12 



Soon after being attacked, the leaves assume a yellowish color, 

 and upon close examination numerous clusters of yellow spores are 

 seen on the under side. Theso spores are produced in untold 

 numbers and are soon scattered by the wind. Coming in contact 

 with other leaves, they so rapidly spread the infection that in a 

 few days, from the product of a few clusters the whole tree is 

 affected. The leaves soon turn yellow and fall to the ground, where, 

 after they have become brown, may be found in place of the yellow 

 masses of spores, numerous black clusters in which are produced the 

 winter spores. These, surviving the winter, come in contact with 

 tlie new leaves in the spring or summer, germinate, and undergo 

 their round of existence. 



RESULTS OF THE USE OF FUNGICIDES. 



To check this disease the trees were sprayed with the Bordeaux 

 mixture July 26th, 28th, and August 11th, and 25th. The result of 

 this spraying is shown in the following cuts made from photographs, 

 Fig. 1 showing the trees unsprayed, and Fig. 2 those that were 

 sprayed. 



All of the trees were employed in this test, every other three being 

 sprayed. In every ease the results were the same, i. e., the three 

 trees treated having perfectly healthy foliage, while those not sprayed 

 were badly diseased. The results are not as plainly shown in the 

 photographs as was actually the case owing to the delay in obtaining 

 the pictures ; the leaves of the poplar being constantly in motion 

 several attempts had to be made extending over a period of several 

 days, before a satisfactory negative could be obtained, and in the 

 meantime the leaves were ripening rapidly and many had fallen from 

 the trees that were sprayed. 



PUMPS AND mate:rials. 



Spraying pumps and materials are now kept for sale by nearly all 

 dealers in seeds and agricultural and horticultural supplies, and can 

 be obtained from them at reasonable prices. While there are many 

 different kinds of pumps advertised, and while nearly all of those put 

 on the market by the large manufacturers who make a specialty of 

 spraying pumps, are good, it is best, however, to buy those made as 

 near home as possible, on account of the repairs and replacement of 

 parts necessitated by breakage which may occur when least expected. 



