848 EXPERIMENT STATION EECORD. 



through the girdlitvg of the twius. They turn brown, dry out, and crumble, 

 beginning nt the tips :ind outer margins. 



The disease, it is said, usually becomes well developed and conspicuous by the 

 middle or latter part of August. Specimens of diseased material were sub- 

 mitted to pathologists who failed to identify it with any known disease, and 

 this is believed to be tlie first record of its occurrence on apple trees in this 

 country. There seems to be some evidence which suggests a connection between 

 the disease and heavy applications of certain fertilizers, and experiments are 

 in progress to determine this point. 



Hold-over blight in tlie pear, W. G. Sackett {Colorado Stu. Bui. Ill, pp. 

 2-8, figs. 2). — On account of difference of opinion amoug fruit growers as to 

 whether the micro-organisms which produce fire blight in the pear, apple, 

 quince, and apricot can live over winter in diseased limbs, twigs, and fruit 

 under Colorado conditions, an investigation was begun in 1909 and carried on 

 through the winters of 1910 and 1911 to determine whether in addition to 

 occurring in the cankers the organism remains viable over winter in infected 

 twigs. 



Material was collected from widely separated regions, representing a consider- 

 able portion of the orchard district of Colorado, and examined during the winter 

 or early spring, cultures grown, and inoculations made into young pear seed- 

 lings. Out of a total of 83 twigs examined, 21 contained living Bacillus 

 amylovoru^, indicating that the organism is carried over in twigs and small 

 limbs from one season to the other. 



As bavins' an important bearing on the control of this disease, the author 

 quotes from an unpublished experiment of H. R. Fulton, botanist of the Penn- 

 sylvania Experiment Station, which seems to indicate that the bacteria of fire 

 blight do not remain viable in twigs that have been cut and allowed to dry upon 

 the ground. Out of 35 twigs containing the organism when cut, at the end of a 

 week only 4 contained viable bacteria, and most of these had become inactive 

 after 3 to 5 days. 



It is believed from the comparatively rapid death of bacteria in cut twigs left 

 upon the ground that there is no necessity for rigid destruction of cut-off twigs, 

 as has been previously recommended. Further observations, however, will be 

 made on this subject before definite conclusions are warranted. 



Withertip, R. E. Smith {Cal. Cult., 37 {1911), No. 4, pp. 76, 77).— It is 

 claimed by the author from his investigations and from tests made under his 

 supervision that the withertip fungus is absolutely not a parasite on healthy 

 citrus trees or fruit in California, but that it may occur on diseased or much 

 weakened trees, on trees which have received any injury or sudden shock (such 

 as might produce gum disease, dropping of the leaves, die back, or any other 

 diseased condition), on branches or leaves injured by fire, fumigation, or frost, 

 on the leaves, blossoms, or fruit when removed from the tree and partially dead, 

 on fruit weakened by too low a temperature in cold storage, and, in short, on any 

 citrus tissue which is dead or nearly so. 



A contribution to the life history, parasitism, and biolog'y of Botryos- 

 phaeria ribis, J. G. Grossenbacheb and B, M. Duggar {New York State Sta. 

 Tech. Bui. 18, pp. 113-190, pis. 12, fig. i).— The results are given of a study of 

 the fungus B. rihis, which produces a destructive blight or wilt of currants. 



This disease was first noticed by D. G. Fairchild (E. S. R., 8, p. 53) and was 

 ascribed to a sterile fungus. Later on the disease was studied by Durand and 

 reported as due to Nectria cinnabarina (E. S. R., 9, p. 359). As a result of 

 later work, begun by the second author of the bulletin and continued and com- 

 pleted by Mr. Grossenbacher, it was definitely determined that the disease is 



