Medicinal plant species have been used by the ancestors around the world since ancient times. Rosmarinus officinalis is one of the most used medicinal plants, which belongs to the family Lamiaceae. To investigate the effects of different levels of salinity stress along with the induction of bacterial growth stimulation on the amount of essential oil composition in R. officinalis, an experiment was conducted in a randomized complete block design with 12 treatments and five replications. Salinity treatments included 0 (control), 2.5 (T1), 5 (T2), 7.5 (T3), 10 (T4) and 12.5 (T5) NaCl g/L, and the bacterium was pseudomonas fluorescence. The percentage of essential oils showed a significant relationship with increasing salinity either alone or in composition with plant growth-promoting rhizobacteria (PGPR) inoculation treatments and it increased with increasing salinity levels to treatment 4 (T4, 10 g/L NaCl) but decreased with further increases in salinity levels in treatments without using PGPR and it was constant in treatment with using PGPR. Phellandrene, one of the main compounds of essential oils, showed a trend like the whole amount of essential oils in both group of treatments. Abiotic and biotic factors may influence the different mechanisms and limit the interactions between plant and beneficial bacteria, resulting in less-than-acceptable performance in plant growth promotion and management of diseases. In this context, the results revealed that the application of PGPRs can help improve the essential oil yield in R. officinalis even in salinity conditions.

Biochar has been recognized as a promising and efficient material for soil amendment. However, its effects on seed germination are variable due to its alkaline pH and/or the presence of phytotoxic substances. In this study, two types of biochar (B1 and B2) were mixed with soil at different concentrations (0%, 5%, 10%, 25%, 50% and 100%, w:w), and both the solid and liquid fractions of these mixtures were tested on the germination of basil, lettuce and tomato seeds. Furthermore, solid fractions subjected to a pre-washing treatment (B1_W and B2_W) were also investigated for their effects on seed germination. Three germination parameters were then measured: seed germination number (GN), radicle length (RL) and germination index (GI). Biochar B2_W at 10% increased both RL and GI in basil by 50% and 70%, respectively, while B1 at 25% increased these parameters in tomato by 25%. No effects or negative effects were recorded for lettuce. Liquid fractions (L1 and L2) generally hampered seed germination, suggesting the presence of potentially water-soluble phytotoxic compounds in biochar. These results point to biochar as a suitable component for germination substrates and highlight that germination tests are critical to select the best performing biochar according to the target crop.

The growing interest in bioplastics and bio-based crop management products in agriculture is driven by the Sustainable Development Goals of the 2030 Agenda. However, recent research has raised concerns about the sustainability of bioplastics due to their potential negative impact on crop growth and yield, with implications for the environment and human health. In this study, wood distillate (WD) was evaluated as a natural enhancer of plant growth and defence system to mitigate the negative impact of a starch-based bioplastic on basil (Ocimum basilicum L.) plants. The study analyzed physiological and biochemical changes in basil plants subjected for 35 days to single or combined treatments of WD and bioplastic by measuring biomarkers of healthy growth, such as soluble proteins, sugars, vitamin C, and malondialdehyde (MDA). The results showed that WD promoted basil development, whereas the presence of bioplastic hindered it. Interestingly, WD did not affect sugars but increased vitamin C by 12 %, which is considered a positive effect as changes in sugar levels could indicate plant stress. In contrast, bioplastic resulted in reduced sugars (-41 %) and increased (+17 %) MDA level, while vitamin C content remained unchanged. However, when WD was added to plants grown with bioplastic, it elevated the levels of all examined parameters, except for sugars and vitamin C, which experienced reductions (-66 % and 33 %, respectively). Intriguingly, despite this reduction, the observed direct correlation between sugar and vitamin C contents was maintained, indicating that the decrease in sugar content may have reached a critical threshold. This study suggests that the use of WD has the potential to alleviate the adverse effects of bioplastic on basil growth and development and highlights the importance of adopting sustainable practices in agriculture, as well as the need for a critical assessment of the environmental impact of new technologies and products.