VARIABILITY IN THE DYNAMICS OF PHOTOSYNTHETIC INDICATORS IN MELON PLANTS ACCORDING TO GROWTH AND DEVELOPMENT STAGES

This article examines the variability in the dynamics of key photosynthetic parameters in two promising melon (Cucumis melo L.) cultivars—Gunash and Sadaf—cultivated under open-field conditions in the Absheron region. The study evaluates several physiological and biochemical indicators, including leaf surface area, photosynthetic potential (PP), net photosynthetic productivity (NPP), specific leaf surface density (SLSD), plastid pigment concentrations, the coefficient of economic efficiency of photosynthesis (CEEP), overall economic efficiency (CEE), and the accumulation of both crude and dry biomass. The findings indicate that SLSD and total biomass (crude and dry) progressively increase from the onset of the vegetative stage through to fruit formation and mass ripening. The early-maturing cultivar Gunash exhibited the most pronounced increases during the initial fruit formation stage, whereas in the mid-maturing cultivar Sadaf, these increases peaked during the mass ripening phase. Substantial variation in NPP, SLSD, and CEE was observed throughout plant ontogenesis, with maximum values recorded during the mass ripening period in both cultivars. Furthermore, chlorophyll and carotenoid accumulation in melon leaves followed a tri-phasic peak pattern, with the timing of each peak being cultivar-specific.