Evaluation of Characteristics of the Latest Tetraploid, Medium-maturing Italian Ryegrass (Lolium multiflorum) Cultivars in Cold Climates in Japan

Abstract

Japanese nursery companies recently marketed three medium-maturing Italian ryegrass cultivars. ‘Tachisakae’ and ‘Yukitsuyoshi’ were sold as snow-endurant cultivars; ‘Fūjin’ was sold as a lodging-resistant cultivar. We investigated the yield performance, lodging-resistance, and snow-endurance of these new cultivars in cold climates, including an old snow-endurant cultivar ‘Nagahahikari’ and an old lodging-resistant cultivar ‘Hitachihikari.’ All tested cultivars showed high yields. The two latest snow-endurant cultivars, ‘Tachisakae’ and ‘Yukitsuyoshi’, are therefore suitable for cold climates. In highland areas with over 100 days of snow cover, ‘Yukitsuyoshi’ particularly demonstrated equally good snow-endurance as that of ‘Nagahahikari’. However, ‘Yukitsuyoshi’ and ‘Nagahahikari’ were lodging in early heading stage, whereas ‘Tachisakae’ showed slightly better lodging-resistance than ‘Yukitsuyoshi’ and ‘Nagahahikari’. It is thus desirable that snow-endurant cultivars should acquire the same degree of lodging resistance as the ‘Fūjin’ and ‘Hitachihikari’ cultivars.