Standardization of plant growth regulators on growth and flowering of spider lily (Hymenocallis speciosa L.)

An investigation was conducted on the standardization of plant growth regulators on growth and flowering of spider lily (Hymenocallis speciosa L.) in Department of Floriculture and Landscape Architecture, College of Horticulture, Mudigere (Under the University of Agricultural and Horticultural Sciences, Shivamogga) during the academic year 2019-2020. The experiment was laid out in Randomized Completely Block Design (RCBD) and replicated thrice with nine treatments viz., Gibberellic acid (150 and 200 ppm), Naphthalene acetic acid (150 and 200 ppm), Chlroemquat Chloride (500 and 1000 ppm) and Benzyl Adenine (100 and 200 ppm) along with the control (water spray). The plants were sprayed with different plant growth regulators thrice at 45, 75 and 105 days after planting. The results revealed that GA3 @ 200 ppm recorded maximum plant height (69.67 cm), number of leaves (40.92), leaf length (60.67 cm), leaf breadth (6.67 cm), leaf area (5789.51 cm2), plant spread (E-W) (70.75 cm) and plant spread (N-S) (55.57 cm), minimum days taken for spike emergence (91.33), minimum days taken from bud initiation to harvesting of a flower spike (9.47) and the maximum flowering duration (30.00). The treatment NAA @ 200 ppm recorded maximum chlorophyll a (2.84 mg/g), chlorophyll b (2.87mg/g) and total chlorophyll (5.71 mg/g) content of the leaves.