Photochemical and phytomass aspects of pomegranate seedlings grown under water salinity and foliar nitrogen fertilization

Abstract

Pomegranate is a fruit with potential for exploitation in the Brazilian Northeast as medicine and food. However, the qualitative and quantitative scarcity of water resources is common in this region, requiring the use of water with high salt contents in irrigated agriculture. The adoption of strategies to reduce the harmful effects of salt stress in plants is therefore necessary, and foliar nitrogen (N) fertilization is a promising alternative. The objective of the work, therefore, was to evaluate the photochemical and phytomass aspects of pomegranate seedlings grown under irrigation water salinity and foliar nitrogen fertilization. The experiment was performed in a randomized block design, in an incomplete factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.50, 1.15, 2.75, 4.35 and 5.00 dS m^-1) and five nitrogen doses - N (0.0, 0.33, 1.15, 1.97 and 2.30 g L^-1), totaling nine combinations, generated by the Central Composite Design, with four repetitions and two plants per repetition. Foliar N application at a dose of 1.37 g L^-1 increased the production of leaf and root dry phytomass at 90 days after emergence. Salt stress reduced the photochemical activity and phytomass production of pomegranate seedlings, while there was a stimulus by increasing N application up to 2.3 g L^-1.

Keywords: nitrogen, photochemical efficiency, Punica granatum L., salt stress.