170 EXPERIMENT STATION RECORD. 



growth checked. It is known thai the organism survives in the soil fur at least 2 

 years and that beets and mangels are subject to attacks of the same organism, conse- 

 quently, in rotation these crops should be omitted. 



Rolling the tubers in sulphur and treating the infected soil with the same fungi- 

 cide have given results that fully repaid the cost of material and labor. The appli- 

 cation of quicklime, while effective, has not been as efficient as powdered sulphur. 

 < ias lime ami winter plowing have been practically useless as means of combating 

 this disease. 



Some diseases of cane specially considered in relation to the leaf-hopper 

 pest, and to the stripping of cane, R. C. L. Perkins [Hawaiian Forester and 

 Ayr., 1 [1904), No. 4, PP- 80-84)- — The relation between the pineapple disease in its 

 various forms and the injury produced by leaf-hoppers, etc., is pointed out, and notes 

 are given on other diseases of cane in which there appears to be no connection 

 between the disease and insect attacks. 



Onion blight, H. H. "Whetzel [New York Cornell Sta. Bui. 218, pp. 139-161, figs. 

 17). — In 1903 a serious outbreak of onion blight or mildew caused by Peronospora 

 schlt ideniana was reported. The disease seemed to spread from definite spots in the 

 onion field where first noticed, and later investigations showed that it was rather 

 generally distributed throughout the principal onion-growing districts of the State. 

 The attack was so severe as to materially reduce the crop, and inquiries brought out 

 the fact that it was prevalent the previous year and probably other years, but the 

 fungus made its appearance so late in the season as to do comparatively little injury. 



The present report is a preliminary one, designed to interest onion growers and 

 gardeners in checking the disease, and is to be followed by investigations of the 

 nature and control of this disease. For the prevention of the disease it is recom- 

 mended that the plants be sprayed with Bordeaux mixture, attention paid to the 

 location and drainage of the land, and raking and burning of tops after harvesting, 

 and although there is considered little danger of distributing the disease through the 

 seed the author recommends soaking them for 30 minutes or more in a 0.5 per cent 

 solution of formaldehyde before sowing. 



A technical account is given of the fungus causing the blight, and brief notes are 

 given of a secondary fungus (Macrosporium parasitiewm), which blackens the bulbs 

 and is associated with the blight. Notes are also given on injury by onion maggot, 

 onion thrips, and a disease known as white tips, the nature of which is not definitely 

 known. 



A new eggplant fungus, C. < >. Smith (Jour. Mycol,, 10 (1904), No. 71, pp. 98, 99, 

 figs. 6). — In the autumn of 1903 the author observed a disease of eggplant which 

 proved to be new to Delaware. At first it was thought to be caused by the spot fun- 

 gus (Phyllosticta hortorum ), but subsequent investigations showed that this was not the 

 case. The fungus producing the disease agrees so closely with Ascochyta lycopersici 

 that in the absence of authentic specimens it has been referred to that species. 



Inoculation experiments with pure cultures have demonstrated that this fungus is 

 parasitic on eggplant, tomato, horse nettle, and Jamestown weed. A technical 

 description of the organism is given. 



Vitality of Pseudomonas campestris on cabbage seed, H. A. Harding and 

 F. C. Stewart (Science, n. ser., 20 (1904), No. 4->7, pp. 55, 56). — Investigations are 

 reported in which it is stated that the organism causing black rot of cabbage may live 

 on dry cabbage seed for at least 10 months. 



In the experiment reported cabbage seed was wet with water into which a culture 

 of P. campestris had been thoroughly stirred. The seed was then dried and stored in 

 test tubes, some of which were plugged with cotton and others were plugged with 

 cotton and then sealed with paraffin. Once a month the seeds were tested for the 

 presence of living germs, and although the experiment was unfinished at the end of 

 10 months living germs were found both in the paraffined and unparaffined tubes, 



