VIOLET 



VIOLET 



3479 



the walk, but by means of a board to be hooked onto 

 the heating pipes, all plants may be conveniently 

 reached. Coldframes for violet-culture are simple in 

 construction. They are of the usual type, being 6 feet 

 wide, 12 inches high in front, and 16 to 18 inches high 

 at the back. Ordinary 3 by 6 sash may be .used. 

 These frames may be made any length in locations 

 where the soil is porous and well drained; the frames 

 may be lower than the surrounding soil. This gives 

 some advantages in winter although it is back-breaking 

 work at any time properly to care for the plants and 

 pick the flowers in such frames. 



In sections where the climate is comparatively mild, 

 violets may be planted directly in the open ground and 

 the frames, which may be movable ones, may be set 

 over the plants about the middle of September. Violet 

 houses do not need much heat, merely enough in fact 

 to keep out the frost. The tendency is to overheat and 

 there are probably more good crops spoiled by too 

 much rather than too little heat. Hot water is usually 

 depended on for heating both houses and frames. 

 For the average houses a boiler capacity of 1,200 to 

 1,500 square feet will be required for every 10,000 

 plants. With the present cost of materials and labor it 

 is safe to figure the cost of a plain style of house such 

 as already described at about 50 cents a plant. A 

 house 12 feet wide and 100 feet long will hold about 

 2,000 plants and should cost complete from $850 to 

 $1,000. 



Marketing is one of the most important factors con- 

 nected with commercial violet-growing and is seldom 

 understood in all its details. The grower should be 

 thoroughly familiar with the many needs and require- 

 ments of the market and be able to supply these 

 demands, for upon his ability to do this depends 

 largely his success or failure from a financial standpoint. 

 Violets are prized chiefly for their delicate perfume, and 

 as this diminishes in proportion to the length of time 

 they are picked, the best market, other things being 

 equal, is the one which requires the least possible delay 

 between picking the flowers and placing them in the 

 hands of the customer. 



The crop may be disposed of at retail or wholesale or 

 through a commission merchant. Each method has 

 its advantages and disadvantages, and in deciding 



3950. Growing violets in solid beds. 



which one to adopt the grower must be guided by 

 existing conditions. He must in any event have a 

 thorough knowledge of the requirements of the market 

 as regards quality of the flowers, size, shape, and 

 arrangement of the bunch, and should at all times 

 exercise the utmost care in picking, packing, and 

 shipping, so that the flowers may reach the customer 

 in the best and most attractive condition. The kind 

 of bunch varies from year to year, and each large city 



3951. Violet spot disease. 



is likely to have its own style. The various styles are 

 wonderfully exacting in their requirements and great 

 skill is required to bunch the flowers properly. 



The cultivated violets are subject to a number of 

 diseases, each of which is characterized by one or more 

 distinct symptoms. The principal diseases are as 

 follows, their destructive- 

 ness being in the order in 

 which they are discussed: 



Spot disease (Alternaria 

 violx) (Fig. 3951), also 

 called leaf-spot, leaf-rust, 

 and smallpox, is the most 

 widespread and destruct- 

 ive known in America. It 

 attacks principally the 

 foliage, normally produ- 

 cing definite circular whi- 

 tish spots, frequently with 

 concentric rings, of a 

 darker shade, very often 

 with a light central por- 

 tion resembling the bite 

 or sting of an insect. Cer- 

 cospora viols. Phyttosticta 

 violse, Septoria violce, and 

 the like, produce spots 

 very similar in outline and 

 appearance to those caused 

 by Alternaria violas, but 

 only under conditions 

 peculiarly favorable to 

 these fungi do they cause 

 any serious loss. 



Root-rot (Thielavia 

 basicola) is very trouble- 

 some and destructive in 

 some localities, especially to young plants that are 

 transplanted during hot dry weather. It causes the 

 browning or blackening of the parts attacked and the 

 final death of the plant. 



Wet-rot (Botrytis sp.) attacks leaves, petioles, flower- 

 stalks, and flowers, causing a moist or soft rot. It is 

 sometimes very destructive, especially with large 

 plants growing in a damp stagnant atmosphere, where 

 there is insufficient ventilation and light. 



Leaf-fading or yellowing is induced by a variety of 

 conditions, but as yet little that is definite has been 

 ascertained regarding its cause. 



It is difficult to exterminate any of the diseases 

 named after they once gain a foothold. However, they 

 can be held in check and often entirely prevented by 

 selecting and propagating exclusively from strong 

 vigorous disease-resistant plants, and by keeping them 

 in the best possible growing condition. Careful atten- 

 tion must be given to watering, cultivation, and ven- 

 tilation, and the dead and dying leaves and all runners 

 should be destroyed as fast as they appear. 



Although violets are attacked by a number of 

 insects and other related enemies, only a few do suffi- 

 cient injury to warrant discussion here. 



Aphides (Aphis sp. and Rhopalosiphum violae) are 

 generally known as the green and the black aphis or 

 the green- and black-fly. They cause the young grow- 

 ing parts to curl and twist, resulting in a stunted ill- 

 formed plant. They work their way into the young, 

 unopened flower-buds, and, thrusting their bills through 

 the overlapping petals, feed on the juice. Each punc- 

 ture produces a greenish white blotch on the petal, and 

 the flower becomes dwarfed, distorted, and worthless 

 for market. Aphides can be easily controlled by fumi- 

 gating with hydrocyanic acid gas, and this is now in 

 general use. To each cubic foot of space in the house or 

 frame use .15 gram of 98 per cent cyanide of potash for 

 double varieties and .10 gram for single varieties. 

 Handle the cyanide and gas with utmost care, as both 



