Indian Journal of Plant Sciences ISSN: 2319-3824 (Online) An Online International Journal Available at http://www.cibtech.org/jps.htm 2012 Vol. 1 (2-3) Jul.-Sept. & Oct.-Dec., pp.133-136/Sudhakar and Kumar Research Article 133 EFFECT OF GROWTH REGULATORS ON GROWTH, FLOWERING AND CORM PRODUCTION OF GLADIOLUS (GLADIOLUS GRANDIFLORUS L.) CV. WHITE FRIENDSHIP *M. Sudhakar and S. Ramesh Kumar Department of Horticulture, Faculty of Agriculture, Annamalai University, Annamalai Nagar (Tamilnadu), India *Author for Correspondence ABSTRACT An experiment was carried out to study the effect of growth regulators on growth, flowering and corm production of Gladiolus Gladiolus grandiflorus L. cv. white friendship during 2011 in floriculture yard, Department of Horticulture, Faculty of Agriculture, Annamalai Nagar. Four growth regulators viz., GA 3 , NAA, CCC and MH each at three concentrations in addition to water spray as control comprised thirteen treatments of this experiment. The experiment was laid out in a Randomized Block Design (RBD) with three replication. All the growth and yield parameters were periodicaly observed. The results revealed that the growth regulators application significantly influenced the growtrh and yield of Gladiolus sp cv. white friendship. The maximum No. of florets/spike, spike length (cm) and flower length (cm) were obtained were obtained with GA 3 @100ppm as compared to rest of the treatments. Whereas CCC @500 ppm was found the best interms of corms and cormels production. Key Words: Gladiolus, Gibberellic acid, NAA, CCC, MH, Regulators INTRODUCTION Gladiolus is a flower of glamour and perfection which is known as the queen of bulbous flowers due to its flower spikes with florets of massive form, brilliant colours, attractive shapes, varying size and excellent shelf life. Gladiolus is grown as flower bed in gardens and used in floral arrangements for interior decoration as well as making high quality bouquets (Lepcha et al., 2007). To enhance of yield and quality of any flower crop various cultural management practices like good planting material, spacing, irrigation, plant protection etc., are required. The planting material i.e. corm is the important factor which governs the growth and development of gladiolus. The physiological functions inside the corms are controlled by plant growth regulators. Plant growth regulators are the organic chemical compounds which modify or regulate physiological processes in an appreciable measure in plants when used in small concentrations. They are readily absorbed and move rapidly through tissues when applied to different parts of the plant. It has generally been accepted that many plant processes including senescence, are controlled through a balance between plant hormones interacting with each other and with other and with other internal factors (Mayak and Halevy, 1980). Although growth retarding chemicals did not increase the number of flowers, they produced flowers with compact shape, developed short stalk, flowers remained fresh for a longer period and they suppressed the height of the plant (Bhattacharjee et al., 1974). It is known fact that application of growth regulators such GA 3 , NAA, CCC and MH had positive effects on growth and development of gladiolus plants at different concentrations. The reports indicate that the growth and yield of gladiolus was enhanced by application of GA 3 (Umrao Vijai et al., 2007 and Rana Peanav et al., 2005), NAA (Suresh Kumar et al., 2008), CCC by (Jinesh patel et al., 2010 and Leena Ravidas et al., 1992) and MH by (De et al., 2002). Hence the present study was conducted to find the effect of growth regulators on growth, flowering and corm production of gladiolus Gladiolus grandiflorus L. cv. White friendship. MATERIALS AND METHODS This experiment was conducted in floriculture unit, Department of Horticulture, Faculty of Agriculture, Annamalai University, Annamalai nagar, India during 2011. Soil of the experimental plot was sandy