Influence of temperature and photoperiod on growth and yield components in oats (<i>Avena sativa</i>)

Abstract

Two oat cultivars, Clintland 60 and Garry, were grown to maturity in controlled environments under two temperature regimes with daylength held constant and under two daylengths with a constant temperature pattern. Plants were moved between environments at panicle initiation and at anthesis, dividing the growth period into three phases.Growth and development were hastened by warm temperature and by long days. Temperature treatments caused greater variation in the duration of growth phases in Garry than in Clintland 60, but Clintland 60 was affected more by daylength. Higher plant dry weights were obtained from cool temperature treatments; response to daylength was inconsistent.Grain yield was not closely associated with duration of growth phases. The effect of temperature and daylength on yield components was markedly different in the two cultivars. The greatest grain yield response in Clintland 60 resulted from cool temperature during panicle initiation to anthesis, attributable to increased fertile tiller development. Daylength had limited effect on components. In Garry the greatest yield response was from cool temperatures during anthesis to maturity, with increases in all components. Short days before anthesis increased grain size and number.Implications of observed responses relative to cultivar performance in the field are discussed.