Mentha spicata and Salvia fruticosa composts as soil amendments in tomato cultivation

Abstract

Τhe potential use of the aromatic plants Mentha spicata L. (spearmint) and Salvia fruticosa Mill. (sage) as soil amendments was evaluated. For this purpose, tomato seeds were sown in pots that had been filled with composts made from these plants and mixed with soil collected from an organically cultivated tomato field. A 2×2×4 [two types of fertilizer (synthetic and organic), two types of compost (M. spicata and S. fruticosa) and four compost rates (0%, 2%, 4% and 8%, w/w)] factorial experiment was used; the experiment was conducted twice in a growth chamber and lasted 60 days. At 0, 20, 40 and 60 days, after the establishment of the experiment, the soil bacterial and fungal abundance, the growth of nitrifying bacteria, the number of emerging weeds and the shoot length of tomato plants were measured in all treatments; at the end of the experiment, the above and belowground biomass of tomato plants was also determined. Soil microbial density increased with increasing compost rate of both species; the highest fungal and bacterial densities were recorded at 40 and 60 days, after the establishment of the experiment, respectively. Nitrifying bacteria were present in all treatments and at all sampling times. Both composts had a stimulating effect on tomato growth, which was remarkably pronounced with M. spicata. In contrast, weed emergence was reduced, but only in soils amended with M. spicata. The results suggest that M. spicata compost added at a rate of 4% to 8% is a very promising soil amendment, since it stimulates tomato growth, increases soil bacterial and fungal abundance and inhibits weed emergence. Further research is needed to elucidate the mode of action of M. spicata compost, its effect under field conditions and its possible use in mixed crop, rotational crop or cover crop systems.

Inhibitory and stimulatory effects of essential oils and individual monoterpenoids on growth and sporulation of four soil-borne fungal isolates of Aspergillus terreus, Fusarium oxysporum, Penicillium expansum, and Verticillium dahliae

“…Yet this property does not bar them from persisting in the soil environment long enough to exert their effects. For example, in previous works by our team (Karamanoli et al 2008;Chalkos et al 2010), it was reported that spearmint essential oil persists long after addition to the soil, exhibiting a modified yet active composition.…”

Salvia officinalis L. coverage on plants development

“…Different results were obtained in tests carried out by Chalkos et al (2010). These authors tested two species of Lamiaceae Family, Mentha spicata and Salvia fruticosa, using soil mixtures with both species, during 60 days.…”

Allelopathic Activity of Spearmint (Mentha spicata L.) and Peppermint (Mentha × piperita L.) Reduces Yield, Growth, and Photosynthetic Rate in a Succeeding Crop of Maize (Zea mays L.)

“…In particular, Argyropoulos et al [20] reported a negative effect on seed germination and seedling length for Mentha spicata essential oils not only in the case of weeds but also for tomato and cotton crops, while similar results have been reported for Mentha × piperita water extracts on tomato seeds germination and seedling growth. In contrast, Chalkos et al [23] reported that incorporating Mentha spicata composts in growth media at various rates (0-8% w/w) significantly increased tomato growth while inhibited weed emergence at the same time. In another study, Naeem et al [25] observed that rapeseed (Brassica napus L.) retarded the growth of maize seedlings, although the negative effects diminished at high salinity levels.…”

“…Peppermint (Mentha × piperita L.) and spearmint (Mentha spicata L.) are perennial aromatic plants cultivated worldwide [19], while both crops as well as other Mentha species exhibit allelopathic activity against weeds through their plant extracts or essential oils [20][21][22][23][24]. However, despite the positive effects of Mentha crops on weed control, their negative effects on plant growth and yield of crops has been observed.…”