DISEASES OF PLANTS. 443 



have boen followed by a study of the belunior of oats on sandy or clayey soils 

 npon the addition of various fertllizinfr materials. 



Light clayey soils show a tendency to produce oat sickness, this increasing 

 with the proportion of sand present. Treatment with alkali is injurious, but 

 that with acid fertilizers is helpful. In the case of sandy soils, superphosphate 

 and aninioniuni snlpliate are found helpful. 



Clover and lucern leaf spot. Ivy Massee (Jour. Econ. Biol., 9 {l!)Vf), No. 2, 

 pp. 65-(n, fi(js. Jf). — A description is given of the leaf spot of clover and alfalfa 

 due to I'sciidopczha trifolii. 



In addition to species of Trifolium. the fungus occurs on a number of species 

 of Medicago and also on TrigoncUa f anion gra'c urn As preventive measures, the 

 destruction of wild host species iu the vicinity of fields is advised, and, as the 

 fungus is borne on the seed, it is suggested that the seed be treated with hydro- 

 gen peroxid. 



A fungus disease of berseem, J. Chrestian and R. Maiee {Bui. Agr. Algcric, 

 Tunisic, Maroc, 20 {IDL'f), Ko. 10, pp. 316-32.'f, figs. 6). — A description is given 

 of Rh(ib(lo.^pora alcxandrina n. sp., a fungus which has been found in xVlgeria to 

 be quite destructive of berseem or Egyptian clover {Trifolium alcrandrinuni). 



The late blight of potato, S. K. Basu {Agr. Jour. Bihar and Orl'i.^a [India], 

 1 {1913), No. 2. pp. 142-149, fig. 1). — (Jiving an account of the sudden appear- 

 ance, quick spread, and destructive effects of Phytophthora infestans, which was 

 observed at and near the Sabour Experimental Station, India, during the very 

 foggy, misty weather which prevailed about Christmas, 1912, injuring potato 

 crops in some instances from 50 to 90 jier cent, the author cites evidence of its 

 having been brought down in mycelial form with seed potatoes shipped from 

 the hills on account of seed scarcity in the plains. No other solanaceous plants 

 were attacked by this fungus, but no potato variety iu India has proved im- 

 mune to late blight, although young plants are more resistant thereto. 



Late planting is suggested, and spraying with Bordeaux mixture has appar- 

 ently helped in some cases. 



A blight-proof potato {Queensland Agr. Jour., n. ser., 2 {1914), No. 2, pp. 

 103-106). — An account is given of a productive variety of potatoes, New -Era, 

 which after about six years' trial is claimed to be totally resistant to blight and 

 also unusually resistant to frost. 



A blight and frost resisting variety of potato {Gard. Chron., 3. ser., 56 

 {191 ff), Nos. 1450, p. 250; 1452, p. i?SO).— These two notices refer to the variety 

 of blight proof potato above noted. The New Era potatoes, when tested iu the 

 British Isles, are said to have showii susceptibility to both late blight and 

 frost injury in that region. 



Potato canker, O. Appkl {Deut. Landw. Finesse, 4I {1914), No. 67, pp. 794, 

 795, pi. 1). — A description is given of black scab or canker of potato (due to 

 Chriisophlijetis cndobiotiea) which is said to have appeared iu Germany in 

 IOCS, but which is believed to be confined to a few small areas. No remedial 

 measures are offered except complete destruction by fire of all plants on 

 affected soil and the employment of such land for other crops during at least 

 five years. 



Potato scab, G. P. DAkNFXL-SMiTn (Agr. Gaz. N. S. Wales, 25 {1914), No. 

 10, pp. 809-872). — A number of causes of scab in potatoes are described, among 

 them i)hysical agencies, attacks of nematodes, and various fungi. According to 

 the author the fungi causing scab in Australia ai'e Oospora seabies, Rhizoctonia 

 solani, and Spondiilorhtdiuni atrovit-eus. Other fungi, such as Spongospora 

 .subirrranea and i^jiiichiitrium endobioticum, while producing scab of potato 

 tubers, have not yel been report<'d in (hat country. 



