Growth and yield of rice under variable application methods of zinc with and without arbuscular mycorrhizae in normal and saline soils

Salinity is a major abiotic stress that adversely affects the crop's growth, especially cereals. It caused an ionic imbalance in soils, resulting in poor uptake of micronutrients. Among these micronutrients, zinc (Zn) is essential when cultivating cereals like rice. On the other hand, application methods of micronutrients, i.e., Zn, can over this issue in salt-affected soils. Scientists also recommend the inoculation of arbuscular mycorrhizae (AMF) to improve Zn uptake and alleviate salinity stress. That’s why the current study was conducted to enhance rice production in salt-affected soils using different application methods of Zn with and without AMF. For that, 12 treatments were applied in 3 replications following a randomized complete block design (RCBD). Results showed that AMF inoculation under ZnS performed significantly best in normal soil for the enhancement in shoot fresh weight (47.14%) and dry weight (46.36), photosynthetic rate (47.09%), transpiration rate (50.76%) and stomatal conductance (67.44%) over SS. A significant improvement in Zn grains concentration also validated the efficacious functioning of ZnS over No Zn and ZnF with AMF+SS. In conclusion, ZnS with AMF is a good approach for the alleviation of salinity stress and improvement in Zn grains concentration in rice. More investigations at the field level are suggested on other cereal crops in different climates to proclaim ZnS with AMF as the best treatment for mitigating salinity stress and enhancing Zn concentration in cereals grains

Impact of seed priming and compost application on yield and growth attributes of cluster bean in salinity stress

Guar bean is a commercial and export crop in Pakistan. The increase in the saline area due to arid climatic conditions in Pakistan is an excellent threat to guar bean production. Guar can tolerate salinity stress to some specific extent, but its production can be affected above it. Seed priming helps accept salinity stress in many crops, but limited studies have been conducted on its effect on cluster beans' productivity. Therefore, it is essential to evaluate new cultivars of cluster bean with seed priming before their recommendations to cultivate on saline lands. Thus, two years of field experiments (2018 and 2019) were conducted at the Research Farm of MNS-University, Multan, Pakistan, to evaluate the seed treatment (hydropriming and potassium nitrate) and soil treatment (compost) on four cultivars of guar bean (BR-2017, S-5885, S-6165, and S-6547). The treatments were applied in a Randomized Complete Block Design (RCBD) with the split-plot arrangement. The medicines (control, hydropriming, potassium nitrate, and compost) are in main plots, with their sub-plot variety. The seed of the guar bean was dipped in deionized water for hydropriming and in 2% potassium nitrate solution for potassium nitrate seed priming for two hours before sowing while compost (10 Mg ha^-1) was applied during the seedbed preparation. BR-2017, among other cultivars (S-6165 and S-6547), showed higher plant height, grains per pod, fodder yield, leaf area index, relative water contents, and transpiration rate. The BR-2017 showed 8.33, 94.9, and 69.5% higher grains per pod than S-5885, S-6165, and S-6547, respectively, with potassium nitrate application in crop growing season 2018. The peroxidase, super oxidase dismutase, catalase, potassium contents in the Leaf, potassium contents in the root, and sodium contents in the Leaf and root were higher in variety S-6165. The potassium nitrate seed application increased the grains per pod, pod length, fodder yield, leaf area index, peroxidase, catalase, potassium content in Leaf and root, and transpiration rate. The potassium nitrate priming showed higher potassium contents in the root by 6.8, 2.2, and 3.3% compared to control hydropriming and compost treatments in 2019. Thus, BR-2017 and S-6165 with potassium nitrate seed priming can help achieve the yield potential of the guar bean. However, long-term field studies on different climatic zones are recommended to revalidate the current findings

Exogenous application of proline and glycine betaine mitigates nickel toxicity in mung bean plants by up-regulating growth, physiological and yield attributes

Nickel (Ni) toxicity is a serious threat to plant yield, especially when present in the soil, and its amount is increasing with each passing day. This study addresses the mitigation of this toxicity using proline and glycine betaine. The effect of exogenous glycine betaine (50, 100 mM) and proline (30, 60 mM) application on the morpho-physiological and yield attributes of Mung bean [Vigna radiata (L.) Wilczek] under varying levels of nickel stress (0, 100, 125, and 150 mg Ni/kg of soil) were investigated in this study. Data for growth and yield parameters were collected after 30, 45, and 65 days, respectively. The results showed that under nickel stress, root length, shoot length, fresh weight, chlorophyll contents, gas exchange characteristics, and yield attributes were reduced compared to the control. Foliar applications of proline (30, 60 mM) and glycine betaine (50 mM) improved all growth parameters, gas exchange characteristics, leaf carotenoid content, and yield attributes. The root length, shoot length, and gas exchange characteristics all correlated positively and significantly. On the other hand, root length, chlorophyll, and photosynthetic rate had a negative correlation. In Ni-stressed plants, the application of 100 mM glycine betaine caused additional damage. The exogenous application of 30 mM proline appeared to be the most effective treatment for nickel toxicity in mung bean plants. The results show that nickel toxicity has a negative impact on mung bean growth and yield, whereas optimal doses of both osmolytes have a high potential to alleviate nickel toxicity. The growth of mung bean was enhanced by foliar sprays of proline and glycine betaine, which improved gas exchange and increased chlorophyll and carotenoid levels. In the future, the identified treatments can optimally be used to obtain a high yield after the resilience development

Evaluating the effects of cadmium under saline conditions on leafy vegetables by using acidified biochar

Crop development and yield are hampered by salinity and heavy metal (HM) stresses. Heavy metals enter the food chain due to crop plants' absorption when cultivated in areas where HM exceed their threshold levels. Among different heavy metals, cadmium (Cd) is a notorious one. Higher-water solubility made Cd a potential toxin for crops and consumers. On the other hand, salinity also deteriorates plant productivity by negatively affecting many morpho-physiological and genetic attributes. To address these issues, i.e., HM toxicity and salinity stress, acidified biochar can be a game changer. In recent years, the use of biochar has gained increasing attention. Due to the characteristic structure of the biochar, it absorbs Cd and releases critical micronutrients in the soil. Because of its many micropores and significant ion exchange properties, biochar is an appropriate amendment for improving soil properties and immobilizing Cd. Furthermore, improvement in soil microbial population can also play an imperative role in developing better rhizosphere ecology. That’s why the current review addressed the detrimental effects of salinity and Cd, and the positive impact of biochar on crop productivity. This review also covers the knowledge gap regarding using acidified biochar in alkaline soils. The emphasis was placed on elaborating the beneficial impacts of acidified biochar on plant output and soil composition maintenance

Innate strategic potential of olive trees to mitigate drought in water deficit regimes

Olive is becoming most interesting for cultivation in arid and semiarid areas owing to its economic significance, drought tolerance, and capacity to withstand shallow poor-quality soils beyond the Mediterranean Region. The study area was not included among the suitable areas for olive cultivation during the first phase in Pakistan. The evaluation of olive germplasm under water deficit at new climatic zones has become a dire need of the moment under the climate change scenario. The present study was designed to evaluate the natural adaptability potential of olive cultivars of diverse geographical origins to water scarcity in the study area. Four selected cultivars (BARI-1, Ottobratica, Leccino, and BARI-2) were grown under hotter and dryer climates and subjected to four water deficit levels (25%, 50%, 75%, and 100% field capacity). The effects of olive cultivars, water deficit levels, and their interactions on the following parameters were estimated using standard protocols. The extent of all considered parameters was diversely affected and significantly different among the cultivars except chlorophyll contents. The highest amounts of TFA, TSS, POD, and APX were found in BARI-1, followed by Leccino, Ottobratica, and BARI-2. Leccino was better than BARI-1 in proline, SOD, and CAT, while BARI-2 occupied the lowest rank. The highest protein contents and chlorophyll were found in BARI-2 and Ottobratica, respectively, compared to others. The pattern of variation among all the above parameters was highly significant and directly correlated with the deficit levels except protein contents. TSP decreased with increasing water deficit, while all other parameters increased with increasing water stress. There was no significant difference between 75% and 50% FC levels in chlorophyll contents. The highest value of proline and the augmented activities of POD and APX were found in Leccino at 25% FC, while CAT activity in the same cultivar was higher at 75% FC. 25% FC announced the utmost parts of TFA, TSS, and SOD activity in Bari-1. 75% FC showed the highest rate of TSP in Bari-2 and chlorophyll contents by 75% FC in Ottobratica. Generally, based on observations, all studied cultivars seem to be drought tolerant, while Leccino, Bari-1, Bari-2, and Ottobratica were more tolerant from one another, respectively, and may survive under water deficit conditions (25% FC) successfully at the climate of the study area

Growth of spinach as influenced by biochar and Bacillus endophyticus IGPEB 33 in drought condition

Drought is a major problem in the world, cause of various crops yield loss among abiotic factor. The impact of biochar and Bacillus endophyticus IGPEB 33 on spinach growth and root parameters and soil enzyme activities in drought conditions was studied. A net-house experiment was carried out at IGPEB, Kibray, Uzbekistan. Four treatments, such as control, biochar alone, B. endophyticus IGPEB 33 alone, and a combination of biochar and B. endophyticus IGPEB 33, were used in the experiment. After sixty days, plant growth and root traits were measured. The results showed that the combined application of biochar and B. endophyticus IGPEB 33 significantly enhanced plant height by 45%, leaf number by 61%, and leaf length by 58% compared to those of the control plants under drought conditions. Moreover, Bacillus endophyticus IGPEB 33 with biochar significantly enhanced root length, projected area, root surface area, root volume, root diameter, and soil enzyme activities (catalase, urease, invertase) compared to the controls. The results concluded that the joint application of biochar 1% and Bacillus endophyticus IGPEB 33 positively influences soil enzyme activities, root parameters, and growth in spinach under drought stress

Alleviation of drought stress in high yielding modern barley cultivar with the help of combinations of endophytic bacteria and vitamin B

Barley (Hordeum vulgare L.) is amongst the most extensively cultivated food crops around the globe. Increasing pollution and environmental constraints negatively affect overall climatic features. The effects of these agents on agricultural dynamics have motivated various biotic and abiotic stresses that have significantly decreased global rainfall patterns causing drought conditions and affecting sustainable agriculture directly. Endophytes have recently gained heedfulness for their usage in the alleviation of several types of stresses. Similarly, the use of certain growth regulators like thiamine (vitamin B) is also proved to be a promising approach. A pot investigation was done on barley to determine the impact of seed coating using thiamine (Vitamin B) and soil inoculation of Pseudomonas putida and Bacillus subtilis bacterial strains on drought stress mitigation at two irrigation regimes. The results showed that under drought stress, drought-tolerant endophytic bacteria improved barley seedling development and biochemical characteristics. The bacterial strain Pseudomonas putida and thiamine significantly decreased the severe impacts of drought stress, according to morphological, biochemical, and molecular characterization of barley. Combined bacterial strains and vitamin B enhanced plant vigour under drought stress. Our data validate the use of bacterial root endophytes as a potential tool for diminishing the impacts of drought on the early growth stages of barley seedlings

Effect of soil and foliar applied micronutrient consortia on alleviation of micronutrient deficiency in kinnow (Citrus noblis x Citrus deliciosa)

The deficiency of micronutrients in citrus orchards is a big issue. It not only deteriorates the fruit quality, buts also plays a major role in decreasing the yield. High soil pH, electrical conductivity (EC), CaCO_3, and low organic matter contents are some of the vital factors which usually decrease the uptake of applied micronutrients in plants. On the other hand, foliar application of micronutrients is considered as one of the meaningful approaches to overcome this issue; it not only increases nutrient uptake, but also decreases the application rate of inorganic fertilizer. Scientists have worked on soil and foliar application of micronutrients to plants, but limited literature is available on the effect of micronutrient consortia on citrus. Due to this reason, the current study was conducted to explore the effectiveness of application of micronutrient consortia to alleviate micronutrient deficiency in citrus. There were 10 treatments applied with 4 replications following a randomized complete block design. Results showed that application of T10 as soil (T1 +250 g ZnSO₄ +150 g borax + 550 g FeSO₄ +200 g CuSO₄ + 350 g MnSO₄/plant) and foliar application (T1 + 0.6% ZnSO₄ + 0.5% boric acid + 0.6% FeSO₄ + 0.5% CuSO₄ + 0.5%MnSO₄). remained significantly best compared to all other treatments for improving fruit weight, vertical diameter, horizontal diameter, number of seeds, and seed weight in citrus. A significant enhancement in the yield of citrus due to T10 as soil and foliar application validated the effectiveness of the treatment compared to the control. In conclusion, growers are recommended to apply T10 as soil (T1 +250 g ZnSO₄ +150 g borax + 550 g FeSO₄ +200 g CuSO₄ + 350 g MnSO₄/plant) and foliar application (T1 + 0.6% ZnSO₄ + 0.5% boric acid + 0.6% FeSO₄ + 0.5% CuSO₄ + 0.5%MnSO₄) for the improvement of citrus growth and yield.

Effect of temperatures and salinity on seed germination rate of rosary pea from Mount Vifa of Saudi Arabia

Abrus precatorius L. is a valuable herbaceous medicinal plant with a wide range of therapeutic properties. The present study aims to investigate some of the biological characteristics of Abrus precatorius in Saudi Arabia by studying its germination potential and shortening of its dormancy period at constant and varied temperature regimes under control and salt conditions. Seeds were collected from a wide thermal range of continuous and changing temperature systems and tested for their response to heat and salinity. Preliminary experiments have revealed that seeds could not germinate unless they were treated with H₂SO₄ to break dormancy. According to the findings, cock-eye seeds germinated much better in variable and constant temperature systems (25, 25/15, 30/20, 35/25°C). The germination rate was 98% at 35°C. It dropped to 26% at 5°C, MDG was zero seed/day, and T₅₀ was not obtained. After 20 days at 15°C. However, seedlings did not develop at low variable and constant temperatures (5, 15/5°C). The seeds of Abrus precatorius were observed to be resistant up to 400 mM NaCl. Salinity substantially affected the germination of A. precatorius seeds compared to the control (0 mM NaCl). With 200, 400 and 600 mM NaCl, the germination rate reduced by approximately 60 to 90 and 100%, respectively, compared to the control. This study will provide baseline data and help revive endangered species like A. precatorius plants and their critical adaptation for preserving Saudi Arabia's biodiversity and survival in highly salinized environments

Change in lettuce nutrients, soil enzymes, soil microbial biomass and activities under chromium toxicity

The toxicity of heavy metals in the soil plays a detrimental role in microbial activities. Higher concentrations of Cr causes restriction of enzyme secretion in soil by disturbing the microbial population and proliferation. On the other hand, the cultivation of crops in such Cr-contaminated soils also caused a significant decline in nutrient uptake in the plants. That’s why the current pot study was conducted to explore the impacts of different Cr application rates on soil enzymes activities and lettuce plants' nutrient concentration. A total of 6 treatments were applied in 5 replicates. The treatments include T0 =control (no Cr), T1=50 mg, T2=100 mg, T3=150 mg, T4=200 mg, and T5=250 mg Cr/kg soil. Results showed that increasing concentration of Cr toxicity caused a significant decrease in SMBP, SMBS, alkaline phosphatase activity, and arylsulphatase over control. A significant decline in macronutrient N, P, K, Ca, and Mg concentration in lettuce validated the negative impacts of Cr on lettuce when cultivated in Cr toxicity, i.e., 50, 100, 150, 200, and 250 mg Cr/kg soil. The increasing level of Cr also significantly minimized the concentration of Zn, Cu, Mn, Fe, and S in lettuce when grown in Cr-contaminated soil. In conclusion, increasing Cr toxicity is inversely related to soil enzymes activities and lettuce nutrient uptake. More in-depth investigations are required to explore the impacts of Cr on nutrient uptake in crops and enzyme activities in soil under different soil textures and cultivated crops type

Investigating the impact of microbial plant activator treatment at different dosages on the quality characteristics of saffron growth

Activators are products applied to plants or soils to enhance plant productivity and regulate physiological processes. Recently, activators have been used for sustainable crop management. However, few studies have investigated the use of activators for medicinal and aromatic plants and saffron cultivation. Therefore, this study aims to examinexamine the impact of various amounts of Albit, microbial plant activator, on corm and leaf quality focusing on sustainable saffron cultivation. Two separate experiments were conducted to apply activators to corm and leaves, with four different doses (0, 2, 4, 8 mL) used in each application. The weight of the harvested corm indicated that the activator application to the corm was the most effective, resulting in 331.90 g. The highest yield was obtained with the corm x 8 mL treatment, which produced 342.97 g, and the application x treatment interaction, which made346.20 g. When assessing the effect of activator application on saffron pharmacological agents, the highest average amount of safranal was obtained in the corm application with a concentration of 717.68 ppm.

Furthermore, further research is being conducted to develop additional methods for increasing plant resilience to drought stress, which is one of the significant impacts of global climate change. This study on microbial plant activators has revealed the performance components of saffron in dry conditions. In summary, the results of this study suggest that Albit application to corm and leaves has a positive effect on saffron growth and pharmacological properties, highlighting the potential of microbial plant activators for sustainable saffron cultivation. Further research is necessary to optimize the use of activators in different growth conditions and to explore their potential use in other medicinal and aromatic plants

Salicylic acid foliar spray promotes yield, yield components, and physiological characteristics in foxtail millet under drought stress

Drought is one of the major factors affecting plants' growth and development. , The application of plant hormones like salicylic acid (SA) is known to increase a crop’s resistance to drought stress (DS) and help plants grow under drought conditions. Therefore, the present study aimed to evaluate the effect of salicylic acid foliar spray (SAFS) on yield and yield components of foxtail millet under different levels of DS. The present study reports the effect of SA foliar spray on yield and its components in foxtail millet Basten cultivar under drought stress conditions with three irrigation levels (45%, 65%, and 85% humidity of field capacity) as the main factor and four SA levels (0 to 2 mM) as the subplot. The results revealed that the fresh forage yield (36.76 ton/ha) and plant height (89.6 cm) were obtained from control and three mM SAFS treatments. The highest stem yield (6.971 ton/ha), leaf yield (4.947 ton/ha), grain yield (2.568 ton/ha), panicle length (18.7 cm), seed number per panicle (3670), 1000-seed weight (3.64 g) and several leaves per plant (11.43) were obtained by foliar spraying of 1.0 mM SA under normal conditions. The maximum harvest index (61.66%) was obtained under moderate stress conditions and 1.0 mM SA foliar spray. The highest levels of chlorophyll a, b, and total chlorophyll were 6.35, 4.02, and 10.37 mg/WW, respectively, from the treatment without drought stress and the application of 1.0 mM SA. The results showed that spraying 1.0 and 3 mM SA under stress and normal conditions improved yield components in foxtail millet Basten cultivar in Sistan weather conditions.

Interactive potential effects of moringa leaf extracts and plant growth promoting rhizobacteria against aphid attack on a newly developed wheat variety

Wheat is an important agronomic staple crop compared with other cereals. Many factors, including abiotic and biotic stresses, can reduce wheat products, such as attacks by the insect-like aphid. The technologies of moringa leaf extracts (MLE) and plant growth-regulating rhizobacteria for the control of aphid attacks were studied in the current experiment to determine the effectiveness of non-pathogenic bacteria Pseudomonas fluorescens (WCS417r) and Moringa leaf extracts against aphid infestation in wheat. The investigation was laid out in three replicates arranged under a split-plot design with two factors as a treatment, i.e., MLE and P. fluorescens mixed with the soil of wheat seedlings, but MLE was sprayed as foliar application twice, at 20- and 30-days. The aphid-infested and non-infested plants were observed to check the validity of aimed objectives. It was observed that aphid infestation mitigated the plant's novel production due to decreased plant growth, metabolism, and specific physiological pathways. On the other hand, treatments of MLE and bacteria mitigated the devastating effects of aphid infestation and improved plant growth. Plant root and shoot characters were highly improved when compared with untreated plants. Photosynthetic rates were enhanced by 24-41%, and H₂O₂, AsA, phenolics, proline, and MDA were reduced by 25-52% because of applied treatments. All these improvements lead to stable crop production and are highly recommendable for sustainable agricultural practices

Synergistic effects of biochar and arbuscular mycorrhizal fungi on enhancing Elymus elymoides growth in saline coastal soil

The study aimed to investigate the effect of biochar (BC) application on soil properties, Elymus elymoides growth, and mycorrhizal fungi diversity. Soil samples were treated with different rates of BC (1%, 2%, and 5%) and inoculated with arbuscular mycorrhizal fungi (AMF) or without AMF. The results indicated that the application of BC at 2% and 5% rates significantly increased the soil pH by 4.3% and 5.8%, respectively. Moreover, the exchangeable potassium (K) levels showed a significant increase in soils treated with BC, i.e., K levels increasing by 66.7% and 211.1% at 2% and 5% BC application rates, respectively. Conversely, sodium (Na) levels in the soil decreased significantly with increasing BC application rates. The soil organic carbon (SOC) levels showed a significant increase in the treatment groups compared to the control group, with increases of 150%, 177.78%, and 222.17% in BC1, BC2, and BC5, respectively. The cation exchange capacity (CEC) values also showed a significant increase in BC1, BC2, and BC5, with increases of 14.81%, 29.63%, and 44.44%, respectively, compared to that in the control group. In terms of Elymus elymoides growth, BC2 showed the highest percent increase in plant height with 54.83%, reaching 27.33 cm, while BC1 and BC5 also had significant increases of 13.23% and 49.35%, respectively, reaching 20 cm and 26.33 cm. However, when AMF was added to the treatment groups, the plant growth decreased for all groups, with BC2 showing the highest percentage decrease of 28.07%, reaching 19.67 cm. The results of the mycorrhizal fungi diversity showed that biochar application had a significant effect on the growth and diversity of mycorrhizal fungi, with the BC and BC + AMF groups showing the most inhibitory effects. The addition of biochar had a negative effect on all types of mycorrhizal fungi, with the species of important genera such as Rhizophagus, Glomus, Clarediogous, and Redochera decreasing to 39.67%, 22.67%, 18%, and 16.33%, respectively. However, the addition of biochar and AMF together led to an increase in the abundance of Rhizophagus to 62.67%, Glomus to 67.67%, Clarediogous to 38.33%, and Redochera to 16.67%.

Silicon regulates growth, yield, physiological responses, and tissue concentration of lead in Brassica campestris L. grown in lead contaminated soil

Heavy metal contamination of agricultural land causes serious problems for the ecosystem. Industrial waste, sludge, petrol, fertilizers, paints, and explosive materials contribute to the occurrence of heavy metals, particularly lead (Pb), in the environment, which causes adverse effects on soil, plant, and human health. The accumulation of Pb interrupts plant growth, which becomes a part of the food chain, thereby compromising food safety. Various methods have been used to overcome the toxicity of Pb. Silicon (Si) can be utilized to protect agricultural plants from the damaging impacts of Pb. Brassica species are multipurpose and famous crops cultivated all over the world. Silicon plays a positive role to promote growth, yield, and the physiological attributes of specifically Brassica campestris L. cultivated in soils enriched with heavy metals. The main objective of this study was to assess the beneficial role of Si to promote growth, yield and physiological functions of Brassica campestris L. cultivated in the Pb-contaminated soil by reducing the Pb concentration in plant tissues. Therefore, a pot experiment was conducted to assess the effect of applied Pb [0 (control), 500 and 1000 mg kg^-1 soil] on the growth, some key physiological attributes, and yield of B. campestris at varying levels (0, 200 and 400 mg kg^-1 soil) of Si application. The results illustrated that Pb toxicity at 1000 mg kg^-1 caused a significant reduction of 27% in total chlorophyll contents, 88.4% in relative water contents, 85.7% in membrane stability index, 37.3% in plant height, 20.9% in root dry weights, and 70.2% in grain yield. The Si application improved physiological and growth parameters and reduced the concentration of Pb in plants. Thus, application of Si at 400 mg kg^-1 was found to be more effective in alleviating the harmful effects of Pb on the growth and yield of B. campestris grown in Pb-contaminated soil by reducing Pb concentration in shoots and grains