Growth and productivity of Salvia officinalis L. under Mediterranean climatic conditions depends on biofertilizer, nitrogen fertilization, and sowing density

Abstract

Salvia officinalis L. is an important medicinal herb of high soil and climatic adaptability and thus the main goal of the current study is to investigate the effect of mycorrhizae, the plant density and the nitrogen fertilization (using bio-fertilizers) on the yield and growth characteristics. For the purpose of the study, a field experiment was established at the Experimental Farm of the University of Thessaly, Velestino, in 2017, 2018 and 2019, respectively. The experimental design was a factorial split-split-plot design with Mico-plus being the main factor (Trt1: control, Trt2: mico-plus which contains non composed plant residues, 3% Glomus mosseae and Glomus intradices, 1 × 108UFC/g Bacillus spp, Pseudomonas spp., and Streptomyces spp., and 1 × 108UFC/g Trichoderma), plant density the sub-factor (P1: 10,000 and P2: 20,000 plants ha−1) and N-fertilization the sub-sub factor using bio-fertilizers (N1: 0, N2: 40, and N3: 80 kg N ha−1) with three replicates. Height, leaf area index and leaf yield were measured by samplings at the ideal collection stage (start of the flowering period). The use of mico-plus and nitrogen fertilization resulted in significantly higher yield. Furthermore, plant density had a negative effect on measured values, leading to reduced leaf yield and lower leaf area. The higher produced leaf yield and leaf area (7296 kg ha−1 and 4.47 leaf area index, respectively) were recorded in the third year for the treatment of the lower plant density with the higher N-dressing where mico-plus was used (MP1N3). Therefore, sage seems to be a promising perennial cultivation characterized by satisfactory yields under low inputs in similar soil-climatic environment, while the use of mico-plus should be taken into consideration, especially in the case of poor and abandoned lands. © 2020 Elsevier B.V.