344 EXPERIMENT STATION RECORD. [V'>1. 37 



ing, based upon the author's investigations previously noted (E. S. R., 36, 

 p. 237). 



The freezing of fruit buds, F. L. West and N. E. Edlefsen ( Utah Sta. Bui. 

 151 (1917), pp. 3-24, fiff^- 6). — This bulletin reports methods used by the authors 

 in conducting freezing studies of detached branches and also of whole trees. 

 The results obtained on between 5,000 and 6,000 buds of apples, peaches, cher- 

 ries, and prunes are reported and the literature on the subject is reviewed. 



In addition to improving the methods of freezing buds in the laboratory an 

 equipment was devised for freezing branches without removing them from the 

 tree. It was also found that the whole tree could be frozen under natural 

 conditions by surrounding it with a tauk of ice and salt. The factors that enter 

 into the problem are thus satisfactorily controlled and accurately determined. 

 Frost damage can be measured by the injured buds and also by the yield of 

 fruit in the fall. 



The investigation shows that the fruit buds in the same orchard do not have 

 a uniform freezing point. An orchard can usually stand two or three freezes 

 without losing more than half of its buds, thus leaving enough buds for a 

 normal fruit crop. 



Data are given on some preliminary studies with .Jonathan apples and 

 Elberta peaches. The results show in general that the further developed the 

 buds are the more sensitive they are to frost. There is a range of at least 5° F. 

 between the temperature at which only about 5 per cent of the buds are dam- 

 aged and the temperature that will kill all of them. With Jonathan apples in 

 full bloom, 28.5° caused no damage and 24° killed about half of the blossoms. 

 The following temperatures will kill about 50 per cent of Elberta peach buds 

 in various stages of development : When they are slightly swollen, 14° ; when 

 well swollen, 18° ; when they are showing pink, 24° ; when they are In full 

 bloom, 25° ; and when the fruit is setting, 28°. In the case of Double Nattie 

 cherries 29° causeil no damage when the fruit was setting but 24° killed practi- 

 cally all of them. Prune buds are slightly hardier than those of the other kinds 

 of fruit testetl. 



Pruning fruit trees, W. H. Alderman and E. C. Auchtek (IVcif Virginia 

 Sta. Bui. IGi (1917), pp. S-40, figs. 55).— The purpose of this bulletin is to 

 present simple and practical directions for pruning based upon the most recent 

 information available. In addition to a discussion of the general principles of 

 pruning directions are given for pruning and training the apple, peach, cherry, 

 plum, pear, and quince at the time of planting and in subswiuent years. Some 

 of the data secured in the station's recent experiments in pruning apple trees 

 (E. S. R., 36, p. 535) are also included. 



The Taylor system of pruning, A. Taylob (San Jose, Cal.: Eaton d Co., 

 1917, pp. 79, pi. 1, figs. 38). — A treatise on pruning fruit trees with special 

 reference to California conditions, based on the author's experience extending 

 over a period of 25 years. 



The influence of pruning upon the fruit spur system of the apple, V. K. 

 Gaedneb (Ann. Rpt. Oreg. State Hart. Sac., 8 (1916), pp. 66-72).— A popular 

 discussion of this subject, based upon the author's investigations previously 

 noted (E. S. R., 36. p. 237). 



The influence of commercial fertilizers on bearing apple orchards. G. G. 

 Bbown (Ann. Rpt. Oreg. State Hort. Soc., 8 (1916), pp. 36-41).— .K popular 

 summary of the author's investigations, previously noted (E. S. R.. 37. p. 41). 



The selection and hybridization of Ameiican vines in Italy, G. VatasP. 

 (Intemat. Inst. Agr. [Rome], Internat. Rev. Sci. and Praet. Agr., 7 (1916). 

 No. 10, pp. 1393-1404). — An account of the results secured with American 

 species of grapes in the reconstitution of phylloxera-infested vineyards in Italy. 



