Some physiological characteristics of the medicinal plant Lavandula angustifolia in response to drought stress, compost and vermicompost

Medicinal plants play an important role in human health and many people tend to use these drugs. The need for medicinal plants production and research on different subjects which are related is increasing. Therefore, improving the quality of medicinal plants products seems essential. Lavender (Lavandula angustifolia) is an herbaceous medicinal plant that has a long history of treating low levels of jaw, jaundice, asthma, liver and spleen disorders, nausea, asthma, and neurological disorders. In this study, the effect of different amounts of compost fertilizers obtained from solid municipal waste and vermicompost from fruit and vegetable field remnants on qualitative and quantitative characteristics of Lavender plant under drought stress was investigated with three replications.

This research was a randomized design in greenhouse of Shiraz University in 2017 .Treatments include drought stress at three levels of 0, 5 and 9 days, and compost and vermicompost fertilizers each one in three levels of 0, 10 and 30% of the volume of soil pots. The effects of compost and vermicompost fertilizers on growth, physiological characters such as antioxidants property, phenol content, proline and secondary metabolites in essential oil at different salinity stress were measurement. The compost prepared from municipal waste under aerobic conditions and by the activity of microorganisms. The vermicompost was prepared from agricultural waste and fruit by processes using special worms. The data was analyzed using SPSS 16.0 software. Mean comparisons were made by Duncan’s multiple range test at 0.05 (P≤ 0.05).

The results showed that the effect of drought stress on all traits was significant, 10% vermicompost increased root growth. In compost and vermicompost treatments and drought stress, fresh weight of shoot had the highest growth rate in the control plant. The highest amount of proline (10.81 μmol/g FW) was observed in 9-day drought stress treatment with compost and vermicompost 30% and lowest (2.9 μmol/g FW) in control treatment. The antioxidant level of the plant leaves increased compared to the same treatment without stress. The highest antioxidant activity (7.15 μmol/g DW) was observed in drought stress treatment. The highest amount of phenolic content (10.64 μmol/g DW) was observed in plants treated with 10% vermicompost and nine days of drought stress and the lowest amount (5.96 μmol/g DW) was observed in 30% compost treatment and 10% vermicompost treatment without drought stress.

The results indicate that using vermicompost fertilizer in low concentrations can improve the quantitative and qualitative properties of lavender plant under drought stress conditions and the use of compost from solid municipal waste reduces the effective content of lavender plant it turned out. . It is recommended that agricultural waste can be used in the preparation of compost and that urban wastage can be consumed as little as possible