Illustrations 



Fi"- 1. Salt River Valley Farm: Foreman's house completed Septem- 

 ber, 1920 563 



Fig. 2, Salt River Valley Farm: Field Peas as a green winter manure 



crop 5^5 



Fig. 3. Varietal tests of barley in the Yuma Valley; common six row 



on left; beardless in the center; Mariot on right 569 



Fig. 4. Salt River Valley Farm: Field tests with rye; Rozen rye on 



left; Abruzzes rye on right 569 



Fig. 5. Curves showing inheritance of earliness (as indicated by date 

 of appearance of first head) through four generations of a 

 cross between early (Sonora) wheat and a late (Red Turkey) 

 wheat 604 



Fig. 6. Effects of date rot disease; note mummies still hanging to tree 



and on ground 607 



Fig. 7. Field of lettuce near Toltec, infected with bacterial rot 608 



Fig. 8. Head of lettuce from the market, inoculated in the laboratory 

 with bacterial rot from diseased plants taken from field near 

 Toltec 610 



Fig. 9. Trunk of peach tree killed by crown gall. Note the large gall 



at base of trunk on the left side 612 



