342 EXPERIMENT STATION RECOED. 



The apple, A. E. Wilkinson {Boston and London: Ginn & Co., 1915, pp. 

 XII +.'(92, pis. 4, figs. 195). — A practical treatise on modern practices in apple 

 growing, based largely upon recent literature on the subject. 



The succeeding chapters discuss selection of site ; adaptation of varieties 

 to soils ; orchard heating ; selection of the trees ; windbreaks ; the use of stable 

 manure in the orchard ; preparing land for an orchard ; laying out an orchard ; 

 planting; proper pruning; cover crops; fertilizing; cultivation; sod culture v. 

 tillage; irrigation and drainage; intercropping; thinning; insects; diseases; 

 spraying; miscellaneous injuries; picking; grading; packing; marketing; 

 storage; by-products; cooperation; costs, yields, and profits; growing apples 

 for the home ; renovating neglected orchards ; propagation ; pollination ; breed- 

 ing; exhibits, scoring, judging, and describing; color; fruit growing in various 

 sections of the United States; and varieties. Tables on prices in the New 

 York market for 30 years, together with a chart showing the preferences of 

 different United States markets for various apple varieties, are appended. 



Comparison of the growth of apple trees pruned and not pruned in the 

 season of planting, F. J. Cuittenuen {-Jour. Roy. Hork Soc, 41 (1915), No. 1, 

 pp. 97-109). — The experiment here reported was designed to ascertain whether 

 varieties of apples having different growth characters respond differently in 

 respect to tlieir treatment after planting, and whether the use of different 

 stocks makes any difference in this respect. Some varieties were grown on 

 Paradise stock and some on Crab stock. Data secured for different varieties 

 are presented in tabular form and discussed. 



The results as a whole led to the conclusion that all varieties of apples 

 grow better in the first season when pruned at planting than when left un- 

 pruned. The chock imposed by neglect of pruning is felt by trees on Paradise 

 stock for at least tliree years after planting, while unpruned trees on Crab 

 stock appear to recover more quickly and perhaps even to gain slightly in their 

 second and third years. It is believe<l that the difference in behavior of the 

 trees on different stocks may explain the difference which has arisen in practice 

 as between pruning the first and the second years, since trees growing on Crab 

 stock appear to do nearly as well when pruned the second year as if pruned the 

 season of planting. 



Hardiness in the apple as correlated with structure and composition, S. A. 

 IJeach and F. W. At.len, Jr. {loiva Sta. Research Bui. 21 (1915), pp. 159-204, 

 figs. 23). — This bulletin reports in detail several studies conducted to deter- 

 mine some satisfactory Index for distinguishing hardy apple trees before they 

 are old enough to fruit. 



Some 2,000 individual cutting, compression, and penetration tests were made 

 of green and dry scions taken from several varieties of apples growing in 

 Iowa, as well as in other parts of the United States and in Canada. The re- 

 sults of these tests as a whole suggest that there is a rather close correlation 

 between hardness of the wood and the ability to withstand cold. At the same 

 time the variation in certain cases is so great that this conclusion is not given 

 as a hard and fast rule. Twigs from northern sections, except the forms of 

 Malus rivularis and the varieties Red June and Patten, were no harder than 

 twigs from Iowa and farther south. 



The possible correlation between hardne.^s of wood and hardiness was also 

 investigated from the standpoint of specific gravity. The specific gravity tests 

 of dry wood show a density corre.sponding very closely with the mechanical 

 tests showing hardness, indicating that the two tests are fairly accurate means 

 to the same end. Variations in the specific gi-avity of twigs of the same variety 

 from different sources were noted, but twigs of the same variety from the same 

 source gave fairly uniform results. The specific gravity of twigs varies to some 



