Effects of Corm Size and Planting Date on Flower and Corm Production of Gladiolus in Sylhet Region

Abstract

A field study was conducted to investigate the effects of corm size and planting date on flower, corm and cormel production of gladiolus (Gladiolus grandiflorus. A.) in sylhet. In this investigation three corm sizes viz., large (25+2 g), medium (15+2 g) and small (10+2 g) and two planting dates of 25 October and 25 November were included as treatments. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Results indicated that growth and yield of flower, corm and cormel production were largely affected by corm size and planting dates. Large corm with 25 October planting produced the tallest plant and higher number of leaves compared to the 25 November with medium and small corm. Large corm produced maximum flower, corm and cormels. In case of planting dates, 25 October planting required maximum days for spike to flower initiation (15.02), maximum rachis length (34.09 cm), highest number of floret spike-1 (9.77), maximum number of spike (907.16) decimal-1, maximum number of cormels (6271.43)  decimal-1. On the other hand, maximum weight of single spike (53.29 g), maximum number of corm (1.65), maximum number of cormels (1117.09) decimal-1 was obtained from planting dates of 25 November. It was further noticed that interaction effect of corm size and planting dates were significant effects on rachis length (39 cm), floret length (10.25 cm), number of corm plant-1 (2.03), number of corm decimal-1  (1371.99) and weight of spike plant-1 (73.75 g) on 25 November planting with large corm. On the other hand, 25 October planting with large corm was significant in case of number of flower spikes plant-1 (1.77), number of flower spikes decimal-1 (1192.06), number of cormels plant-1 (10.67), number of cormels decimal-1 (7197.33), weight of corm (58 g) and weight of cormels (17.4 g)  plant-1 and weight of corm (39.14 kg) and cormels (11.74 kg) decimal-1. Poor performances in respect of flower, corm and cormel production were observed in the plants grown from small corm and planted on 25 November.