Abstract
From a series of studies conducted on the local maize lines at the Agr. College of the Chungnam National Univ., a few maize lines with many tillers and ears per plant were identified and tentatively named as MET. The purpose of the study was to evaluate the MET lines, which were selfed for five generations, for silage purpose under the different plant densities. A hybrid, Suwon #19 and a synthetic variety, Puyo #3${\times}$#2, were included for comparison. Plant height at harvesting times showed no significant varietal differences. However, the MET lines were very slow in early plant growth compared to the hybrid or synthetic variety, probably due to inbreeding depression of the MET lines. Total fresh weight at the harvesting times was highest in the MET 1 line. The MET 1 line was about 2,000 kgr. per 10a. higher than the hybrid at the harvesting time. The highest fresh weight was obtained when grown under the plant density of 60 ${\times}$ 20cm. Total dry weight per unit area showed the same tendency as the fresh weight. Total dry weight of MET 1 line was about 2.4 tons per 10a., which was about 10% higher than the hybrid, Suwon #19. As the fresh weight, the total dry weight was also highest in the plant density of 60 ${\times}$ 20cm. The grain yield per 10 are of MET 1 was comparable to the grain yield of the hybrid, especially in the low plant density, 60 ${\times}$ 40cm. The average number of effective tillers of MET lines were 4.5, while the mean tiller number of the hybrid or synthetic variety were none. However, the lodging was one of the problem for growing MET lines. The 100 kernel weight of MET lines was about 9 gr., while the 100 kernel weight of the hybrid or synthetic variety was about 30 grm.
다수다얼성 재래종 옥수수 (MET라 칭함)의 자식5세대인 3계통을 Siliage생산을 목적으로 상이한 재식밀도에서 대조품종인 수원 19호, 부여 ＃3 $\times$ ＃2를 공시하여 재배한 결과 그 성적은 다음과 같다. 1. 수확기의 초장에 대한 분산분석은 품종간에 유의차가 인정되지 않았으며, 특히 MET 계통은 교잡종이나 합성 품종에 비해 초기생육이 늦었는데 이는 MET계통이 재내종으로 자식열세 현상때문이라 추측된다. 재식밀도의 차이에 있어서 공시 품종의 초장은 큰 효과를 기대할 수 없었다. 2 수확기에서 총생체중은 MET 1이 교잡종보다 10a당 2000kg이 많았으며 특히, 밀식구인 60$\times$20cm에서 가장 높았다. 3. 단위 면적당 건물중 역시 생체량과 같은 경향의 증감으로 나타났으며, 10a부 MET 1의 총건물중은 2.4톤으로 수원 19호보다 10% 높았는데, 밀식구인 60$\times$ 20cm에서 그 효과가 컸다. 4. 10a당 종실수량은 MET 1 이 교잡종에 비해 소식구에서 낮았다. 5. MET계통의 평균 분얼수는 4.5개인 반면에 교잡종과 합성품종에서는 나타나지 않았다. 6. MET계통의 재배상의 가장 큰 문제로 도복율이 높았는데 MET계통의 착수고를 낮춤으로서 피해를 경감시킬 수 있을 것으로 생각되며 7. MET계통의 100입중은 9gr인 반면에 교잡종과 합성품종은 30gr정도이었다.