28 



UNIV. OF N. H. AGR. EXPERIMENT STATION [BuUctiu 238 



active when dried slowly. However, of all the substances studied this was 

 true only of nitrate of soda. Copper nitrate, copper sulphate, sodium 

 hydroxide, ammonium sulphate, sodium carbonate and sulphuric acid are- 

 more active when dried quickly. 



To obtain an 80 percent kill a necessary strength of the herbicide was 

 found to be for copper nitrate 1% ; sulphuric acid 1.5% ; copper sulphate 

 1.8%; ferrous sulphate 10.0%; and ammonium sulphate 36%. (State 

 Fund.) 



TIME STUDIES IN ORCHARDS 



Filler trees in apple orchards have little value under New Hampshire 

 conditions with cheap land and the sod mulch system, according to the eco- 

 nomic fruit studies being made by H. C. Woodworth and G. F. Potter. 

 Even with permanent trees, the highest value, based on expected earnings, 

 seems to come at twenty years of age. On account of the piling up of costs 

 by compound interest the importance of having a tree come to bearing early 

 is clearly shown. An early-bearing tree may have paid for itself at 16 

 years of age, while a late-bearing tree may require 27 years. 



The time studies indicate that two skilled men can care for 3.000 trees 

 with extra unskilled help at certain seasons. In growing the fruit, pruning, 

 spraying and thinning require special training and skill and must, therefore, 

 be done by the orchardist himself and the crew of trained men. Picking 

 up brush, fertilizing, tillage, mowing, mulching, protection, propping and 

 picking apples may be done by men of ordinary intelligence upon short 

 instruction. Thinning also could be done satisfactorily by the better class 



More efficient methods in this orchard have saved time and labor in filling 



the spray tank 



of day labor available. It is thought, therefore, that in the case of large 



