Soo DISEASES OF CULTIVATED PLANTS 



early in the season the crop is seriously curtailed. The 

 general aspect of the diseased foliage closely resembles that 

 due to Phytophthora infestans, but the spots are more 

 sharply defined, and the fruit of the fungus is quite different 

 to that of Phytophthora. 



According to the author several forms are included in the 

 life-cycle of the fungus, Alternaria, Macrosporium, Clado- 

 sporium, and Phoma. The last-mentioned form persists on 

 the dead leaves during the winter, and starts the disease the 

 following season. 



Spots at first minute, blackish-brown, then expanding, and 

 frequently occupying the entire leaf surface, at first angularly 

 circular and sharply defined ; sterile hyphae endogenous, 

 filiform, flexuous, septate, branches pallid, becoming super- 

 ficial and creeping, and producing here and there cylindrical, 

 simple or sparingly branched, truncate, dusky conidiophores. 

 Conidia very variable, typically obclavate, acrogenous, some- 

 times in short chains, 4-8-septate, one or other of the cells 

 with a vertical septum, dusky, size variable, 20-50x8-16 p, 

 apex sometimes cuspidate and paler. 



Spraying with half strength Bordeaux mixture is said to 

 check the disease if applied on its first appearance. Diseased 

 tops should be burned, as the Phoma present would continue 

 the disease another season. 



Vanha, J., Mitteil. LandesL-Versuchst. fur Pflanzenkr., 

 Brunn, n., 1904. 



Sporodesmium brassicae (Massee) is reported as causing 

 considerable injury to Brassica campestris (L.), var. Sarson 

 (Prain), at Tehroot, in the Bengal Presidency. The leaves, 

 and more especially the pods are attacked, the fungus form- 

 ing cloudy, olive - green patches that soon kill the part 

 attacked. 



Spots indeterminate, olive grey or green ; conidia obclavate, 

 pale brown, septate, becoming muriform, 160-200X25-35 p. 

 Conidiophores fasciculate, short, stout. 



Massee, Kew Bulletin, 1901, p. 153. 



ALTERNAEIA (NEES.) 



Hyphae fasciculate, somewhat erect, almost simple, short ; 

 conidia clavate, muriformly septate, produced in chains, but 

 soon separating, coloured. 



