Spring Barley Responses to Nitrogen Fertilizer and Ethephon in Regions with a Short Crop Growing Season

Abstract

Abstract Aspects of intensive management practices such as high N fertilization inputs and plant growth regulator use could potentially increase cereal yields in regions with a short crop‐growing season and occasionally dry and hot weather. A field experiment was carried out for four years (1987 to 1990) at Agronomy Research Centre of McGill University, Canada to evaluate the response of spring barley ( Hordeum vulgare L.) cv. Cadette, Laurier and Leger to N rates (0, 70 and 140 kg N ha −1 ) and ethephon (2‐chloroethyl phosphonic acid) growth regulator treatment. The application of higher than conventional N level (70 kg N ha −1 ) did not increase barley yields under dry weather conditions and when the soil N resources were high. The high levels of N did increase the grain crude protein concentration by 2 to 10 g kg −1 , as did ethephon treatment. The feed quality of spring barley was improved. Ethephon treatment reduced grain yield due to a severe reduction in the number of grains spike −1 , and/or 1000‐grain weight, although the number of spikes m −2 was increased. Thus, the overall effect of ethephon treatment on yield was inconsistent and was influenced to a large extent by the prevailing weather conditions.