Cultivar Differences Among Barley Plants Grown with Different Nutrient Treatments¹

Abstract

Even though cultivar purity determinations of spring barley (Hordeum vulgare L.) can often be made using characteristics of grain or small seedlings, many cultivars are so similar that separation based on such characteristics is not possible. For this reason experiments were conducted to find additional plant characteristics useful for cultivar determinations. Seeds were planted in sand and plants were supplied with a complete nutrient solution or with a solution lacking nitrogen (—N) or phosphorus (—P) and were grown with continuous light. Because seedlings became chlorotic when they were grown without nitrogen or without phosphorus, the complete solution was used on the —N flats after the 14th day and on the —P flats after the 19th day. This permitted continued growth so observations could be made on internode length and tiller number. Five weeks after planting, cultivars differed significantly in length of internodes above first, second, third, fourth, and fifth leaf nodes. Length of first and second leaf internodes was affected greatly by nutrient treatments and cultivars differed markedly. Cultivars also differed significantly in tiller number per plant but not in stem diameter. Internode length and tiller number of plants grown with special nutrient treatments can be useful along with other characteristics in distinguishing spring barley cultivars.