Effects of closing date on seeding and hardseededness of balansa, gland, Persian and arrowleaf clovers on East Coast dryland

Abstract

Four annual clovers (Arrowleaf (Trifolium versiculosum), balansa (T. michelianum), Persian (T. resupinatum) and gland (T. glanduliferum)) were sown on five East Coast dryland farms and one moist Taranaki site. Hardseededness was measured at all sites and seed production and hardseededness was measured at three sites following different closing dates. There were no differences in seed size for any species between sites or closing dates. High levels of seed (500-700 kg/ha) were set by balansa and arrowleaf clovers after an early closing date (early September). Flowering and seed production decreased with later closings. Gland clover was the earliest to flower and with Persian clover was very susceptible to early grazing. Gland clover produced virtually no seed as flowers had already been grazed prior to the first closing. Arrowleaf clover produced very high levels (>92%) of hard seed and Persian very low levels (<1%). Lack of hardseededness led to Persian clover seed being lost to false strikes, with most seed germinating in the seed head following January and February rains. Balansa, when carefully managed, appears to be the only annual clover which regenerates in its second season in East Coast dryland conditions. Keywords: arrowleaf clover, Persian clover, balansa clover, gland clover, hard seed, seed production.