University of Arizoxa 



319 



once a week so that the lack of water was probably not a limiting 

 factor of growth. Kach plant was cut as soon as the first blooms 

 appeared. Table \'I11 shows the dates of cuttings and yields per 

 plant from fifteen selected plants selected from Plot 156, which 

 came originally from the Evergreen Nursery. A similar study was 

 made of each of the 342 plants. 



TABLE VIII. — WEIGHTS OF ALFALFA PRODUCED PER PLANT WITH DATES FOR 



EACH CUTTING, 1918 



It is seen from an inspection of Table VIII that all plants are 

 considerably reduced in yield as the summer advances. In no case, 

 except in that of plant No. 1, was the yield of the fourth cutting 

 more than one-fourth of that or the first cutting. The yields of 

 plant No. 6 dropped from 800 grams at the first cutting on May 3, 

 to 48 grams at the fourth cutting on July 26. In these studies it is 

 not the absolute yield per plant which is considered important, since 

 it has not been shown that yield per plant is indicative of mass yield. 

 Selections for increase will be made from those plants whose sum- 

 mer cuttings are high percentages of their respective first cuttings. 



The 61 pedigree races sown in rows, and the 18 large field 

 plots on the Salt River Valley Farm were continued in 1918 for 

 further study of yield and quality of hay for the different strains. 

 Owing to the shortage of water due to a break in the irrigation 

 main in mid-summer only three cuttings which furnished com- 

 parable data were made from the field plots. The last cutting was 

 made July 1. In searching for high summer yielders a comparison 

 was made between the yields of the first cuttings, April 16, and 

 those made July 1. Table IX shows these comparisons. 



