Plant growth regulators treatments modulate growth, physiology and quality characteristics of Cucumis melo L. plants

Our objective was to identify the effects of Gibberellic acid (GA3), Prohexadione-Calcium (Prohex-Ca), Cycocel and Ethephon applied as foliar sprays, on pre- and post-harvest physiology and quality characteristics of melon (Cucumis melo L.). GA3 promoted melon growth, while a significant inhibition with Cycocel and Ethephon was observed. The chlorophyll a+b concentration as well as the chlorophyll fluorescence characteristics were negatively affected by Prohex-Ca, Cycocel and Ethephon application. The maximum quantum yield of PSII (Fv/Fm) was declined showing an impairment of the primary photochemical efficiency of the photosynthetic apparatus during the time course of the experiment. The significant decrease of Fv/Fo is an indicator of structural damage, which occur in the thylakoids and affects the photosynthetic electron transport. With GA3 application, fructose, glucose and soluble solids remained unchanged, whereas ascorbic acid content increased significantly.