148 HATCH EXPERIMENT STATION. [eJan. 



C. Sturgis,* who describes what is evidently the same disease 

 in Connecticut, has succeeded in producing it by inoculating 

 sound leaves with the fungus, thus leaving no doubt that 

 the Alternaria is the cause of the trouble. This fungus is a 

 mould-like growth, consisting of a mass of fine filaments 

 which grow upon and in the leaf, consuming its substance 

 and vitality. It reproduces itself by the above-mentioned 

 spores, which are blown by the wind from the surface of the 

 affected leaves to fresh ones, and there germinate and produce 

 the disease. It is not entirely clear why the leaves near the 

 centre of the hill should be the first to show the disease, 

 unless, perhaps, it is because they are the oldest leaves, and 

 thus are growing less vigorously than the outer ones, and 

 less able to resist the attacks of such a fungus. It should 

 not be supposed that the disease spreads outward to the 

 other leaves through the plant itself, as the nature of the 

 fungus shows that this is not the case, but that it spreads 

 entirely by means of the spores which are carried through 

 the air. 



As the disease was so far advanced when we first saw it, it 

 was pretty evident that no treatment would be of much avail 

 in checking it. A portion of the field was sprayed with 

 Bordeaux mixture, but the weather continued, as it had been 

 for some time previous, very rainy, and before a second 

 spraying could be made almost every leaf in the field was 

 dead and withered. Some of the melons had reached 

 sufficient size to mature, but nothing like a full crop was ob- 

 tained. The same disease was met with in one other locality 

 during the season, and no doubt occurred in various parts 

 of the State, though melon-raising is not much practised 

 here. There is no apparent reason why this disease should 

 not be as successfully treated by spraying with Bordeaux 

 mixture as are many similiar ones which are largely pre- 

 vented by this means. Experiments will be made another 

 season by spraying at the time of blossoming, and several 

 times thereafter during the season. Knowing the nature of 



* Report Connecticut Agricultural Experiment Station, 19 (1895), p. 186, and 20 

 (1896) , p. 267. See also Ohio Bulletin 73, p. 235, and 89, p. 117 ; Journal Mycology, 

 vii, p. 373. 



