B. P. I.— 556. 



IMPROVEMENT OF THE WHEAT CROP IN 



CALIFORNIA. 



INTRODUCTION. 



An impression exists among many California farmers that the 

 soil will no longer produce profitable yields of good milling wheats. 

 This impression is strengthened by two well-recognized facts: 

 (1) That under past and present methods of wheat culture the soil 

 is failing in many localities to produce as large crops as heretofore, 

 and (2) that the Australian and Club varieties, the most widely 

 grown California wheats, are extremely starchy. As only these 

 very starchy varieties have been extensively grown, it has become 

 necessary for the millers to import large quantities of Turkey wheat 

 from the Middle West to blend with the California wheats. 



In order to discover varieties better adapted to California needs 

 than those commonly grown, the Office of Grain Investigations of the 

 Bureau of Plant Industry has for a number of years conducted ex- 

 tensive tests of wheat varieties, including many of foreign origin. 

 In this way it was hoped to improve the California wheat crop in 

 both yield and milling quality. As improved methods of cultivation 

 are necessary also to obtain profitable yields of nitrogenous wheats, 

 an effort has been made to determine the effect of deep plowing and 

 the addition of humus to the soil in the form of winter green-manure 

 crops. The time of plowing, the conservation of moisture, and 

 the eradication of weeds have also been considered. If the State is 

 to continue the profitable use of its grain lands and derive from them 

 the largest possible return, it is quite necessary that there be an im- 

 provement in the general practices of cultivation and in the varieties 

 grown. 



The investigations covered by this report are in general based 

 upon results obtained and observations made during a number of 

 years, a part of the time in cooperation with the California Agricul- 

 tural Experiment Station. An effort has been made to so correlate 

 the results and observations that they will be of benefit to the Cali- 

 fornia grain grower in effecting improvement in soil fertility, in the 

 32912— Bui. 178—10 2 7 



