多數多蘗性 옥수수 硏究 Ⅱ. 多數多蘗性 옥수수의 主要作物學的 特性

Studies on the maize with multiple ears and tillers Ⅱ. Agronomic characteristics of maize(zea mays L.) with multiple ears and tillers(MET)

To investigate agronomic characterisitics of maize with multiple ears and tillers(MET), 20 inbred lines were crossed with one inbred., IK, which developed at the Chungnam National University for the multiple ears and tillers per plant. The 20 inbred lines used in the study were consisted of eight lines originated from IRI, Korea, seven lines from various parts of Korea and five lines from the U.S. For the convenience of summarizing the results, the 20 lines crossed were grouped into three(G1, G2 and G3) according to the origin of inbreds. The 20 lines crossed were planted on April 10, 1987 under two different plant densities(60cm by 30cm and 60cm by 60cm). The number of effective tillers per plant varied significantly with plant densities. The higher the plant density, the less the tiller number per plant. The highest tiller number per plant(4.5 per plant) was obtained from the cross between 1K and IRI/Woolnungdo and IK/Waesungri under plant density of 60×60cm. The ear and kernel numbers per plant, and 100 kernel weight appeared to increase between IK and IRI/Woolnungdo, IK and IRI-8 and IK and Waesungri showed higher ear and kernel number per plant than other crosses. The group 3(G3) which were the crosses between IK and U.S. inbred lines showed heavier 100 kernel weight than other G1 and G1. Fresh weight per unit area was compared between low and high plant density, and the fresh weight was heavier in higher plant density than in lower plant density. The average fresh weight of crosses between IK and IRI-4, IRI-8, IRI/Woolnungdo and Waesungri were 9 tons per 10a. The dry weight of these crosses were over 2,200kg per 10a. The average grain yield per 10a was about 700kg when the plant density was high(60×30cm). The grain yield per 10a was 520kg at the lower plant density(60×60cm). The silking dates varied with crossing group. Group 3 was about 7 days eariler than other two group in silking dates. The ear height of G3 and G1 were 136cm and 150cm, respectively. The ear height of G2 was between the ear height of G1 and G3. G1 and G3 showed higher lodging percent than G3.