The vegetative growth period of grape vines
1. Sap flow period
This period is the time when the sap flows in the spring until the buds sprout and develop leaves. At this stage, a large amount of colorless and transparent liquid flows out from the wound of the branch and vine, which is the wound flow. The appearance of wound flow indicates that the root system begins to absorb a large amount of water and nutrients, marking the beginning of vegetative growth. The size of the wound flow is related to the variety and soil moisture. The soil moisture is high, and the wound flow is large; the soil is dry, and there is almost no wound flow. The bruising fluid contains 0.1% to 0.2% dry matter (2/3 of which are sugars and nitrogen, and 1/3 is minerals). The bruising fluid is caused by the absorption of water by the roots from the soil and the effect of root pressure.
Management points: At this time, it is necessary to strengthen the loosening of the soil, increase the ground temperature, and reduce the soil temperature to avoid causing too many mechanical wounds to the fruit trees.
2. Grape budding and new shoots, inflorescence growth period
The buds begin to germinate when the average temperature of the grapes is stable at around 10°C during the day and night. About two weeks later, with the increase of temperature, the growth of new shoots gradually accelerated, and the inflorescence continued to differentiate, forming branches and flower buds at all levels. The growth rate of flowering shoots reaches its peak, reaching a length of 60-80 cm, which is about 60% of the total length of the year. After entering the flowering stage, a large amount of nutrients are transferred to the reproductive organs, and the growth of new shoots begins to slow. The duration of this period is 30 to 50 days.
Management points: In the early stage of grape growth, the growth of new shoots, inflorescences and roots all depend on the nutrients stored in the plant. After the leaves are fully grown, they can gradually change to rely on the photosynthetic products of the year. Insufficient nutrition during this period will seriously affect the yield and quality of the current year and the growth results of the next year. Nitrogen and phosphorus fertilizers must be applied in time and irrigated. In order to save nutrients, the sprouts should be removed in time, the shoots should be fixed, and the load should be adjusted reasonably.
3. Grape blooming period:
This period from the flowering of grapes to the termination of flowering, generally lasts 7 to 12 days. The grapes begin to bloom when the temperature rises to around 20°C. The optimum temperature for flowering is 25-30°C. In case of low temperature and rainy weather during the flowering period, the flowering period will be prolonged, which will affect pollination and fertilization.
Management points: During the flowering period of grapes, due to flowering, growth of branches and leaves, and differentiation of flower buds, a large amount of nutrients are consumed. Before and after flowering, fertilizers must be applied, and vines must be tied, topped, and auxiliary shoots removed in time. , improve the fruit set rate. For female flower varieties and varieties with poor pollination, artificial assisted pollination should be carried out.
4. Grape berry growing period:
Grapes begin to expand from the ovary to the berry growing period before the berries are colored. Grapes generally set fruit for 3 to 4 weeks, and the first growth peak of grape berries occurs. This is the period when the growth of berries is the largest, accounting for about 2/3 of the total growth of berries. The seeds begin to harden as the berry growth slows. After that, the berries showed a second growth peak, reaching the desired size of the variety. The duration of this period is 35-60 days for early-maturing varieties, 60-80 days for medium-maturing varieties, and more than 80 days for late-maturing varieties.
Management points: During this period, the grape fruit grows rapidly, the growth of new shoots is slowed down and the growth of thickening is accelerated, the base begins to lignify, the flower buds of winter buds are vigorously differentiated, and nutrients are consumed more. shoot growth. In addition, this period is the season of high temperature and multi-temperature. It is necessary to strengthen the control of pests and diseases, protect the leaves of grapes, and improve the photosynthetic capacity.
5. Grape berry ripening period:
This period is from the beginning of discoloration of the grape berries to full ripeness. During this period, the volume of grape berries no longer increased significantly, mainly due to the accumulation and transformation of nutrients. At the same time, the skins of the grapes softened, showing the color that the variety should have. The sugar content increased rapidly, and the acid content and tannins gradually decreased.
Grape varieties with different uses have different requirements for berry maturity. As long as the ratio of sugar to acid is suitable, table grape varieties have good flavor and can be harvested with less maturity, especially grapes for export.
Management points: During the ripening period of grapes, berries accumulate a lot of nutrients, new shoots are gradually lignified, flower buds continue to differentiate, and roots also begin to store nutrients. During this period, it is necessary to increase the application of phosphorus and potassium fertilizers to protect the leaves. In the case of a lot of rain, pay attention to drainage to prevent the grapes from cracking and rotting.
6. Grape shoot maturity and deciduous stage:
In general grape varieties, in the late stage of berry maturity, the new shoots have begun to lignify from the base. After the grape berries are harvested, the lignification of the new shoots is accelerated, and the mature shoots turn brown or brown. As the temperature drops, the leaves gradually age, and the base of the petiole forms an abscission layer, which gradually falls off from the base of the branch upward.
Management points: After the grapes are harvested, basal fertilizer should be applied early to accelerate the maturity of the branches and create a good material basis for the plants to survive the winter.
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