Agriculture and horticulture
Mohammad Hadi Shojaei Baghini; Mahdi Naghizadeh
Abstract
Background and objectives: Cumin (Cuminum cyminum L.) is one of the oldest aromatic plants in the world, known medicinally as the second domesticated medicinal plant in Iran. Drought stress, as oxidative stress, affects plant biochemical, physiological, and morphological responses. One of the ways to ...
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Background and objectives: Cumin (Cuminum cyminum L.) is one of the oldest aromatic plants in the world, known medicinally as the second domesticated medicinal plant in Iran. Drought stress, as oxidative stress, affects plant biochemical, physiological, and morphological responses. One of the ways to increase plants' resistance to environmental stress is to use plant growth regulators such as brassinosteroids and melatonin. These hormones increase plant performance in both stress and non-stress conditions. Plant growth regulators, by affecting plant metabolites, stimulating phytohormone biosynthesis, enhancing nutrient absorption, improving defense mechanisms, stimulating root growth, and improving gas exchange, contribute to plants' quantitative and qualitative performance in stress and non-stress conditions. Although some research shows that the use of plant growth regulators such as brassinosteroid and melatonin, which are of natural origin and compatible with the environment, has a significant effect on reducing adverse effects caused by environmental stresses; however, the combined use of these plant hormones is less reported. Therefore, in this research, the influence of the foliar application of brassinosteroid and melatonin on some physiological traits, including amount of malondialdehyde, hydrogen peroxide, electrolyte leakage, activity of antioxidant enzymes, accumulation of carbohydrates and proline, malondialdehyde, hydrogen peroxide as well as quantitative and qualitative yield of cumin was examined under water deficit conditions.Methodology: This research was conducted in the research greenhouse of the Faculty of Agriculture, Shahid Bahonar University, Kerman, Iran. A factorial experiment in a randomized complete block design with six replications was carried out in 2022. The experimental treatments included different levels of drought stress (100 % and 50 % field capacity; F.C.), melatonin (0 and 100 μM), and brassinosteroid (0 and 0.75 μM).Results: The results showed that water deficit increased the amount of malondialdehyde, hydrogen peroxide, electrolyte leakage, activity of antioxidant enzymes (peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) and superoxide dismutase (SOD)), as well as raised the accumulation of carbohydrates and proline in cumin plants. Indeed, brassinosteroids and melatonin significantly increased antioxidant enzyme activities and the concentrations of osmolytes. It also decreased the levels of malondialdehyde, hydrogen peroxide as well and electrolyte leakage in drought-stressed plants. Drought stress resulted in reduced cumin grain yield. In contrast, under these conditions, the percentage of cumin seed essential oil was increased. Foliar application of brassinosteroid and melatonin in stress and non-stress conditions improved cumin yield.Conclusion: Overall, it was concluded that the use of brassinosteroid and melatonin increased the resistance of cumin plants against drought stress by increasing the activity of antioxidant enzymes, increasing the accumulation of compatible osmolytes such as proline and carbohydrate, and maintaining the stability of the membrane and ultimately enhancing the yield of cumin seeds. The application of melatonin and brassinosteroid also affected the quality of the product and increased the percentage of cumin essential oil; however, the positive effects of brassinosteroid and melatonin were greater than those of brassinosteroid or melatonin applied separately.
Improvement and breeding
M. Naghizadeh; R. Kabiri; K. Maghsoudi
Abstract
Ascorbic acid and melatonin as the biostimulants affect the biosynthesis of phytohormones, facilitate and increase the nutrients uptake, enhance the defense mechanisms, stimulate the root growth, and finally, increase the quality and quantity of the product by affecting the plant metabolites. This study ...
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Ascorbic acid and melatonin as the biostimulants affect the biosynthesis of phytohormones, facilitate and increase the nutrients uptake, enhance the defense mechanisms, stimulate the root growth, and finally, increase the quality and quantity of the product by affecting the plant metabolites. This study was conducted in a randomized complete block design with three replications to investigate the effects of foliar application of melatonin and ascorbic acid on the grain yield and mucilage content of Plantago ovata Forssk. in the research greenhouse of Bardsir Faculty of Agriculture, Shahid Bahonar University of Kerman in 2020. The experimental treatments included the foliar application of distilled water (control), melatonin 100 μM, ascorbic acid 100 μM, and melatonin 100 μM + ascorbic acid 100 μM. The foliar application treatments continued from the time of complete establishment of seedlings (3-4 leaves) to the physiological maturity stage of seeds (four times every two weeks). The results showed that the foliar application of melatonin and ascorbic acid (single and combined application) enhanced the number of tillers per plant, number of spikes per plant, spike length, number of seeds per spike, and 1000-seed weight significantly. The highest grain yield was obtained from the foliar application of melatonin (59.98 g.m-2) and melatonin + ascorbic acid (61.85 g.m-2) without statistically significant differences with each other. The ascorbic acid foliar application also significantly increased the grain yield by 6.61% compared to the control. The foliar application of ascorbic acid, melatonin, and melatonin + ascorbic acid increased the mucilage content by 12.29, 19.89, and 23.80%, respectively compared to the control. The application of melatonin alone or in combination with the ascorbic acid, without statistically significant differences with each other, had the greatest positive effect on increasing the mucilage percentage. The mucilage yield was obtained 10.03, 13.47, 14.94, and 15.64 g.m-2 in the control, ascorbic acid, melatonin, and melatonin + ascorbic acid treatments, respectively. Based on the results, it can be concluded that the foliar application of melatonin and ascorbic acid could improve the quantitative and qualitative yield of P. ovata, and among the treatments their combined application was more effective.
Agriculture and horticulture
M. Naghizadeh; R. Moradi
Abstract
This study was conducted to investigate the potential of lavender (Lavandula angustifolia Mill.) and chamomile (Matricaria chamomilla L.) additive intercropping to improve the radiation use efficiency as a factorial based on the randomized complete block design with three replications at the research ...
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This study was conducted to investigate the potential of lavender (Lavandula angustifolia Mill.) and chamomile (Matricaria chamomilla L.) additive intercropping to improve the radiation use efficiency as a factorial based on the randomized complete block design with three replications at the research farm of Bardsir Agricultural Faculty, Shahid Bahonar University of Kerman, in 2018-2019 crop year. The experimental treatments included the fertilizer at four levels (1- Control, 2- NPK: 69-46-25 kg ha-1, 3- Cow manure: 20 t ha-1, and 4- Combination the half values of NPK and cow manure) and the planting pattern at three levels (1- Sole cropping of lavender, 2- Sole cropping of chamomile, and 3- Additive intercropping of lavender (main plant) and chamomile (associated plant)). The results showed that the total leaf area index of the two plants in intercropping was significantly higher than the sole cropping of them. The combined application of cow manure + NPK caused the highest lavender dry matter (DM) (868 kg ha-1), chamomile flower yield (366 kg ha-1), essential oil percentage of chamomile (0.56%) and lavender (0.80%), and radiation interception (1321 MJ m-2) in all the planting patterns. There was no significant difference between the planting patterns in terms of essential oil percentage. Due to the canopy overlap of the two plants in the intercropping, the value of photosynthetic active radiation (PAR) intercepted during the growing season in the intercropping treatment was higher than the sole cropping of both plants. The land equivalent ratio (LER) in terms of PAR (LERPAR) varied between 1.33 and 1.37 in fertilizer treatments. The highest radiation use efficiency (1.63 g DM MJ-1 radiation) was obtained for chamomile in the intercropping at the cow manure + NPK treatment. In general, the results illustrated that the application of cow manure + NPK treatment and intercropping of lavender and chamomile could be an appropriate approach for more efficient radiation use and improving the quantitative and qualitative yield of the two plants.
