In this study, we analyzed the relationships between weather factors and photosystem II activity (Fv/Fm), as a measure of photochemical efficiency, in three cool-season turfgrasses commonly planted on golf courses in Jeju, South Korea: perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), and creeping bentgrass (Agrostis palustris Huds.). In all three turfgrasses, Fv/Fm was higher during late summer than during early summer. However, in late summer, Fv/Fm was significantly lower in perennial ryegrass than in the other two species. In early summer, Fv/Fm in perennial ryegrass and Kentucky bluegrass was positively correlated with mean low temperature and extreme minimum temperature, whereas, in late summer, this parameter in Kentucky bluegrass and creeping bentgrass was positively correlated with relative humidity, and in creeping bentgrass was negatively correlated with mean high temperature, mean low temperature, and extreme maximum temperature. These results indicate that raising low temperatures is favorable for perennial ryegrass and Kentucky bluegrass in early summer, whereas, in late summer, the lowering of high temperatures proves to be beneficial for creeping bentgrass, and raising relative humidity is conducive to the growth of Kentucky bluegrass and creeping bentgrass. These findings will contribute to improving the selection and management of turfgrasses on golf courses and sports fields.

Abstract
1. 서 론
2. 재료 및 방법
    2.1. 조사 장소 및 기간
    2.2. 식물재료
    2.3. 엽록소형광과 SPAD 값의 측정
    2.4. 기상자료의 수집
    2.5. 통계 분석
3. 결과 및 고찰
    3.1. 광계II 활성과 SPAD 값
    3.2. 온도요인과 광합성 효율의 상관성
    3.3. 습도, 일사량, 강우량과 광합성 효율의 상관성
4. 결 론
감사의 글
REFERENCES

• 고석찬(제주대학교 생물학과) | Koh Seok Chan (Department of Biology, Jeju National University, Jeju 63243, Korea) Corresponding author