Effect of Plant Growth Regulators on Growth, Fruit Yield and Quality in Cantaloupe Plant (Cucumis melo Var. Cantaloupensis cv. Shahpasandi)

Plant growth regulators may leave positive effects on different plants. A factorial experiment using RCBD was conducted to study the impact of brassinosteroied (Br) and ethephon on growth and development of cantaloupe (Shahpasandi) in 2014, in Kerman University Research Station, Kerman, Iran. Three levels of Br (0, 0.5 and 0.75 mM) as seed soaking and two levels of ethphon (0 and 250 mg/l) as foliar spray at 4- and 20-leaf stage were used. Br was effective on all examined traits with the exception of leaf relative water content, leaf dry weight and fruit quality. Br at 0.75 mM was most effective, producing the highest amount of leaf area (200 cm2/plant), fruit weight per plant (2.9 kg) and total fruit yield per hectare (50 tons). Relative to control, Br increased fruit reducing sugars concentration, leaf soluble protein contents, leaf chlorophyll concentration, and fruit number by 50%, 21%, 23.8% and 42%, respectively. Ethephon treatment applied at 20-leaf stage increased fruit reducing sugar concentration, leaf chlorophyll, and fruit number by 52%, 19.1% and 14.8%, respectively. Interactive effects of the two factors was significant for chlorophyll a and carotenoids concentrations. However, Br at 0.75 mM level and ethephon applied at 20-leaf stage were more effective than other treatments but Br at 0.75 mM increased the fruit yield by 41%.