DISEASES OF PLANTS. 965 



proportional to the amount of copper sulphate used. The quality of 

 lime affected the mixture very appreciably, the mixture containino- 

 the best lime precipitating the slowest. The proportion of lime exerted 

 the same effect as the amount of copper. Fresh, well-slaked lime 

 gave a better mixture than poorly slaked, but fresh air-slaked lime 

 was about its equal. Older air-slaked lime produced a mixture that 

 separated very rapidly. Allowing- the milk of lime to stand for two 

 days was pi-actically without effect upon the different mixtures, the 

 results with milk of lime which had been exposed to the air being 

 almost identical with freshly made. Bordeaux mixture made l)y 

 pouring the lime into the copper solution was much inferior to the 

 others. Where the copper mixture was poured into the lime and 

 where both mixtures were poured into a third vessel, the mixture was 

 about the same. Heat was found to cause a separation in the mixture 

 in proportion to the increase of temperature. 



Monilia diseases, P. Sorauer [Ztschr. Pflanzenkrank. , 10 {1900), Nos. 3-4, pp. 

 148-154; 5, pp. 274-^84, figs. ^). — In continuation of a previous article (E. S. R., 11, 

 p. 949), the author describes the diseases caused b}' Monilia on cherries, prunes, 

 hazelnuts, and upon the twigs of apple, pear, etc. Numerous inoculation experi- 

 ments are reported, in which it was found possible to transfer the fungus from the 

 apple to the hazelnut, cherry, apricot, and grape; and from a hazelnut to the apple, 

 prune, haw, and grape. In the last case the development was meager and inocula- 

 tion often failed. In the second part of the paper a description is given of the action 

 of the fimgus upon twigs of the apple, pear, etc. 



Die-back disease of apricots, E. M. Sage {Jour. Agr. and Ind., South Australia, 

 4 {1900), No. 5, pp. 4i^5-4^8, figs. '2). — An account is given of a disease of apricot trees 

 in which the limbs were slow in starting out one season and the following year began 

 to die back a distance of 1 to 3 ft. from the end, in some cases the entire limb dying. 

 The trees had been planted on rather poor soil, and the author attempted to restore 

 their vitality by the use of fertilizers. It was found that liberal applications of bone 

 superphosphate i)roduced a decided improvement in the condition of the trees. 



The olive knot, F. T. Bioletti {California Sta. Rpt. 1898, p. 178, fig. i).— In Bul- 

 letin 12G of the station (E. S. R., 10, p. 55) an account is given of the occurrence, 

 symptoms, and distribution of the olive knot in California. In the present publica- 

 tion a brief account is given of successful inoculation experiments, which proved that 

 the disease is of a contagious nature and that it is due to a specific l)acterium. 



Experiments in combating some diseases of grapes, apples, and pears, K. 

 MoHR {Ztschr. Pflanzenkrank., 10 {1900), No. 5, pp. ^70-^7^).— An account is given 

 of spraying grapes, apples, and pears for the prevention of the powdery mildew of 

 the grape and scab of apples and pears. A compound of Bordeaux mixture and sul- 

 phur, and a solution of Ijasic calcium suljiliid, were used. For the grape mildew the 

 author stated that Bordeaux mixture alone is of little value, the sulphur compounds 

 being much preferable. The results of his experiments showed the value of the 

 mixtures in which sulphur entered in different forms. 



The influence of winter on the fungus diseases of grapes, H. S('hle(;el 

 ( Weinbuuu. Weiiiltaiiilel., 1900, Xo. IS, pp. 117-118). 



Tlie grape mildew and its prevention, Steglich {Silclis. Landiv. Ztschr., 48 

 {1900), No. 18, pp. 193-195). 



Concerning the fungus which causes the black rot of grapes, A. von Jacz- 

 weski {Ztsclu-. Pfianzenkrank., 10 {1900), No. 5, pp. 257-267, figs. 5).— The author has 

 reported the results of studies on the causes of the black rot of grapes, from which 



