Lengthening Versus Shortening Dark Periods and Blossoming in Sugar Cane as Affected by Temperature

Abstract

Sugarcane, an intermediate day plant, clearly received a stronger stimulus to flower during lengthening nights than during shortening nights. Flowering was vigorous under warm, lengthening nights (21[degree]) but less so under cool, lengthening nights (16-17[degree]). Warm or cool shortening nights either failed to induce flowering altogether or reduced it substantially. Under the warmer nights the inductive dark period was 10 hr 57 min to 11 hr 26 min whether the nights were lengthening or shortening. Under cooler conditions, it was longer by 20 min tonearly 2 hr.