Where tomatoes are grown on a large scale and where the product brings only a small price per bushel, expensive methods of handling and training can not be profitably followed. The common practice in growing tomatoes for the general market and for canning purposes in localities north of New York City is to sow the seed very thinly in a hotbed about March 15 and allow the plants to grow slowly without transplanting them until they can be put in the field about June 1. The plants, even with the most careful attention, when grown under these conditions will become long and thin stemmed, with a small tuft of leaves at the top.
Setting the Plants.—Plants more than a foot high which have been grown under these conditions should be treated somewhat as follows: Instead of attempting to set the plant deeply and maintain it in an upright position, remove all except three or four of the top-most leaves about the growing point. Dig a shallow trench along the row—a trench 3 or 4 inches deep—slightly sloping from a deep point at one end to the surface of the ground at the other. Place the bare stem of the tomato and the root in this trench, with the root in the deepest portion, cover the stem throughout its length with fresh soil, and pack this firmly. Under these conditions the plant will take root throughout the length of the buried stem, and in a short time the added root system which is thus given the plant will force it into vigorous growth. Plants of this character which are to be grown on an extensive scale are never trained. They are allowed to grow at will, and the fruits are gathered as they ripen without special attention to keep them off the ground or otherwise to care for them.
Length of Season.—The season of fruit production is longer in the higher than in the lower latitudes. This is a rather interesting and unexpected condition. Normally one would expect to find that the tomato would begin maturing its fruit earlier and would continue bearing longer in the latitude of the city of Washington than it would in the latitude of Boston; but this is not the case. Tomatoes in the latitude of Washington and south of this point come into bearing, quickly produce a heavy flush of fruit, and then refuse to do more, and in order to have a continuous supply throughout the season it is necessary for market gardeners and truckers to plant seeds in succession so as to keep up a continuous supply.
Fertilizers.—Since the tomato is grown exclusively for its fruit, those fertilizers which induce a large growth of plant and foliage are not desirable in the production of this crop. Soils vary greatly in regard to the quantity of available plant food they contain. The use of a fertilizer is determined largely by the character, mechanical condition, and composition of the soil. If a soil is deficient in all the essential elements of plant food—nitrogen, potash, and phosphoric acid—the application of any one or even two of them will not materially influence the yield of the crop. On the other hand, on soils deficient only in potash or phosphoric acid, or both, little would be gained by adding nitrogen, which is already in excess, to the other element or elements to be applied. Economy of operation, as well as the general effect upon the soil, must also be considered. This may be influenced by the character of the season, but should be based on the increased yield and increased net receipts of the crop.
As a general rule, readily soluble, "quick-acting" fertilizers which produce an early growth and early ripening of the crop are most desirable. Heavy dressings of stable manure tend to produce too much vine, and are seldom or never employed. If stable manure is used it is at a moderate rate, usually not more than one or two shovelfuls to a plant. This, if well decomposed and thoroughly incorporated with the soil, is very stimulating to the young plant and consequently very beneficial. Any fertilizer used should be applied, in part at least, at the time the plants are transplanted to the field.
Cultivation.—As soon as the young seedling plants from the hotbed or greenhouse are transferred to the field they should be given clean cultivation with implements which stir the surface of the soil but do not produce ridges or furrows. When the plants are set in check rows 4 feet apart each way it is possible in field culture to keep the plantation almost free from weeds by the use of horse hoes. If, however, the plants are set so that cultivation can be carried on only in one direction, hand hoeing will be necessary to keep down weeds between the plants in the row. Where land is not expensive, and where labor costs heavily, the cost of producing a crop of tomatoes can be decidedly lessened by planting in check rows and carrying on the cultivation by horsepower.
The grower should bear in mind, however, that the object of cultivation is not merely to kill weeds. The destruction of weeds is an important factor and in itself sufficient to justify clean culture, but the preservation of a soil mulch for the purpose of husbanding the moisture of the soil during periods of drought is of even greater value. With care in the choice of implements both results can be attained with the same expenditure of labor.
Harvesting and Marketing.—The fruits should be gathered two or three times a week if the tomato is grown as a truck crop. When used for canning purposes the harvesting periods need not be quite so close, and when the fruits are to be shipped some distance they should be gathered as soon as partially colored, instead of allowing them to become colored on the vine. The fruit of the tomato is velvet green up to the time the ripening process begins, and at this stage, if the products are to be shipped long distances, the fruits should be harvested. For home markets, however, the fruits should be allowed to ripen upon the plant.
In harvesting, none except sound fruits of a similar stage of maturity should be harvested and packed in any one receptacle. Leaky fruits and deformed fruits should be rejected. In packing tomatoes for the market, those that are symmetrical in form and uniform in size and of a like degree of ripeness should be selected for filling any one receptacle.
Varieties for the North.—There are a large number of sorts of tomatoes, each one possessing some points of merit or difference which distinguish it from all others. These differences enable the intelligent cultivator to select sorts for special purposes, as well as for special soils and climates. The varying demands of the markets and the different soil and climatic conditions presented in the various sections of the United States where the tomato is grown can only be satisfied by a variety list as variable as are the conditions.