Effect of Corm Size and Nitrogen on the Growth and Flowering of Gladiolus (Gladiolus grandiflorous L.)

An experiment was conducted to evaluate the effect of corm size and nitrogen on the growth and flowering of gladiolus. The experiment considered with three corm sizes viz. small (11-20g), medium (21-30g) and large (31-40g) and four levels of nitrogen viz. 0, 80, 100 and 120 kg ha-1. Both corm size and nitrogen exhibited significant effect in almost all parameters studied. Considering the corm size, a gradual increasing trend in plant height, number of leaves plant-1 and length of leaves found with small to large sized corm. The highest length of flower stalk, length of rachis, number of floret spike-1, percentage of flowering plant and number of spike ha-1 were recorded in large sized corm. Considering the nitrogen fertilizer, the number of leaves plant-1 and width of leaves increased gradually with increasing nitrogen fertilizer. The highest length of flower stalk, rachis, number of floret spike-1, weight of single spike at harvest, percentage of flowering plant and number of spike ha-1 were recorded in the plot treated with 120 kg nitrogen ha-1. Considering the combined effect of corm size and nitrogen fertilizer, the highest length of flower stalk (76.53 cm), length of rachis (40.05 cm) at harvest, percentage of flowering plant (98.52%) and number of spike ha-1 (193920) was recorded from the plot of large sized corm with 120 kg nitrogen ha-1, whereas the lowest length of flower stalk (42.23 cm), rachis (19.67cm) percentage of flowering plant (56.64%) and number of spike ha-1 (145150) were recorded in the plot of small sized corm with no nitrogen. The highest net return (686845.2) and benefit cost ratio (2.464) were also obtained from the treatment combination of large sized corm and 120kg nitrogen ha-1.