Talk:Horticulture/Tomato
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[edit] Transwikied "Cultivation and Uses"
The following is a snip from the version of the [wikipedia article on tomatoes as found on June 7, 2006, 5:35 GMT]. For information about the editors, please see the history page of that article.
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The tomato is now grown world-wide for its edible fruits, with thousands of cultivars having been selected with varying fruit types, and for optimum growth in differing growing conditions. Cultivated tomatoes vary in size from cherry tomatoes, about the same 1-2 cm size as the wild tomato, up to 'beefsteak' tomatoes 10 cm or more in diameter. The most widely grown commercial tomatoes tend to be in the 5-6 cm diameter range. Most cultivars produce red fruit, but a number of cultivars with yellow, orange, pink, purple, green, or white fruit are also available. Multicolored and striped fruit can also be quite striking. Tomatoes grown for canning are often elongated, 7-9 cm long and 4-5 cm diameter; these are known as plum tomatoes.
Tomatoes are one of the most common garden vegetables in the United States, and along with zucchini have a reputation for outproducing the needs of the grower.
As in most sectors of agriculture, there is increasing demand in developed countries for organic tomatoes, as well as heirloom tomatoes to make up for flavor and texture faults in commercial tomatoes. Quite a few seed merchants and banks provide a large selection of heirloom seeds. Tomato seeds are occasionally organically produced as well, but only a small percentage of organic crop acreage is grown with organic seed.
[edit] Growing needs
Tomato plants can be easy to grow, producing a significant amount of fruit for a small amount of work, which is perhaps why 80% of American gardens include some kind of tomato. They can be raised from seeds by planting indoors eight weeks before it will be warm enough to plant outside, or they can be planted as purchased seedlings directly in the ground.
Tomato plants need acidic (5.0 to 6.0 pH) soil, a balance between the three primary fertilizer nutrients, and thrive in warm weather. Inexpensive ways to naturally increase soil acidity include using pine needles as mulch, and mixing either used coffee grounds or sawdust into the soil. Pine needles (and the soil under pine trees) are very acidic, and though used coffee grounds are not very acidic, they and sawdust cause a chemical change in the soil, lowering its pH. Fresh coffee grounds, or a 4:1 dilution of water:coffee, can be used for a quick, direct acidity boost.
To prevent cutworms, tomato seedlings' most vicious predators, one can place an open-ended can so that it surrounds the plant, or wrap it with something like foil or paper, or simply brace its stem with popsicle sticks or toothpicks, all of which seem to deter this moth larva from wrapping around and cutting off the baby plant at its base or leaves.
Tomato plants can be grown much closer together than the standard 3' apart, if staked, trellised, or caged, all of which are methods of holding up vining plants to allow them to put more energy into growing fruit. Recent, peer-reviewed science suggests that red plastic mulch (sheets of plastic, dyed specific colors which reflect red and higher frequencies of light) increase fruit production by as much as 20%.[citation needed]
While tomato plants do best with eight or more hours of direct sunlight, they may do better if shaded during noontime sun if the temperature is above ninety degrees. Some gardeners will actually throw fine cloth over the plants around noon on very hot days.
Indeterminate plants require at least twenty gallons of soil in order to grow in a container; it's better to use determinate varieties for containers, instead.
Tomatoes tend to grow faster and produce more fruit when companion planting. Marigolds repel aphids and grow well with tomatos, and Basil both repels insects (even mosquitos) and improves fruit flavor. Other companion plants for tomatoes are asparagus, onion/garlic/chives, nasturtium, rose, and parsley. Tomato plants are, themselves, good companion plants for chili peppers, helping shade their fruit.
[edit] Varieties and cultivars
There are a great many tomato varieties grown for various purposes. This section attempts a listing of some of the more common varieties. Heirloom varieties are becoming increasingly popular, particularly among home gardeners and organic producers, since they tend to produce more interesting and flavorful crops at the possible cost of some disease resistance. Hybrid plants remain common, however, since they tend to be heavier producers and sometimes combine unusual characteristics of heirloom tomatoes with the ruggedness of conventional commercial tomatoes.
Tomato varieties are roughly divided into several categories, based mostly on shape and size. "Slicing" or "globe" tomatoes are the usual tomatoes of commerce; beefsteak tomatoes are large tomatoes often used for sandwiches and similar applications; plum tomatoes or paste tomatoes are bred with a higher solid content for use in tomato sauce and paste; and cherry tomatoes are small, often sweet tomatoes generally eaten whole in salads.
Tomatoes are also commonly classified as determinate or indeterminate. Determinate, or bush, types bear a full crop all at once and top off at a specific height; they are often good choices for container growing. Indeterminate varieties develop into vines that never top off and continue producing until killed by frost. As an intermediate ground, there are plants sometimes known as "vigorous determinate" or "semi-determinate"; these top off like determinates but produce a second crop after the initial crop. Many, if not all, tomatoes described as heirlooms are indeterminate.
Commonly grown varieties include:
- Beefsteak VFN (a common hybrid resistant to Verticillium, Fusarium, and Nematodes)
- Big Boy (a very common determinate garden cultivar in the United States)
- Black Krim (a purple-and-red variety from the Crimea)
- Brandywine (a pink, indeterminate beefsteak type with a considerable number of substrains)
- Burpee VF (an early attempt at disease resistance in a commercial tomato)
- Early Girl (an early-maturing globe type)
- Gardener's Delight (a smaller English variety)
- Juliet (a grape tomato developed as a substitute for the rare Santa F1)
- Marmande (a heavily ridged variety from southern France; similar to a small beefsteak and available commercially in the US as UglyRipe)
- Moneymaker (an English greenhouse variety)
- Mortgage Lifter (a popular heirloom beefsteak known for gigantic fruit)
- Patio (bred specifically for container gardens)
- Roma VF (a plum tomato common in supermarkets)
- Rutgers (an heirloom commercial variety)
- San Marzano (a plum tomato popular in Italy)
- Santa F1 (a closely guarded Chinese grape tomato cultivar popular in the USA and parts of southeast Asia)
- Sweet 100 (a very prolific, indeterminate cherry tomato)
- Yellow Pear (a yellow, pear-shaped heirloom variety)
Most modern tomato varieties are smooth-surfaced, but older tomato cultivars (and some modern beefsteaks) often show pronounced ribbing, a feature that may have been common to virtually all precolumbian varieties. In addition, tomatoes come in colors other than red, including yellow, orange, pink and purple, though such tomatoes are not widely available in markets.
There is also a considerable gap between commercial and home gardener varieties; home varieties are often bred for flavor to the exclusion of all other qualities, while commercial varieties are bred for such factors as consistent size and shape, disease and pest resistance, and suitability for mechanized picking and shipping.
[edit] Diseases and pests
Tomato cultivars vary widely in their resistance to disease. Modern hybrids focus on improving disease resistance over the heirloom plants. One common tomato disease is tobacco mosaic virus, and for this reason smoking or use of tobacco products should be avoided around tomatoes[citation needed]. Various forms of mildew and blight are also common tomato afflictions, which is why tomato varieties are usually marked with letters like VFN, which refers to disease resistance to verticillium wilt. fusarium fungus, and nematodes.
Some common tomato pests are cutworms, tomato hornworms, aphids, cabbage loopers, whiteflies, tomato fruitworms, flea beetles, and Colorado potato beetles.
Transplanted tomatoes may begin to show yellow leaves at the base. According to hothouse tomato pioneer, Dan Busch, "With your leaves turning yellow, the tomato plant needs to be fertilized. The fertilizer that you need to use needs to be well balanced, meaning 20-20-20, and if you do not want to use this kind of fertilizer, use blood meal and fish emulsions. This will give you a good source of nitrogen, then you will need to add phosphorus (rock phosphate or super phosphate). Slow growing plants is a sure sign of low phosphorus. Be sure to read the instructions on the blood meal and fish emulsion because it is easy to over fertilize. The real issue here is the nutrition. The yellowing of the leaves is not uncommon with a new transplant, because any nutrition is gone by the time you take it home. If the plants are weak, this is an indication of low potassium. To get potassium in the soil you can add granite dust or wood ash. Call around to local garden centers to find these items.
[edit] Pollination
In the wild, original state, tomatoes required cross pollination; they were much more self incompatible than domestic cultivars. As a floral device to reduce selfing, the pistils of wild varieties extended farther out of the flower than today's varieties. The stamens were, and remain, entirely within the closed corolla.
As tomatoes were moved from their native areas, their traditional pollinators, (probably a species of halictid bee) did not move with them. The trait of self fertilility (or self pollenizing) became an advantage and domestic cultivars of tomato have been selected to maximize this trait. This is not the same as self-pollination, despite the common claim that tomatoes do so. That tomatoes pollinate themselves poorly without outside aid is clearly shown in greenhouse situations where pollination must be aided by artificial wind, vibration of the plants (one brand of vibrator is a wand called an "electric bee" that is used manually), or more often today, by cultured bumblebees.
The anther of a tomato flower is shaped like a hollow tube, with the pollen produced within the structure rather than on the surface, as with most species. The pollen moves through pores in the anther, but very little pollen is shed without some kind of outside motion.
The best source of outside motion is a sonicating bee such as a bumblebee or the original wild halictid pollinator. In an outside setting, wind or biological agents provide sufficient motion to produce commercially viable crops.
[edit] Hydroponic and greenhouse cultivation
Tomatoes are often grown in greenhouses in cooler climates, and indeed there are varieties such as the British "Moneymaker" and a number of cultivars grown in Siberia that are specifically bred for indoor growing. In more temperate climates it is not uncommon to start seeds for future transplant in greenhouses during the late winter as well.
Hydroponic tomatoes are also available, and the technique is often used in hostile growing environments as well as high-density plantings.
[edit] Picking and ripening
Tomatoes are often picked unripe (which are colored green at the time), and ripened in storage with ethylene. Ethylene is the plant hormone produced by many fruits and acts as the cue to begin the ripening process. These tend to keep longer, but have poorer flavor and a mealier, starchier texture than tomatoes ripened on the plant. They may be recognized by their color, which is more pink or orange than the ripe tomato's deep red.
In 1994, Calgene introduced a genetically modified tomato called the FlavrSavr which could be vine ripened without compromising shelf-life. However, the product was not commercially sucessful (see main article for details) and was only sold until 1997.
Recently, stores have begun selling "tomatoes on the vine" which are ripened still connected to a piece of vine. These tend to have more flavor (at a price premium) than artificially-ripened tomatoes, but still may not be the equal of local garden produce.
Also relatively recently, slow-ripening cultivars of tomato have been developed by crossing a non-ripening variety with ordinary tomato cultivars. Cultivars were selected whose fruits have a long shelf life and at least reasonable flavor. These have been nicknamed "Thrushworthy Bumbletots," as the name of them is the name of the machine system(s) used to clean the tomatoes before processing to be canned or shipped. The name is an example of onomatopoeia.
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