450 EXPERIMENT STATION EECOED. 



toms and remedies of diseases of tlie orchard and garden under Missouri condi- 

 tions, directions for the proper preparation and application of the various 

 standard fungicides and insecticides, a list of the different types of sprayers 

 and where they can be purchased, data as to the cost and value of spraying, 

 and a list of publications on the use of sprays. 



Apple canker (Nectria ditissima), A. Dtjcloux (Rev. Eori. iParis'l, 82 

 (1910), Nos. 21, pp. ,506-508; 22, pp. .520-52.^) .—Thf^ distribution and severity 

 of this disease in France is given, together with resistant and susceptible va- 

 rieties and their pomological characters. 



"Sooty blotch:" A new fungus disease of apples, E. S. Salmon (Gard. 

 CJiron., 3. set:, J,8 (1910), A'o. 1251, p. U3, figs. 2).— Attention is called to the 

 appearance in England for the first time of the sooty blotch (Phyllachora 

 pomigcna) on certain varieties of apples, where it spreads in storage, causing 

 considerable damage to the fruit. 



The control of Fusicladium, E. Voges (Ztschr. PflanzenJcrank., 20 (1910), 

 No. 7, pp. 3S.5-393; rev. in Gard. Chron., 3. ser., ^8 (1910), No. 1250, p. J,32).— 

 In a general discussion of the means of combating the apple scab (F. dendri- 

 iicum) it is claimed that the chief danger of reinfection in the spring lies in 

 the hibemation of the fungus in the young shoots. Winter spraying, however, 

 is of little value as the fungicide is unable to reach the bulk of the mycelium in 

 the infected shoots. Spring spraying has proved to be the most efficient means 

 of controlling this disease. 



The development of Gnomonia erythrostoma, the cause of cherry leaf 

 scorch disease, F. T. Brooks (Ahs. in Proc. Cambridge Phil. 8oc., 15 (1910), 

 No. 6, pp. 53'/, 535). — The present investigation concerns an examination of the 

 life history of the fungus from the cytological standpoint. The author sum- 

 marizes the life history of this pyrenomycete, stating that infection of the 

 foliage occurs in the early summer by means of the ascospores. Spermogonia 

 and " coils " are formed in the diseased leaves, the coils ultimately developing 

 into peritheeia. During the summer the vegetative mycelium passes down the 

 leaf stalk and prevents the formation of the absciss layer. On this account the 

 diseased leaves remain on the trees throughout the winter and become the 

 source of reinfection the following season. 



The morphological and cytological characters of the fungus are described at 

 some length. 



Winterkilling of twigs, cankers, and sun scald of peach trees, F. M. 

 Rolfs (Missouri Fruit Sta. Bui. 17, p. 101, pis. 13). — This bulletin deals with 

 a diseased condition of peach trees, often designated as winterkilling of the 

 twigs, cankers of the limbs, and sun scald of the limbs and trunks. The re- 

 sults are also given of cultures of VaJsa Icucostoma on artificial media and of 

 inoculation experiments with this fungus on living wood of various species of 

 the AmygdalaceiB. The hyph^e of this fungus were usually found associated 

 with the diseased condition described, especially when the trees had been 

 weakened by winter injuries or from other causes. 



Infections on the limbs and trunks of normal trees often produce cankerous 

 wounds, while on trees weakened from any cause, especially when the root 

 system is invaded by one of the root rot organisms, sun scald areas may de- 

 velop. The perithecial stroraata form abundantly on the limbs and trunks of 

 the trees, rarely on the twigs, while the pycnidial stromata usually develop 

 freely on the twigs and branches, but may also be found on the larger limbs 

 and trunks. The pycnidia and peritheeia usually develop in distinct stromata, 

 but occasionally mixed stromata occur. The fungus grows readily on most 

 media, but is most characteristic on the Hiss plate media. 



