CHAPTER X. 



DISEASES AND PESTS OF THE MAIZE CROP. 



Every crop has its pest. 



— Proverb. 



Overgrown, through long years of peace and neglect, with grass and alien 

 weeds. 



— Hawthorne. 



Plant Diseases. 



SPEAKING broadly, maize in South Africa appears to be less chap. 

 seriously affected by disease than most crops ; though the x - 

 maize plant is the host of certain rusts and smuts, they 

 do not appear — at present, at least — to materially affect the 

 yield. The principal diseases are: brown rust {Puccinia 

 Maydis Bereng), red rust {Puccinia purpurea Cooke), maize 

 smut or " brand " {Sorosporium reilianum (Ktihn) McAlp.), 

 dry-rot {Diplodia Zece (Schw.) Lev.), and leaf scorch {Hel- 

 inintlwsporiuiu turcicum Pass. J. 



361. Brown Rust of Maize. — This is a fungus, Puccinia 

 Maydis Bereng (Pig. 156), which usually appears when the 

 maize plants are in flower, or a little earlier. At first a few 

 isolated brown pustules are to be seen on the leaves and, later, 

 the leaves and sheaths are gradually covered with pustular 

 areas, which bear both the uredo- and teleuto-spores. Accord- 

 ing to the Plant Pathologist of the Department of Agriculture, 

 Union of South Africa, abundant teleutospore masses are 

 formed on the leaves, sheaths, and stalks towards the close 

 of the rust season, and the incubation period of its uredo-stage 

 is of considerably shorter duration as compared with that 

 of other cereal rusts, viz. five and six days instead of about 

 ten days ; this must aid in the rapid spread of the disease. 

 The parasite is widely distributed, occurring practically wher- 



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