Proceedings of Seventeenth Normal Institute IIT 



nitrogen, and at the end of the fourth year the difference was 

 much greater, while the leaf surface was 4 times as great. 



The set of fruit buds was in the ratio of 76 to 60 for nitrogen- 

 treated and untreated trees, and the quantity of fruit on the 

 former was nearly double that on the trees not receiving nitrogen. 

 The nitrogen delayed maturity and weakened color, through the 

 exclusion of sunlight by the heavy foliage. 



Lime and potash were without favorable effect, the latter pos- 

 sibly deleterious. 



Pruni7ig. (Oreg. 130.) This bulletin of Y2 pages, illustrated 

 with 59 figures, is a very comprehensive study of the principles 

 and practices of pruning. It includes a study of plant physiology 

 as related to pruning, a study of fruit buds and their develop- 

 ment, and articles on pruning young trees, apple and pear trees, 

 and prune trees, by four authors. While the pruning practices 

 are handled from the western standpoint, of course, the principles 

 are so thoroughly discussed, and the results from the operations 

 so plainly shown by excellent illustrations, that the book is well 

 worth study by any horticulturist or fruit grower. 



Profits from spraying twenty-fi,ve Missouri orchards in 1914. 

 (Mo. 124.) This 100-page bulletin is a splendidly stocked arsenal 

 of arguments for spraying, for the use of institute men and county 

 agents. Several orchards showed gains of from $300 to $400 

 per acre from spraying. Full details of methods and cost are 

 given for the separate orchards, and the costs are well summarized 

 for all, by application. 



INSECTS AND DISEASES 



Observations and experiments on San Jose scale. (111. 180.) 

 It has been the belief that there is little or no danger of the spread 

 of San Jose scale by ripe apples, as it was held that the scales die 

 as the apples ripen. Experiments here recorded show, however, 

 that females live and reproduce freely on such apples plucked 

 from the tree and kept at the ordinary room temperatures, for a 

 period of., at least eight weeks. Infested apples taken from cold 

 storage in December gave similar results, young scales appearing 

 for twenty-five days. 



Exact breeding experiments, made in 1906, showed that from 

 the last-born descendants of successive females only two complete 



