CHAP. 



DISEASES AND PESTS OF THE MAIZE CROP 443 



enough to harbour a crop of borers for next season. Where 

 steam-ploughing is practised, however, and the stalks are x - 

 buried 12 to 18 inches below the surface, this is fairly efficacious, 

 and in fact it seems the only practicable method where a 

 farmer has between 1,000 and 6,000 acres under maize. 



409. Early and Late Planting to avoid Stalk-borer.— 

 Early planted maize may miss the stalk-borer, but is liable 

 to destruction by the spring brood of cutworms, and if the 

 area under crop is large, the application of poisoned bait 

 may be impracticable. Late planted maize, on the other 

 hand, is in the best condition for the second brood of borers 

 y\ 405) and to provide a supply of them to pass the winter, 

 and is in danger from early frost. Moreover, as the emergence 

 of the moths lasts over a period of four to six weeks, variation 

 in time of planting with a view to avoiding the borer is of 

 doubtful utility. 



410. Trap Crops for Stalk-borer. — " A few rows of maize 

 planted very early would render good service by attracting 

 the moths so that the eggs for the first brood would be deposited 

 on these few rows. It would be an easy matter to go over 

 them, say once a week, to destroy the plants showing signs 

 of withering. An early breed of maize is preferable for this 

 purpose because it tends to grow more rapidly and so 

 augments the effects of early planting. It must be remem- 

 bered, however, that unless the trap maize is looked after 

 carefully, it is a positive clanger because it will be the means 

 of saving the eggs from the earliest moths and ensure the 

 greatest possible number of the first brood coming to maturity " 

 (A/ally, 1). Kaffir corn and sorghum appear to be more 

 attractive to the stalk-borer than the maize plant, and might, 

 therefore, prove more useful as trap crops. 



411. Ensiling and Shredding Maize as a Remedy for Stalk- 

 borer. — "For either ensilage or fodder the maize could be 

 cut some time before the second brood of larvae has matured. 

 Although no test has been made, it is difficult to see how 

 they could survive in the silo. They survive without difficulty 

 in maize cut and dried in the ordinary way for fodder but 

 they would stand little chance of escaping the shredder. In 

 case the fodder was dried without shredding, the coarse stalks 

 should be collected and burned before the middle of September, 



