Fungus Diseases of Plants. 105 



no effect on them after the thread-like mycelium (as the roots of 

 fungi are called) has once entered the tissues of the attacked 

 leaf, stalk or berry. 



The copper and lime compound (Bordeaux mixture or copper 

 mixture of Gironde) is now regarded as the most effective means 

 against infection in case of grape diseases. For the vegetable grower 

 who wishes to employ blue vitriol as preventive of potato rot, 

 celery blight, melon vine disease, etc., I would advise to use the 

 modified form of eau celeste, as most convenient to apply, safe 

 and, I believe, effective. I have made and used it as follows, 

 viz. : One pound of copper sulphate is dissolved in a gallon of 

 hot water, and liquid commercial ammonia, a little at a time, 

 added until the copper is all precipitated at the bottom of the 

 vessel. Now three gallons of water are added, and the whole 

 allowed to settle. The clear liquid on top, which contains sul- 

 phate of ammonia the substance liable to burn tender foliage 

 even worse than rust must be poured off, when the precipitate 

 (copper) is dissolved by the addition of a little more ammonia. 

 This gives us a clear liquid of a beautiful deep-blue color ; and 

 when ready for use, it is diluted to 22 gallons. The gardener 

 fortunate enough to have a spraying apparatus, can now apply it 

 to potatoes, celery and melon and cucumber vines, or other 

 plants subject to the attacks of fungus diseases. This should be 

 done early in the season, before the germination of any of the 

 spores can take place, and repeated at least every ten days or two 

 weeks during the period of danger. Celery leaf blight develops 

 most rapidly during hot and dry weather, but having once 

 obtained a firm foothold in a plant or patch, remains sometimes even 

 during the cool and moist fall weather, otherwise so well suited 

 to the wants of celery. Applications of eau celeste may check, 

 but will not eradicate it, and the only hope is in making 

 them early and often enough, i. e., using them merely as a 

 preventive. 



In the absence of a spraying apparatus the application can 

 be made with a whisk broom, the vine and plant sprinkler 

 mentioned in preceding chapter, or with a fine rose garden 

 sprinkler, but will be more wasteful and expensive. 



Tomato Rot. The abundant use of stable manure seems to 

 predispose tomato plants to the attacks of rot, but some varieties 

 appear to be more liable to take the disease than others, and 

 feeble plants less so than very vigorous ones. Sulphate of 

 potassium in solution (one-half ounce to the gallon of water) 

 applied by means of a spraying apparatus, taking care to 

 thoroughly wet all parts of the fruit, is recommended as a remedy. 

 The first application should be made on the half-grown fruit, 

 and the operation repeated at intervals of ten days or two weeks 

 until the fruit begins to color. 



