Photochemical efficiency, biomass and chlorophyll of phyális under salinity and biostimulant

Abstract

Physalis peruviana L. has great exploitation potential especially for small producers in the Brazilian Northeast. However, production in semiarid regions may be limited by high salt content in soils and water sources used for irrigation. Thus, this study evaluated the application of Ascophyllum nodosum seaweed extract as saline stress attenuator in P. peruviana L. The randomized block design was used, in an incomplete 5 × 5 factorial scheme, with five of electrical conductivities of the irrigation water (0.50, 1.23, 3.00, 4.77 and 5.50 dS m-1) and five increasing concentrations of kelp extract (0.00, 1.45, 5.00, 8.55 and 10.00 mL L-1), with nine combinations generated by the Central Box matrix, with four replicates of four plants to evaluate the effect on phytomass accumulation, chlorophyll fluorescence and pigment content. Results showed, salinity significantly reduced biomass production and chlorophyll fluorescence and pigment indices. However, when plants were treated with 9.9 mL L-1 seaweed extract they increased biomass production and seedling quality. On the other hand, up to 4.1 mL L-1, the biostimulant increased dark-adapted fluorescence indices which indicate it reduces damages to the photosynthetic apparatus caused by salt-stress and thus improving photosynthetic activity and photoassimilates production. Thus the application of A. nodosum seaweed extract attenuates the deleterious effect of salt stress in photosynthesis and thus in biomass production of P. peruviana plants.