54 



EUST ON GRAPES. 



soakings of water. This will keep the foliage of the 

 vines full of sap ; and, for some reason known to itself, 

 red spider prefers foliage that is suffering for lack of 

 moisture to that which is crisp and full of it. 



RUST ON GRAPES. 



This is a disease that makes its appearance on the 

 berries in a few days after they are set ; every grape- 

 grower is too familiar with it to make it necessary I 

 should describe it. Some have said it is caused by 

 handling the berries while thinning them ; others, by 

 being rubbed with the hair of the thinner's head ; others, 

 again, by cold currents of air. I am not prepared to 

 say but that any or all of these causes will produce 

 rust ; but I am certain that the most fertile source of 

 it is the application of sulphur to the pipes or flue 

 about the time the grapes come into bloom. I was led 

 to suspect this some time ago, by observing that in 

 houses where the foliage was affected with a sort of 

 green warty excrescence on the back of the leaf — of 

 which more hereafter — the very day sulphur was 

 applied to the pipes, these green warts, if I may term 

 them such, became black, and killed, to all appearance. 

 Here, then, was a case where the sulphur was affecting 

 organised vegetable matter. This led me to suspect it 

 might be the cause of rust, in as far as it was as likely 

 to be able to affect the young and tender skin of the 

 embryo grape as that of the parts of the leaves referred 

 to ; and I was confirmed in this belief by the following 

 circumstances :— In a house of vines, where Ave also 

 grew French beans and strawberries, red spider was 

 very troublesome, and before the grapes came into 

 bloom I had the pipes painted with sulphur. This 



