542 



GROWING BUSH FRUITS 



the supply of humus with its moisture-holding properties, and 

 to cultivate frequently, than to rely upon irrigation. 



(b) Fertilizing the Plants, The addition of organic matter 

 is especially important in the fertilization of brambles. Mois- 

 ture is often as much of a limiting factor to cane growth and 

 fruit production as soil nutrients. Organic matter improves 

 the physical condition of the soil so that its moisture-holding 

 capacity is greatly increased. 



Before the plants are set, a heavy application of barnyard 

 manure should be plowed under and the soil thoroughly culti- 

 vated. Under many conditions the addition of 8 to 10 tons 

 of manure per year and the turning under of cover crops will 

 be sufficient to maintain vigorous canes and heavy fruit pro- 

 duction. 



There is very little experimental evidence relative to the 

 fertilization of the brambles. Experimental results in New 

 York, Oregon, and Rhode Island show that red raspberries 

 respond especially well to applications of nitrate of soda. 

 When this material is added, not only are more canes pro- 

 duced but also the individual canes are more vigorous and 

 have larger leaves. Fruit production is also increased to 

 some extent. From 150 to 300 pounds of nitrate of soda per 

 acre are added, depending upon the soil and the growth of 

 the plants. 



The evidence relative to the fertilization of black rasp- 

 berries, purple raspberries, and blackberries is very meager. 



In North Carolina, two applications of fertilizer are gen- 

 erally made to dewberries after the first year. The first ap- 

 plication is made just as soon as the canes have been tied up 

 in the spring. The formula used varies somewhat in the dif- 

 ferent sections and with the different growers, but one that is 

 often used consists of 2 per cent nitrogen, 10 per cent phos- 

 phoric acid, and 8 per cent potash. From 500 to 700 pounds 

 per acre are used. 



The second application is made immediately after the crop 

 has been harvested and the canes cut off. Some growers use 



