BIKNNIAL RKPORT, 1927 AND 1928 311 



[)articularly for the early winter season. It has been learned that conns 

 may be kept in cold storage during the sununer and phinted in early 

 October. Thus the rest-period is altered by prolonging it. Though good 

 plants resulted from such stored corn)s, these plants did not produce 

 blossoms except in instances for which no explanation can be given. Four 

 varieties were planted each with a range of soil temperature from 50° to 

 95° F. at intervals of five degrees. These soil temperatures were kept 

 constant by automatic temperature tank apparatus. Of the four varieties, 

 (Albania, Arlon, Los Angeles, and Wilbrink) Arlon produced three spikes 

 of blooms. There were four plants at each temperature and each spike 

 of blossoms was at a different temperature. Thus no conclusions can be 

 drawn from soil temperatures in their relation to blooming. The ap- 

 pearance of the plants indicated that the best growth was obtained be- 

 tween the temperatures of 65° and S5 F. 



Since soil temperatures had no effect on blossoming, histological study 

 has been made relative to the formation of the floral tissue. The results 

 indicate that in the variety used. Crimson Glow, differentiation occurs 

 and has become prominent at about five weeks from the time the corms 

 are planted. Under natural out-of-door conditions this would be at the 

 time when the daylight is becoming much longer, a fact which may 

 account for lack of blooms when gladiolus is planted in the autumn. Ex- 

 periments are now under way to ascertain if normal daylight can be 

 supplemented by artificial light in such a way that gladiolus will blossom. 

 Carnation Blight. (E. F. Guba, Waltham.) Study of Carnation Blight, 

 caused by Alternnrin dianthi S. & H., has been conducted at the Market 

 Garden Field Station since March, 1928. This disease and red spider are 

 among the most serious obstacles to successful culture of carnations 

 in this State. Frequent syringing of the plants with water as a control 

 measure for red spider is the main factor in the spread of blight in the 

 houses. This danger is removed b.\' the use of vajiorized naphthalene for 

 the control of red spider and hence if only blight-free plants are housed, 

 control of blight under glass becomes greatly simplified. It seems evident, 

 therefore, that successful control of blight in the greenhouse depends 

 largely on ability to prevent infection and development of the disease on 

 young plants in the field. 



Studv of the effect of fung-icides on germinating spores at 50° and 

 90° F. has shown that sulfur dust is not toxic and that copper dust is 

 tox-'c if moisture is present. Similarly Bordeaux mixtures 2-2-50 and 

 4-4-50 are toxic to spores in the water drop. The toxicity of copper 

 fungicides is related to the length of time water is present. The lethal 

 action of liquid lime-sulfur in 1-10 and 1-40 dilutions at 90°F. to spores 

 in the water drop is noted, although it is not considered as striking as 

 that of Bordeaux. In general dry lime-sulfur residues are superior to 

 dry Bordeaux residues. This effect of lime-sulfur is most pronounced at 

 higher temperatures. Naphthalene vaporized at the rate of one pound 

 to 5,000 cubic feet, the amount recommended for controlling red spider, 

 exerts no lethnl effect upon the spores. 



Stud.\' has revealed the value of a spreader in preventing foliage in- 

 fect'on. Complete foliage covering is provided by the addition of either 

 fish oil or linseed oil at the rate of .3 per cent of the diluted spray. 



Eggplant Wilt. (E. F. Guba, WalthanO- Wilt of eggplant is caused 

 by the fungus VerfAcillium albo-atrwm R. & B. which enters the roots from 

 infested soil. Because of the impracticability of soil disinfection, the 

 problem of control has been approached chiefly from the standpoint of 

 resistance to the disease. 



