How long is the grape harvest period? Key points to note when picking and key post-harvest management techniques
Grape is one of the oldest fruit tree species in the world, also known as putao, caolongzhu, cizi cherry, bodhizi, and shanhulu. It originated in western Asia and is cultivated all over the world.So how long is the grape harvest period roughly? What should be noted? What are the key post-harvest management techniques?
How long is the grape harvest period roughly?
Generally, grape berries begin to ripen at the end of August and the beginning of September, and harvesting usually starts at this time and can continue until mid-October. A small number of grapes used to make noble rot white wine are harvested as late as November.
What should be noted when picking grapes?
1. It is best to do it in the morning on a sunny day after the dew has dried. Picking is not suitable in rainy weather or just after rain.
2. Grapes harvested on hot days must be transported to a cool place and spread out to dissipate heat before packaging, otherwise quality and weight will be reduced. 3. The berries have high water content and thin skins, so when harvesting, place them gently and pack them shallowly.
4. For table varieties, they should be picked in stages and batches to ensure the flavor of the fruit.
5. To ensure quality during harvesting, hold the cluster stem with one hand or support the cluster with the palm, and with the other hand hold scissors and cut at the base of the fruit stem. 6. For harvested clusters, if there are diseased, insect-damaged, damaged, or deformed berries, trim them off at any time before boxing.
7. In all stages of grape harvesting, loading, transport, sorting, packaging, and marketing, proceed as quickly as possible to maintain the freshness and commercial quality of the grapes.
What are the key post-harvest management techniques for grapes?
In actual production, many fruit growers often relax management of grapes after harvesting, resulting in poor maturation of the current year's shoots, inhibited root development in autumn, and effects on the yield and quality of the next year's grapes. Therefore, strengthening later-stage management of grapes is crucial for high-quality, high-yield, and stable production in the coming year.
1. Protect autumn leaves. Protecting leaves after harvest and enhancing their photosynthetic capacity plays an important role in increasing the stored nutrients of the tree. In the late growth stage, the use of tebuconazole and sulfur-based pesticides must be strictly controlled to prevent premature leaf aging and reduced photosynthetic intensity.
2. Pruning and orchard cleaning. Continue to do tip pinching and lateral shoot removal, remove tendrils and thin, weak branches and vines, and remove severely diseased leaves to reduce nutrient consumption, regulate the flow of nutrients in the tree, and promote plump and mature buds. Also clear weeds in the orchard, and take the pruned diseased shoots, diseased leaves, diseased fruits, dead branches, and debris out of the orchard in a centralized manner, burying them deeply or burning them to reduce sources of pests and diseases.
3. Apply post-harvest fertilizer well. After fruit harvest, when the fruit load is heavy and the tree vigor is relatively weak, quick-acting nitrogen fertilizer can be applied to enhance leaf photosynthesis in the later stage and restore tree vigor. Apply about 20 kg of quick-acting nitrogen fertilizer per mu, or spray 0.3% urea solution on the leaves, spraying 2~3 times continuously. If the tree vigor is vigorous, apply less to prevent late extension of new shoots and wasteful consumption of large amounts of nutrients. Apply base fertilizer as early as possible after harvest.
4. Apply base fertilizer early. In southern China, the most suitable time for applying base fertilizer is one month after grape harvest. The base fertilizer is mainly organic fertilizer, combined with phosphate fertilizer. Apply 3000~5000 kg of organic fertilizer (farmyard manure) and 50 kg of phosphate fertilizer per mu. Because this is the peak period of root growth, wounded roots heal easily. Loosening the soil in combination with fertilization can cut fine roots, playing a role in root pruning, and can promote the development of many new roots in the current year. In early spring of the next year, they can absorb a large amount of nutrients from the soil. In autumn, aboveground growth gradually stops, while underground growth remains vigorous. The absorbed nutrients are mainly accumulated and stored, which can raise the level of nutrient storage in the tree, help flower bud differentiation in the current year, enhance overwintering ability, benefit sprouting in the coming year, further flower bud formation, and early growth of new shoots after flowering. Because the tree's nutrient level is high and flower bud quality is good, the fruit-setting rate can be increased, laying the foundation for a bumper harvest the following year.
5. Loosen the soil to prevent waterlogging and drought. In summer and autumn, orchards are prone to heavy weed growth. After harvest, cultivate and weed in time. This soil cultivation is often carried out together with base fertilizer application, generally to a depth of about 20 cm, shallower near the trunk and deeper outward. The purpose of loosening the soil can also be achieved by opening fertilizer trenches. When there is a lot of rain, clear the trenches and drain in time. If autumn drought or winter drought occurs, irrigate in time and keep field water-holding capacity no lower than 60% to keep the soil moist.