Agriculture and horticulture
A. Koushki; A. Alinejadian-Bidabadi; A. Maleki
Abstract
To investigate the effects of rice husk biochar application on the various physiological and biochemical characteristics (fresh and aerial parts dry weight, plant height, percentage and essential oil yield,and content of chlorophylls, carotenoids, nitrogen, phosphorus, and potassium) of peppermint ...
Read More
To investigate the effects of rice husk biochar application on the various physiological and biochemical characteristics (fresh and aerial parts dry weight, plant height, percentage and essential oil yield,and content of chlorophylls, carotenoids, nitrogen, phosphorus, and potassium) of peppermint (Mentha piperita L.) under different irrigation regimes, a factorial pot experiment with different levels of biochar (0, 3, and 6 t.ha-1) and irrigation (100% of full irrigation (control), 60, 80, and 120% of full irrigation) was conducted in a completely randomized design with four replications in the research greenhouse of Lorestan University in 2019. The results showed that the highest and lowest of aerial parts fresh weight were obtained in the 3 t.ha-1 biochar + 120% of full irrigation (24.2 g.pot-1) and 3 t.ha-1 biochar + 60% of full irrigation (13.3 g.pot-1) treatments, respectively. At the 60% of full irrigation level, the dry weight, height, essential oil yield, and N and P concentration of the plant aerial parts significantly decreased by 39.8, 33.3, 26.2, 17.2, and 8.7%, respectively compared to the control; while the essential oil percentage and K concentration of aerial parts had an increasing trend. The amount of a, b, and total chlorophyll, and carotenoids decreased under the water stress conditions. The highest amount of total chlorophyll was observed in the 6 t.ha-1 biochar + 100% of full irrigation treatment. The application of 6 t.ha-1 biochar increased the fresh and aerial parts dry weight, plant height, percentage and essential oil yield, photosynthetic pigments, and N, P, and K concentration of aerial parts compared to the no biochar application, significantly. The results showed that the 6 t.ha-1 biochar + 120% of full irrigation treatment increased most of the traits studied. However, due to the importance of peppermint in terms of essential oil production, the highest essential oil percentage was obtained at the highest level of water stress.
F. Salarpour; H. Farahbakhsh
Abstract
Recently, the application of SA has increased to improve plants’ resistance to stresses such as drought. Hence to investigate SA effects on morphophysiological characteristics of Fennel (Foeniculum vulgare Mill.) under drought stress, a split plot experiment based on latin square design with three ...
Read More
Recently, the application of SA has increased to improve plants’ resistance to stresses such as drought. Hence to investigate SA effects on morphophysiological characteristics of Fennel (Foeniculum vulgare Mill.) under drought stress, a split plot experiment based on latin square design with three replications was carried out at the research farm of Shahid Bahonar University of Kerman in 2012. Three levels of drought stress (50, 75 and 100% of field capacity) and three concentrations of SA (0, 0.5 and 1mM) were considered as main and sub-plot treatments, respectively. Foliar application of SA was performed at 3-to 4-leaf growth stage and before application of drought stress. Results showed that the drought stress reduced the number of fertile umbel/plant, the number of fertile umbellate/umbel, the number of grains/umbellate, relative water content, chlorophyll, carotenoids and grain yield, while increased electrolyte leakage when compared with control. Salicylic acid reduced electrolyte leakage, while increased the number of fertile umbel/plant, the number of fertile umbellate/umbel, the number of grains/umbellate, RWC, chlorophyll, carotenoids and grain yield when compared to control (No SA application). Interaction of drought stress × SA on the number of fertile umbel/plant, the number of fertile umbellate/umbel, RWC, carotenoids and grain yield was significant. Increasing photosynthetic pigments, RWC and decreasing electrolyte leakage indicates a reduction in oxidative damage and implies SA role in tolerance of fennel to drought stress.