Time of flower buds initiation of Zoysia japonica and Z. matrella

Abstract

Although Z, japonica and Z, matrella are short day plants, japonica and one group of matrella flower once a year (spring to early summer), but the other group of matrella flowers twice a year (fall and spring) . Core samples of japonica and matrella cv. Koraishiba were taken from the field at ten days interval and transfered into the growth room controlled at 25 ± 1.5°C and 16 hr daylength. Flowering and vegetative growth were investigated. And also the apexes of upright stems were collected from plants in the field for the histological invest lgat ions. We observed that the flower buds of japonica and both groups of matrella were initiated during early summer to late fall, and deduced that the strain induced during late summer to late fall produced inflorescences twice a year, but that those induced during middle to late fall only in spring. This seemed to result from the difference in the sensitivity for short daylength and temperature.