VARIABILITY ANALYSIS AND EFFECT OF GROWTH REGULATORS ON DORMANCY, GROWTH AND YIELD OF GLADIOLUS

Abstract

I he IC carch \\ l'i can icd Olli ut Fl111 il ulturc I xpcrimcntal Fann or I Ioruculturc R1..·-.L':11d1 Centre (HRC). Bangladesh Agricultural Research lnstitutc (BARI), Joydcbpur, Gazipur Ju1111~ \p1il 2005 lo June 2006. I he li1~1 experiment included twenty seven ~·l:tdiolus genotypes. These were planted to measure variability, character association among them and evaluation in respect of yield and yield contributing characters to select promising line (s) as well as studies on the genctical parameters for further improvement of the crop. Another experiment was conducted to break the dormancy as well as more number of corm productions by BAP, Ethrel and GA3. The results indicated the existence of wide variability among the genotypes on their physic-morphological characters along with yield and yield attributes. Genotypes varied from 58 to 110 cm and 20-58 cm in spike length and raehis length respectively. Number of flower was the highest in GL-23 (15) and lowest in GL-07 (6). Number of corrnel and cormel weight of the genotypes significantly differed and ranged from 05 to I 0 and 4.8 to 15 g respectively. Considering genetic parameters, high genetic coeflicient variation values were observed for number of flower, vase life, spike length, rachis length, number of corrncl and weight of cormcl. Correlation studies revealed that positive association of flower yield (spike length) with all the characters both at gcnotypic and phcnotypic level except number of leaves, length of leaves, breadth of leaves, days to 50% spike initiation, flower size, number or corm and weight of conn. Path coefficient analysis indicated maximum direct contribution towards yield through rachis length followed by flower number, vase life, number of cormcl and weight of cormel. Large variations in qualitative characters were also observed. Based on these selection criteria, the genotypes GL-02, GL-023 and GL~024 were identified as good genotypes. All the concentration of BAP, Ethrcl and GA3 showed in dormancy breaking but differed markedly. Induction of dormancy breaking in the control was less. I lowcver, BAP 150 ppm showed a promotive effect in extent of dormancy breaking. lt was also in envisaged that BAP al 150 ppm was found best for corm production.