302 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



of new crops. At present the number of crops which it is found 

 possible to grow there is very limited. Several of these, such as pota- 

 toes and beans, wliich are now grown extensively, are seriously 

 aft'ected by disease if groAvn more than one year on the same land. 

 New vegetables and forage crops suitable to these rather unusual 

 lands should be tried in such a way as to ascertain whether they can 

 be profitably produced under existing economic conditions. 



During the past year the attention of the department has been 

 called to the desirability of undertaking investigations in the Uncom- 

 pahgre Valley in Colorado in the vicinity of the towns of Montrose 

 and Delta. The recently completed Gunnison Tunnel has brought 

 an increased supply of irrigation water into this valley and will result 

 in the development of a large acreage of hitherto unused land. A 

 considerable portion of the land in this valley is admirabl}'^ suited to 

 the production of fruit, alfalfa, and sugar beets; but considerable 

 areas in the valley have soils the salt content of which is dangerously 

 high. 



On both this project and in the Pecos Valley of New Mexico it has 

 become evident that the long-continued production of high-priced 

 orchard fruits may result in abnormal conditions of the soil which 

 may jeopardize the health and vigor of the fruit trees. The nature 

 of these abnormal conditions is not well understood, nor are the most 

 suitable remedies known. In view of the magnitude of the interests 

 involved, not only in these vallej^s, but in numerous other irrigated 

 regions of the West, it seems highly desirable to undertake investiga- 

 tions to determine the causes of the conditions which prevail and the 

 best remedies for improving them. It is therefore thought desirable 

 to inaugurate as soon as possible both in the Uncompahgre Valley in 

 Colorado and in the Pecos Valley in New Mexico a series of physio- 

 logical and pathological investigations in connection with field sta- 

 tions of this bureau in order to work on these problems of plant 

 nutrition in irrigated agriculture. 



ALKALI AND DROUGHT RESISTANT PLANT BREEDING, 



The work of breeding drought-resistant crop plants, testing the 

 alkali resistance of crop plants, and investigating the physiology of 

 drought resistance and alkali resistance is being continued under the 

 direction of Mr. T. H. Kearney. 



Drought-resistance physiology. — In cooperation with the Physi- 

 cal Laborator}^ rapid progress is being made in ascertaining what 

 factors render certain species and varieties of crop plants better 

 adapted than others to dry-land agriculture. It is believed that the 

 solution of this problem will greatly facilitate the work of plant 

 breeding and variety testing for drought resistance. The results of 

 these investigations to date indicate that the most important factor 

 is economical use of the available soil moisture, as shown by a maxi- 

 mum crop production with a minimum expenditure of water. Fur- 

 ther light on this subject is expected from the results of experiments 

 noM^ in progress, in which many of the important crop plants of the 

 arid regions are being grown side by side under such conditions that 

 the quantity of water used and the amount of crop produced by each 

 can be accurately determined. These studies, which are regarded as 



