Summary of Vineyard Farming – Growing Grapes Commercially- Grape production–if done rationally and on a scalable basis- can be a good source of long term income. However, vine growing, either for raw consumption (table grapes) or winemaking, is a choice that will “tie” you and your land up for at least two decades. Thus, this decision requires extensive research and a clear business plan.
First of all, you have to know that many countries have very strict regulations about giving licenses for grapevine growing. Secondly, it is always better to have your own land (at least 4-5 hectares), because growing grapes requires many years of field exploitation. The average vine plant matures and gives the maximum yield about 7-8 years after planting. Thus, if you consider renting a field, fixed costs will increase, and no one can assure you that you will be able to occupy this field a decade from now.
In a few words, the vine is a perennial plant, with a great variety of growing techniques. As a general rule, winemaking varieties mature and give a good yield about 7-8 years after planting. On the other hand, contemporary table grapes varieties (intended for raw consumption of grapes) can reach their maturity and give the maximum yield just two years after planting. They can continue to give a good yield for about 15-17 years, and then most table grapes producers plow and destroy the crop because it cannot give a good yield anymore.
Tissue and soil nutrient testing for cold climate grapes
Most commercial grape growers start the vine from grafted plants. However, in some countries that the soil is free from phylloxera, they may prefer autogenous plants. It is important not to plant a new vineyard in the same place an old one has been recently removed. The soil there will most probably be depleted and possibly infected. The time window between replanting can be 2-5 years (ask a local licensed agronomist). Variety selection is very crucial. Each vine variety has unique quality characteristics that can be expressed only under specific climate and soil conditions and growing techniques.
Variety selection is a restrictive factor when growing grapes. The rootstock and scion varieties should be consistent and -of course- choosing the proper variety for your climate is crucial. In general, vines prefer warm and dry summers and cold winters (not frosty), soils with less than 25% clay content and a small percentage in gravel content, although these depend again on the rootstock variety. Sufficient amounts of organic matter are also required. High humidity levels during the summer will most probably increase fungal infections. Temperatures lower than -3 °C (27 °F) during spring or lower than -15 °C (5 °F) during the dormancy period will cause damage on wood, young shoots, and buds. In addition, soil temperatures should be over 5 °C (41 °F) in order for the vine to reclaim in maximum the soil organic matter. Optimum pH and RH levels depend on the variety. Generally, optimum pH levels are between 6,5 and 7,5. However, there are varieties that grow well in levels close to 4,5 or even 8,5.
Once you have done with all the bureaucracy and variety selection, you have to start the pre-planning processes. Vine producers till the land at that time and remove any previous crop remains. However, very heavy tillage in the inclined ground may have unpleasant consequences, such as erosion. Extremely inclined fields need to be leveled. If not, water will most probably rinse from upper levels and gather in lower levels, causing waterlogged conditions.
Next, producers install the drip irrigation system, when it comes to irrigated vineyards. When they are ready for transplanting, they make small holes in the ground, where they plant the seedlings. Fertilization, Drip Irrigation, and Weed Management are applied in most cases.
After transplanting, it is time to apply the shape and training method of the vine. There are several training systems to choose from, depending on the vine variety, environmental and soil conditions, harvesting techniques, and of course, the experience of each grape farmer. Producers give the wanted shape on their vines using support and pruning. This procedure in most cases requires 2-3 years in winemaking varieties and 1-2 year in table grapes varieties
Once they have performed trellis implementation and shaping, they start the annual work schedule, which includes pruning, deadheading, defoliation, and grape thinning. Some grape growers remove most of the developing sprouts, during the whole growing period, in order to encourage the plant to devote its resources in fewer but higher in quality fruits. Of course, this method is not preferred by all grape growers.
It is crucial to monitor the crop almost daily during the growing season in order to prevent the spread of diseases and other negative circumstances. Harvesting can be made manually, using scissors or knives, or mechanically by harvesting tractors. However, table grapes can only be harvested manually. Each method has its pros and cons. Traditional vineyards in Europe that produce wines of high-quality and low quantity yield are harvested manually.
Grape harvesting time is difficult to be generalized. It is a combination of variety together with climate conditions, soil characteristics, and growing techniques. Rarely can we harvest grapes the same date we harvested the previous year. Even on the same farm, with the same vine varieties, harvesting time of vines may differ. Generally, we could say that in the northern hemisphere, most varieties mature from August to November, while in the southern hemisphere from March to August. After harvesting, grape growers carefully separate healthy grapes from diseased, clean them carefully, and either cool and store them in order to be sold raw or start the winemaking procedure. After harvesting and foliage drop, the vine starts to enter the dormancy period periodically.
As far as yield is concerned, in general, when we harvest table grape varieties, we can harvest a bigger yield than when we grow wine varieties. But even among wine varieties, there are great differences in yield. Every farmer has to make informed and fact-based decisions and find the proper balance between quantity and quality. Some European grape producers (Sauvignon or Cabernet varieties) claim that they don’t want to harvest more than 6 tons of grapes per hectare, because a higher yield will dramatically decrease the product quality. Although this yield may seem incredibly low compared to other varieties, it is more than enough to financially support the producer, because the product can be marketed at a premium price. On the other hand, medium and low-quality winemaking varieties can give 20-40 tons per hectare or even more, but they cannot be marketed at a high price. Table grape varieties can give a yield of 20-50 tons per hectare.
