DISEASES OF PLANTS. 565 



Weeds as indices to soil fertility ( Farnu rs' Gaz., 56 ( 1891 ), No. 38, p. 571). — The 

 kinds and conditions of soils in England considered to he indicated hy the presence 

 of certain plants are discussed. 



Cuscuta and its destruction, Gr. Hetjzb (Jour. Agr. Prat., 2 (1897), Xo. 48, pp. 

 815, 816). 



DISEASES OF PLANTS. 



On the probable winter condition of the fungus of peach scab, 

 W. C. Sttjrgis {Connecticut State Sta. Bpt. 1896, pp. 269-271) .—The 

 author received early in March specimens of peach twigs which showed 

 evidences of a diseased condition. Microscopic examination of both 

 diseased and normal bark showed the same condition prevailing as the 

 result of fungus growth upon peach and apricot. At the time of the 

 first examination careful search failed to show any spores in connection 

 with the mycelium, but later twigs were collected showing a connec- 

 tion between the spores and mycelium. 



The author considers the evidence conclusive that the fungus caus- 

 ing the scab of peaches and other stone fruits passes the winter in a 

 sterile condition on the twigs of the previous season's growth. Thus 

 far the winter condition has not been observed on other than peach, 

 apricot, and almond trees. The occurrence of the fungus upon the 

 twigs suggests the advisability of cutting away and burning the new 

 wood while the fungus upon it is still dormant. In less severe cases 

 great benefit would probably result from 2 thorough sprayings with 

 a solution of 1 lb. of copper sulphate to 25 gal. of water applied to the 

 trees before the buds begin swelling in the spring. If the previous 

 crop of leaves or fruit has shown much scab it is recommended to 

 gather and burn all the refuse before the copper sulphate is applied. 



On the susceptibility of various root crops to potato scab and 

 the possibility of preventive treatment, W. C. Sttjrgis {Connecti- 

 cut State Sla. Bpt. 1896, pp. 263-206).— On laud that was known to be 

 thoroughly infested with the potato scab fungus experiments were made 

 with radishes, parsnips, salsify, turnips, carrots, ruta-bagas, maugel- 

 wurzels, and beets. The rows were furrowed out and solutions of lysol 

 and corrosive sublimate were applied as equally as possible from a 

 watering pot and the seed sown. The germination of the seed and the 

 growth of the plants were extremely irregular owing to the chemicals, 

 while the check rows which had been treated with water only showed 

 good growth and gave a perfect stand in every instance. 



From the results of the experiments as given it appears that beets, 

 mangel- wurzels, turnips, and ruta-bagas are susceptible to a marked 

 degree if planted in soil infested with potato scab fungus, while radishes, 

 parsnips, salsify, and carrots show little if any susceptibility to the 

 disease. It also appears that solutions of either corrosive sublimate or 

 lysol applied before seeding to soil infested with potato scab will 

 decidedly lessen the amount of scab upon root crops subject to the dis- 

 ease. It is, however, questionable whether these solutions used in 



