Annual bluegrass was regenerated from a segment with an inflorescence node at high rate (over 90%). And this phenomenon was observed in populations from putting green and orchard, suggesting that regeneration from a segment with an inflorescence node is reproduction style common to this weed. Regenerated plants derived from the node showed higher tolerance to heat and drought stress as compared to that of the plants derived from seeds. In conversely, the plant derived from seeds showed higher tolerance to freeze rather than the plant derived from nodes. These results indicate that segments having inflorescence nodes detached from mother plants caused by clipping may act as an important tool for canceling a summer stress as well as reproduction.

The main objective of this study is to reduce weeding costs of rural levee banks by using Zoysia japonica ‘Asagake’ to convert existing weeds. Asagake is one of the registered cultivars of Z. japonica Steud. in Japan. It quickly grows by producing with many vigor solons. ZNET (Zoysiagrass Net-planting Technique) is the advanced broad-casting sprigging method that is also developed in Japan. It consists of two cotton nets and sprigs. Sprigs are unfirmly oriented between the two cotton nets and rolled, but easy to carry into or quickly rolled-out onto planting area. We discussed the effects of with and without weed free bed soil, two sprig sizes and herbicide application on Asagake’s cover rates of one year after planting during the established period. The 5-cm-thick layer of weed seed-free, decomposed granite bed soil showed the most effective as the factor that contributed 60 to 80% on Asagake’s cover rates at one year after planting, because of the less weed competition. However, two sprig sizes (9 and 18 cm length, at the rate of 402 and 242 sprigs per square meters respectively) and herbicide application (asulam at the rate of 0.185 a.i. per square meters) had no or much less effects on Asagake’s cover rates of one year after planting.

Two types of turfgrasses, the warm-season and the cool-season, are widely used for covering the surface of athletic fields and golf courses. We investigated the microstructures of the leaf and root surfaces of Tifton419 as a warm-season grass and Kentucky bluegrass as a cool-season grass. The warm-season a grass had characteristic silica structures (silica body). They are speculated to be protectors against predators or to strengthen against mechanical stresses. While the leaves of the cool-season grass had characteristically scrobiculated micro structures in which air may be retained, we suggested that these pockets might insulate the plant from very low temperatures.