DISEASES OF PLANTS. 453 



The effect of plowing under green rye to prevent potato scab, 

 F. C. Stewart (New York state Sta. Bui. 138, pp. 629-631).— The wide- 

 spread notion that potatoes will be free from scab if grown on soil on 

 which green rye has been plowed under just before planting was inves- 

 tigated by the author. The land used for the experiment was fairly 

 uniform and in 18 ( .)6 had grown a crop of potatoes which was so scabby 

 that a large part of the crop was unmerchantable. Eye was sown on 3 

 alternating plats October 12 and was plowed under April 26, being at 

 that time about 6 in. high. Tlie plats were planted April 28 and half 

 of all the seed tubers were soaked in corrosive sublimate before planting. 

 The yield of the various plats is tabulated, and it appears that the 

 total yield as well as the proportion of those free from scab was less on 

 the plats where green rye had been turned under than on the others, 

 while the unmerchantable tubers were considerably in excess on these 

 plats. The conclusion drawn from this experiment is that the practice 

 of plowing under green rye to prevent potato scab is not to be recom- 

 mended, inasmuch as it tends to increase rather than diminish the 

 amount of scab and may also reduce the yield. The large amount 

 of scab on all the plats showed the uselessness of treating seed with 

 fungicides when they are to be planted in .soil known to be scab-infested. 



Department of bacteriology, H. II. Lamson (New Hampshire Sta. 

 Bui. 48, pp. 146, 147). — A report is given of work carried on during the 

 year, partly in continuation of work previously reported (E. S. E., 9, p. 

 763). Brief notes are given on leaf spot of apples, orange rust of 

 quinces, and blaek knot of plums and cherries. For the leaf spot, due 

 to Phyllosticta pirini, applications of Bordeaux mixture seem to have 

 had but little effect. The orange rust of quince trees was also but little 

 affected by the treatment, and the results of experiments conducted with 

 Bordeaux mixture for the prevention of black knot will not be apparent 

 until the season succeeding the application of the fungicide. 



A brief report, is made on the use of Ceres-pulver for the prevention 

 of smut of oats and barley. But little smut occurred in any of the 

 grain, but the author thinks there was slightly less where the seed was 

 treated than in the other lots. 



Experiments with potato scab in which the effects of different ferti 

 lizers were tested were continued, as well as experiments for the pre- 

 vention of early and late blight. 



An experiment was undertaken with Nitragin, but the culture was 

 too old when used and the trial was made on so small a scale that uo 

 conclusions can be drawn. 



Effects of common salt on the growth of carnations and car- 

 nation rust, F..C. Stewart (New York State Sta. Bui. 138, pp. 634- 

 636). — Some florists having advocated the use of a solution of salt in 

 the form of a fine spray on the foliage of carnations, believing that it 

 prevented the attacks of rust (Uromyces caryophyllinus) and also gave 

 the plants more vigor, the author conducted a series of experiments 

 with 50 rooted cuttings which were potted in 6 in. pots, sunk in soil 



