Day-Length Control of Inflorescence Initiation in the Grass Rottboellia Exaltata L.F.

R. exaltata is a strict short·day plant with a critical photoperiod of about 13 hr. The number of short days required for inflorescence initiation varies with age, being 6 with plants 5 weeks old. Exposure to additional short days increases the rate of inflorescence development. The expanding leaf is the one most sensitive to short.day induction and removal of the leaves below it accelerates inflorescence development.