FUNGICIDES, ETC. 281 



fifteen gallons. Put the potatoes in a bag and immerse 

 for one and a half hours. Dry and cut and plant. 

 CAUTION. Corrosive sublimate is & poison, and should 

 be handled with care. 



Seed-Bed Treatment. The treatment of seed beds for 

 protection against "damping off" and other fungi has 

 been discussed in connection with the seed-bed diseases 

 of tobacco (page 149). 



SULPHUR 



Sulphur is one of the cheapest fungicides that we 

 have. It has a fungicidal value either in the pure form 

 or combined with other substances. For many years 

 sulphur has been the favourite remedy for mildews on 

 plants grown in artificially-heated glass houses, the 

 sulphur being made into a paste and placed upon the 

 steam or hot-water pipes, and thus allowed to give off 

 sulphur fumes. 



Owing to the fact that sulphur seemed to be of 

 but small efficiency in controlling organisms other than 

 mildews, it soon fell into disuse in combating diseases 

 of field crops. Bordeaux mixture proved more efficient 

 and easier to handle, and practically replaced all 

 other commercial fungicides. However, the foliage 

 and fruits of many plants proved to be susceptible 

 to serious injury from applications of Bordeaux mix- 

 ture, and many investigators were on the look-out 

 for a new fungicide which would be as efficient as 

 Bordeaux mixture and still harmless to the tenderest 

 of foliage. 



Peach diseases were particularly hard to handle, 

 Bordeaux mixture practically defoliating the trees. In 

 1907 W. M. Scott, of the United States Department of 

 Agriculture, was successful in checking some peach 

 disease with a combination of lime and sulphur. 

 Lime sulphur had been used for years as a remedy for 

 scale insects on dormant trees, but was entirely too 

 caustic in its action for use upon trees in full leaf. 

 From Scott's experiments there have grown up two 



