106 CHAPTER VI, 



by poisoned bait scattered over the infested land; the stalk- 

 borer by growing catch-crops early in the season, winter 

 ploughing, and by the American plan of harvesting; and the 

 granary pests by fumigation with carbon bisulphide. 



(i2) Other Animals. — There are a number of animals 

 which cause damage to this crop, such as : Baboons, Cape 

 monkey, ground squin-els, porcupines ; crows, springhares, 

 partridges and pheasants. Systematic shooting and poisoning 

 aj-e fairly effective measures in dealing with these. 



(3) Diseases. — The most common diseases are : Brown 

 Rust of Maize (Puccinia maydis), alternate host Oxalis 

 corniculata. Although bad in certain seasons and in limited 

 localities, it has not proved a serious menace so far. Certain 

 varieties are more resistant than others, e.g., vigorous growing 

 varieties, like Potchefstroom Pearl, etc. Maize Smut or Brand 

 (Sorosporium reilianum), common in all parts of the world 

 where maize is grown. Prevention should be aimed at. Use 

 new seed from smut-free fields, and where possible burn all 

 affected maize early, and avoid using fresh manure from 

 animals fed with affected plants. Ear-rot of Maize (Diplodea 

 zeae), very common in South Africa, and is the source of a 

 disease causing paralysis in cattle. 



The American plan of harvesting should be followed to 

 guard against this disease, which is most common on fallen 

 cobs. Rotate crops, and where possible burn old affected 

 plants or bury very deeply by ploughing. 



Leaf Scorch or Maize Blight (Helminthosporium turci- 

 cum) occurs, but is of little economic importance. 



Weeds. — Perennial. — Cynodon dactylon (Quick), Cy- 

 perus rotundus, or escultentus (Vintjes), Convolvulus arvensis 

 (Bindweed), and Rumex acetosella (Sheeps' Sorrel). 



Annuals. — Amaranthus paniculatus (Pigweed), Bidens 

 pilosa and leucantha (Black-jack), the grasses Chloris virgata 

 and Panicum la3vifolium. Datura stramonium and tatula 

 (Stinkblaar), Physalis minima (Wild Gooseberry), Tagetes 

 minuta (Khaki-bos). 



Parasitic. — Striga lutea (Witchwecd or Rooibloom) is con- 

 trolled by growing a hos.t plant such as Sudan or teff grasses, 

 which can be harvested when the parasite is in bloom ; after 

 this the land is ploughed before the weed has a chance to seed. 

 This is probably one of the worst weed pests of the maize crop 

 in the Union, 



