Grapes in the
GRAPES IN THE classroom
California’s table grape growers support teachers and students in the classroom by providing lesson plans for teachers, activities for students, information on health and nutrition, and printed materials such as stickers, posters, and recipe cards. Contact the commission at [email protected] for more information.
HISTORY OF Grapes
History 1: The California Tradition of Viticulture
For more than two centuries, Californians have been cultivating grapes.
Viticulture, or the science, production, and study of grapes, first began in California in the late 1700s when Spanish friars arrived to establish Catholic missions. Because the native grapes were sour and made poor wine, the friars brought over grapes from Europe and planted their own vineyards to make sacramental wine.
In the mid-1800s, prospectors poured into California. They came looking for gold until some discovered that there might be more money in grapes. Shortly after the Gold Rush, California’s fledgling agricultural society declared, “Capital put into vineyards would bring greater rewards than…fluming rivers for golden treasures.”
Their instincts were good. California’s warm, dry climate turned out to be ideal for growing grapes. Today, more than 856,000 acres across California are planted with fresh grape, wine, and raisin vineyards, and 99 percent of U.S. commercially-grown table grapes are from California.
6000 B.C.
Vitis vinifera grape (common grape vine) varieties are first cultivated near northern Iran between the Black and Caspian seas.
3000 B.C.
Cultivation reaches Egypt and Phoenicia.
2000 B.C.
Viticulture reaches Greece.
1000 B.C.
Viticulture reaches Italy, Sicily, and North Africa.
500 B.C.
Viticulture reaches Spain, Portugal, and France, then spreads across Europe to the British Isles.
1839
Kentucky native William Wolfskill plants the first table grape vineyard in California.
Mid-1800s
Hungarian expatriate Colonel Agoston Haraszthy, often called the “Father of California Viticulture,” brings 100,000 cuttings of Vitis vinifera varieties from Europe to California.
1860
English settler William Thompson plants a Mediterranean grape called the “Oval Kishmish” near Yuba City north of Sacramento. This popular green variety is now known as the Thompson Seedless.
1869
Fresh table grapes are first shipped to eastern markets.
1970
Per capita consumption of grapes in the United States reaches 2.5 pounds.
Today
Per capita consumption of grapes in the United States hovers around 8 pounds.
History 2: Four Seasons in the Valleys of the Sun
The California table grape season begins in late spring when the first grapes are harvested in the Coachella Valley, California’s southernmost growing region. By mid-July Coachella’s season ends and harvest moves north to the San Joaquin Valley. Through late fall the harvest of fresh California grapes continues.
Sequential harvesting from south to north combined with advanced storage techniques means that varieties of California table grapes are available from May through January.
History 3: The Life Cycle in the Vineyards
The winter months are an important part of the California table grape growing cycle. Growth and development stop temporarily and the vines rest. This stage is called “dormancy.” At this time, growers prune the vines and set them up for the upcoming cycle to begin. Pruning and training of the vines are two of the most important aspects for quality grape production – growers decide how much and which parts of the previous season’s growth to remove in order to regulate vegetative growth (shoots and leaves) and crop load (grape clusters) to produce quality grapes and optimum yield.
In early spring tiny buds on the vine start to swell and green leaves appear. Appearance of the first green leaves through the bud scales is called bud break. Growth is slow at first. As the mean temperature rises, growth and shoot elongation accelerate. After three or four weeks, the period of most rapid growth begins – where shoots can grow an average of one inch or more per day. As the days warm up, flowers bloom, then shatter, to make way for the tiny green grapes that will eventually ripen into clusters. Berry size increases rapidly. Sunlight and warm temperatures are vital to the physiological functions of the grapevine (such as photosynthesis).
The point in the growing season when ripening grapes begin to soften is called “veraison.” During ripening, colored varieties gradually change color from green to either red or black, while green varieties become translucent. Sugars start to accumulate in the berries. The interval from veraison to harvest is different for each variety. Unlike many fresh fruits, grapes are harvested fully ripe. After they’re picked, they do not become sweeter, so timing is everything.
Determining when grapes are ripe is a real science and both the U.S. Department of Agriculture and California Department of Food and Agriculture are involved in setting and monitoring grape production standards. Sugar content, color, and bunch and berry size and uniformity are all measured before harvest begins, and the workers who decide which grapes to clip are trained professionals with years of experience.
Once picked, fresh grapes are easily damaged by rough handling, warm temperatures, excessive moisture, and decay-causing organisms. Consequently, grape bunches are carefully inspected and then immediately packed by hand into shipping containers — sometimes right in the field.
Shortly after picking, the field heat is removed from the fruit in cold storage facilities. From this point until they reach their destinations — markets throughout the world — the grapes will be maintained in a carefully regulated environment to assure they arrive in just-picked condition.
ABOUT California TABLE GRAPES
Californians have been cultivating grapes for more than two centuries. Today, 99 percent of U.S. table grapes are produced in California's warm, dry climate that is ideal for grape growing. With 89 grape varieties grown, California grapes come in three colors—green, red, and black—and are in season from May through January.
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