408 MAIZE 



CHAP, it was evident that the little yellow sorrel, Oxalis corniculata, 

 x - was in part responsible for the rust epidemics in the mielie ; 

 but whether it is the only host for the aecidial stage of the 

 rust is a matter for further investigation. Strange to relate, 

 the first yEcidium recorded on Oxalis was collected in South 

 Africa as far back as 1876 by the late Prof. P. MacOwan on 

 Oxalis Bowiei and was named and described by Von Thuemen 

 as JEcidium Oxalidis. Whether this vPxidium is the same 

 fungus as that which occurs on Oxalis cymosa and on Oxalis 

 corniculata seems at present doubtful, although Arthur is of 

 opinion that they are identical. 



" My reason for regarding the ^Ecidium on Oxalis Bowiei 

 to be different from that on Oxalis corniculata, is due to the 

 fact that repeated inoculations of Oxalis Bowiei, Oxalis setosa, 

 Oxalis Smithii, and Oxalis corniculata, have only resulted in 

 the infection of the last-mentioned plant, whereas the others, 

 which are endemic to the country, have always remained 

 immune. 



" Specimens of the artificially infected Oxalis corniculata 

 leaves were submitted to Prof. P. Magnus of Berlin and the 

 /Ecidia were confirmed by him as being identical with Aicidium 

 Peyritschianum Magn., which was collected on the same species 

 of Oxalis in the Austrian Tyrol in the year 1893 " {Evans, 4). 



The brown rust has not hitherto been regarded as a 

 serious pest of the maize crop in South Africa, but Mr. Pole 

 Evans considers that before very long it will have to be 

 reckoned with as one of its most serious enemies; "the more 

 that maize is grown, the more the disease will manifest itself". 

 He (3) does not suggest remedial measures other than " paying 

 all possible care and attention to the cultivation of rust- 

 resistant varieties, while those which show tendency to rust 

 should be discontinued at all costs, as they are to a large extent 

 responsible for the rapid spread of the disease," but he hopes 

 " shortly to publish full details regarding the life-history of this 

 rust". 



362. Red Rust of Maize, — This is the fungus Puccinia 

 purpurea Cooke ; as far as observations in South Africa go it 

 is at present confined to the Province of Natal. It is readily 

 distinguished from the brown rust of maize by the discolora- 

 tion produced in the leaf by the uredo-pustules, which are 

 distinctly red, to blood-red {Evans, a). 



