IX.TITRIOI'S INSECTS AND FUNGI. 28? 



the soil, which is as much to be avoided as the other 

 extreme. 



Kemedy. If copper in even minute quantities is on the 

 leaves and branches so that it will be distributed over the 

 surface whenever it rains or is wet with dew the spores 

 cannot germinate, and the remedy to apply is to spray the 

 branches thoroughly with copper sulphate, 1 Ib. to 25 gals., 

 or strong Bordeaux mixture, before the leaves unfold, when 

 all of the earlier spores upon them will be destroyed. Then 

 if the trees are where the latter mixture will not be too 

 conspicuous that may be applied at intervals of from two to 

 four weeks through July and August. If the trees are in 

 a very conspicuous place, the dilute copper sulphate, 1 Ib. 

 to 250 to 300 gals., may be used, or the ammoniacal car- 

 bonate of copper will be equally effectual if applied more 

 frequently as often as every two weeks and after heavy 

 rains. The great advantage of the Bordeaux mixture is 

 that it holds the copper firmly to the leaves and with every 

 rain or heavy dew minute quantities are dissolved and the 

 spores are prevented from germinating. 



LEAF-BLIGHTS. The leaf-blights are unlike the rusts in 

 that they attack and destroy small portions of the leaves, 

 and when these spots or places of attack become numerous 

 the whole leaf is destroyed and it soon falls off. Among 

 the most destructive of the leaf-blights are the CATALPA- 

 U:AF SPOT (Phi/Host icta catalpce) , CHERRY- AND PLUM- 

 LI: A F BLIGHT (Cylindrosporium Padi), MAPLE-LEAF SPOT 

 (Phyllosticta acericolor], SYCAMORE-LEAF BLIGHT (Glceo- 

 sporiumnervisequum), ROSE-LEAF SPOT (Actinonema rosce), 

 etc. 



Remedy. As with the rusts, the copper must be on the 

 plants to destroy the spores when they come in contact with 



