DISEASES OP PLANTS. 743 



Three fungus diseases worthy of consideration, G. Kock {Verhandl. K. K. 

 Zool. Bot. Gesell. Wien, 59 {1909), Xos. 1-2, p. (^/S); 3-^, pp. (//9-57); abs. in 

 Centbl. Bakt. [etc.], 2. Abt., 25 {1909), No. 19-25, pp. 5i9, 520).— The 3 diseases 

 noted are melon mildew iPseudoperonospora cubensis), gooseberry mildew 

 {SpJurrotheca mors-uvw) , and the leaf roll disease of the potato {Fusarium sp.). 



The author discusses the life history and dissemination of the melon mildew 

 and its systematic position in the PeronosporeiTe. It was found that in Austria 

 the pumpkin bad a greater resistance to tbe disease tban the umskmelon and 

 both of these greater than the cucumber. Experiments with 7G varieties of 

 cucumbers showed that tbe susceptibility of each variety to the mildew was 

 very different, (be climbing cucumber or ghei'kin having the greatest immunity 

 as previously noted (E. S. R., 20, p. 247). For the control of the disease a 1 

 per cent Bordeaux mixture proved effective. Soil and seed disinfection are 

 also reconnnended. Tbe ai)i)lic!ition of tbe Bordeaux mixture i'e<luced the yield 

 of fruit, presumably because of a checking of tbe transpiration and assimilation 

 in the leaves and a consequent decrease in tbe quantity of fruit set. 



The gooseberry mildew is claimed to have been introduced from 3 different 

 centers of infection, Ireland, Denmark, and Russia, which accounts for the 

 prevalence througbcmt Austria of tliis fungus. It is especially destructive to 

 certain varieties of Austrian gooseberries. Spraying with a 2 per cent solution 

 of Bordeaux mixture is reconnnended. 



Tbe autbor believes tbat tbe leaf roll disease of the potato is duo to a fungus 

 parasite, aided by ulliei' fMctoi's. sucb iis weatber, cbaracter of soil, etc. 



The control of melon and cucumber blight and bean anthracnose, C. D. 

 Jarvis {Connecticut Starrs Sta. Rpt. 190S-9, pp. XXXI, XXX//).— Spraying 

 experiments have been in progress at the Connecticut Storrs Station for 6 

 years for the control of melon and cucumber bligbt {l*1asmopara cubensis). 

 The conclusions derived from the exiieriments are tbat Bordeaux mixture will 

 not completely control tbe disease, but will cbeck its develojunent sufficiently to 

 permit tbe maturing of the crop. Tbe fungicide has an injurious effect upon 

 tbe foliage and tbe flowers, and in seasons of little or no bligbt may decrease 

 tbe yield of fruit. Tbe results of the 6 years' experiments, however, show that 

 even with tbe injurious effect it has upon the plant, it pays to spray melons 

 and cucumbers with Bordeaux mixture every year as a safeguard against 

 disease. Half-strength Bordeaux mixture, 2:2: 50, was found to give as good 

 results as the full-strength mixture, and its injurious effect was less pronounced. 



A brief account is. given of spraying experiments for the control of bean 

 anthracnose. It was found that this disease can be controlled by repeated and 

 thorough sprayings, but tbe foliage must be completely covered with the mix- 

 ture from tbe first week in July to the maturing of the fruit. 



Diseases of cultivated plants in the Tropics, C. Brick {Jahresber. Ver. 

 Angew. Bot., 6 {1908), pp. 223-258, figs. 6; abs. in Centbl. BaJct. [etc.], 2. Abt., 

 25 {1909), Xo. 19-25, pp. 522, 523).— The fungi that attack cacao, coffee, India 

 rubber, and other plants, are briefly described, and remedies suggested for 

 each disease. 



Bacteria causing plant diseases, G, Kock {Monatsh. Landiv., 2 {1909), 

 p. 2-'i7; (lbs. in Cent hi. Bnlt. [etc.], 2. Abt., 25 {1909), Xo. 19-25, pp. 521, 522).— 

 The author has compiled a list of the diseases of plants known to be caused by 

 bacteria and also those that are supposed to be thus produced. It is stated that 

 no direct application of fungicide will, as a rule, control bacterial diseases, but 

 that each species demands special methods for its prevention or eradication. 



Exotic fungi, G. Massee {Roy. Bot. Gard. Kew, Bui. Misc. Inform., 1910, 

 Xo. 1, pp. 1-6, pi. 1). — The author describes as new 16 species of fungi, the 

 majority from the West Indies. Of tbis number the following may become of 



