Grapes in United States

There are three broad classes of grapes that are grown in United States: Vitis lubrusca, Vitus vinifera and Vitis rotundifolia. Grapes are grown mainly in California, New York, Pennsylvania, Michigan and Ohio.

Washington, Missouri, and Arkansas also produce same grapes. There are many varieties of grapes but there are predominant in this country. Grapes are utilized to produce unfermented grape juice, vinegar, wine, raisins, jams and jellies, and as the fresh product for table. Approximately 70 percent of the world’s grape production goes into wine.

Thompson seedless grapes are used in canned fruit cocktail. There is a direct relationship between the soluble solids content of the berries and the percentage of berries that develop internal browning.

Grapes can be produced on a number of different types of soils. Fertility is not as important as soil structure. Sandy or gravelly clay loams are most desired.

Grapes are planted as vines or cuttings from older plants. The cuttings produce arms bearing fruit, the greatest yields coming after 3 years of growth. Properly pruned and cared for, vines produce fruit for many years.
Grapes in United States

Grape harvesting

Grapes are harvested when they reach a critical stage for sale or processing.  The timing of harvest is probably the single most important viticultural decision taken each season.

Percentage soluble solid by weight (in Brix) is used as a primary measure of the fruit’s suitability for harvest.

Wine grapes are harvested at a range of soluble solids from approximately 17-30 degree Brix. In California, European grapes are harvested from June to October about 80 to 120 days after blossoming. North America grapes are harvested during September and October, about 90 to 120 days after blossoming.

Grapes are harvested by machine or hand. Bunch grape cultivates ripen their primary crop uniformly enough that an entire vine is harvested at one time.

This facilitates both hand and machine harvesting.

Hand harvesting
Hand harvesting is used for all table grapes and many wine and raisin grapes. The hand picking allows more selective picking because all grapes do not mature at the same rate.

There is less damage to the vineyard trellis and irrigation systems than machine-harvested fruit.

In hand harvesting the pickers use a sharpened grape hook or a knife to sever the peduncle. However, the disadvantages of manual harvesting outweigh its advantages. In addition to labor costs, and inadequate availability, manual harvesting is slower, stops during inclement weather, and seldom occurs 24 hours a day.

Mechanical harvesting 
Machine harvesting grapes has many advantages and some disadvantages. Machine harvesting is much more economical and faster than the manual method.

It has been estimated that in Europe, mechanical harvesting reduces the time involved from 160 – 300 h/ha to 0,6 – 1.2 h/ha and the cost from 1600 – 2000 Euro/ha to 400 – 550 Euro/ha.
Grape harvesting

Grapes crop

Grapes are the world’s largest fruit crop with approximately 60 million tons produced each year. Worldwide estimates are that approximately 8 million hectares are currently planted to grapevine.

Almost all this fruit is from one species – Vitis vinifera L. This species grows best in a Mediterranean type of climate with long, relatively dry summers and mild winters.

Botanically, the grapevine is a liana, a climbing tree. In the wild, the grapevine starts as an understorey plant growing rapidly and upward clinging to other plants to eventually reach the top of their canopies.

Vitis vinifera probably originated somewhere in the Middle East between India and the Mediterranean Sea. Grapes were undoubtedly first used as table fruit that is consumed directly from the wine.

The majority of the fruit is processed into wine, but significant portions of the worldwide crop are destined for fresh consumption, dried into raisins, processed into non-alcoholic juice and distilled into spirits.

Several factors influence grapevine growth and ripening capacity for a particular grape: heat accumulation, length of the growing season, number and distribution of sunshine hours, rainfall amount and pattern, diurnal temperature range, evapotranspiration and humidity.
Grapes crop