scholarly journals Castor bean (Ricinus communis L.) responses to drought stress and foliar application of Zn-nano fertilizer and humic acid: grain yield, oil content, antioxidant activity, and photosynthetic pigments

2021 ◽  
Vol 49 (4) ◽  
pp. 12003
Author(s):  
Ali RAHBARI ◽  
Jafar MASOUD SINAKI ◽  
Ali DAMAVANDI ◽  
Shahram REZVAN

Castor bean is considered as an important non-edible oilseed crop and source of castor oil, which has many applications ranging from cosmetics to the biofuels industry. Humic acid (HA) results from organic matter decomposition and is beneficial to plant growth and development. In the present study, a two-year experiment was conducted in Damghan, Iran, to study the physiological responses of castor bean to foliar application of zinc nano-chelate (Zn-nano) and HA under drought stress. The drought stress was used as the main treatment in three levels: normal irrigation as control, irrigation up to 75 BBCH scale (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie) (mild stress), and irrigation up to 65 BBCH (severe stress). Foliar application of HA in three levels (non-application, application of the recommended rate and two times more than the recommended rate), as well as Zn-nano fertilizer in two levels (application at 1.5 part per thousand (ppt) and non-application) as subplots. The drought stress, HA, and Zn-nano fertilizer could significantly affect the number of capsules, the number of seeds, 100-seed weight, seed yield, oil yield, protein percentage and yield, activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), and chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (total Chl) contents. In addition, severe drought stress resulted in reducing the number of capsules (33.9%), the number of seeds (32.7%), 100-grain weight (16.0%), as well as seed (43.0%), oil (59.3%), and protein (29.9%) yield. Based on the results, the highest yield components, oil and protein contents, and photosynthetic pigments were achieved in the foliar application of HA (recommended rate) and Zn-nano fertilizers under normal irrigation during the second year. Further, the foliar application of Zn-nano fertilizer led to a decrease in the activities of CAT, SOD, and POD enzymes. According to partial regression analysis, the recommended rate of HA application the changed the nature of relationships governing the characteristics, especially under drought stress conditions. Finally, the foliar application of HA (recommended rate) and Zn-nano fertilizers could create an excellent resistance to drought stress in castor under dry and semi-arid climate conditions by improving yield and yield components and physiological traits.

2019 ◽  
Vol 8 (2) ◽  
pp. 90-100
Author(s):  
Farhad Masoudi Sadaghiani ◽  
Majid Amini Dehaghi ◽  
Alireza Pirzad ◽  
Mohammad Hossein Fotokian

Introduction: Chamomile is one of the oldest and most valuable medicinal plants from the Asteraceae family. In addition to pharmaceutical uses, its essential oil is extensively used in perfumery, cosmetics, food industry and aromatherapy. This experiment was conducted with the aim of investigating the effect of osmolytes foliar application on biochemical characteristics, and the yield of German chamomile under drought stress conditions. Methods: The experiment was conducted as a split plot with randomized complete block design with three replications during the 2016-2017 growing season. Three levels of irrigation, 50 (control), 100 (mild stress) and 150 mm (severe stress) evaporation from evaporation pan class A, and spraying treatments, NS (no-spraying), W (distilled water), MeJA (methyl jasmonate), SA (salicylic acid), HA (humic acid), GB (glycine betaine) and GABA (γ-aminobutyric acid) were considered as the main plots and sub-plots, respectively. Results: Analyzed data indicated that proline, total soluble sugars (TSS), and essential oil yield were enhanced with the increase of drought intensity and the maximum amount was registered under severe stress, while the severe drought caused a substantial reduction in protein concentration of leaves and dried flower yield. Proline concentration of leaves significantly increased with exogenously applied spraying treatments under severe drought. All spraying treatments except GB under severe stress, caused higher TSS concentration than those subjected to mild stress. SA, HA, and GABA treated plants had significantly higher protein concentration compared to NS treatment. Plants that treated with GABA had the highest dried flower and essential oil yield. Conclusion: The present study suggests that osmolytes foliar application can ameliorate the detrimental effects of drought on chamomile plant through alteration in yield and biochemical variables.


2004 ◽  
Vol 55 (7) ◽  
pp. 797 ◽  
Author(s):  
D. L. Sharma ◽  
W. K. Anderson

Small grains that pass through a 2-mm slotted screen (sievings or screenings) are one of the most important causes of price dockages of wheat in Australia because grain size variation greatly affects flour yield and commercial value. The aims of this study were to examine the effects of season, time of sowing, plant population, and applied nitrogen, and their interactions with cultivars, on small grain screenings. Twenty-one field experiments involving 16 new cultivars and elite crossbreds, and various management variables, were conducted in the medium (annual rainfall 325–450 mm) and low (annual rainfall <325 mm) rainfall zones of the Northern Agricultural Region of Western Australia over 3 diverse cropping seasons (1999–2001). Rainfall events towards the end of the season were critical to the level of screenings. Screenings were higher in season 2000 with terminal drought stress, but were low in 2001 despite severe drought stress during early growth. Delayed seeding caused higher screenings in 1999 (average rainfall with even distribution) and in 2000 (terminal drought) but not consistently in 2001 when early drought stress restricted tillering and spike size thereby constraining the yield level. Strong varietal and time of sowing interactions were evident but the relationship between maturity group and the level of screenings was not consistent. Rather, the ability of cultivars to adjust yield components was more important; 82% of the total variance in small grain screenings was accounted for by a regression model based on variety-specific kernel weight, post-heading rainfall (from about 2 weeks before anthesis), and location factors. The effect of increasing plant population on screenings was mostly negative, with some minor exceptions for a few cultivars in the low-rainfall zone. As applied nitrogen was increased, screenings generally increased and cultivar influenced this trend more than rainfall zone. It is postulated that for a cultivar to be unaffected by applied nitrogen, it should have inherently higher grain weight as well as high stability of grain weight across nitrogen levels. Applied nitrogen had a significant effect on screenings only at higher plant populations. In experiments where the level of screenings exceeded 5%, the yield components that were significantly associated with screenings, in order of relative importance, were grain weight > grain number/area > grain number/head > grain yield. Cultivars differed in production of screenings in response to plant population, nitrogen fertiliser and sowing time. Harrismith was the most sensitive cultivar and Wyalkatchem was overall the most tolerant cultivar. Delayed seeding had the least effect on the screenings of cultivars Westonia, Carnamah, and Wyalkatchem. Carnamah was the most stable cultivar against higher levels of applied nitrogen, whereas Westonia required high plant numbers to contain screenings. It is concluded that cultivars can be classified according to specific sensitivities, and appropriate management practices may be suggested to growers.


2019 ◽  
Vol 25 (1) ◽  
pp. 70-78
Author(s):  
Fatemeh BAREKATI ◽  
Eslam MAJIDI HERVAN ◽  
Amir Hossein SHIRANI RAD ◽  
Ghorban NOOR MOHAMADI

2018 ◽  
Vol 30 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Rozita Kabiri ◽  
Ali Hatami ◽  
Hakimeh Oloumi ◽  
Mehdi Naghizadeh ◽  
Fatemeh Nasibi ◽  
...  

Abstract Melatonin, as an indoleamine molecule, regulates a wide range of physiological functions during the growth, morphogenesis and response of plants to biotic and abiotic stresses. In this research, the effect of exogenous application of melatonin (0 (distilled water), 50, 100 and 150 µM) to the leaves of Moldavian balm plants grown under different levels of drought stress (100% (control), 80%, 60% and 40% of field water capacity) was investigated. The results indicate that plants which were treated with 100 µM melatonin showed the greatest leaf surface area, lateral branching, flower length and activities of antioxidant enzymes (superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase). Foliar application of 100 µM melatonin had no significant difference in catalase activity in comparison with the control and other concentrations of melatonin under normal, moderate and severe drought stress conditions. The lowest H2O2 content and lipid peroxidation (electrolyte leakage, concentrations of malondialdehyde and other aldehydes) were obtained at the concentration of 100 µM melatonin under severe drought stress. This concentration also significantly increased the chlorophyll content and enhanced the relative water content; however, foliar application of 100 µM melatonin had no significant effect on leaf length and proline content compared with the control under normal and stress conditions. The obtained results suggested that foliar application of 100 µM melatonin was more effective than the concentrations of 50 and 150 µM melatonin in reducing the adverse effects of moderate and severe drought stress.


2018 ◽  
Vol 40 (1) ◽  
pp. 39392 ◽  
Author(s):  
Clístenes Williams Araújo do Nascimento ◽  
Marise Conceição Marques

 The remediation of lead-contaminated areas poses a serious challenge to soil chemists because Pb has low solubility in soil. Thus, Pb phytostabilization is considered to be an attractive remediation technique. Castor bean (Ricinus communis) is an oilseed crop known for its tolerance to heavy metals, and our aim was to assess the early detection of Pb toxicity and the effects of Pb on the biomass, photosynthetic pigments, antioxidative enzyme activities, and total soluble proteins of this plant. Specimens were grown in a nutrient solution spiked with Pb concentrations of 25, 50, 100, 150, or 200 µmol L-1. A control without Pb was also grown. The results show that X-ray chlorophyll fluorescence is an efficient technique for the early detection of photosystem II alterations driven by Pb toxicity. Castor bean was tolerant to the Pb doses tested; plants presented no changes in photosynthetic pigments, defense enzyme activities, or total soluble proteins in leaves. Given its ability to tolerate and accumulate Pb in its roots, castor bean is a viable alternative for phytostabilization and phytoattenuation of lead-contaminated areas. It is also economically attractive for industrial and biofuel oil production while being used for remediation. 


2011 ◽  
Vol 23 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Gabriela B. Arcoverde ◽  
Bruno M. Rodrigues ◽  
Marcelo F. Pompelli ◽  
Mauro G. Santos

Stomatal conductance (g s), transpiration (E), relative water content (RWC), superoxide dismutase activity (SOD), malondialdehyde (MDA), leaf carbohydrate soluble (LCS), free amino acids (FAA) and total protein (TP) content were measured under mild and severe drought stress in young potted Jatropha curcas L. in the greenhouse. The plants were kept for 12 days under three different water regimes, control (well hydrated), 50% irrigation control (mild stress) and 25% (severe stress), after rehydration were measured on the second and fourth day. Both mild and severe stress decreased g s and E; however, only severe stress reduced LCS, FAA and TP content and increased SOD activity (70%) and MDA content (60%) compared with the control. Moreover, under these conditions the plants showed severe leaf senescence. These results show that only severe drought stress decrease foliar metabolism in potted plants. These results show that severe drought decreased metabolism and leaf RWC, in potted plants. However, 48 h under a moderate stress is enough to drive the stomatal control is the main barrier against water loss. Finally, in the fourth day after rehydration the plants under a moderate and severe drought even had a g s and E reduced in both evaluation periods.


2021 ◽  
Vol 12 ◽  
Author(s):  
Marziyeh Jafari ◽  
Alireza Shahsavar

Plant secondary metabolites are compounds that play an important role in plant interactions and defense. Persian lime and Mexican lime as the two most important sour lime varieties with high levels of secondary metabolites, are widely cultivated in tropical and subtropical areas. Melatonin is a pleiotropic molecule that plays a key role in protecting plants against drought stress through regulating the secondary metabolite biosynthesis pathway. This study was performed as a factorial experiment consisting of three factors in a completely randomized design (CRD), including four concentrations of melatonin (0, 50, 100, and 150 μM), three levels of drought stress [100% (control), 75% (moderate stress), and 40% (severe stress) field capacity (FC)], and two Citrus cultivars. The experiment was conducted for 60 days in a greenhouse condition. Based on the results of this study under severe drought stress, melatonin-treated crops had higher total flavonoid and total phenolic contents than the untreated crops. The highest level of essential oils components was observed on 100 μM foliar application of melatonin under severe drought stress in both varieties. The main component of the essential oil was limonene in both Citrus species. Moreover, based on the analysis of the results, hesperidin was the main polyphenol in both varieties. Since the use of melatonin often increases the production of secondary metabolites, this study can be considered as a very effective method for controlling the adverse effects of drought stress in citrus for both industrial and horticultural aims.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Heba A.A. A. Hegazy ◽  
A. E. Awad ◽  
M. A. I. Abdelkader

In order to amend the harmful effect of soil salinity stress in common sage plants by foliar spray with salicylic acid (SA) and humic acid (HA), two pot experiments were conducted at the Nursery of ornamental plants, Agric. Fac., Zagazig Univ., Sharkia Governorate, Egypt in lath house during the two winter consecutive seasons of 2018/2019 and 2019/2020. The aiming of this work was to investigate the effect of foliar application treatments i.e., sprayed with distilled water (control), 200 ppm salicylic acid (SA), 750 ppm humic acid (HA), 1500 ppm HA, 200 ppm SA+750 ppm HA and 200 ppm SA+1500 ppm HA under various soil salinity levels (0.0, 1000 and 2000 ppm) as well as their combinations on yield components, salt resistance index and volatile oil production as well as some chemical constituents of Salvia officinalis plants. These experiments were arranged in a split-plot design with three replicates. The main plots were occupied by different soil salinity levels and the sub plots were entitled to different salicylic acid and humic acid acids concentrations. The obtained results referred to that herb fresh and dry weights per plant as yield components, volatile oil percentage and volatile oil yield per plant as volatile oil production as well as salt resistance index (%) were recorded. Also, total carbohydrates percentage and total chlorophyll (SPAD unit) in sage leaves was determined. Results showed that using soil salinity levels (1000 and 2000 ppm) significantly decreased yield components, volatile oil yield per plant, total carbohydrates percentage and total chlorophyll content compared to control. In contrast, increasing soil salinity levels gradually increased volatile oil percentage and proline content. In addition, the maximum values of the most of all above mentioned traits were achieved by treating sage plants with 200 ppm SA+1500 ppm HA. Generally, it could conclude that 200 ppm SA+750 or 1500 ppm HA, showed a uniform influence in qualifying of common sage y


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254452
Author(s):  
Shahbaz Khan ◽  
Abdul Basit ◽  
Muhammad Bilal Hafeez ◽  
Sohail Irshad ◽  
Saqib Bashir ◽  
...  

Changing climate, food shortage, water scarcity and rapidly increasing population are some of the emerging challenges globally. Drought stress is the most devastating threat for agricultural productivity. Natural plant growth substances are intensively used to improve the productivity of crop plants grown under stressed and benign environments. The current study evaluated whether leaf extract of different moringa (Moringa oleifera L.) could play a role in improving drought-tolerance of rice (Oryza sativa L.). Rice plants were grown under three drought conditions, i.e., no, moderate and severe drought (100, 75 and 50% field capacity, respectively). Moringa leaf extract (MLE) obtained from four landraces (Multan, Faisalabad, D. G. Khan and exotic landrace from India) was applied during critical crop growth stages, i.e., tillering, panicle initiation and grain filling. Drought stress adversely affected the gas exchange attributes, photosynthetic pigments, antioxidant enzymes’ activities, yield and quality parameters of rice. Application of MLE from all landraces significantly improved physiological, biochemical and yield parameters under stressed and normal environmental conditions. The highest improvement in gas exchange traits (photosynthetic rate, stomatal conductance and respiration rate), photosynthetic pigments (chlorophyll a, b and carotenoids) and enzymatic activities (superoxide dismutase, catalase) and oxidative marker (H2O2) was recorded with MLE obtained from Faisalabad landrace. The application of MLE of Faisalabad landrace also improved yield and grain quality of rice grown under drought stress as well as drought-free environment. Thus, MLE of Faisalabad can be successfully used to improve growth, productivity and grain quality of rice under drought stress.


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