DISEASES OF PLANTS. 147 



although D. maijdis was prevaleut in some cases. This latter species has been 

 recently described as being injurious in Illinois (E. S. K.. 20, p. 153). 



Experiments upon the effect of formalin upon the g'ermination of oats, 

 F. L. STi:vK?fs (Xortli ('(ii-oUiki »S'/(/. Npt. t'J08, pp. SO-oii). — Experiments were 

 conducted to determine the effect of different strengths of formalin, the time 

 of soaking, the effect of quality of seed grain, etc. The solutions used varied 

 from 1 oz. of formalin to i g;il. of water to 1 oz. to 3 gal. and the time of 

 treating from 2 to 24 hours, and a number of varieties of oats were included 

 in the testi^ 



The greater strength solutions were decidedly injurious, but there was little 

 difference where the dilution was 1 oz. to 1 gal. or 1 oz. to 3 gal. Marked 

 differences 'n varieties were noted in their resistance to the injurious effect of 

 formalin, and in experiments in which the. effect of the quality of the seed on 

 resistance to formalin was tested it was found that the better the quality the 

 less the injury due to the treatment. Where seed was treated with I oz. of 

 formalin to 1 gal. of water, the loss of germinating power was very slight with 

 good seeds and somewhat more with the medium grade, but the treatment was 

 quite destructive to the poorer seed. This is held to be a valuable elimination, 

 and is of benefit in removing the poorer seed to the betterment of the sowing. 



The influence of Bordeaux mixture on the assimilation of potato plants, 

 O. KiRCHNEK (Ztscln: Pflunzenkrank., IS (1908), No. 2, pp. 65-81).— A review 

 is given of a considerable number of experiments of others that were held to 

 indicate larger yields due to spraying, the i-esults being attributed to a stimu- 

 laling effect of Bordeaux mixture and to its having proloiiged the growing 

 season of the plants. The author then describes his own experiments in spray- 

 ing potatoes, as carried out during 3 seasons. 



The plats were so situated as to be partially shaded. The first year there 

 was but little difference in favor of or against the spraying, and no I'hytoph- 

 thora was observed on the plants of one series while there was a very slight 

 attack on the untreated plants in the other. In 1905 more favorable returns for 

 spi'aying were obtained. In 1907 potatoes v/ere again planted where the experi- 

 nient of 1904 had been conducted and the plants sprayed 4 times with a 2 per 

 cent Bordeaux mixture. The yields and percentages of starch were decidedly 

 in favor of the unsprayed plats in this experiment. If the yield of the un- 

 sprayed plats is represented by 100, the average of the sprayed plats would be 

 69.4 per cent as to tul>ers, and 68.4 per cent as to starch. 



The summer of 1907 was very cold and cloudy, and it is thought that the 

 presence of Bordeaux mixture on the leaves impaired their assimilatory 

 activity. Whether the same results would be obtained during a bright warm 

 season is thought doubtful, and further investigations are required to determine 

 this point. 



Diseases of sugar beets, O. Fallada (Ostcrr. Ungar. Ztsclir. Zuckcrindus. u. 

 Laiuhr.. 38 (1909). Xo. 1. pp. 11-11). — A brief account is given of some of the 

 more common diseases to which the sugar beet is subject, among them the root 

 I'ot due to Phomn hrhr. dry rot, beet scab, bacteriosis of beets, the root I'ot 

 caused by Rlnz'xtonia riolnccn, club root due to Mii-romnnax hciw, and various 

 leaf diseases, including those caused by Ccrcosporo hcticola, Spondcstiiiinii 

 piifrrfdcirns. Ramiilaria l>cfa, and the curly top disease. 



Boot diseases of sugar cane, F. A. Stockdale (Wci^t Indian HiiL, 9 (1908), 

 No. 2, PP.J03-116). — A description is given of the root disease caused by Mar- 

 asmin-s Kacchari. with suggestions for its control. The means recommended in- 

 cliide the use of fungicid(-s for the disinfection of cane cutting.s, rotation, and 

 tlie elimination of rattoon crops. 



