TOMATO CULTURE: A PRACTICAL TREATISE ON THE TOMATO TEXT

spot, which gradually enlarges until the fruit is rendered worthless. The decayed spot is often covered in its later stages by a dense black fungous growth (_Alternaria fasciculata_ (C. & E.) J. & G. syn. _Macrosporium tomato_ Cke.), formerly thought to be the cause of the rot, but now known to be merely a saprophyte. Point-rot sometimes occurs in greenhouses, but is more common in field culture. It is one of the most destructive diseases of the tomato, but its nature is not fully worked out, and a uniformly successful treatment is unknown. It has been thought to be due to bacterial invasion, but complete demonstrations of that fact have not yet been published. The physiological conditions of the plant appear to be important. The disease is worst in dry weather and light soils, where the moisture supply is insufficient, and irrigation is beneficial in such cases. Spraying does not control point-rot so far as present evidence goes. =Anthracnose--ripe-rot=--(_Colletotrichum phomoides_ (Sacc.) Chest.), is distinguished from the point-rot by the fact that it occurs mainly on ripe or nearly ripe fruits, producing a soft and rapid decay. Widespread losses from this cause are not common, but when a field becomes infected a considerable proportion of the crop within a limited area may be destroyed if humid or rainy weather prevails. Preventive measures only can be employed. These should consist in collecting and destroying diseased fruit and in staking and trimming the vines to admit light and air to dry out the foliage. Bordeaux mixture applied after the development of the disease would be of doubtful efficiency and would be objectionable on account of the sediment left on the ripe fruit. DISEASES OF THE ROOT OR STEM =Damping off.=--Young plants in seed-beds often perish suddenly from a rot of the stem at the surface of the ground. This occurs as a rule in dull, cloudy weather among plants kept at too high a temperature, crowded too closely in the beds or not sufficiently ventilated. Several kinds of fungi are capable of causing damping off, under such conditions. _Preventive measures_ are of the first importance. Since old soil is often full of fungous spores left by previous crops, it is the wisest plan to use sterilized soil for the seed-bed. When the young plants are growing, constant watchfulness is required to avoid conditions that will weaken the seedlings and favor the damping off fungi. _Watering and ventilation_ are the two points that require especial skill. Watering should be done at midday, to allow the beds to drain before night, and only enough water for the thorough moistening of the soil should be applied. Ventilation should be given every warm day as the temperature and sunshine will permit, but the plants must be protected from rain and cold winds. Work the surface of the soil to permit aeration and do not crowd the plants too closely in the beds. If damping off develops something can be done to check it by scattering a layer of dry, warm sand over the surface, and by spraying the bed thoroughly with weak Bordeaux or by applying dry sulphur and air-slaked lime. =Bacterial wilt= (_Bacterium solanacearum_ Erw. Sm.).--This disease, which also attacks potatoes and eggplants and some related weeds, is one of the most serious enemies of the tomato. It is known to occur from Connecticut southward to Florida and westward to Colorado, but is most prevalent in the Gulf States, where it has greatly discouraged many growers. _Its most prominent symptoms_ are the wilting of the foliage and a browning of the wood inside the recently wilted stems. An affected plant wilts first at the top, or a single branch wilts, but later the entire plant yellows, wilts and dies. Young plants wilt more suddenly and dry up. The disease progresses more rapidly in plants that have made a succulent, luxurious growth, while those with hard, woody stems resist it somewhat. _The disease is due_ to the invasion of bacteria, which enter the leaves through the aid of leaf-eating insects, or through the roots. They plug the water-carrying vessels of the stem, shutting off the water and food supply of the plant. If the stem of a plant freshly wilted from this disease be severed, the bacteria will ooze out in dirty white drops on the cut surface. =Remedial measures= entirely satisfactory for the control of bacterial wilt have not yet been worked out. The best methods to adopt at present are the following: (1) _Rotation of crops._--The field evidence is that this disease is in many cases localized in old gardens or in definite spots in the field. It appears also that the infection left by a diseased crop can remain in the soil for some time. It is therefore advised that tomato growers should always practice a rotation of crops, whether any disease has appeared or not, and that in case bacterial wilt develops they should not plant that land in tomatoes, potatoes, or eggplants for three or four years. The length of rotation necessary to free the soil is not known, but will have to be worked out by the individual grower. (2) _Destruction of diseased plants._--The bacteria causing wilt not only spread through the soil but are carried by insects from freshly wilted to healthy plants. Diseased plants thus become dangerous sources of infection, and it is evident that all such should be pulled out and burned. This is particularly important at the beginning of the trouble when the eradication of a few wilting plants may save the remainder. (3) _Control of insects._--To lessen the danger from spread of wilt by insects, the measures advised in the next chapter for the control of leaf-eating insects should be adopted. In this connection it should be mentioned that the use of Bordeaux mixture for leaf blights, as previously recommended, has an additional value in that the coating on the leaves is distasteful to insects and helps to keep them away. (4) _Seed selection._--Work done at the Florida experiment station indicates that resistant varieties may be secured, but there are as yet none in commercial use. This is an important line for experimenters to follow up. There is no proof that the disease is spread through seed from diseased plants. =Fusarium wilt.=--This disease and the one following resemble the bacterial wilt so closely, as far as external characters go, that they are difficult to tell apart. The parasites, however, differ so materially in their nature and life history that the field treatment is quite different. There are also differences in geographical distribution that are important, for while the Fusarium wilt occurs occasionally throughout the southern states, it is known to be of general commercial importance only in southern Florida and southern California. _The symptoms of the disease_ are a gradual wilting and dying of the plants, usually in the later stages of their development. Young plants die, however, when the soil infection is severe. There is a browning of the woody portions of the stem, and when a section of this is examined under a compound microscope the vessels are found to be filled with fungous threads, which shut off the water supply. _The infection_ in the Fusarium wilt appears to come entirely from the soil. Little is known of its manner of spread, except that the cultivation of a tomato crop in certain districts appears to leave the soil infected so that a crop planted the next year will be injured or destroyed. The fungus does not remain in the soil for a very long time in sufficient abundance to cause serious harm. A rotation of crops that will bring tomatoes on the land once in three years has been found in Florida to prevent loss from Fusarium wilt. _This fungus does not attack any other crop_ than tomatoes, so far as known, though it is very closely related to species of Fusarium producing similar diseases in cotton, melon, cowpea, flax, etc. Fusarium wilt has not been found in fields and gardens in the northern states, but tomatoes in greenhouses there are sometimes attacked by it or a related Fusarium, which also occurs in England. When greenhouse beds are infected the soil for the next crop should be thoroughly sterilized by steam under pressure. =Sclerotium wilt.=--This disease resembles the two preceding in its effect on the plant, which wilts at the tip first, and gradually dies. Its geographical range is more restricted. It seems to be confined to northern Florida and the southern part of Georgia and Alabama, where it occurs in gardens and old cultivated fields. The fungus causing this wilt attacks the root and the stem near the ground, working in from the outside. There is not the browning of the wood vessels characteristic of the two preceding diseases. If an affected stem is put in a moist chamber made from a covered or inverted dish, there will develop an exceedingly vigorous growth of snow-white fungous mycelium which, after a few days, bears numerous round shot-like bodies, at first light-colored, then becoming smaller and dark-brown. These are the sclerotia or resting bodies of the fungus. This fungus, called _Sclerotium_ sp., or "Rolf's Sclerotium," is noteworthy because it attacks potatoes, squash, cowpea, and a long list of other garden vegetables and ornamental plants. The only satisfactory means of control is rotation of crops, using corn, small grain, and the Iron cowpea, a variety immune to this and other diseases. Susceptible crops should be kept from infected fields for two or three years. =Root-knot= (_Heterodera radicicola_ (Greef) Mül.) attacks tomatoes in greenhouses and is in some cases an important factor in southern field culture. It is caused by a parasitic eelworm or nematode, of minute size, which penetrates the roots and induces the formation of numerous irregular swellings or galls, in which are bred great numbers of young worms. The effect on the plant is to check growth and diminish fruitfulness, in advanced cases even resulting in death. _The remedy in greenhouse culture_ is thorough soil sterilization. In the open field this is impracticable and recourse must be had to a rotation with immune crops, which will starve out the root-knot. It must now be borne in mind that the root-knot worm can attack cotton, cowpea, okra, melons and a very large number of other plants. The only common crops safe to use in such a rotation in the South are corn, oats, velvet beans, beggar weed, peanuts, and the Iron cowpea. The use of other varieties of cowpea than the Iron is particularly to be avoided, on account of the danger of stocking the land with root-knot. Fortunately, the disease is serious only in sandy or light soils. =Rosette= (_Corticium vagum_ (B. & C.) var. _solani_ Burt.) is a disease of minor importance, which occurs in Ohio, Michigan, and scatteringly in other states. The fungus causing it (_Rhizoctonia_) attacks the roots and base of the stem, forming dark cankers. The effect on the plant is to dwarf and curl the leaves and to restrict productiveness. The potato suffers more severely from the same trouble. Rotation of crops and liberal application of lime to the soil are advised for the control of rosette in tomatoes. INDEX PAGE Adaptations of varieties, 97 as to habit, 97 as to foliage, 100 as to fruit, 102 Botany, 1 Canning, cost of, 118 on the farm, 118 Essentials for successful, 119 Catalog descriptions incomplete, 110 Characteristics of blossom, 25 Characteristics of fruit, 26 Development from original form, 26 Effect of conditions on, 26 Quality, 26 Characteristics of plant, 20 Checking of growth, effect upon, 20 Natural environment, 20 Uniform growth, importance of, 21 Characteristics of root, 23 Characteristics of stem and leaves, 24 Classification, 4 Cherry, 5 Cultivated varieties, 10 Currant, 4 Pear, 7 Cold-frames, construction, 53 Commercial importance of crop, 18 Cost of crop, per acre, 121 as grown for canners, 117 Covers for plant beds, 55 Cultivation, 76 Care and thoroughness necessary, 76 in greenhouse, 77 in home garden, 77 Diseases, 131 Bacterial wilt, 142 Blight, early, 135 Blight, leaf, 134 Blight, Western, 134 Cracking of fruit, 132 Damping off, 141 Edema, 133 Fusarium wilt, 144 Leaf curl, 132 Leaf mold, 135 Leaf spot, 134 Mildew, downy, 135 Mosaic disease, 133 Phytoptosis, 138 Point rot, 139 Root knot, 146 Sclerotium wilt, 145 Yellows, 134 Diseases, remedies for, 131 Bordeaux mixture, preparation of, 136 Preventatives of, 143 Spraying apparatus, 137 Spraying, importance of, 136 Sulphur spraying, 139 Distances for setting plants, 68 in field, 68 in greenhouse, 70 in home garden, 69 Drainage, importance of, 31 Essentials for best development, 28 Cultivation, 32, 76 Effect of shade, 28 Food supply, 31, 43 Heat, 30 Moisture, 30 Sunlight, 28 Exposure, 38 for early crop, 39 for greenhouse, 40 for home garden, 40 Fertilizers, 43 Amounts, 43 Character, 44 Experiments with, 45 for general application, 44 for greenhouse, 45 for home garden, 45 Flats, construction, 57 Gathering fruit, 91 Habit, 22 Handling fruit, 92 History, 14 Hotbeds, construction, 51 Hotbeds, growing fruit in, 70 House, construction, 49 Insects injurious to tomatoes, 123 Blister beetle, 125 Colorado potato beetle, 125 Cut worm, 123 Flea-beetle, 124 Stalk-borer, 127 Tomato fruit worm, 128 Tomato worm, 126 White fly, 130 Location of field as determining profit, 38 Manure Fall dressing, 41 for cold-frames, 55 for greenhouse soil, 37 for hotbeds, 51 in preparing ground, 46 Origin, 10 Origin of name, 14 Packing, 94 Pollinating, 77 Pollination, 25 Prices obtained at canneries, 118 for hothouse fruit, 122 for select field grown fruit, 122 Profits on crop, 122 Propagation of plants, 48 from cuttings, 49 from seed, 48, 49 in cold-frames, 53 in hotbeds, 51 in temporary greenhouses, 49 Pruning, 80 Ripening on the vines, 90 Ripening after frost, 95 Sash, cost, 49 for hotbeds, 52 for cold-frames, 53 Seed breeding, 112 Essentials to success, 113 Growing and saving commercial seed, 115 Methods followed, 115 Prices received, 116 Yields obtained, 116 Importance of breeding from individual plants, 114 Importance of exact ideals, 113 Methods recommended, 113 Principles underlying, 112 Setting plants, 70 Conditions favorable and unfavorable, 70, 71 in field, 70 in greenhouse, 74 in home garden, 74 New Jersey method, 71 Other methods, 73 Soil Composition, importance of, 24 Conditions essential, 41 Preparation, 41, 46 for greenhouse, 47 for home garden, 47 Soil Preparation, for main crop, 46 Importance of, 46 Selection, 33 for early crop, 36 for greenhouse, 37 for home garden, 36 for main crop, 34 Previous crop, 41 Sorting, 92 Staking, 79 Starting plants, 59 Effect of shade, 29 for early fruit, 63 for forcing, 67 for home garden, 67 for late crop, 65 in flats, 59 in greenhouse, 59 Pricking out, 60 Right conditions, 62 Spotting boards, 61 Unfavorable conditions, 63 Watering, 60 With least labor, 66 Succession, practice in the South, 42 Training, 79 for greenhouse, 88 for home garden, 85 Types, 14 Value, development of, 16 Variations, in foliage, 100 in fruit, 102 Coloring, 106 Flesh, 105 Ripening, 106 Shape, 102 in habit, 97 Varietal differences, as to foliage, 100 as to fruit, 102 as to growth, 97 Variety names, 108 Sources, 109 Varying application, 110 Watering, danger in, 30, 60 Yielding capacity, 22 Yield per acre, 117, 121 Yield per foot of greenhouse bench, 122 Transcriber's Notes The following typographical errors have been corrected: Page 61: "... necessary. When plants are set in ..." (had 'plans'). Page 107: "... these respects we have varieties ..." (had 'resepcts'). Page 117: "... the question, "What is the best ..." (had 'queston'). Page 148: "Mildew, downy, 135" (had 'downey'). Page 149: "Pollinating, 77" (had 'Pollenating'). Page 149: "Pollination, 25" (had 'Pollenation'). The archaic spelling of "hight" is as used throughout the original. '_' is used to denote italics, and '=' is used to denote bold typeface.