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THE FARMERS HANDBOOK. 



Maize Rust (Puccinia vmydis Bereng). 



This rust is not of great economic importance, being rarely known to give 

 rise to epidemic damage, but in selecting maize for seed purposes, badly 

 rusted samples are undesirable. The rust produces tliree kinds of spores, 

 viz. : — uredospores, teleutospores, and mesospores. 



The uredospore is primarily a spore for the rapid reproduction of the 

 species. As a rule it is produced in immense numbers ; it is provided with 

 a thin wall, having projections of some sort to act as a holdfast, and it 

 generally infests the leaf or slieath, through which it breaks in longitudinal 

 tissures. 



Rust {Puccinia maydis) on Maize Leaf. 



The teleutospores are generally formed towards the end of the active 

 vegetative period of the host plant, and are often called " winter spores," in 

 contrast with the uredo or " summer spores." They are specially adapted 

 and equipped for continuing the species over periods of drought, or damp, 

 or cold, or seasons of scarcity. 



Mesospores simply represent imperfectly developed or abortive teleuto- 

 spores. They may, however, in certain cases, perform the function of a fully 

 developed teleutospore. 



A fourth form of spore is produced when the teleutospores are germinated 

 on species of Oxalis, plants of this genus being intermediate hosts for the 

 rust. These spores (fecidiospores) are capable of reinfecting the maize 

 plant. 



Formerly the rust occurring upon sorghum was thought to be the same 

 as that occurring on maize, but the two are now regarded as distinct species. 



The prevention of rust is to be sought by the selection and cultivation of 

 the most rust-resisting plants, and by the adoption of the best agricultural 

 methods, clean cultivation, judicious rotation, and suitable manuring and 

 fallowing. 



