This study was conducted to investigate changes in the productivity of Italian ryegrass seeds according to the timing of harvest after heading in the southern region. The Italian ryegrass variety ‘Greencall’ was sown in Jinju, Gyeongsangnam-do, in the fall of 2022. Four harvest timings were tested (30, 40, 50, and 60 days after heading), with a randomized complete block design and three replicates. Sowing in the test plots took place on October 10, 2022, and harvesting was carried out from 30 days after heading on May 18 to 60 days. The plant height was the longest (99.1 cm) in the plot harvested 30 days after heading and decreased as the harvest was delayed. No significant differences were observed among treatments in terms of lodging resistance, disease resistance, and cold resistance. However, lodging severity increased over time after heading (7∼9). Disease incidence was also higher in plots harvested 50 and 60 days after heading. The length of the spike was shortest (38.76 cm) in the plot harvested 50 days after heading, and the number of seeds per spike was the lowest (42 seeds/spike) in the plot harvested 60 days after heading. The dry matter content of seeds increased with the delay in harvest, while dry matter yield decreased, with the lowest yield observed in the plot harvested 40 days after heading (3,031 kg/ha, p<0.05). The dry matter content of seed straw was highest at 75.73% in the plot harvested 50 days after heading and dropped to 34.99% 60 days after heading due to rainfall. The dry matter productivity of the seed straw was the lowest in the plot harvested 40 days after heading. The feed value of the seed straw also decreased with delayed harvest, with an average RFV (Relative Feed Value) of 91. In conclusion, the optimal harvest timing for fall-sown Italian ryegrass intended for seed production in the southern region appears to be 30 days after heading.

ABSTRACT
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 이탈리안 라이그라스 재배
    2. 이탈리안 라이그라스의 수확
    3. 종자특성 평가
    4. 사료가치 분석
    5. 기상 상황
    6. 통계처리
Ⅲ. 결과 및 고찰
    1. 생육특성
    2. 종자특성
    3. 종자 및 짚의 생산성
    4. 채종 짚의 사료가치
Ⅳ. 요약
Ⅴ. 사사
Ⅵ. REFERENCES

• Yan Fen Li(서울대학교 국제농업기술대학원)
• Xaysana Panyavong(서울대학교 국제농업기술대학원)
• Li Li Wang(서울대학교 그린바이오과학기술연구원)
• Li Zhuang Wu(서울대학교 국제농업기술대학원)
• 유영상(서울대학교 국제농업기술대학원) | Young Sang Yu (Graduate School of International Agricultural Technology, SNU, Pyeongchang 25354, Korea)
• 김종근(서울대학교 국제농업기술대학원, 서울대학교 그린바이오과학기술연구원) | Jong Geun Kim (Graduate School of International Agricultural Technology, SNU, Pyeongchang 25354, Korea, Research Institute of Eco-friendly Livestock Science, GBST, SNU, Pyeongchang 25354, Korea) Corresponding author