28 PEACH LEAF CURL: ITS NATURE AND TREATMENT. 



north on the Atlantic coast, so that the relations of annual rainfall to 

 the constant prevalence of curl may be more fairly decided. 



In the following remarks on this subject I have left out of consid- 

 eration the temporary influence of exceptional seasons and, as far as 

 possible, the special influence of local features. The subject should 

 be viewed from the broad field above pointed out. In southern Cali- 

 fornia leaf curl is not recognized as a generally prevalent and serious 

 trouble, but there is evidence which shows that its prevalence increases 

 from San Diego northward to the San Bernardino Mountains. The 

 average annual rainfall varies from about 10 inches at the former place 

 to 16 inches at Los Angeles, which is not far from the mountains. In 

 the San Joaquin Valley the prevalence of curl increases as a whole from 

 the south central portion toward Sacramento and the north. The 

 average annual rainfall, which is 7 inches at Tulare, 9 inches at Fresno, 

 11 inches at Merced, and 14 inches at Stockton, reaches 20 inches at 

 Sacramento, about which center curl is quite prevalent. The average 

 rainfall at Oakland is 23 inches, and curl is quite troublesome there. 

 In the Sacramento Valley curl is frequently quite prevalent, and the 

 rainfall varies from 20 inches at Sacramento and Chico to 34 inches at 

 Redding. About Ashland, in southern Oregon, the rainfall is 23 

 inches, and the disease is about as in the Sacramento Valley. Farther 

 north in Oregon curl becomes decidedly more prevalent and injurious 

 at the west of the Cascade Mountains, and increases as Portland is. 

 approached. The rainfall is 35 inches at Roseburg, 46 inches at 

 Albany, and 49 inches at Portland. From Albany to Portland the 

 peach industry has been greatly injured by curl, and on its account 

 many growers in this region have considered peach culture a failure. 



Curl, it seems, was introduced into the central part of the Willamette 

 Valley, Marion County, nearly half a century ago. Prior to that 

 time the peach was successfully grown in that region in spite of the 

 humidity of the climate. In the Patent Oflice Report for 1855, p. 

 298, there is a statement of the situation in Polk and Marion counties 

 from 1852 to 1855. This statement was from Mr. Amos Harry, of 

 Farm Valley, Polk County, Oreg., and is of special interest in this 

 connection. Mr. Harry says: "The peach in this county has been 

 afiected with a disease known as the 'curled leaf,' which threatens to 

 destroy the trees. It made its appearance at Mill Creek, in Marion 

 County, in 1852, and extended considerably on that side of the river 

 (Willamette River) in 1853, but had reached most parts of the valley 

 in 1854-55. Some trees seem to escape it much more than others, but 

 if the malady increases for two years to come as it has for two past, I 

 fear we shall come entirely short of this delicious fruit. Some think 

 it is owing to cold, wet weather, and recommend shortening all the 

 limbs as a remedy, and some experiments seem to favor this idea. 

 Others think it is produced by an insect, and that no remedy will save 

 the trees unless it can be applied to the whole surface of the leaves." 



