Bul. 582, U. S. Dept. of Agriculture. PLATE IV. 
Fia. 1.—A BROAD, SHALLOW, WEED-COVERED IRRIGATION DITCH—THE USUAL CONDITION. 
It is exceedingly difficult to keep the land clean when every irrigation after midsummer deposits 
fresh weed seed. 
Fic. 2.—A STRAWBERRY FIELD ON PROVO BENCH. 
Bare spots in the rows indicate the presence of insect pests. 
