Methods to Encourage Early Sprouting in Grapes
Comprehensive introduction to the methods for encouraging early sprouting in grapes and detailed explanation of grape bud promotion techniques, let's explore the specific content with the editor!
Grapevines require a certain amount of chilling to end dormancy and start sprouting. The main methods to promote early sprouting of grape buds include the concentrated pre-chilling method, lime nitrogen treatment, and intermittent sprinkling method. In the northern regions with forced cultivation and in the southern open-field cultivation where there is insufficient chilling, grapevines often experience uneven sprouting and delayed timing, leading to earlier harvest periods for the grapes that sprout early. Below, we provide a detailed introduction to the methods for promoting early sprouting in grapes.
1. Conditions for Early Sprouting of Grapes
Grapes usually sprout from the end of March to early April in spring. For grapevines to sprout, they require a certain amount of chilling, which is achieved through low-temperature vernalization to break dormancy. The chilling requirement for grapes is for the ambient temperature to remain below 7.2°C for a continuous period, usually 1000 to 1500 hours. Early maturing varieties generally require about 1000 hours of chilling, while some varieties need longer chilling periods, from 1800 to 2000 hours.
In the northern regions with forced cultivation, or greenhouse cultivation, insulation during the autumn and winter seasons can prevent grapevines from sprouting at the normal time. For grapevines grown in the open field in the south, warm winters can also prevent early sprouting. Measures need to be taken in the warm winter climates of southern regions to promote early termination of dormancy in grape buds.
2. Methods to Promote Early Sprouting of Grapevines
1. Concentrated Pre-Chilling Method
For most grape varieties with forced cultivation, before the leaves fall in autumn, pre-chilling treatment can be carried out by promptly covering the greenhouse when the ambient temperature drops to 7.2°C, thus maintaining the greenhouse temperature at a lower level. At night, the greenhouse vent should be opened, and during the day, the grass curtain should be covered and shaded. After 30 to 40 days, the chilling requirement can be met.
2. Lime Nitrogen Treatment
Lime nitrogen can be used to break dormancy, usually at the end of the dormant period. The method is to apply lime nitrogen to the grapevine stems 20 to 30 days before sprouting, which can usually promote sprouting 1 to 2 weeks earlier.
3. Intermittent Sprinkling Method
Intermittent sprinkling can be used to reduce the ambient temperature at night, that is, during the grape dormancy period, wait until the night temperature does not exceed 12°C, and then sprinkle water on the trunk every hour. This method is effective.
4. Other Dormancy-Breaking Treatments
Other substances can also cause grape buds to break dormancy, including plant growth regulators such as gibberellin and cytokinins, and certain sulfur compounds found in plants like onions and garlic. A mixture of gibberellin, nitrates, and urea can also promote early sprouting.
3. Care Management to Promote Early Sprouting
Appropriate light, temperature, moisture, and sufficient soil nutrients are required for early sprouting. Grapes can sprout when the temperature is around 15°C in early spring. Before sprouting, the soil should be kept moist, with water灌溉 provided through small drip irrigation every 10 to 15 days. After watering, it is necessary to loosen the soil and remove weeds promptly. Before sprouting, additional nitrogen and phosphorus fertilizers can be applied, and plant growth regulators such as brassinolide can be sprayed at the base of the grapevine to enhance the tree's vigor.
It is also necessary to use insecticides such as avermectin, pymetrozine, and pyrethroids to control pests like the grape leafhopper, grape hawkmoth larvae, and wax scale insects to prevent damage to the plant that could lead to the drying and death of branches. Additionally, appropriate pruning should be carried out in winter to accumulate the nutrients needed for sprouting and growth.
The above is a comprehensive introduction to the methods for encouraging early sprouting in grapes and detailed explanations of grape bud promotion techniques, hoping to bring some related knowledge about green plants to green plant enthusiasts.