Growth, chlorophyll fluorescence and gas exchange of pepper (Capsicum chinense Jacq.) plants in response to uptake and partitioning of nutrients

ABSTRACT Habanero pepper (Capsicum chinense Jacq.) does not have a specific fertilization. Therefore, the aim of this study was to evaluate growth, photosynthesis and accumulation of macro and micronutrients of habanero pepper plants. Plants were established in nutrient film technique (NFT) hydroponic systems. Two universal balanced solutions (Steiner and Hoagland) were compared versus a conventional solution (control: Soria solution). The concentration of macro and micronutrients in roots, stems, and leaves, photosynthetic activity of plants, total nitrate, amino acid and protein contents, and growth parameters were evaluated. According to the results, concentrations of K, Mg, Ca, Cu and Zn in plant tissues were higher in the Steiner and Hoagland treatments than control. In addition, the Steiner and Hoagland treatments increased the maximum photosynthetic rate (Amax) (81% and 80% respectively), light-saturated CO2 assimilation rate (Asat) (3.8-fold and 3-fold, respectively) and maximum catalytic activities of Rubisco (Vcmax) (51% and 30% respectively) with respect to the control. Hoagland treatment increased total nitrate content (3.66 mg g-1 FW), but Steiner treatment increased amino acids in leaves (169.97 mg g-1 FW) and control increased total proteins (1.49 mg g-1 FW). Steiner and Hoagland solutions significantly increased plant height (59% and 41% respectively), leaf area (1.26-fold and 1.02-fold, respectively), and total dry mass (80% and 69% respectively) with respect to the control solution. The results suggest that Steiner and Hoagland nutrient solutions provided nutrients that improve growth and photosynthetic activity. Moreover, total nitrate, amino acid and protein accumulation depend on the N source employed in nutrient solutions.