A Cold-Tolerant and Early-Heading Italian Ryegrass New Variety, 'Kogreen'

This experiment was carried out to breed the cold-tolerant variety of Italian ryegrass (Lolium multiflorum Lam.) at the Grassland and Forage Crops Division, National Livestock Research Institute, RDA at Suwon, Korea, from 1999 to 2005. The new variety `Kogreen` is a diploid variety with a green leaf color and had semi-erect habit in late autumn and erect growth habit in early spring. The heading date of `Kogreen` was on May 4, and for `Florida 80` was May 2, both are considered as early-heading variety. `Kogreen` was wider by 0.7mm in flag leaf width, longer by 2 cm in flag leaf length and shorter by 1cm in plant length than the control variety, Florida 80. Stem width of `Kogreen` was similar to that of `Florida 80` and `Hwasan 101`. cold tolerance of `Kogreen` was better than that of `Florida 80`. Dry matter(DM) yield (12,884kg/ha) of `Kogreen` was 3% less than that of `Florida 80`. in vitro dry matter digestibility was 74.7% and total digestible nutrient was 65.1%, which are 3.6% and 1.5% higher than those of `Florida 80`, respectively. Acid detergent fiber and neutral detergent fiber of `Kogreen` were 30.1% and 54.1% which are 1.9% and 1.3% lower than those of `Florida 80`, respectively.