748 experime:s^t station record. [Voi.4i 



discolored, aud the brownish tissue was either dead or in the process of dis- 

 coloration. From this tissue a bacterial organism was obtained, aud inocula- 

 tion experiments indicate that it was responsible for the trouble. The author 

 reviews some of the literature pertaining to the bacteria which cause diseases 

 of corn, pointing out some of the differences, but makes no attempt to describe 

 the organism at present. Attention is called to a bacterial disease of foxtail 

 previously described (E. S. R., 40, p. 643), but the organisms isolated from 

 foxtail and corn roots and leaves have not been identified as the same species. 



Seed potatoes and potato diseases, G. R. Bisby {Minn. Hort., 46 {1918), No. 

 ■i, pp. 164-167, figs. 2). — In addition to precepts based on experiences regarding 

 the maintenance and improvement of potatoes through breeding operations, the 

 author gives an account of experiments carried on for some years with potato 

 late blight. This disease was best controlled with Bordeaux mixture, the 

 beneficial effects (as evidenced in the increased yield in case of Rural and 

 Early Ohio) inci'easing with the concentrations employed ranging from a 

 2 : 2 : 50 to 5 : 5 : 50 solution. 



Investigations on potato diseases, IX-X, G. H. Pethybeidge {Dept. Agr. 

 and. Tech. Instr. Ireland Jour., 18 {1918), No. 4, pp. 41O-4I6; 19 {1919), No. S, 

 pp. 271-292, pis. 2).— The continuation of this work (E. S. R., 39, p. 249) was 

 still somewhat limited in scope during the seas(jn pf 1917, though experiments 

 were carried out at two stations, both in the County of Galway. The first 

 outbreak of blight {Phytophthora infestans), noted June 12, was retarded by 

 good weather, but August was favorable to the spread of blight. Spraying, 

 however, reduced the loss considerably. 



Burgundy mixture alone was used in 1917. this fungicide being more con- 

 venient to prepare and apply, equal to Bordeaux in efficacy, and generally 

 preferred by farmers in Ireland, The diffierences observed as between the 1 

 and the 2 per cent strength were slight, though the latter is preferred where 

 only two sprayings are employed and where cost of material is not the prime 

 consideration. 



Resistance was shown by a few varieties in marked degree. Chfden Seedling 

 and Champion II v.-ere almost completely resistant, while " K " Seedling, Sham- 

 rock, and Northrn Invincible) were less so. Great Scot, Provost, Kerr Pink, 

 Dominion, and Burnhouse Beauty, though known to be immune to wart disease 

 (black scab) (which is, however, absent from the west of Ireland), were 

 not resistant to blight {P. infestans) , to coi-ky or powdery scab (Spongospora), 

 or to pink rot (P. erythroseptica). 



The work carried out in 1918 was also somewhat limited in scope, consisting 

 chiefly in spraying trials against ordinary blight, though trials on a small 

 scale with certain disease resistant varieties were carried on this year. 



Conditions for the spread of blight were on the wliole not very favorable. 

 The efficacy of the 2 per cent and that of the 1 per cent Burgundy mixture 

 w'ere practically equal. A second and a third spraying were highly remunera- 

 tive in every case ; a fourth spraying was so in three cases and paid for itself 

 in the fourth instance. Any physiological check attending the use of the spray 

 was small and temporary. Substitutes for soda were tried witli somewhat 

 favorable but not conclusive results. 



Blight resistance showed a general correspondence to the tendencies noted 

 the previous year. Pink rot (P. erythroseptica) was very prevalent in some 

 western districts in 1918, causing considerable loss. Varieties resistant to 

 black scab (though not to pink rot) as named in order of their resistance were 

 Kerr's Pink, Dominion, Burnhouse Beauty, Provost, and Great Scot. 



Silver scurf (Spondylochidinni atrovirens), which is of little importance 

 beyond the results due to a slight skin blemish of the tuber, was widely preva- 



