Initial growth of carnauba (Copernicia prunifera) progenies under saline water

The carnauba ('Copernicia prunifera' [Miller] H. E. Moore) is a palm tree that has multiple uses and is of great economic and social importance for extractive families in Northeast Brazil. The objective of this work is to analyze the effect of saline water on the production of different progenies of carnauba. The experiment is arranged in a 5 x 36 factorial scheme in a randomized complete block design, with five replications and five plants per replication. The treatments consist of five levels of irrigation water salinity (with commercial NaCl levels, free of iodine: 0, 25, 50, 75, and 100 mM) and 36 free-pollination progenies. The following characteristics are evaluated: foliar length (H), collecting diameter (DC), survival rate (TS), number of leaves (NF), dry shoot mass (MSPA), dry mass of the root system (MSSR), and dry mass ratio of the root system to the shoot. The results reveal similar behavior among the progenies for the evaluated characteristics. However, significance is observed for the parameters leaf length, collection diameter, and survival rate when the progenies are subjected to salinity above 9.6 dS m-1. Another significant factor is the accumulation of Na+ in the aerial and radicular parts in salinity levels of 7.1, 9.6, and 12.0 dS m-1, with the root system being the most affected site. Thus, the tested progenies exhibit similar behaviors in tolerance to irrigation water salinity. Since the carnauba can produce seedlings in water with electrical conductivity of up to 9.6 dS m-1, this species is characterized as a bioindicator of saline soils and is recommended for planting in degraded areas.