Effects of time of nitrogen application on the yield and characteristics of the seed produced by Demeter fescue (Festuca arundinacea)

Abstract

Ammonium nitrate, applied in winter and in spring (at head emergence) increased the seed yield of a commercial crop of Demeter fescue (Festuca arundinacea) by up to 54 per cent. The nitrogen treatments each involved a total of 90 lb nitrogen an acre, which was divided differently between the two times of application. The early nitrogen applications increased the number of fertile tillers, but not the yield per tiller, whereas late applications increased only the yield per tiller. The germination percentage of the seed was affected only transiently by nitrogen treatments, but seed size was increased by the late nitrogen application. Thus the number of viable seeds per unit weight of sample was reduced by late nitrogen. The greatest yield of viable seeds was produced by a combination of 60 lb nitrogen in early August and 30 lb nitrogen in late September at heading.