210 Bulletin 37. 



The average rainfall at the six stations in the watershed of 

 the Salt and its tributaries is, according to available records, as 

 follows : 



Jan. 1 Feb. I Mar. | Apr. | May \ June \ J uly \ Aug. \ Sept. | Oct. I Nov. I Dec. 

 1.84 1 1.46 1 1.57 I . 81 | 0.64 | 0.30 | 2.27 1 2.57 | 1.20 | 0.95 | 1.08 \ 1.90 



It will be seen that although the rainfall is heavier during 

 the summer than during the winter, the flow of the river is much 

 greater during the latter season. The parched condition of the 

 watershed and the rapidity of evaporation during the hot summer 

 months are undoubtedly responsible for the failure of most of the 

 rainfall of that season to reach the valleys below. The precipita- 

 tion during July, August and September is one-sixth greater than 

 that of December, January and February, yet during these three 

 summer months the flow of the river is less than one-third what 

 it is during the three winter months. Hence, during the months 

 of December, January and February, an average of over three 

 times as much water is available for irrigation as during the sum- 

 mer period of most abundant supply. 



PREVALENT METHODS OF ORCHARDISTS. 



The practice among orchardists, before the experiments were 

 begun at the Station farm, had been (and to a considerable ex- 

 tent is yet in many parts of the Territory) to begin the irrigation of 

 their orchards during February or March, about the time the de- 

 velopment of the buds began, and irrigate about once a month 

 until October, or as often as water could be obtained. During con- 

 siderable of this period the amount of water available was usually 

 inadequate to the demands of the trees, and orchards frequently 

 suffered from drought. The methods of applying the water and 

 the subsequent treatment of the orchards, varied very much. 

 Some fruit-growers applied the water through temporary furrows 

 about three feet apart, some through permanent ditches made 

 between the rows of trees, and some by flooding the entire surface 

 of the soil. In some cases an irrigation was followed by cultiva- 

 tion, as soon as the soil had dried sufficiently. In many cases 

 orchards were seldom or never cultivated, some growers believing 



