COLORADO EXPERIMENTS ON PINON. 



19 



the soil is adobe, very thin, and underlaid by the Mancos shales. 

 The trees were of various sizes; those of medium size generally 

 occurred in groups, while the old trees usually stood alone. There 

 was heavy underbrush, which made the work of placing the cups 

 very difficult. The many defects in the trees, such as gnarled, 

 twisted, and partially dead butts, and low limbs, further complicated 

 the problem. It was necessary to place some of the cups 2 or 3 

 feet from the ground because of these conditions. One hundred and 

 twenty-three cups were hung on 4 acres, approximately 31 cups to. 

 the acre. Ninety-five trees were tapped; of these 67 had 1 cup 

 and 28 had 2 cups. The diameter of the tapped trees ranged from 

 7 to 26 inches about 1 foot above the ground. Plate IV shows a 

 single pinon on the edge of the experimental area. 



The method of placing the cups was the same as in the Arizona 

 experiments, except that no attempt was made to limit the minimum 

 diameter of tapped trees or the number of cups placed on any one 

 tree. The chipping was done by a ranger who soon became accus- 

 tomed to handling a hack. 



WEATHER CONDITIONS. 



Table 13 shows the weather conditions at Mancos while the turpen- 

 tine experiment was in progress. Mancos is at approximately the 

 same elevation as the pinon area. 



TABLE 13. Weather record at Mancos, Colo., June to October, 1911 (U. S. Weather 



Bureau}. 



YIELD. 



The weight of dip secured from the pinon area at th3 various 

 dippings is shown in Table 14. 



TABLE 14. Weight of dip obtained from pinon pine in Colorado (123 cups). 



