Impact of phosphorus and luminosity in the propagation, photochemical reactions and quality of Lippia alba (Mill.) N.E.Br. seedlings

Abstract

Lippia alba (Mill.) N.E.Br. (lemongrass) is a spice and medicinal plant species, with fledgling studies related to mineral nutrition and luminosity on foliar and vegetative responses. Thus, the aim of this study was to assess the foliar aspects and production of L. alba under two light conditions (full sun and shading of 50%) and four levels of phosphorus-P (0, 150, 300 and 450 mg kg-1). The L. alba seedlings presented changes in physiological indices and photochemical responses based in chlorophyll-a fluorescence. The phosphate fertilization has helped mitigate light stress on synthesis of chlorophylls. The greatest leaf biomass production occurred with addition of P. The principal components analysis explained 74% of the variability, the leaves number, initial fluorescence and specific leaf area in principal component 1 (PC 1) and buds number, survival and leaf area in PC 2 were representative characteristics. In the cluster analysis, two groups were formed, with lower distances between P300 full sun and P450 shading (2.31). Seedlings cultivated under full sun presented higher survivability and seedlings quality. Production of L. alba seedlings should be performed under full sun with addition of 450 mg kg-1 of phosphorus.