BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 279 



ten to fifteen years of age have averaged not over 40 pounds per year 

 and 100 pounds is probably a maximum production for large, mature 



FIG. 61. Franquette walnut, natural size. 



trees of this variety. Groves of nursery-grafted trees in their sixth year 

 after planting have scarcely averaged 10 pounds per tree. 



