TOMATO DISEASES I39 



applied to this trouble denotes its cause, an extremely 

 small mite (Phytoptus calacladophora Nal.), which 

 by its presence on the leaves or stems so irritates them 

 as to result in the abundant development of modified 

 plant hairs, which shelter the mites and form the 

 fuzzy covering characteristic of the disease. A rem- 

 edy for phytoptosis is available in the sulphur com- 

 pounds. The following one is particularly recom- 

 mended by Prof. P. H. Rolfs, to whom our knowledge 

 of the disease is due : 



Preparation of sulphur spray. — Place 30 pounds 

 of flowers of sulphur in a wooden tub large enough to 

 hold 25 gallons. Wet the sulphur with 3 gallons of 

 water, stir it to form a paste. Then add 20 pounds of 

 98 per cent, caustic soda (28 pounds should be used 

 if the caustic soda is 70 per cent.) and mix it with the 

 sulphur paste. In a few minutes it becomes very hot, 

 turns brown, and becomes a liquid. Stir thoroughly 

 and add enough water to make 20 gallons. Pour off 

 from the sediment and keep the liquid as a stock so- 

 lution in a tight barrel or keg. Of this solution use 

 4 quarts to 50 gallons of water. Apply with a spray 

 pump whenever the disease appears, and repeat if re- 

 quired by its later reappearance. The use of dry sul- 

 phur is also recommended. 



DISEASES OF THE FRUIT 



Point-rot. — This trouble, called also "blossom-end 

 rot," and "black-rot," occurs on the green fruit at 

 various stages of development, as shown in Fig. 43. 

 It begins at the blossom end as a sunken brown spot, 



