Response of Arucula Cultivars to Saline Nutritive Solution Enriched With Potassium Nitrate

The quality of water used to prepare a nutritive solution is a fundamental factor for plants to express their maximum yield potential, however, due to an emerging water scarcity, the use of saline water is turning into a challenge for producers and scientists. The present study was developed to evaluate the effect of potassium nitrate in two arucula cultivars fertigated with saline nutritive solutions in semi-hydroponic system. It was used a randomized block design, in factorial scheme 2 × 4, with two arucula cultivars (Cultivada and Folha Larga) and four nutritive solutions [S1-standard nutritive solution; S2-standard nutritive solution + NaCl (7.5 dS m-1); S3-S2 + 50% of KNO3; S4-100% of KNO3], with three replicates, with each experimental unit represented by a gutter of 1.5 m filled with coconut-fiber based substrate and 30 plants per replicate. Plants were collected 40 days after planting and evaluated for following variables- height, amount of leaves, leaf area, above ground fresh matter, above ground dry matter, leaf succulence, percentage of dry matter, and specific leaf area. Cultivada is more productive than Folha Larga, but presented higher sensibility to salinity. Increase of salinity in the water for preparation of nutritive solution negatively affects arucula cultivars’ development in semi-hydroponic system. The use of potassium nitrate reduced the effects of salinity on the Folha Larga’s development, but did not inhibit negative effects of salinity in any cultivar. Growth of arucula, Folha Larga, using saline water in semi-hydroponic system is feasible with addition of 50% of KNO3.