44 EXPEKIMENT STATION EECOED. 



In connection witli the work with bush fruits a number of crosses were made 

 of raspberry and blackberry plants in 1909 and 1910. Over 600 seedlings 

 secured from these crosses began fruiting in 1912, and the more promising rasp- 

 berry and blackberry crossbreds have been planted out for further trial. One of 

 the original blackberry crosses is so promising with respect to earliness that it 

 has been used as a parent in crosses made during the past two years. 



Bhubarb culture, J. L. Stahl (Washington Sta., West. Wash. Sta. Mo. Bui., 

 2 {1915), No. 12, p. 16).— Brief practical directions for growing rhubarb are 

 given, consideration being given to the soil, propagation, and transplanting, 

 tillage, forcing rhubarb, and varieties. 



Becommended varieties of fruit for Idaho, C. C. Vincent and G. J. Down- 

 ing {Idaho Sta. Bui. 83 {1915), pp. 15, fig. i).— In this bulletin the authors 

 divide the State into eight districts and give lists of varieties of orchard and 

 small fruits recommended for culture in each district. The principal varieties 

 of apples are also considered with reference to their strong and weak points. 



Standard varieties of tree fruits, J. L. Stahl {Washington Sta., West. 

 Wash. Sta. AIo. Bui., 1 {1913), No. //, pp. 2-6, figs. S).— Horticultural descrip- 

 tions are given of a number of varieties of apples, pears, plums, and cherries 

 which are adapted for both the home and the commercial orchard in western 

 Washington. 



Studies in fruit bud formation, J. H. Goueley {New Hampshire Sta. Tech. 

 Bui. 9 {1915), pp. 80, pis. 9, figs. 13). — This paper comprises a progress report 

 covering a period of seven years on studies of certain factors with reference 

 to their influence on fruit bud formation. The work was started in 1908 in a 

 Baldwin apple orchard which is receiving various cultui'al and fertilizer treat- 

 ments. An outline of the orchard plats, together with the practical results of 

 the various treatments for a 5-year period as measured by growth, yield, and 

 size of fruit has been previously noted (E. S. R., 31, p. 141). In the present 

 report data dealing with the following factors are given and discussed : Ni- 

 trate formation, soil moisture, organic and inorganic matter content of the 

 soil, the laying down of starch in the twigs, the relation of leaf area to buds 

 formed, relation of rainfall to yield and growth, the influence of cultural treat- 

 ments, and effect of commercial fertilizers. A resume and bibliography is 

 given of literature bearing on the formation of fruit buds and on the reserve 

 food in plants, mostly in fruit trees. 



Summarizing the results of soil studies which were conducted during the 

 years 1913 and 1914, the author finds that apple trees carrying a heavy load 

 of fruit will suffer materially when the moisture content of the soil drops to 

 6.5 or 7 per cent in sandy soil and 12 per cent in a loam soil. " The moisture 

 under sod in this experiment has run a little higher than where clean culture 

 is practiced. The moisture is higher where a green crop is plowed in annually 

 than where clean culture is practiced. 



" The formation of nitrates is greatly reduced in a sod orchard. Nitrification 

 takes place much more rapidly where a leguminous cover crop is plowed in 

 than where clean culture is followed. Nitrates are found in great abundance 

 throughout the season where nitrate of soda is applied as a fertilizer, but it 

 is entirely washed out or decomposed over winter. Calcium carbonate applied 

 to the soil in question has augmented the formation of nitrates. It appears in 

 this soil that nitrate formation of from 20 to 40 parts per million as an aver- 

 age for the growing season is essential for the maximum vigor of the trees and 

 abundant fruit-bud formation, and that above this an excess will not of itself 

 increase the growth of the trees or number of fruit buds formed." 



With reference to the laying down of starch in the twigs, a heavier deposi- 

 tion of reserve food material in the storage tissues was found in the case of 



