FERTILIZERS 7 



must be used with caution, especially upon red rasp- 

 berries and blackberries; otherwise it may cause ex- 

 cessive growth, with consequent lack of hardiness and 

 diminished fruitfulness. It is best applied in fall or 

 early winter, that it may become available during the 

 early part of the growing season. If applied in spring 

 it may cause a late fall growth, with increased loss 

 from winter -killing. 



Upon the grounds of the Rhode Island Experiment 

 Station, plots which have received no fertilizer of any 

 sort since 1890 have in some cases given as good 

 yields of raspberries and blackberries as plots which 

 have been given a good dressing of chemicals every 

 year during that time. Plots treated with mineral fer- 

 tilizers alone have, in nearly every instance, outyielded 

 plots where nitrogen was used in connection with them. 

 These results are tentative only, because while the fer- 

 tilizer application has been carried on long enough to 

 give reliable results, only the first season's yields of 

 bush -fruits are available. The yields and the appear- 

 ance of the plants growing upon the plots are signifi- 

 cant. The soil is a light, sandy loam, underlaid with 

 a gravelly subsoil, and is naturally unproductive. 



All growers agree that potash is the most impor- 

 tant element of fertility in fruit-growing. With the 

 tree -fruits it often heightens color; whether it is as im- 

 portant with bush -fruits is not fully determined. From 

 present knowledge it seems probable that 100 pounds 

 of muriate of potash per acre, annually, will furnish an 

 abundance of potash upon most soils. If leguminous 

 cover -crops are employed they will supply all the 



