) ARIZONA AND COLORADO. 167 



best methods of eradicating the pest, because the plants are not 

 allowed to go to seed." 



The Russian thistle -when young and tender is relished by cat- 

 tle, but "as it reaches maturity and its feeding value becomes 

 greater its hardening needles cause it to be avoided by stock. In 

 the process of siloing, the needles are softened and the plant is 

 again rendered palatable. The plants are very bulky in propor- 

 tion to the substance which they contain, and apparently large 

 quantities of them will be reduced to small bulk in the silo. The 

 entire plant should be pulled to avoid waste in harvest. Unless 

 finely cut, the thistles cannot be packed in the silo sufficiently 

 to exclude air and prevent spoilage."* M. B. Hassig, Cope, Col- 

 orado, who siloed several tons of Russian thistles, states: "I had 

 twelve feet of silage made of Russian thistles on top of corn 

 silage. I covered this with dirt, but not as much as I shall after 

 this, as the air penetrated the earth and spoiled about two feet 

 of the silage. The balance was well preserved and relished by 

 the cattle." 



He adds that after the thistle silage was exhausted the cattle 

 consumed the corn silage with greater relish. 



Corn is the preferable silage crop for all sections of Colorado 

 in which it will equal other fodders in yield. Colorado Bulletin 

 No. 8 recommends for the irrigated sections the following varie- 

 ties: Iowa Silver Mine, Iowa Gold Mine, Improved Learning, 

 Pride of the North, Colorado Yellow Dent, and Ratekin's Yellow 

 Dent, and for the unirrigated districts, the White Australian. 

 Squaw corn, Parson's High Altitude corn, Colorado Yellow Dent 

 and Colorado White Dent. 



Owing to the good quality of alfalfa hay, the abundance of root 

 crops and the difficulty of getting good yields of corn, the silo 

 is not used to any great extent in Utah, although some experi- 

 mental work along this line is planned by the Station at Logan 

 in the near future. 



Alfalfa and cow peas, already discussed in Chapter VII, are 

 not usually made into silage, except as they are mixed with corn 

 or sorghum. If siloed alone, they should be very well matured 

 and thoroughly packed. Mixed in proportion of one part cow peas 



*Colorado Bulletin No. 8. 



