Factors affecting on propagation and production of clove bean [Ipomoea muricate (L.) Jacg.]; an underutilized vegetable crop in Sri Lanka

Clove bean (Ipomoea muricata) is one of the neglected and underutilized vegetable crops available in Sri Lanka. Three experiments in the present study were conducted to find out (1) the best storage period and condition for the clove bean seeds, (2) the effect of the number of nodes and the leves on rooting of cuttings and (3) the suitable potting mixture and fertilizer type for growth and yield of clove bean. The first, second and third experiments were set up as two factor factorial completely randomized design, simple completely randomized design and two factor factorial randomized completely block design, respectively. The interaction effect between storage period and storage condition on final germination percentage and germination rate index was not significant. However, final germination percentage and germination rate index were significantly affected only by storage conditions where seeds stored under room temperature showed greater performances. The number of roots, total root length, vigour scale for roots and bud growth were not significantly different among cuttings with single or double nodes and presence or absence of full leaf or half leaf. The interaction effect between potting mixture and fertilizer type was not significant for measured parameters. However, the number of pods per vine, fresh and dry weight of edible portion and total above-ground dry biomass vary with the potting mixture and fertilizer type. The highest values were recorded in potting mixture prepared by topsoil: sand: compost, 1:1:1 and organic fertilizer treated plants. Fresh and dry weight of non-edible portion was significantly influenced by potting mixture and fertilizer type, respectively. Root dry weight and shoot to root ratio were not significantly influenced by the treatment. According to the results of the three experiments, it can be concluded that seeds of the clove bean can store for two months under room temperature without significant loss of germination. Furthermore, the number of nodes and presence or absence of leaf or half leaf did not influence the rooting of cuttings. High growth and yield of clove bean could be achieved when growing plants in the potting mixture prepared by topsoil: sand: compost 1:1:1 and supplied with organic fertilizer.