DISEASES OF PLANTS. 259 



protoplasm of the cells to the injurious action of concentrated sap. 

 Remedies which have ])een sug-gested by numerous investigators are 

 cited by the authors, although no experiments seem to have been made 

 b}^ them in controlling tlie disease. 



Spraying for the prevention of apple scab, L. R. Jones and 

 W. A. Orton [Verinoiit iSfa. Ri)t. 1899^ j^P- lo6-lo9). — In continua- 

 tion of experiments reported in 1898 (E. S. R., 11, p. 356), a block of 

 5 trees near the middle of the orchard was experimented with, in which 

 Paris green, copper sulphate, and Bordeaux mixture containing Paris 

 green were compared, different rows of trees being sprayed a different 

 number of times. The yield from the different trees is shown, and 

 from the table the importance of early spraying and 1 or 2 applica- 

 tions of Bordeaux mixture after the blossoms have fallen is emphasized. 

 The important point brought out b}" this investigation is that an apple 

 tree which had not been sprayed in the experiments of 1897 and 1898, 

 but was sprayed during the time of this experiment, bore more scabby 

 apples than all the rest of the orchard where the trees were sprayed. 

 This would indicate the importance of spraying every season and the 

 cumulative effect to be derived from such treatment. 



The prevention of peach-leaf curl, W. A. Murrill {JVeir York 

 CornJl Sta. Bui. ISO, j,j>. J^U-JJ^, dgrns. 6').— In Bulletin 161 of this 

 station (E. S. R., 11, p. 161) the appearajtice and life history of the 

 fungus causing the loaf curl of the peach are described at some length 

 and results of experiments for its prevention are given. 



In the present bulletin 2 years' experiments are summarized, which 

 lead to the conclusion that leaf curl of the peach can be readih' con- 

 trolled when proper auQl timely treatment is given. The orchards 

 selected for the experiments represented a variet}^ of conditions of 

 soil, moisture, and exposure, and were composed of a number of varie- 

 ties of peaches, some of which were chosen on account of their well- 

 known susceptibility to the disease. The plan of the orchard and 

 outline of investigation for each of the experiments are given in detail. 



The trees were spraj^ed with different strengths of solutions of 

 Bordeaux mixture, potassium sulphid, ammoniacal copper carbonate, 

 copper sulphate, and lime. Of the substances employed as fungi- 

 cides, Bordeaux mixture proved most useful, and the treatment recom- 

 mended for peach-leaf curl, based upon these and other experiments, 

 is as follows: 



" Spray with Bordeaux consisting of 6 lbs. of copper sulphate, 4 lbs. of good quick- 

 lime, and 50 gal. of water about the first of April when the buds are beginning to 

 swell. 



' ' Spray again when the petals have fallen with Bordeaux consistmg of 2 lbs. of 

 copper sulphate, 2 lbs. of good quicklime, and 50 gal. of water. If the weather of 

 April and early May is warm and dry this second spraying may be omitted." 



