Cultivo do coentro sob soluções nutritivas preparadas em águas salobras com diferentes predominâncias catiônicas

Abstract

The prevalence of different cations, notably Na+ and Ca2+, in brackish waters used in the preparation of nutrient solutions, impact in different ways the physiological aspects of cultures, even under the same concentration. Therefore, this research was developed with the objective of evaluating photochemical efficiency, water relations and the production of coriander plants, cv. Verdão submitted to nutritive solutions (1.6; 3.2; 4.8; 6.4 dS m-1) prepared in saline water with different salts (NaCl, CaCl2.2H2O, MgCl2.6H2O). The experiment was carried out at the Federal Rural University of Pernambuco in a greenhouse at the DEAGRI/UFRPE Fertigation and Salinity Laboratory (8° 01' 07" S e 34° 56' 53" W e 6,5 m de altitude) between november and december of 2019. The experimental design was in randomized blocks, factorial scheme 4 x 3, with four blocks. In the hydroponic structure, the tubular gutters were arranged vertically, a closed system with two daily circulations was adopted, and the solution reservoir was replaced with the respective brackish water used in the preparation of the nutrient solution. Based on the evaluation of photochemical efficiency and water relations, the production of total fresh and dry mass, aerial part and root was analyzed. The data were subjected to analysis of variance at the 0.05 probability level. It was found that the greatest damage to the photosynthetic and productive process was seen under prevalence of Mg2+ > Ca2+ > Na+ in water. On the other hand, the different cationic prevalences provided differences in the damage caused by increasing concentration on water uptake, water use efficiency and the production of aerial fresh and dry mass up to the limit of 6.4 dS m-1. The increase of salt concentration in water limited gs, E and water consumption, whose unfoldings were measured in the production of biomass of the aerial part and root.