COST OF PRODUCING APPLES IN YAKIMA VALLEY. 7 



The codling moth is perhaps the worst pest of the valley, but with 

 thorough spraying at the correct periods it is believed that it may be 

 controlled. The other insect pests of economic importance now 

 known to be in the valley are San Jose scale, oyster-shell scale, 

 Lecanium scale, woolly aphis, green aphis, and rosy-apple aphis. 



Apple and pear scab are now found to a limited extent, but thus 

 far have caused but little damage. 



CLIMATE. 



The climate of Yakima Valley is decidedly arid, and without 

 irrigation the growing of agricultural crops would be impossible. 

 The temperature during the summer often reaches 100° F., but be- 

 cause of the relatively low humidity it is not oppressive. The winters 

 are generally mild with but light snowfall. 



There was an annual average of 187.4 growing days at Yakima 

 in the five years 1910-1914, inclusive. The Ahtanum Valley itself 

 is well protected from severe winds; but in the lower valley, where 

 the country is more open, winds often cause crop damage. 



The mean annual precipitation for the five years 1910-1914, 

 inclusive, at an altitude of 1,070 feet, North Yakima was 6.64 inches; 

 in the Moxee Valley at an altitude of 1,000 feet it was 7.47 inches. 

 For the 22 years 1893-1914, inclusive, the mean annual precipitation 

 of the Moxee Valley was 8.36 inches. The greatest precipitation 

 takes place in the months of November, December, and January, and 

 the least occurs in the months of April, July, and August. 



For the most part the climate of Yakima Valley may be said to be 

 very pleasing and healthful. 



TOPOGRAPHY. 



Yakima County receives its water for irrigation purposes from the 

 Yakima River and its tributaries. This river has its source on the 

 eastern slope of the Cascade Mountains, taking an easterly and 

 southeasterly course, entering the northern part of Yakima County 

 and flowing into the Selah Valley, a plain about 4 miles in length. 

 At the end of this valley it passes through a narrow gap into 

 the upper Yakima Valley. From here it pursues its southerly 

 course east of the city of North Yakima and about 6 miles south 

 passes through what is known as Union Gap and enters its lower 

 valley, in which are located Parker, Zillah, and Sunnyside. The 

 upper valley is bounded on the north by Selah Ridge and Cowiche 

 Ridge, and on the south by Yakima Ridge and Ahtanum Creek. 

 The valley 'between the Yakima and Selah Ridges east of Yakima 

 River is known as the Moxee Valley and that between Yakima and 

 Cowiche Ridges west of Yakima River is known as the Ahtanum 

 Valley. The total length of this valley is from 75 to 80 miles and the 

 width is not greater than from 5 to 6 miles. The slopes of the 



