Seed germination and seedling development in Taro (Colocasia esculenta)

Abstract

Two taro (Colocasia esculenta (L.) Schott var. esculenta) cultivars from Fiji and Papua New Guinea were grown at the University of the South Pacific, Laucala Campus, Fiji to produce seeds for seed storage experiments. Gibberellic acid at a 500ppm concentration was used to induce flowering. Very few flowering shoots (inflorescence) were observed in the Fiji cultivar and all pollinations were unsuccessful. However the PNG cultivar flowered well and was used to obtain seed after hand pollination. Hand pollination was carried out to ensure seed setting in developing fruits in the inflorescence. Seeds were extracted in the laboratory after harvesting mature inflorescences. Experiments were conducted on seed moisture content, desiccation, germination, seedling development and seed storage behaviour of taro (Colocasia esculenta) seeds. Seed moisture content was determined using oven methods and air-drying. Results demonstrated that taro seeds have a moisture content of 12-13% after air-drying for three to four weeks. Seeds were dried to desired moisture contents in a desiccator over silica gel. After drying to 5% moisture content seed viability was tested by germinating seeds on moist filter paper at room temperature with 65% relative humidity and seven to eight hours day length. Preliminary seed germination tests demonstrated up to 83% germination for seeds with 13% moisture content. Germination occurred within five to seven days. Maximum germination was achieved within 21 days. The highest germination (80%) was achieved with seeds with 12% moisture content. Results indicated there was no relationship between moisture content and seed germination. Normal seedling development and growth was recorded after germination.