Pilzkrankheiten der Pflanzen 
145 
31ELHUS, 1. E., The Powdery Scab of Potatoes ( Spongospora 
Solani) in Maine (Science^ N. S., 1913, 38, [25 July], 133). 
The first appearance of this disease in the United States is 
reported on June 23 at H oui ton, Maine, on Potatoes shipped fioin 
another point in the state. Eigthy-four diseased Potatoes were found in 
four barrels, representing a shipment of 500 barrels. The source of the 
disease was not known. Humphrey (Madison, Wise.). 
HARTER, L. L., Foot rot of Sweet Potatoes (Jour. Agr. Research. 
1913, 1, Nr. 3, 251—273; Pis. 23—28). 
An organism, Plenodomus destruens , previously described (Phytopath. 
3, 243—245. figs. 2, 1913) by the same author has been observed to 
cause Foot rot of Sweet Potatoes in Virginia causing losses of 10 
to 50 per cent of the crop. The disease appears as a blackened area on 
the stem near the soil line and extends upward 4 or 5 inches, girdling 
the stem and causing the leaves to wilt, turn yellow and fall off. Roots 
and vines may also be invaded. The fungus is able to survive the wintei 
in its pycnidial condition on diseased parts. The parasitism of the oiganism 
has been established by inoculation experiments both in the field and in 
the green house. Inoculation on other hosts resulted in the infection of 
Ipomoea coccinea , but I. puvpurae and I. hedevacea appear to be immune. 
The fungus is readily cultivable on artificial media at an optimum tem¬ 
perature of about 21,9 0 C. 
Among the suggestions for control are the selection of healthy 
Potatoes for seed, since it is probable that the malady is disseminated 
principally by means of the slips from diseased roots; seed disinfection in 
mercuric chloride (1:1000) is recommended to destroy spores which 
may be adhering to the surface; the seed beds should also be sterilized, 
decayed potatoes should not be thrown where they may be a souice of 
infection; crop rotation should be practised. F. A. Wolf (Auburn, Ala.). 
EDGERTON, C. W. and MORELAND, €. C„ Diseases of the Tomato 
in Louisiana (Louisiana Agr. Exp. Stat. 1913, Bui. 142, 23pp.; 2 figs.). 
This work constitutes an account of the more common maladies of 
Tomatoes in Louisiana giving the symptoms by which they may be 
differentiated and the best known methods for their control. Ten diseases 
are known to occur within the state: Tomato wilt (. Fusarium Lycopersici ), 
Early blight {Alternance Solani ); Sclerotium wilt disease {Scle¬ 
rotium Rolfsii)\ Root knot {Heterodera radicicola ), Blossom end 
rot (cause not definitely proven); Leaf mould {Cladosporium fulvuni)\ 
Anthracnose ( Gloeosporium fructigenuni ); Southern Tomato blight 
{Bacterium solanacearum ), Leaf curl (caused by a rapid change in the 
soil moisture); and Damping off {Rhizoctonia sp.). 4he first two onl) 
are productive of serious damage and are carefully considered. Tomato 
wilt is spread by the growing of the mycelium through the soil, by per¬ 
mitting old diseased material to remain in the field, by the dispersal of 
spores though the agency of the wind, animals etc., by planting seed from 
diseased plants and by planting seeds in infected seed beds. Control of 
this disease, aside from sanitation and crop rotation, gives promise of very 
satisfactory results from selection of wilt resistant plants. This phase of 
the work is still in progress. 
Mycologisches Centralblatt, Bd. IV. 
10 
