Changes in Growth and Physiological Parameters of xAmarine Following an Exogenous Application of Gibberellic Acid and Methyl Jasmonate

xAmarine hybrids are attractive ornamental geophytes grown for cut flower production. Their cultivation is limited due to lesser flowering percentages and lesser bulb weight gain. To optimize the growth and propagation of geophytes, plant growth regulators (PGRs) are used, but so far none have been tested in xAmarine. We investigated the effect of gibberellic acid (GA(3); 50, 100, and 200 mg dm(-3)) and methyl jasmonate (MeJA; 100, 500, and 1000 mu mol dm(-3)) on growth, flowering, bulb yield, and select physiological parameters of xA. tubergenii "Zwanenburg". PGRs were applied as foliar sprays on the 70th and 77th day after planting. GA(3) treatment at 200 mg dm(-3) exhibited the greatest leaf number, leaf length, bulb weight, daughter bulb number, CO2 assimilation intensity, greenness index, total sugars, and total protein content in bulbs. GA(3) application at 100 and 200 mg dm(-3) accelerated flowering and at 50 and 100 mg dm(-3) significantly increased the bulb flowering percentage. MeJA at all tested concentrations prolonged anthesis time and reduced the bulb flowering percentage. GA(3) at all concentrations and MeJA at 500 and 1000 mu mol dm(-3) stimulated daughter bulbs formation. GA(3), especially at 200 mg dm(-3) can improve anthesis and increase xA. tubergenii "Zwanenburg" bulb yield.