth, topdressing at the young fruit stage. The main purpose of topdressing at the young fruit stage is to promote the enlargement rate of grape berries and reduce the proportion of small berries. The young fruit stage is also a period of vigorous growth of the grape root system, and at this time a large amount of nutrients is needed to support plant growth; fifth, topdressing at the berry stage and after picking. At the berry stage, topdressing with potassium fertilizer and phosphate fertilizer is mainly carried out when the grape berries are coloring, and after picking, topdressing should also be done with potassium fertilizer and phosphate fertilizer, mixed with an appropriate amount of nitrogen fertilizer.

2.4 Water Management

Grapes have a strong drought tolerance during growth, and when the soil moisture content reaches about 65%, root and new shoot growth is optimal. When the moisture content exceeds 80%, it is unfavorable for grape growth, and aeration is needed. When the moisture content is below 35%, new shoots will stop growing, so the water during the grape growing process should be scientifically managed. First, before grape budding. Before budding is the first critical period of grape water management; at this time grape new buds emerge, new shoots grow, inflorescences gradually develop, and the root system is also in a period of vigorous growth, making it a critical period for water management. Due to long-term drought in the north, if watering is not carried out immediately, it will lead to a low budding rate and, in severe cases, cause the branches to dry out; second, the tenth day after flowering. The tenth day after grape flowering is also a critical period for water management; at this time grape new shoots grow rapidly, the base begins to lignify, leaves enlarge, new inflorescences form, the root system needs to grow new roots, and the root system's water absorption in the soil reaches its most vigorous level; this is also the first berry stage, with relatively high water demand; third, the berry coloring stage and ripening stage. During the grape berry coloring stage, the berries begin to accumulate sugar, and strengthening water management and supply during this period is conducive to improving yield and quality and also helps increase the yield in the next year. During the berry ripening stage, soil moisture is sufficient in areas with adequate rainfall. However, irrigation is needed in cases of insufficient rainfall or poor soil water retention capacity. Maintaining appropriate soil moisture content during the berry ripening stage can make the grapes develop well and have good sweetness. At this time the water should not be excessive, as excessive water easily results in low sugar content and poor storability; fourth, the period of burying soil for cold protection. The Jilin region is relatively dry, and a small amount of watering should be carried out before burying the grape branches in soil in winter, to ensure that the grapes have sufficient water and nutrients when overwintering.

2.5 Bagging Management

The purpose of bagging is to ensure that the grapes are brightly colored, high quality and free of damaged berries, and it can also prevent damage to the grapes from pests and diseases, reduce the amount of pesticide spraying, reduce pesticide residues, improve grape fruit quality, and increase product value.