In all farming systems, weeds are the most expensive pest to manage, accounting for 30% of potential losses. In organic farming, the problem may be further amplified by restrictions on herbicides, thus making weeds the main problem faced by organic farmers in the field. In this sense, much research is focusing on the allelopathic potential of plants as an ecological weed control tool. Many plant species can release allelopathic compounds with high phytotoxicity that can be used in weed control. Species belonging to the Lamiaceae family have been studied widely for this purpose, and their essential oils (EOs) appear to be promising bioherbicides. However, there are still many challenges for their development. Considering these aspects, a review of the bioherbicidal effect of EOs from Mediterranean Lamiaceae could help identify the most effective ones and the challenges for their actual development.

Goji (Lycium barbarum L.) has recognized nutritive and antioxidant properties and many products are commercialized for health in food market. Besides its food use, goji has been the subject of more than 2000 years of traditional Chinese medicine, using berries, root bark, and leaves. Here, the potential of the liquid culture in temporary immersion system (TIS) by using the bioreactor Plantform^TM was tested for the large-scale production of high-quality goji shoots and the subsequent production of total phenols and flavonoids. The three tested immersion cycles differently influenced the shoot quality in terms of proliferation and hyperhydricity. The best immersion cycle (time and frequency) was proven to have the shortest daily immersion time (6 min every 24 h) which ensured good levels of relative growth and multiplication rate, very limited onset of hyperydricity, and the longest shoots, promoting direct rooting after only 30 days of culture. In comparison with the semisolid culture, the TIS culture resulted in an increase of the total phenolic content (TPC) and in a lower value of the total flavonoid content (TFC). However, considering the higher quantity of biomass produced in the Plantform^TM bioreactor, the difference in terms of TFC productivity between semisolid medium and TIS liquid culture was proven to be statistically equivalent.

Arbuscular mycorrhizal (AM) symbiosis is widely investigated in aromatic herbs. Several studies have shown different effects on secondary metabolites, biomass production, as well as oil quantitative and qualitative aspects. The seeking to increase the yield of plants and their oils is an interesting topic in the world of medicinal and aromatic plant production. In tune with that, this study evaluated the effectiveness of two mycorrhiza fungi, Funneliformis mosseae (syn. Glomus mosseae) and Septoglomus viscosum (syn. Glomus viscosum), on three species from Lamiaceae family: Salvia officinalis L., Origanum vulgare L., and Thymus vulgaris L. besides untreated control. It was found that the effect of symbiosis on growth was more favourable with S. viscosum than other AM fungus. The S. viscosum inoculation raised the yield of essential oil in oregano. Analysis of gas chromatography/mass spectrometry showed that manool obtained the highest abundance in leaf essential oil of inoculated sage; thymol was the major component whatever the treatment in thyme and lower relative content of carvacrol was reported with arbuscular mycorrhizal fungi inoculation in oregano. The results suggest the mycorrhizal inoculation as a promising technology in sustainable agricultural system to improve the plant productivity performance. Specific inocula are strategic to enhance the chemical profile of essential oils.

In order to quickly and efficiently evaluate the salt tolerance of alfalfa, salinity tests were conducted on Medicago sativa L. var. australis, var. icon, var. loi, and var. gea, under in vitro conditions. Pregerminated seeds of four varieties were subjected to five different NaCl concentrations (0, 50, 100, 150, 200 mM). The influence of saline stress was estimated on the basis of survival percentage, growth parameters, and electrolyte leakage. The seedlings surviving on the medium enriched with salt at the highest concentration were presumed to be tolerant and represented the mother plants for the production of in vitro clones. In the following step, the clones were evaluated in vitro to confirm the salt tolerance. The influence of mild salt stress (75 mM NaCl) on the growth parameters of selected clones was examined. At the end of this trial, the proline accumulation and sodium content in alfalfa shoots were also quantified. The results suggest an increased level of proline promotes salt tolerance. Medicago sativa L. var. icon is highly tolerant in comparison with the other varieties tested. In vitro selection of M. sativa L. varieties on salt-containing media allowed us to obtain clones with increased salinity tolerance.

The current study aimed to assess the allelopathic effect of Rosmarinus officinalis L. essential oils (EOs) to define the potent effect against weed species, by exploring distinct chemotypes and their main compounds. The EOs from eight accessions were characterized. Their components were identified by gas chromatography, and four chemotypes were defined; C1 (α-pinene), C2 (camphor), C3 (α-pinene/1,8-cineole), and C4 (α-pinene/1,8-cineole/camphor). Four concentrations of the EOs (400, 800, 1200, and 2400 μL/L) and the main compounds of each chemotype were tested in a laboratory assay against Amaranthus retroflexus L. and Lolium perenne L. in pre- and post-germination. The results showed that the EOs significantly affected all the tested parameters (germination, early growth, and physiological and histological parameters of the weeds under study) in a dose, chemotype, and species dependent manner. A. retroflexus was more sensitive than L. perenne at germination level being significantly inhibited at the lowest dose of all the chemotypes. The latter all exhibited significant effects but with a higher potency of C2 (camphor chemotype) and C3 (α-pinene/1,8-cineole chemotype), as well qualitative differences in the induced damage. Our results thus increase knowledge about the role of the monoterpene composition in bio-herbicidal effect, which can help in the development of EO based bio-herbicides.

The micropropagation appears to be a valid alternative method for the production of large-scale, phenotypically homogeneous, and disease-free plants, particularly for spring globe artichoke genotypes. Nevertheless, micropropagated plants have some problems during the acclimatization in field environments. The inoculation with arbuscular mycorrhizal fungi appeared to overcome the transplanting stress. Therefore, a comparison was drawn between the field performances of different vegetative propagation techniques (micropropagated/mycorrhized and offshoots cultivation) of early globe artichoke clones over two growing seasons. The micropropagation/mycorrhization appeared to deliver a better field performance in terms of both plant growth and productivity traits as compared with offshoots cultivated. In particular, the micropopagated/mycorrhized plants exhibited the highest vegetative growth values than the offshoots of the cultivated ones, such as the plant height and the main floral stem length. The micropopagated/mycorrhized plants were also more productive, exceeding the head yield of offshoots cultivated ones by about 63%. However, the micropopagated/mycorrhized plants accumulated almost a month late on the first harvest respect to offshoots cultivated ones. Our data also showed that the effects of the new proposed propagation method were genotype- and season-dependent. Accordingly, some plant growth and productivity traits showed significant ‘propagation method × genotype’ and ‘propagation method × growing season’ interaction. This study revealed that the micropropagation, as well as the mycorrhization, could represent an efficient and sustainable cropping system to reintroduce and increase the productivity of autochthons landraces.