The validity of each of these points varies greatly with conditions; in fact, the answer to the whole question depends largely upon the location and the ideas of the grower. In trying to reach a conclusion, it is well to realize that training makes certain radical changes in the plant. It loses leaves through pruning, it is supported from the ground, and it is spaced differently. Since the leaves manufacture the basic substance for themselves, and for the rest of the plant, removal of leaves reduces the resources of the plant. H. C. Thompson[17] has found that the root system is reduced about in proportion to leaf reduction. It is fairly clear that single-stem training greatly reduces the yield per plant, and other methods result similarly in proportion to the severity of pruning. When plants are spaced closely enough together the yield may be brought up to that of areas unpruned and unstaked. Idaho experiments indicate that staking alone does not affect the total yield, but that it does favor early maturity under the different pruning systems. The disadvantages of training are largely economic. Will the marketing conditions justify the extra cost of staking and pruning? Experiments have shown pretty clearly that sunscald, blossom-end rot and cracking are worse on trained plants. Using varieties of good foliage will help the first trouble while uniform and adequate water supply achieved by selection of suitable land, by building humus content of the soil and by irrigation will solve the latter two problems. Thompson found increased yield of early fruit. Other evidence is somewhat conflicting but, in general, it supports Thompson. It is generally agreed that pruned plants yield larger, cleaner and more perfectly formed and colored fruits. Ease of spraying or dusting and of picking is important. For pruned plants, 3-1/2 feet between rows and 1-1/2-2 feet between plants is about right. To train or not to train is a question that one must answer for himself as the controlling factors vary too widely--costs of stakes, wire and labor, prices of early tomatoes and possibility of cultivating a more or less fancy trade. VII THE ETERNAL BATTLE WITH INSECTS AND DISEASES The tomato, in most regions, is not one of our most "pestered" crops. Although over thirty diseases of tomatoes are discussed in books and bulletins, most of them are only occasionally serious or are subject to definite control methods. Enemies are generally worse in the warmer climates. Most home garden tomatoes and many commercial crops are grown without benefit of spray or dust. If trouble arises, county agent or college specialist can usually advise, suggesting methods suitable for local conditions. Experience must, of necessity, be the guide in shaping a program and costs must be carefully balanced against results.