High temperature during August plantings of sweet potato [Ipomoea batatas (L.) Lam.] reduced the number of storage roots/plant, increased top weight, and gave low yield. November planting, when the temperature was relatively low, had no effect on root formation but resulted in small roots. Yields were related to the accumulated temperature of the first 60 days after planting (DAP) and the relationship was quadratic. Regression analysis revealed that the highest yield (15.3 t·ha–1) in 1981–82 was obtained when the mean daily temperature of the first 60 DAP was 22.4°C. Analogous data for 1983–84 were 17.7 t·ha–1 and 23.1°.
Associate Crop Management Specialist.
Senior Research Assistant.
Received for publication 13 May 1987. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.