Harvest Date and Cultivar Effects on Forage Yield and Quality of Fall Sown Oat

수확시기와 품종이 추파연맥의 사초수량 및 사료가치에 미치는 영향

This experiment was carried out to determine harvest date and cultivar effects on the agronomic characteristics, forage yield, and quality of fall sown oat (Avena sativa L.) at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon from August to November 1993. The experiment was arranged in a split plot design with three replications. The main plots were consisted of the harvesting dates, suchas early (11 October), mid(21 October), and late(1 November), the subplots were consisted of different maturities of oat cultivars, such as 'West', 'Cayuse' and 'Magnum'. The first heading date of an early maturing culivar, West, was observed on 10 October, and the heading increased up to 30% at the late harvesting date. The average dry matter (DM) content of oat cultivars increased significantly from 12.8 to 15.9% as the growing stage progressed(p<0.01). The average dry matter percentage of West, Cayuse, and Magnum was 15.4, 13.4, and 13.5%, respectively. The crude protein (CP) content of oat cultivars decreased significantly from 20.1 to 13.3% as the harvesting date was delayed(p<0.01), and the CP contents of midseason and late maturing cultivars, Cayuse and Magnum, respectively, were significantly higher than that of an early maturing cultivar West (p<0.01). The mid harvesting date showed the highest acid detergent fiber(ADF) and neutral detergent fiber (NDF) contents than the other harvesting dates, and an early maturing cultivar West had higher ADF and NDF contents than the midseason and late maturing cultivars, Cayuse and Magnum, respectively. The in vitro dry matter digestibility(IVDMD) of oat cultivar West decreased as the harvesting date was delayed, but that of Cayuse and Magnum decreased only by the mid harvesting date. Cayuse and Magnum showed 3~4% higher digestibility than West. The correlation coefficient between IVDMD and ADF content was -0.86. The average dry matter yield of oat cultivars increased from 2,901 to 5,901kg/ha as the harvesting date was delayed(p<0.01), but no significant difference was found among oat cultivars. The corrdelation coefficient between DM yield and gorwing degree days(GDD) was +0.86. The results of this study indicate that a delay in harvesting date would be recommendable for the increase of dry matter yield when fall-sown oat is grown. Especially, the DM yield of the midseason and late maturing cultivars, Cayuse and Magnum, respectively, can be increased without much change of forage quality although the harvesting date are delayed.

본 시험은 수확시기 및 품종이 추파 인맥(Avena sativa L.)의 생육특성, 사초수량 및 사료가치에 어떤 영향을 미치는가를 알아보기 위하여 1993년 8월 26일부터 11월 1일까지 서울대학교 농업생명과학대학 부속실험목장의 사초시험포장에서 실시되었으며, 수확시기로서 조기(10월 11일), 중기(10월 21일) 및 만기(11월 1일)를 주구로 하고, 품종('west', 'Cayuse' 및 'Magnum')을 세구로 하는 분할구 시험법으로 3반복 설계배치 하였다. West 품종만이 10월 10일에 첫 출수를 하였으며, 만기수확시기에는 30%의 출수율을 보였다. 건물 함량은 수확시기가 늦어짐에 따라서 12,8%에서 15.9%로 증가하였으며(p<0.01), West, Cayuse 및 Magnum 품종이 각각 15.4, 13.4 및 13.5%의 건물률을 나타내었다. 조단백질 함량은 수확시기가 늦어짐에 따라서 20.1%에서 13.3%로 감소하였으며(P<0.01), 중생종과 만생종인 Cayuse와 Magnum이 조생종인 West보다 2% 더 높은 조단백질 함량을 나타내었다(p<0.01). ADF와 NDF 함량은 중기수확기에 가장 높았으며, 조생종인 West가 중생종과 만생종인 Cayuse나 Magnum에 비해서 더 높은 ADF, NDF 함량을 나타내었다. West의 in vitro 건물소화율은 수확시기가 늦어짐에 따라서 감소하였으며, Cayuse와 Magnum은 중기수확기까지만 감소하였다. Cayue와 Magnum 품종이 West에 비해서 3~4% 더 높은 in vitro 건물소화율을 나타내었다. in vitro 소화율과 ADF 함량간에는 -0.86의 높은 부(負)의 상관관계를 보여주었다. 매수확시기별 ha당 평균 건물수량은 2,901kg에서 5,901kg로 증가하였으며(p<0.01), 품종간의 유의성은 없었다(p<0.05). 건물수량과 유효적산온도(GDD)간의 상관관계는 +0.86으로 높은 상관관계를 나타내었다. 이상의 연구 결과를 종합할 때 추파연맥을 재배시 건물수량의 증수를 위해서 수확시기를 늦추는 것이 바람직하다고 생각된다. 특히 중생종과 만생종인 Cayuse와 Magnum은 수확시기를 늦추어도 사료가치의 큰 변화없이 건물수량 증수가 가능할 것이다.