POTATO DISEASES IN K)0J. 3OI 



Can Our Spraying Methods Be Improved? 



After going over hundreds of acres of potatoes this past 

 summer and talking with the growers as to the methods used 

 in spraying, the writer would answer this question with a 

 decided affirmative. A most encouraging fact is that many of 

 the growers themselves agree with this conclusion and state 

 their determination to return to the more thorough practice 

 formerly in vogue. It is probably not excessive to state that 

 in most districts at least 30 per cent of the crop in 1907 was lost 

 from rot, to say nothing of the reduction in yield from the early 

 killing of the tops. In many cases 50 per cent or 60 per cent 

 and even 75 per cent of the crop went to the starch factory. 

 The station experiments and the results obtained by growers 

 who followed similar methods indicate that a large proportion of 

 this loss could have been prevented by proper spraying. 



Spraying must always be looked upon as a form of insurance, 

 and for potato blights is a preventive and not a cure, hence it 

 must be begun before the blight appears. Various causes are 

 responsible for the losses during 1907. The almost entire 

 absence of late blight for a few seasons led some to question 

 the value of spraying and many of these individuals announced 

 their intention of not spraying at all this season. These, and 

 many others from one cause and another, waited till their plants 

 were well infested and then began to spray — a proceeding about 

 as effective as turning a hose on the outside walls of a house 

 to stop a fire in the interior partitions. Here, frequently, enough 

 bordeaux was used during the season but not at the proper urne. 

 Others were provided with sprayers having single nozzles so 

 placed as to be only a few inches above the full grown tops. 

 They drove over the fields with these carts leaving a deep blue 

 line about 6 inches wide on the center of the foliage of each 

 row and went their way apparently satisfied, for had they not 

 applied 50 gallons per acre? Here again, it is possible that 

 enough bordeaux was used, but it was not properly distributed 

 to protect the entire foliage. In cases where the entire foliage 

 was not covered with bordeaux the unprotected leaves blighted 

 and the spores from their surfaces were washed down into the 

 soil and thus infected the tubers with rot. 



