CLIMATIC REQUIREMENTS 



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for on the high plateau of the Transvaal, at 5,000 to 6,000 feet chap. 

 elevation, the season is usually too short for late-maturing IL 

 breeds of maize, and almost every year a proportion of the 

 crop of medium-late sorts — such as Hickory King — is seriously 

 injured. This is due to the sudden though temporary fall of 

 temperature which frequently precedes the advent of the real 

 winter by two or three weeks, when the frost is often suffi- 

 ciently severe to injure the unripe grain. A remedy can be 

 found in autumn tillage and earlier planting to bring the crop 

 sufficiently forward to miss the frost ; but too early planting 

 often results in loss from cut-worms. When the South 

 African maize crop is once ripe, frost does not injure it, and it 

 can be left standing in the field to dry out, through the winter, 

 without fear of injury. As there is considerable difference in 

 the time required for the maturity of different breeds, the 

 earlier-maturing sorts should be used at the higher altitudes ; 

 some of these yield rather less than the longer-growing sorts, 

 and farmers are reluctant to drop the latter, even though they 

 entail greater risk. 



At lower altitudes, as along the coast of Natal, the Ubombo 

 Range in Swaziland, and the adjacent portion of the Transvaal, 

 the season between frosts is so long that two successive crops 

 of maize-grain can be matured in the same year. 



Temperature appears to have no direct effect upon yield 

 per acre, but it does influence the maturing of the grain, and 

 often in this way affects the yield of marketable grain, especi- 

 ally at higher altitudes and in the southernmost of the maize- 

 growing districts of South Africa. 



In Argentina frost is apt to cause a considerable loss of crop. 



Where the crop has been thrown late, from one cause or 

 another, the stalks may be cut just before the time when frosts 

 are expected, and " stooked " in the field. This does not 

 interfere with the proper filling out and ripening of the grain 

 if the crop is not cut before the grain has begun to harden. 

 Not only does this method enable farmers on the High-veld 

 to save their crop from injury by frost, but it results in a saving 

 of some 50 per cent of the feeding value of the " stover". At 

 the suggestion of the writer this method was tried by several 

 High-veld farmers in the Transvaal, during the very backward 

 season of 1909-10, with excellent results. 



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