20 EORAOE-CROP EXPERIMENTS AT SAN ANTONIO. 



inoculated with soil giving much the best growth. The cuttings con- 

 tinued so light, however, that there was not sufficient return for the 

 expense of culture. 



Table XV .—Comparative yields of varieties of alfalfa. 



S. P. I. 



No. 



Source of variety. 



Yield per 

 acre. 



12549. 

 12846. 

 14786. 

 L8627. 



L8628 

 18664. 



Argentina 



Tripoli 



Turkestan 



Arabia (irrigated seed) 



Arabia (nonirrigated seed; . 

 Provence, France 



Pounds. 

 400 

 320 

 4S0 

 120 

 400 

 80 



The best yield made by alfalfa in rod-square plats was 880 pounds 

 an acre at one cutting. The other cuttings were only clippings 

 made for the purpose of protecting the alfalfa from the drought as 

 much as possible. 



Four varieties of alfalfa were seeded under irrigation in one-tenth 

 of an acre plats in September, 1909. Two of these plats were almost 

 completely ruined, and the other two badly injured by root-rot before 

 July, 18, 1910. The root-rot proved, perhaps, more destructive 

 than usual in these plats. 



POSSIBILITIES OF ALFALFA. 



Where alfalfa is grown in the vicinity of San Antonio under irri- 

 gation it is generally necessary to replant the fields or portions of 

 them every fall. Where this is clone the reported yields indicate 

 that alfalfa is a fairly satisfactory forage crop. On the Sewer farm, 

 south of San Antonio, five to eight cuttings are ordinarily obtained, 

 although the last cuttings are light and mixed with native grass and 

 weeds. Where root-rot has destroyed the plats the vacant areas 

 are taken up by grass and weeds. 



It must be admitted that the possibilities of alfalfa in soils infested 

 with root-rot are limited, and the writer has yet to see a cultivated 

 field of any area in the black soil of this section that is not infested 

 with this fungus. That the light, sandy soils south of San Antonio 

 are in some instances less infested, if not entirely free from the 

 fungus, has also been observed, but whether these isolated areas are 

 of sufficient extent to permit the establishment of permanent alfalfa 

 fields is yet to be demonstrated. The best superficial method of 

 determining whether the root-rot fungus is in the soil is to observe 

 the cotton fields. If there are small areas of varying size with dead 

 cotton plants, the farmer will be safe in concluding that the fungus is 

 in his fields. 



[Cir. 106] 



