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Differences between grape vines and fruit trees
Grapevines are a species of woody vines used to propagate many cultivated and wild varieties of grape. There are both wild and cultivated species of grape in the genus Vitis. Grapevines do not have seeds like most trees. Grape seeds are small, usually grape sized and generally contain very little nutritional value. Thus they are not widely used for human consumption, though they are used for animal feed. Some grapevine seeds are fed to fattening livestock.
A grapevine leaf is a compound leaf made up of a leaf base, lamina and petiole. Each lamina is divided into leaflets by a sinus. A grapevine leaflet is a small leaflet of a compound leaf that is attached directly to the sinus and extends in length only a few millimeters. The leaf bases that form the stem of the vine are called petioles. Grapevine flowers are simple and usually produced in umbels, although some forms have solitary flowers. They have 5 tepals that surround a single, small, often hooded, stamen. The small, almost always bisexual and unisexual flowers (that form male and female structures) open in the morning and close before noon.
Grapevines are in the order Lamiales, closely related to asparagus and artichokes, and the most cultivated of the orders in the Caryophyllales. Grapevines are one of two genera of Vitis, and there are about 80 species. The genus Vitis consists of diploid (2n=26) grape vines, with chromosome number 2n=12×13, and tetraploid (4n=52) grape vines with 2n=18×9.
Grape vines usually have a single stem (a single trunk), with a length up to 30 meters. All grapevines have tendrils, for creeping along the ground or climbing trees, with leaves like a terrestrial herb or with petioles. All grapevines have clusters of flowers in a single row, a few to dozens. There are three types of stem: basal, axillary and terminal.
All forms of grape are cultivated for their fruit, with some forms grown primarily for their leaves. The fruits are usually grape berries, but the leaves are sometimes the edible product. The berries may be eaten fresh or used in making wine. The berries of many wine grapes are large and sweet, and are generally eaten fresh or used to make jam or jelly. In the United States, only a handful of wine grapes are used to make commercially available wine.
Cultivation of grape vines has a long history, going back to the earliest wine drinkers. Many domesticated plants can be traced to their original cultivation in wine-growing regions. Modern viticulture has an extensive science and technology foundation.
It takes of vines to produce a single bottle of wine and most vintages require of vines for every of wine. The majority of the wine grapes of the world are grown in the cooler climates of Europe and Asia, though other regions, such as Canada, New Zealand, Australia, Argentina, South Africa, Chile and South America, produce wine.
Grapevines are usually grown in fields. Each vine is tied to a stake at its base, and then trained against trellis systems with a framework that includes wires, pipes and supports. The framework is generally made of metal and is referred to as a trellis. To support the weight of the vine and trellis system, two parallel pieces of lumber, spaced on opposite sides of the vine, are placed perpendicular to each other. These are known as furrows.
All forms of grape are cultivated for their fruit, with some forms grown primarily for their leaves. The fruits are usually grape berries, but the leaves are sometimes the edible product.
The fruit are the part of the vine and ripen when the sugars are at a high enough level to be used in wine-making, which is generally in October and November in most wine-producing countries. Fruit development is characterized by the size of the berries, color, shape, and position on the vine. All have roles in determining the eventual quality of the wine.
The fruit must be picked when the desired sugar content is reached, in order to prevent spoilage. The grapes are taken by hand or using a specialized device called a grape harvester. Harvesting manually is labor-intensive and takes several people, but is often done outdoors in the warmer months. In many cases, harvesting is done early in the morning, in order to avoid the effects of low humidity in the dew.
The grapes may then be transferred to a transport vehicle or train car that will be used to transport the fruit to a winery.The grapes are usually bunched in some form, though they may simply be placed in rows in the winery's vat room, or left loose in a basket. Grape-picking equipment allows grapes to be harvested in a controlled manner with good efficiency. Grapes are usually not harvested in the very early morning, because the grapes have a tendency to turn blue or black in the morning sunlight. They also tend to shrink slightly as the morning progresses.
In the developed wine regions of Europe, South America, South Africa, Australia, New Zealand, and North America, all the grapes used in the process of making wine are grown on the same land or vineyard. The grapes are harvested all together and processed by the same winery, typically during a one-day or two-day harvest.
In contrast, in less developed regions (typically developing countries), such as those in Asia, Africa, and the Middle East, where the process of making wine is far less developed, grapes are grown on the same vineyard, or on a single plot of land that is owned by one vineyard owner, but the grapes are not harvested all at once. Rather, grapes are taken off of vines in small clusters, and are collected in bins, then sold as bulk grapes to wineries. In this type of situation, the amount of time it takes for a wine producer to harvest a vineyard is a major issue.
A grape-picking machine must be properly designed to meet the needs of a winery or wine producer. To select appropriate equipment, a winery must weigh the type and cost of the grapes to be harvested against the type of harvesting equipment available.
Various machines are available to harvest grapes.
The vine harvester is perhaps the most familiar harvesting device. It consists of a tractor or vehicle mounted with a pair of rotating arms, in which are mounted a pair of rotating brushes that collect grapes from the vine. Each arm can be rotated to a separate side of the vine to allow for collecting at an upward angle of approximately 30 degrees, or can be set to allow for a 90 degree upward angle. The device is mounted to a frame that rests on the ground, and it is possible to adjust the rotation speed of the brush to the size of the vines. However, in regions with larger vineyard sizes, this device is too slow, and the vine will often need to be cut prior to its being ready to be picked.
Tandem grape harvester
Tandem grape harvesters, such as the one pictured, are the first equipment that allows an entire vine to be harvested. The brush of the machine is mounted in a frame that travels along a track behind the tractor.
There are several different models of tandem grape harvesters, all designed to process several hundred pounds per hour. The size and number of grape clusters that can be gathered in a