Abstract
Efforts were made to highlight the role of growth parameters, yield and yield components with special reference to raceme order simultaneously, to provide the comprehensive system of soybean cultivar classification. Soybean cultivar classification of 11 cultivars governed by the cluster analysis based on the above mentioned characters revealed three clusters i. e. A, B and C. Close observation of the analysis showed that the cluster A contains further two sub clusters 1 and 2. Sub cluster 1 occupies Kitamijiro, Enrei and Tatinagaha, while sub cluster 2 occupies Koganesiro and Harosoy cultivars. Similarly sub cluster 3 in cluster B consists of Tatisuzunari and Bragg, while sub cluster 4 consists of Tamahomare, Tanbaguro and Hukuyutaka. Cluster C consists of only one cultivar Touzan 69. Growth characters i. e. growth duration, first flowering, no. of phytomers, stem length and stem weight are mainly responsible to separate the clusters A and B. Yield components i. e. no. of pods, 100 seed weight and weight of perfect seed (seed yield) clearly separate the sub clusters 1, 2 and 3, 4 within the clusters A and B respectively. Low order racemes play a pivotal role for cultivar classification by separating not only the clusters A, B and C but also by differentiating the sub clusters within the clusters. Secondary raceme with compound leaf opens a new chapter by separating all the clusters from each other along with the sub clusters falling in them respectively. The correlation studies revealed that soybean yield under low planting density conditions depends on 100 seed weight and not on the total no. of pods/plant, and also, that yield increase with longer growth duration among clusters is mainly dependent on the no. of pods and seed weight on 2nd order raceme with compound leaf.
