The effect of temperature on tillering of grain sorghum seedlings

Abstract

Seedlings of the Combine Kafir variety of grain sorghum (Sorghum vulgare Pers.) were grown under various photoperiods and at a range of temperatures in the phytotron at Canberra. Buds did not expand into tillers when the average daily temperature exceeded a threshold about 18°C. Plants were stimulated to tiller if they spent a period below this threshold at the 4 or 6 leaf stage, though normally grown at a temperature higher than 18°C. Genetic, physiological, and agronomic implications are discussed.