Effect of spacing and gibberellic acid (GA3) on growth parameters and yield of African mariglod (Tagetets erecta L.) cultivars.

A field experiment was conducted at Horticultural Instructional Farm, Department of Horticulture, College of Agriculture, Junagadh Agricultural University, Junagadh during the winter season, 2005–2006. There were total twenty-four treatments, viz three cultivars (Local Orange, Pusa Basanti and Pusa Narangi), two spacing (60 X 60 cm and 45 X 60 cm) and four GA3 concentrations (0, 100, 200 and 300 ppm), and each were replicated thrice in Factorial Randomized Block Design. All the characters except plant height at both flower initiation and full bloom stages and duration of flowering were significantly influenced by spacing. The plant spread at both flower initiation (46.78 cm2) and full bloom stages (50.78 cm2), number of branches (10.84) per plant were significantly higher in wider spacing (S1) as compared to closer spacing (S2). The flower yield(79.88 q/ha) was significantly higher under closer spacing (S2). All the vegetative growth characters were greatly influenced by GA3 at 300 ppm. It had recorded maximum plant height at first flower initiation(57.37 cm) and fullbloom (63.83 cm); plant spread at flower initiation (49.66 cm2) and full bloom stage (53.95 cm2) and fresh weight of plant (375.85 g). The maximum number of branches (13.62) per plant was observed with 200 ppm GA3. Though GA3 at all the levels significantly influenced yield parameters over control, 100 ppm GA3 recorded maximum flower yield (79.56 q/ha).