DISEASES OF PLANTS. 67 



pp.4)- — The muskmelon blight, it is said, has become a serious pest, and the station is 

 planning a series of experiments for controlling the blight not only on muskmelons 

 but also on watermelons. As preliminary to a statement of the results of the experi- 

 ments, directions are given for checking the spread of the disease by the use of 

 Bordeaux mixture. 



Studies of the scab disease of carrots (Rhizoctonia violacea), J. Eriksson 

 (K. Landt. Akad. Handl. och Tidskr., 4$ {1903), No. 4, pp. 309-334).— The author 

 finds that the different varieties of carrots differ to some extent in their susceptibility 

 to Rhizoctonia. The form of the disease experimented with appeared to ha\ethe 

 faculty of infecting other plants, both wild and cultivated. This paper is essentially 

 the same as that noted in E. S. R., 15, p. 484. — f. w. woll. 



Black rot of cabbage ( Wisconsin Sta. Rpt. 1903, pp. 2~>9-2t;2,ji<js. :.').— An abstract 

 is given of a previous publication entitled, A Bacterial Rot of Cabbage and Allied 

 Plants, by H. L. Russell (E. S. R., 10, p. 155). 



Fungus diseases of fruits in Michigan, B. O. Loxgyear (Michigan Sin. Spec. 

 Jin/. .'■'*, pp. 68, figs. 42). — -This bulletin is designed as a handbook of the must com- 

 mon and destructive diseases of fruits in Michigan. It is based upon the publications 

 of this Department and bulletins of various experiment stations, with notes on the 

 author's observations. 



After briefly describing the causes of the diseases, descriptions are given of a num- 

 ber of the more common forms of parasitic and nonparasitic diseases. Directions are 

 given for the preparation of a number of the better known fungicides, and the bulletin 

 concludes with general recommendations regarding spraying. 



Pear blight, W. X. Hrrr (Utah Sta. Bui. 85, pp. 45-52).— This bulletin gives a 

 resume of the history and nature of pear blight, together with the treatment of the 

 disease which has been found most successful during the past 2 years at the Utah 

 station. The distribution and history of the pear blight, which is due to Bacillus 

 amylouorus, are traced and notes given on the kinds of trees attacked, difference in 

 resistance, and the effect of soils, manures, cultivation, irrigation, and pruning on the 

 development of the blight. 



Injury to peach foliage from spraying with Bordeaux mixture and Paris 

 green, F. W. Card and A. E. Stenk (Rliode Island Sta. Rpt. 1903, pp. 223, 224).— -The 

 results of an accidental application of Bordeaux mixture of ordinary strength to a 

 peach tree are given. The tree lost its leaves, becoming nearly defoliated, but as the 

 application was made early in the season the tree put out new leaves and by mid- 

 summer was in an apparently healthy condition. 



The other injury reported was through spraying tests made in cooperation with 

 this Department. For this purpose samples of Paris green were furnished containing 

 free arsenious oxid, varying from 2.84 to 8 per cent. The peach trees were sprayed 

 with a mixture of 1 lb. to 250 gal. of water. For a few days no injury could be 

 noted, but after 10 days the trees sprayed with the stronger mixtures lost nearly all 

 their leaves and by midsummer many of the branches were dead. Under general 

 conditions it seems unwise to spray peach trees in leaf with either Paris green con- 

 taining free arsenious oxid or with Bordeaux mixture of ordinary strength. 



A root disease in tea, J. B. Carruthers (Circs, and Agr. Jour. Roy. Hot. (hied., 

 Ceylon, 2 (1903), Xo. 6, pp. 111-122). — A description is given of the root disease of 

 tea due to the fungus Rosetliniu radiciperda. The external effects of the fungus are 

 described, as well as the results of culture experiments, the structure and life history 

 of the fungus, and its distribution in Ceylon. The author notes the conditions favor- 

 able to the spread of the disease and suggests various means ior its prevention. The 

 disease seems to be widely spread and to be increasing throughout the island. Its 

 presence is favored by decaying wood in the soil, and it finds its most successful 

 starting point from the roots of dead trees as well as in buried primings. 



For the prevention of the disease the author recommends the isolation of all 



