MAINE APPLE DISEASES. 345 



niesophyll exposed. Sometimes the tender cells thus exposed 

 died, causing the formation of an irregular, dead, brown spot, 

 visible on both surfaces of the leaf. However, in the majority 

 of cases the exposed cells remained green throughout the sea- 

 son." 



They ascribe this to a frost occurring about the loth of May, 

 and the appearance of the trouble first came to their attention 

 about June i. They state that in 1902 this condition was gen- 

 eral throughout New York except in the Hudson Valley and on 

 Long Island. A similar condition has appeared in Maine but 

 no such general occurrence has been observed by the writers. 

 This curling of the leaves as the result of early frosts should 

 not be confused witli that caused by apple scab, aphids or plant 

 lice.* 



Protecting orchards from frost/'"'^ The apple crop in Maine, 

 as in many other parts of the country, is often materially reduced 

 and in some sections may amount to a total failure as the result 

 of frosts occurring at blossoming time or when the fruit is 

 small. From time to time the question of starting fires and 

 smudges in the orchards on cold nights to ward off the frost 

 has been agitated, but the practicability of this has remained 

 more or less of an open question. Recent w^ork in the far 

 West indicates that it is entirely possible, under some conditions 

 at least, to prevent the destruction of the crop in this way at 

 relatively small expense. Interested parties are advised to write 

 to the Secretary of Agriculture, Washington, D. C, for the free 

 Farmers' Bulletin 401 which tells how this work is done. 



Mr. P. J. O'Gara, the author of this bulletin, says: "The 

 results of the past season's work in the Rogue River Valley 

 have shown that many acres of crops valued at from $500 to 

 $1,000 per acre have been saved at a total expenditure of not 

 more than $15 to $20 per acre for firing. Very striking ex- 

 amples have been seen where unsmudged orchards adjoining 

 those that have been smudtred have borne no fruit." 



* See pp. 16 and 17 of the Circular on Apple Tree Insects of Maine, 

 already referred to on p. 340. 



** For many practical suggestions with accounts of successful commer- 

 cial tests in several states in protecting orchards from frost at blossom- 

 ing time the reader is referred to the special "Orchard Heating Num- 

 ber" of Better Fruit. Vol. V, No, 4, October, 1910. 



