Effects of Vermicompost, Compost and Animal Manure on Vegetative Growth, Physiological and Antioxidant Activity Characteristics of Thymus vulgaris L. under Water Stress

Abstract

This study investigated the effect of organic fertilizers on vegetative growth and the physiological and antioxidant activity characteristics of thyme plants grown under stress. A factorial experiment was conducted according to randomized complete block design with 12 combinations and 3 replications in the 2018 growing season. The experiment factors were the implementation of organic fertilizers at 4 levels (vermicompost, manure compost, animal manure, and control) and irrigation regime at 3 levels (Irr1, Irr2, and Irr3, respectively, irrigation after 60, 90, and 120 mm evaporation from A pan). The results showed that With delayed irrigation, the chlorophyll a and b contents, total chlorophyll, and carotenoid decreased, while the application of low water stress enhanced the amount of oil and the oil yield with the respective highest values of 2.61% and 3.68 g/m under mild stress conditions. Nonetheless, higher values for the aforementioned properties were noted with the application of vermicompost. Water deficit decreased nutrient uptake (K, P, and N) and relative water content, biological yield, and seed yield of thyme, indicating that thyme was sensitive to drought, and organic fertilizers application improved nutrient uptake (K, P, and N) and relative water content, biological yield and seed yield of the plant within irrigation levels. The activities of catalase, superoxide dismutase and ascorbate peroxidase were reduced under organic fertilizers such as vermicompost and manure compost as compared with control under drought stress. The plants of thyme showed a good response to organic fertilizers under water deficit circumstances, with vermicompost being the most effective.

The Role of Stress Modifier Biostimulants on Adaptive Strategy of Oregano Plant for Increasing Productivity under Water Shortage

“…Reduced growth and root activity, coupled with increased evaporation and transpiration from the crop area, have been reported as important factors contributing to the decline in RWC [ 8 ]. The decrease in leaf RWC due to severe irrigation regimes is primarily due to the reduced water absorption by the roots and increased water transpiration through the leaves, ultimately leading to the closure of leaf stomata [ 31 ]. The decline in the plant tissue turgor and RWC can represent an initial sign of stress having a direct influence on cell division and size [ 23 ].…”

“…When soil water availability is limited, the uptake of water, the solubility of nutrients in the soil, and their absorption by the roots decrease with negative consequences on photosynthesis and transpiration rates [ 9 , 31 ]. Consequently, plants reduce their growth to compensate for the water deficiency and lack of nutrients as observed in thyme plants under water stress [ 9 , 46 ].…”

Comprehensive evaluation of drought stress on medicinal plants: a meta-analysis

“…It is common for plant yield to decrease under drought conditions. Many studies have reported reductions in plant yield or biomass due to drought stress ( Chrysargyris et al, 2016 ; Aslani et al, 2023 ; Celikcan, Kocak & Kulak, 2021 ; Rahimi et al, 2023a , 2023b ; Abdi et al, 2018 ; Karimi et al, 2020 ). There are multiple mechanisms for drought stress to significantly decreases plant yield and biomass.…”

“…severe stress conditions. Generally, it is expected that chlorophyll levels decrease with stress, as many studies report reductions in chlorophyll under drought conditions ( Aslani et al, 2023 ; Rahimi et al, 2023a , 2023b , Imani et al, 2023 ). However, there are also few other studies suggests opposite that chlorophyll increases under drought stress ( Mulugeta, Sárosi & Radácsi, 2023 ; Emami Bistgani et al, 2017 ).…”

Increasing rainwater use efficiency, gross return, and grain protein of rain-fed maize under nitrate and urea nitrogen forms

“…The efficiency of water use is closely linked to the effectiveness of the use of precipitation since there is no other water source, especially in arid and semi-arid zones of the world where RUE had a stable value of ≈ 4 kg of dry matter ha -1 mm -1 rainfall (Varvel, 1995;Hatfield et al, 2001). Understanding RUE is critical in addressing the challenges of climate change, food security, and environmental degradation (associated with indiscriminate nitrogen fertilizer use) from both socioeconomic and technological perspectives (Zhang et al, 2015;Rahimi et al, 2023).…”