Abstract
The objective of this experiment was to determine agronomic characteristics, and forge yield and quality responses of rye variety to location and year for a double-cropping system in South Korea. Five forage rye varieties ('Koolgrazer', 'Jlee select', '9909', 'Homill22', 'Danko') were evaluated for forage quality and yields during the two growing years (the First year; 2001-2002, and the Second year; 2002-2003) at two locations (the central and southern zone). The heading date of rye in the central zone (Cheonan) was 15 April, and that of the southern zone (Daegu) was 10 April. The heading dates of 'Koolgrazer', 'Jlee select' and '9909' were earlier than those of the others. Although the five varieties had resistance to foliar diseases and insects, these had less lodging resistance. Dry matter (DM) content, DM and total digestible nutrients (TDN) yields had significant differences among rye varieties. DM and TDN yields of the rye varieties at the second year were higher than the first year in the central zone. In the southern zone, DM and TDN yields at the first year were lower than the second year. 'Jlee select' and '9909' had higher DM and TDN yields than the other varieties in both location and year except the first year of the central zone (p<0.001). The crude protein (CP) contents of rye grown in Cheonan were higher than Daegu. The CP content of 'Danko' variety was highest among tested varieties. The acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents were greater for the varieties grown in Cheonan and in the second year. The ADF and NDF contents of 'Danko' were lowest, while 'Danko' in TDN and relative feed value (RFV) was highest among rye varieties. Our study showed that there are differences in forage production and quality from location to location, year to year and variety to variety. Therefore, forage quality and forage production are an important factor for screening forage rye varieties. Early maturing varieties should be recommended as high-yielding forage in a double-cropping system because their production of forage was greatest early in the season.