Abstract
Using field grown five grass species, the regrowth after the autumn final cutting at different date, the reserve carbohydrate content of the living stubble tissue sampled six times from autumn to early spring, survival during winter and regrowth in spring were measured at the Kyushu University in Fukuoka, Japan. The final cutting at late September resulted in promotion of the carbohydrate accumulation following after the regrowth, and accordingly increased winter survival and the spring regrowth. On the contrary, the both cuttings at late October or late November, paticularly the former, severely decreased winter hardiness of all the species due to the consumption of carbohydrate reserved at the cutting date through the regrowth. The differences of winter hardiness among species were apparently attributable to the ability to accumulate carbohydrate in the stubble or the overwintering part. And ranking order for the ability of five species was dallisgrass (Dg)>makarikarigrass (Bp)>setaria (Ks)>Buffelgrass (Bg)≧green panic (Gp). The critical level of reserve carbohydrate in the stubble during winter season for overwintering in this district was assumed to be above ca. 10% as TNC or 4-5% as total sugars.
