54 EXPERIMENT STATION RECORD. 



connection with the treatment for the bitter rot. For the combined treatment 

 of apple scab and bitter rot the trees should be sprayed just before they 

 bloom, as soon as the petals fall, a week to 10 days later, and about 6 weeks 

 after the shedding of the petals, to be followed at intervals of 2 weeks there- 

 after until 7 or 8 applications have been given. 



In a dry, cool season the intervals between the later sprayings may be length- 

 ened. On the other hand, in a hot, humid season it will probably be found 

 necessary to shorten the intervals and increase th.'> number of applications. 

 If the treatment for any reason should be delayed until after it is discovered 

 that infection has taken place, the trees should be thoroughly sprayed twice 

 in rapid succession with an interval of a few days in order to coat the fruit 

 thoroughly as quickly as possible. 



The wrapijing of apple grafts and its relation to the crown-gall disease, 

 H. VON ScHRENK aud G. G. Hedgcock (U. S. Dcpt. A;ir.. Bur. Plant Indus. Bui. 

 JOO. pi. 2, pp. 12). — In a previous publication (E. S. K., 17, p. 779) the nature 

 and cause of crown-gall disease of apple trees and its different types are dis- 

 cussed, and in the present publication only 2 forms are considered, the hairy 

 root and the crown gall. The hard and soft types of the crown gall have not 

 yet been fully differentiated. 



In the present paper an account is given of experiments in which cloth, 

 rubber, waxed pai)er, plain thread, \^axed thread, and plain thread with union 

 waxed were tested to determine their effect in preventing the occurrence of 

 crown gall by providing conditions under which a perfect union is formed 

 between the stock and scion in the shortest possible time. A large number of 

 grafts were made, and the detailed results are shown, from which it appears 

 that wrapping the grafts reduced the number of crown-gall trees very materially. 



The most effective wrapping, so far as the true crown gall is concerned, was 

 that made of rubber, followed closely by cloth. The cloth wrappings, however, 

 showed the liighest percentage of smooth trees, when not only the crown gall 

 but also the hairy root form were considered. From the results thus far 

 obtained, the use of either cloth or rubber as a material for wrapping apple 

 grafts is recommended, and when the question of expense is to be considered 

 it is believed that cloth will be found more desirable, as in most cases it gives 

 results fully as satisfactory as rubber. The writers strongly advise against 

 the wrapping of grafts with thread and subsequently waxing the grafts. 



Peach mildew, O. B. Whipple {Colorado Sta. Bui. 107, pp. 7. flffs. 2). — 

 According to the author, peach mildew has made its appearance in some parts 

 of Colorado, and the purpose of the bulletin is to point out the nature of the 

 disease and describe some of the means of combating it. 



• Notes on rougeot of grapes, L. Ravaz and L. Roos {Co)iipt. Rend. Acad. Sci. 

 [Paris], 1J,1 {1905), No. 6, pp. 36(1. .?67).— The authors claim that this disease 

 is characterized by an accumulation of red coloring matter in the leaves and 

 is produced under vai-ying circumstances. They reject the theory that it is 

 caused by the development of parasites within the leaves and show that it may 

 be produced by the ringing of a branch or the severing of one of the principal 

 veins of a leaf. That the disease is not parasitic they claim is further shown by 

 analyses of many parts of the vines at different stages of growth. Their figures 

 show that in the diseased vines ihere is a large accumulation of starch and 

 sugar in the diseased parts and a deficiency of lime and magnesium in most 

 pai'ts of the affected plants. 



Cranberry spraying experiments in 1905, C. L. Shear (T. »S'. Dept. Afjr.. 

 Bur. Plant Indus. Bui. 10(1, pt. 1, pp. 8 fig. 1). — In a previous publication ( E. S. 

 R., 17, p. 51) a brief account was given of cranberry diseases and the results of 



