The Yield and Maturity Period of Potatoes (Solanum Tuberosum) at Low Latitudes

Abstract

Very definite opinions have been expressed that the potatoes of commerce are long-day plants. For example, Bald [I] writes that commercial potatoes 'produce a full crop where they receive more than 13 hours of full daylight each day. Many will produce 50 to 75 percent. Yield under short-day conditions, but never their maximum crop.' Even more emphatic statements have been made by Driver [2]: 'It has always been difficult, if not impossible, to grow potatoes in tropical countries. This is because potatoes have been bred for and become adapted to the light conditions of temperate regions and form tubers only when the daylight period reaches a certain minimum. In tropical regions, the daylight period does not exceed twelve hours, and this is insufficient to initiate tuber development.' Because short day-length is one invincible circumstance of tropical agriculture, and because the question is fundamental to a policy of potato selection for the tropics, the evidence I. for such statements as the foregoing needs dose examination. It is of course obvious at the outset to anyone aware of the East African potato-growing industry that the last part of Driver's statement does not apply to that country.