Phosphorus fertilization affects growth, essential oil yield and quality of true lavender in Brazil

Abstract True lavender (Lavandula angustifolia Mill.) belongs to the genus Lavandula and is the most cultivated and commercialized species in the world. This specie is used in perfumery industry, but also presents medicinal properties. The production of these metabolites can be affected by several factors, among which is the supply of mineral nutrients. The proposal of this study was to evaluate the adaptability of plants and the mineral complementation of phosphorus in the plant growth and essential oil (EO) yield and quality of lavender in tropical climate, in the north of the state of Rio de Janeiro, Brazil. The seeds were germinated and planted in 20 L pots previously fertilized with five levels of phosphorus (0, 30, 60, 90 and 120 mg/dm3). Two harvests were evaluated, between 2018 and 2019. Lavandula angustifolia Mill. plants showed adaptability to tropical climate, being the best growth results obtained in the second harvest. All the characteristics evaluated in the second harvest showed influence of phosphate fertilization. The nutritional levels allowed to establish the order of accumulation of K > N>Ca > Mg > P > S for macronutrients and Fe > Mn > Zn > B>Cu > Ni > Mo for micronutrients. The significant equations obtained allowed the calculation of the dose of 77 mg/dm3 of P for maximum EO production, with adequate characteristics as for the chemical profile.