144 EXPERIMENT STATION RECORD. [Vol. 41 



Root-rot diseases of tobacco as a cause of uneven growth (especially on soil 

 cropped continuously or too frequently to tobacco), late maturity, and reduced 

 yields are briefly discussed in connection with investigations by Johusoa 

 (E. S. R., 36, p. 349). See also a previous note ( E. S. R., 41, p. 39). 



HORTICULTUaE. 



Adaptation in relation to hardiness, M. J. Dorset (Minn. Hort., 46 (WIS), 

 No. 12, pp. 456-^69, fig. 1). — A contribution of the Minnesota Experiment Sta- 

 tion, discussing seasonal response, or reaction, of varieties to growing con- 

 dition as a basis for a clear understanding of what is ordinarily meant, in 

 horticulture, by adaptation and hardiness. 



Data are given on experiments conducted by J. C. Whitten at the Missouri 

 Experiment Station and described to the author in a letter, which indicate 

 that there is a fundaiuental distinction between a variety, or a clone, and a 

 species in respect to differences brought about as a result of reaction or adapta- 

 tion to their environment. In these experiments seed of native forest trees 

 secured from the northern tier of States so far as possible and from each 

 intervening State to Texas and the Gulf tier were sown at the Missouri Sta- 

 tion over 20 years ago. The northern seed came up first generally. The 

 seedlings from the extreme northern seed made far less height growth at first 

 than those from seed obtained in the center of the natural distribution of 

 the species. The northern seed produced trees which, for the first few years, 

 took a much shorter growing period, starting later in the spring and shedding 

 their leaves much earlier in the fall. Some of the seedlings from the South 

 killed back to the ground the first season. The extreme southern seedlings 

 had a relatively brief rest period, pushing out into growth with the first warm 

 days of late winter or early spring and shedding their leaves very much 

 later in the fall. At the end of 10 years practically all the specimens had 

 reached a common habit of growth and seemed essentially equal in their 

 hardiness. 



Elberta and Old Mixon Free peach trees, propagated from Michigan and 

 Ontario southward to the Gulf States, were planted out at the Missouri Ex- 

 periment Station at 1 year of age. Whitten reports that " we have never been 

 able to detect any differences in hardiness, in phenology, or in habit of growth 

 or characteristics of these introduced trees. Evidently if there was any dif- 

 ference in the trees as propagated in these different States that difference was 

 overcome by their first summer's growth here in the orchard." 



In order to determine something of the season of maturity in Minnesota of 

 plants from the southern and northern range of a species, 3-eye cuttings were 

 obtained from the wild grape {Vitis vulpina) from Arkansas, Missouri, Iowa, 

 and different sections of Minnesota. These were all planted in the same cold 

 frame at the fruit breeding farm at Zumbra Heights. In the fall of 1916 

 the first killing frost killed the leaves completely on those from Arkansas and 

 Missouri, while those from Iowa north were uninjured. Although the differ- 

 ence in frost resistance was striking, there was no marked difference in ma- 

 turity between the several lots in the nursery bed, since the leaves were not 

 green on each lot. The author also cites from the experience of Macoun, 

 who found at the Central Farm, Ottawa, Canada, that with apples there is 

 not only a relation between hardiness and early ripening of fruit, but also that 

 in hardy varieties both fruit and wood ripen early. 



The field testing of copper-spray coating-s, J. R. Winston and H. R. Fulton 

 (U. S. Dept. Agr. Bui. 785 {1919), pp. 9, figs. ^).— This bulletin describes a prac- 

 tical method of testing copper-spray coatings that has been used during two 



