Fungous Diseases of Garden Plants. — 141 



vine after another falls a victim to this blight, and sometimes 

 whole patches are entirely ruined. A specially devised rotation 

 which excludes potatoes, tomatoes, egg-plants, and other crops 

 subject to the attacks of the same disease, 

 is recommended as the most feasible 

 method of preventing infection. Fungi- 

 cides do not seem to possess much virtue 

 in this direction. The ^'cucumber jiiildew*' 

 which attacks the leaves of cucumbers, 

 melons, etc., much in the same manner as 

 the downy mildew affects grape leaves, 

 and the ''melon leaf spot]' which causes 

 light-colored spots in the leaf, and finally 

 holes and openings, and a rather ragged 

 appearance of the foliage, may be fought 

 probably with more success than the bac- 

 terial blight by spraying with Bordeaux 

 mixture or other strong fungicides. 



Diseases Affecting Lettuce. — 

 "Mildezu " is often very troublesome and 

 destructive on lettuce grown under glass. 

 In the first place we should aim to surround 

 the crop in greenhouse or hot-bed with 

 the same conditions which nature pro- 

 vides in early spring to outdoor lettuce. 

 The temperature should not be much 



above 40 degrees at night, nor much Soft Rot of Celery, 

 above 70 degrees during the day. Let- 

 tuce needs plenty of moisture, but water from overhead should 

 be withheld on cloudy days. Always water in the morning of 

 bright days. 



A sure and easily applied remedy is the one suggested by 

 the Massachusetts Experiment Station (Prof Maynard), and con- 

 sists in keeping a kettle or basin of sulphur (brimstone) heated 

 to nearly the boiling point, in the forcing house for three or four 

 hours twice or three times a week. Enough sulphur must be 

 evaporated to fill the room with vapor so that it will be visible, 

 and give a perceptible odor of sulphur. Great caution in the use 

 of sulphur is necessary to avoid its taking fire, for the fumes of 

 burning sulphur will quickly destroy all plant life, and a few 

 minutes of burning might result in the loss of the whole crop in 

 the building. From the testimony of Prof Thos. B. Meehan we 

 have no reason to doubt that a paint of sulphur and linseed oil, 

 put on the hot water or steam pipes in the greenhouse, will 

 effectively prevent the appearance of lettuce and other mildews. 

 On the whole, however, there is no better or surer method 



