Potassium sources and doses in coriander fruit production and essential oil content

Fontes e doses de potássio na produção de frutos e teor de óleos essenciais de coentro

ABSTRACT

Potassium (K) is one of the most required agricultural crop macronutrients, with potassium chloride being the most applied source. However, this fertilizer is not recommended for several crops due to its high chlorine content, promoting final product quality losses, thus being replaced by potassium sulphate. The aim of the present study was to evaluate the production and macronutrient, essential oil and linalool contents of coriander fruits submitted to different potassium sources and doses. The research was performed in a greenhouse, in plastic 46 kg boxes applying a mixture of soil and sand as substrate. The experimental design was of randomized blocks, applying a 2x4 factorial arrangement, with two potassium sources (potassium chloride and sulphate) at four doses (50, 100, 150 and 200 mg of K/kg substrate), performing four replicates. The highest fruit yields, and phosphorus and sulfur fruit contents were verified in plants fertilized with K₂SO₄. The application of increasing potassium doses, regardless of the source, resulted in increased K and decreased Ca contents and did not affect N and Mg fruit levels in the fruits. The highest essential oil concentration in fruits (0.15 g) and linalool in essential oils (0.42 mg) were verified when 153.8 and 131.3 mg of K/kg substrate using K₂SO₄ were applied, respectively.

Keywords:
Coriandrum sativum; nutrients; secondary metabolism; linalool