Eficiência hídrica e partição de fotoassimilados do coentro sob vazões e salinidade da solução nutritiva

Abstract

Given the need to use brackish water in arid and semi-arid regions, hydroponic crops can be used as an alternative form of cultivation in these locations. Thus, the present work was carried out with the objective of evaluating the water efficiency, growth and photoassimilates partition of coriander plants, cv. verdão, exposed to nutrient solutions prepared in brackish water and applied at increasing flow rates in a “Nutrient Film Technique” - NFT hydroponic system. The experiment was carried out in a greenhouse located on the premises of the Department of Agricultural Engineering - DEAGRI, of the Federal Rural University of Pernambuco - UFRPE, in Recife, PE. The experimental design adopted was in randomized blocks, analyzed in a 4 x 4 factorial scheme, with four blocks, being the treatments four nutrient solutions (1.7; 3.0; 4.5 and 6.0 dS m-1) and four increasing flows (1.0; 2.0; 3.0 and 4.0 L h-1) in NFT system. Variables related to water efficiency, growth and photoassimilates partition of plants were measured and the data were submitted to analysis of variance by the F test at a probability level of 0.05. It was verified that the increase in the flow rate of application of the nutrient solution implied in a greater allocation of photoassimilates in the root to the detriment of the shoot and, on the other hand, the increase in the electrical conductivity of the nutrient solution implied in an increase in the percentage of dry mass of the part aerial. The increase in the electrical conductivity of the nutrient solution was the main factor that reduced the productive parameters and accumulation of coriander biomass. It was also verified that the water productivity of the coriander crop was not affected by the interaction between the increase in electrical conductivity and the flow rate of application of the nutrient solution.