Tomatoes are the most widely grown vegetable in the United States. Almost every garden has at least one tomato plant. They can even be produced in window box gardens or in single pots. Commercially, it is of equally great importance. From processing to fresh market, and from beefsteak to grape tomatoes, variety and usefulness of the fruit is extensive.
Tomatoes are members of the plant family which includes peppers, eggplant, Irish potatoes and tobacco. Originating in the area from Ecuador to Chile in the western coastal plain of South America, tomatoes were first domesticated in Mexico. The fruit was introduced to Europe in the mid-1500s.
As members of the nightshade family, tomatoes were considered for many years to be poisonous. Many crops in this family contain highly toxic alkaloids. Tomatine occurs in toxic quantities in the tomato foliage but is converted enzymatically to a non-toxic form in the fruit. The crop was not used for food until the 18th century in England and France. Tomatoes were introduced to the United States in 1710, but only became popular as a food item later in that century. Even as late as 1900, many people held the belief that tomatoes were unsafe to eat.
Tomatoes are an important crop for Georgia growers. Successful tomato production is not easy, requiring highly intensive management, production and marketing skills, and a significant investment. Per acre production cost is high, and yields can be severely limited by pest problems or environment. Tomato production is complex. Expertise in cultural practices, soils and fertility management, pest control, harvesting, post-harvest handling and marketing is crucial to profitable production.
There are two types of tomatoes commonly grown. Most commercial varieties are determinate. These “bushy” types have a defined period of flowering and fruit development. Most heirloom garden varieties and greenhouse tomatoes are indeterminate, which means they produce flowers and fruit throughout the life of the plant.
Recent cool morning temperatures are a signal that autumn and the end of the growing season are approaching. Tomatoes are a tender, warm-season crop cultivated as an annual, but is actually a perennial plant. Sensitivity to frost and cold temperatures it will not survive winter in most of the country. Most tomatoes require about 75 days from transplanting to first harvest and can be harvested for several weeks before production declines. Hot and cool temperatures can negatively affect fruit set and quality. UGA Extension Bulletin 1271 "Georgia Homegrown Tomatoes" provides guidance about harvesting and storing garden tomatoes:
“For best quality, harvest tomatoes when they are fully ripened on the vine. If harvested before they are ripe, but after they reach the mature green stage, tomatoes can be allowed to ripen in the home. Place unripe mature green or pink fruit in a room with a temperature of around 70 degrees Fahrenheit. Fruit should be well-ventilated and not jammed together. Fully ripened fruit may be placed in the refrigerator to prolong keeping, but never put unripened tomatoes in the refrigerator. Tomatoes can last several weeks under refrigeration.”
With next season in mind, harvest leads to consideration of best characteristics and variety performance. Plant breeders have made considerable progress in developing varieties with disease resistance and high production. However, tomato growers can sometime be overheard making comments such as “they just don’t taste like they did years ago.” Little research has emphasized breeding tomatoes that taste good.
That may soon change, according to Manoj Sapkota, a doctoral candidate at the University of Georgia College of Agricultural and Environmental Sciences (CAES) Institute for Plant Breeding, Genetics and Genomics. Increased interest in better-tasting crops, dedicated scientists and the discerning palates of trained taste testers are being marshaled to contribute to the effort to breed better-tasting tomatoes.
A tomato gets its flavor, aroma and color from six classes of volatile compounds. There are a number of genes that control the volatile compounds, and they are very tedious and time-consuming to isolate, Sapkota said.
University of Florida scientists Denise Tieman and Harry Klee have developed methods that use trained human taste testers to help them identify the compounds that are most important to pleasing tomato flavors. These scientists identify tomatoes with excellent flavor through taste testing and use chemical analysis to identify the desirable volatile compounds possessed by the tastiest tomatoes. Tomatoes that are rated most desirable by both human taste testers and chemical analysis become targets for selective breeding. Researchers are now using these procedures to more quickly breed these flavor genes into already successful tomato lines.
Roger Gates is the agricultural and natural resources agent for University of Georgia Extension, Whitfield County. Contact him at email@example.com.