Search

Tomatoes are one of the most important vegetables in every home, especially in South Asian countries, used as a vegetable, ketchup, and condiment in many kitchen recipes. It is a good source of calcium, potassium, folate, vitamin A, vitamin K, and lycopene, which are beneficial for the human body and protect it against different diseases. Nutrient management is a key factor for the best quality production of tomato fruit. The present study was conducted to compare the efficiency of different calcium salts (calcium sulphate, calcium carbonate, calcium nitrate, and calcium chloride) in improving the growth, yield, and other quality-related parameters of tomatoes. A single field experiment was conducted and laid out according to the Randomized Complete Block Design (RCBD) with a single factor in the field and a Complete Randomized Design (CRD)) for postharvest fruit storage. The results obtained from this experiment suggest that plants treated with 2% calcium chloride solution exhibited the greatest plant height (85.27 cm), number of leaves (221), yield per plant (2.3 kg), ascorbate peroxidase (290.75 m mol s−1 kg−1), superoxide dismutase (7.13 m mol s−1 kg−1), catalase (18.74 m mol s−1 kg−1), total phenolics (2.44 mg g−1), and β carotene (0.48 µg g−1). During postharvest storage, the maximum shelf life (18 days), minimum disease incidence (4.78%), weight loss (6.61%), and ethylene production (119.6 µL C2H4 kg−1h−1) rate were also observed in calcium-treated fruits. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is one of the potential carcinogenic toxins for humans, plants, and animals. Higher uptake of Cd in plants causes a significant reduction in productivity that can be remediated using organic amendments. Biochar can absorb Cd and decrease its toxicity. However, the high pH of biochar minimizes its adaptation as an amendment in alkaline soils. As Cd is highly soluble in water, its uptake in rice is a major issue. That is why the current experiment was conducted to examine chemically produced acidified carbon (AC) effectiveness in alleviating Cd-induced stress in rice. There were three levels of Cd (0, 4, and 8 mg kg−1 soil) applied with three levels of AC (0, 0.5, and 1%) for the cultivation of rice irrigated with ground water (GW) and waste water irrigation (WW). Results confirmed that applying 1% AC improved plant height, spike length, and 1000 grains weight over 0% AC under GW and WW irrigations at 8 mg Cd kg−1 soil (8Cd) toxicity. A significant increase in photosynthetic rate, transpiration rate, and stomatal conductance by 1% AC validated its effectiveness in alleviating 8Cd stress in rice under GW and WW. Overall, 1% AC is an effective amendment in alleviating Cd toxicity in rice irrigated with GW and WW at 8Cd. More investigations are recommended at the field level to declare 1% AC as the most effective application rate for mitigating Cd stress in rice. [ABSTRACT FROM AUTHOR]

Less phosphorus (P) availability in calcareous alkaline soils is one of the major problems in achieving an optimum crop yield. Its deficiency in plants adversely affects growth and yield attributes. To overcome this issue, growers incorporate inorganic P fertilizers. However, the need for time in the sustainable management of soil fertility in terms of P. Farmyard manure (FYM) application is one of the most popular organic amendments in this regard. Thus, the current study was conducted to explore the best application rate of FYM in combination with inorganic P fertilizer single super phosphate (SSP). There were six treatments i.e., control (0F), 100%SSP (100P), 25% FYM and 75% SSP (25F+75P), 50% FYM and 50% SSP (50F+50P), 75% FYM and 25% SSP (75F+25P), and 100% FYM (100F+0P), applied in three replications. The design of the experiment was a randomized complete block design. For assessment of treatment response, two wheat cultivars (V1 = Pirsabak and V2 = Atta Habib) were used. Results showed that the application of 50F+50P significantly improved the plant height (20.69 and 32.01%), spike/m2 (35.19 and 30.10%), grain (41.10 and 38.16%), and leaf P (49.82 and 71.32%) compared to control in V1 and V2, respectively. A significant improvement in the grain and the biological yield of wheat V2 also validated the efficacious functioning of 50F+50P over control. In conclusion, 50F+50P has the potential to enhance wheat growth and nutrient concentration over control. More investigations are required for a more precise and balanced synchronization of FYM and SSP for the achievement of maximum wheat yield. [ABSTRACT FROM AUTHOR]

Management of organic matter and micronutrients is very important for the sustainable improvement of soil health. Poor soil organic matter usually results in lower availability of zinc (Zn) micronutrients in plants. Such deficiency in Zn causes a significant decrease in the growth and yield of crops. The need at the current time is to balance the application of organic amendments with Zn micronutrients to achieve optimum crop yields. Thus, the current study was conducted to investigate wheat, using compost as organic matter and Zn as a micronutrient. There were three levels of compost (i.e., control (0C), 5 t/ha (5C) and 10 t/ha (10C)) and four levels of Zn (control (0Zn), 2.5 kg Zn/ha (2.5Zn), 5.0 kg Zn/ha (5.0Zn) and 10.0 kg Zn/ha (10.0Zn)) applied with three replicates. The addition of 10C under 10.0Zn produced significantly better results for the maximum enhancement in plant height (8.08%), tillers/m2 (21.61%), spikes/m2 (22.33%) and spike length (40.50%) compared to 0C. Significant enhancements in 1000-grain weight, biological yield and grain yield also validated the effectiveness of 10C under 10.0Zn compared to 0C. In conclusion, application of 10C with 10.0Zn showed the potential to improve wheat growth and yield attributes. The addition of 10C with 10.0Zn also regulated soil mineral N, total soil N and extractable soil P. Further investigation is recommended with different soil textures to verify 10C with 10.0Zn as the best amendment for the enhancement of wheat yield in poor organic matter and Zn-deficient soils. [ABSTRACT FROM AUTHOR]

Diazotrophic endophytic bacteria (DEB) are the key drivers of nitrogen fixation in rainfed soil ecosystems and, hence, can influence the growth and yield of crop plants. Therefore, the present work investigated the structure and composition of the DEB community at different growth stages of field-grown pearl millet plants, employing the cultivation-dependent method. Diazotrophy of the bacterial isolates was confirmed by acetylene reduction assay and amplification of the nifH gene. ERIC-PCR-based DNA fingerprinting, followed by 16S rRNA gene analysis of isolates recovered at different time intervals, demonstrated the highest bacterial diversity during early (up to 28 DAS (Days after sowing)) and late (63 DAS onwards) stages, as compared to the vegetative growth stage (28–56 DAS). Among all species, Pseudomonas aeruginosa was the most dominant endophyte. Assuming modulation of the immune response as one of the tactics for successful colonization of P. aeruginosa PM389, we studied the expression of the profile of defense genes of wheat, used as a host plant, in response to P. aeruginosa inoculation. Most of the pathogenesis-related PR genes were induced initially (at 6 h after infection (HAI)), followed by their downregulation at 12 HAI. The trend of bacterial colonization was quantified by qPCR of 16S rRNAs. The results obtained in the present study indicated an attenuated defense response in host plants towards endophytic bacteria, which is an important feature that helps endophytes establish themselves inside the endosphere of roots. [ABSTRACT FROM AUTHOR]

Red cabbage is known as the millennium's functional food, which has a lot of importance in our diet because of the health-promoting ingredients present in it. The current study investigated the synergistic relationship of rhizospheric-competent microbial agents (Trichoderma harzianum, Pseudomonas fluorescens, and Bacillus subtilis) in modulating the performance of red cabbage under the field conditions of Middle Gangetic Plains, India. Growth parameters were studied at three developmental stages, viz., pre-cupping, early head formation, and maturity. Our results suggested that the dual application of T. harzianum + P. fluorescens along with the 75% recommended dose of fertilizers (RDF) increased the number of leaves (24.6), leaf area (537.2 cm2), root length (19.8 cm), and micronutrient uptake (Fe, Mn, and Cu) by head of the crop, whereas the co-inoculation of P. fluorescens and B. subtilis along with 75% RDF enhanced plant spread (39.0 cm), earliness (95.2 days), and Zn uptake. Maximum plant height (28.7 cm) and chlorophyll (SPAD, 77.3) were recorded in 100% RDF (120:60:60 kg ha−1) and the combination of T. harzianum + B. subtilis along with 75% RDF, respectively. Interestingly, consortium (T. harzianum + P. fluorescens) bio-primed plants recorded about 14% higher root length in comparison to plants receiving sole fertilizers. The regression analysis revealed a significant relationship of Fe and Mn uptake with chlorophyll (SPAD) and between Zn uptake and the earliness of the crop. The present study indicated that seedling bio-priming with the dual consortium of efficient bio-agents is a viable strategy to lessen our dependence on chemical fertilizers for improving red cabbage production. [ABSTRACT FROM AUTHOR]

Mango fruit quality plays a significant role in fruit storage. It also directly affects the economic value of fruit in the national and international markets. However, deterioration of soil health due to low organic matter is a major hurdle for mango growers. Scientists suggest incorporation of organic matter. However, high temperature and low precipitation lead to oxidation of organic residues in soil. On the other hand, biochar is gaining the attention of growers due to its resistance against decomposition. It can improve soil physicochemical attributes. Limited literature is available regarding biochar effects on the quality attributes of mango. Therefore, the current study was planned to investigate the effects of acidified biochar on mango quality and yield attributes in alkaline soil. Five levels of biochar, i.e., 0, 5, 10, 20 and 40 Mg/ha, were applied in a randomized complete block design (RCBD). Results showed that 20 and 40 Mg/ha acidified biochar significantly enhanced fruit retention, sugar contents, ash contents and TSS of mango compared to control. A significant increase in mango fruit weight and yield per plant validated the efficacious role of 40 Mg/ha acidified biochar over control. Furthermore, the maximum significant decrease in fruit juice acidity signified the imperative functioning of 40 Mg/ha acidified biochar in alkaline soil. In conclusion, 40 Mg/ha acidified biochar application can improve mango quality and yield attributes in alkaline soil. More investigations on different soil types, climatic zones and mango varieties are recommended to declare 40 Mg/ha acidified biochar as the best treatment for improvement in the quality and yield of mango fruit in alkaline soils. [ABSTRACT FROM AUTHOR]

Bitter gourd is one of the important cucurbits and highly liked among both farmers and consumers due to its high net return and nutritional value. However, being monoecious, it exhibits substantial variation in flower bearing pattern. Plant growth regulators (PGRs) are known to influence crop phenology while gibberellic acid (GA3) is one of the most prominent PGRs that influence cucurbits phenology. Therefore, a field trial was conducted at University of Agriculture Faisalabad to evaluate the impact of a commercial product of gibberellic acid (GA3) on growth, yield and quality attributes of two bitter gourd (Momordica charantia L.) cultivars. We used five different concentrations (0.4 g, 0.6 g, 0.8 g, 1.0 g, and 1.2 g per litre) of commercial GA3 product (Gibberex, 10% Gibberellic acid). Results showed that a higher concentration of gibberex (1.0 and 1.20 g L-1 water) enhanced the petiole length, intermodal length, and yield of bitter gourd cultivars over control in Golu hybrid and Faisalabad Long. A significant decrease in the enzyme superoxidase dismutase, peroxidase, and catalase activities were observed with an increasing concentration of gibberex (1.0 and 1.20 gL-1 water) as compared to control. These results indicate that the exogenous application of gibberex at a higher concentration (1.2 g L-1) has a dual action in bitter gourd plant: i) it enhances the plant growth and yield, and ii) it also influenced the antioxidant enzyme activities in fruits. These findings may have a meaningful, practical use for farmers involved in agriculture and horticulture. [ABSTRACT FROM AUTHOR]

Objective: Biochar and a commercial humic acid-rich product, Humac (modified leonardite), represent soil amendments with the broad and beneficial effects on various soil properties. Their combination has been scarcely tested so far, although the positive impact of their interaction might be desirable. Materials and Methods: The dehydrogenase activity (DHA), microbial biomass carbon (Cmic), soil respiration (basal and substrate-induced), enzyme activities, total carbon (Ctot), and both shoot and root biomass yield were measured and compared in the short-term pot experiment with the lettuce seedlings. The following treatments were tested: the unamended soil (control), the Humac-amended soil (0.8 g·kg−1 ), the biochar-amended soil (low biochar 32 g·kg−1 , high biochar 80 g·kg−1 ), and the soil-amended with biochar + Humac. Results: The effect of both amendments on the soil pH was insignificant. The highest average values of Ctot and Cmic were detected in high biochar treatment and the highest average values of basal and substrate-induced respiration (glucose, glucosamine, alanine) were detected in the low biochar treatment. The phosphatase activity and fresh and dry lettuce aboveground biomass were the highest in the low biochar + Humac treatment. Conclusions: Even though the combination of both biochar + Humac decreased the microbial activities in the amended soil (Cmic, DHA, enzymes, substrate-induced respiration) at the low biochar dose, they mitigated the detrimental effect of the high biochar dose on respiration (all the types) and the enzyme (phosphatase, arylsulphatase) activities. In contrast to the previously published research in this issue, the effects could not be attributed to the change of the soil pH. [ABSTRACT FROM AUTHOR]

The excessive use of chemicals and inorganic fertilizers by farmers to increase crop yield is detrimental to the environment and human health. Application of biostimulants such as seaweed extract (SWE) in agriculture could be an effective and eco-friendly alternative to inorganic fertilizers. Biostimulants are natural organic degradable substances. Their application serves as a source of nutrition for crops, possibly improving growth and productivity when applied in combination with the fertilizers. The current study was conducted to evaluate the vegetative growth, reproductive behavior and quality attributes of four onion cultivars, 'Lambada', 'Red Bone', 'Nasarpuri', and 'Phulkara', in response to different concentrations of commercial SWE. Four levels of SWE extract were used, 0% (control), 0.5%, 1%, 2%, and 3%, which were applied as a foliar spray to each cultivar. The application of 0.5% SWE caused a significant increase in total soluble solids, mineral content (N, P, and K), bulb weight and yield. Application at 3% SWE increased ascorbic acid as compared to control. The cultivars responded in different ways regarding bulb dry weight and bulb and neck diameter. Among all cultivars, 'Lambada' showed the maximum bulb dry matter, 'Phulkara' showed enhanced neck diameter whereas 'Red Bone' showed maximum leaf length. It is concluded that 0.5% SWE increased the yield, nutrient contents, and total soluble solids (TSS) of the four onion cultivars whereas 3% SWE, the highest concentration, increased ascorbic acid in different onion cultivars. [ABSTRACT FROM AUTHOR]

Cultivation of crops in salt-affected soils is a major challenge for growers. Despite the use of multiple amendments, salinity stresses adversely affect the crops to some extent. On the other hand, imbalance in the use of boron (B) as a nutrient also creates toxicity. Mismanagement of B fertilizer application decreases the growth and yield of crops. It is necessary to study in depth the adverse effects of salinity and B toxicity. This is why the current research work was conducted in a glass house at Murdoch University, Perth, Australia. The aim of study was to investigate the influence of salinity and B toxicity on carbohydrate partitioning, growth, and ionic composition of two Australian wheat varieties. There were four treatments, i.e., control, high B (15 kg ha−1), salinity (15 dS m−1), and B + salinity. The results showed that the salt-tolerant Halberd (HB) variety accumulated more Na+, B, and Cl− in their leaf sheath and kept the leaf blades free of these toxic ions as compared to the sensitive variety Westonia (WS). Water-soluble carbohydrate (WSC; i.e., glucose, sucrose, fructose, and fructans) concentration increased in response to individual as well as combined constrains of soil salinity and toxic B in the leaf blade of both tolerant and sensitive wheat varieties, but the increase was higher in the tolerant variety as compared to the sensitive one. The concentration of WSCs in leaf sheath of the salt-tolerant wheat variety was increased in response to stress conditions, but those remained low in salt-sensitive ones. Therefore, the salt-tolerant HB genotype was found to be a good source for future wheat breeding programs or to be grown by farmers in B toxic, saline, and B toxic–saline conditions. [ABSTRACT FROM AUTHOR]

A detailed field experiment was carried out to study the effect of conventional and zero tillage and legume intercrops on soil health indicators and cotton productivity and also yield components of leguminous crops at the Research Farm, MNS-University of Agriculture, Multan, Pakistan. The field experiment was comprised of four legume intercrops (no intercrops (sole cotton), mung bean, mash bean, and soybean) and two tillage systems (three years zero tillage (ZT) and long-term conventional tillage (CT)). The CT showed the highest plant height (121 cm), total bolls per plant (22.9 bolls), boll weight (2.74 g) and seed yield (2031 kg ha−1) of the cotton crop, as compared to ZT. The highest leaf transpiration rate (9.28 mmol H2O m−2 s−1), net leaf photosynthetic rate (27.17 µmol m−2 s−1), stomatal conductance (0.493 mmol m−2 s−1), chlorophyll content (62.3 SPAD value), plant height (123 cm), total bolls per plant (24.4), boll weight (2.83 g), and seed yield (2090 kg ha−1) of cotton crop were recorded when it was grown as a sole crop, as compared to legume intercrops. However, soil organic matter (0.77%), phosphorus (8.08 mg kg−1), potassium (253 mg kg−1), and microbial population (7.26 × 106 Cfu) were higher in ZT than in CT. Mung bean showed a maximum number of pods (32), seed yield (173 kg ha−1), biomass (950 kg ha−1), and harvest index (19.0%), when intercropped with cotton. The highest land equivalent ratio and area time equivalent ratio were recorded in mung bean and cotton intercropping, grown under a CT system. Furthermore, the maximum benefit-cost ratio was recorded in mung bean and cotton intercropping, over sole cotton cropping under CT (1.75) and ZT (1.67) systems. The ZT and intercropping of leguminous crops with cotton might be a promising option for increasing the seed cotton yield, seed yield of leguminous crops, system profitability, and sustainability of soil health. [ABSTRACT FROM AUTHOR]

Soil with low fertility is a big problem for achieving citrus productivity. In this regard, the management of macro and micronutrients is essential. Macro and micronutrient deficiency decreased the yield and the quality of citrus fruit. It is the need of the hour to classify the soil fertility status under changing climatic scenarios. The current soil fertility survey was conducted to examine the macro and micronutrient status in the citrus production area. In soil, three depths (0–15, 15–30, and 30–45 cm) were taken for sampling. For leaves, 4–6-months-old non-bearing twigs were sampled from 20 trees per orchard at breast height. Results showed that soil pH (7.1–8.4) was slightly alkaline, electrical conductivity (EC) was non-saline (<4 dSm−1), soil organic matter (SOM) was deficient (<0.86%), and calcium carbonate (CaCO3) was slight calcareous (<8%), at 0–15, 15–30, and 30–45 cm depths. The majority of soil samples were low in nitrogen (N) contents at all depths, i.e., (<0.043) 0–15 (85%), 15–30 (97%), and 30–45 (100%) cm depths. Phosphorus (P) was medium (7–15 mg kg−1) at 0–15 cm (60%) but low (<7 mg kg−1) at 15–30 (63%) and 30–45 cm (82%) depths. Potassium (K) was medium (80–180 mg kg−1) at 0–15 (69%), 15–30 (69%), and 30–45 cm (10%) depths. Boron (B) and manganese (Mn) were medium, and Cu was high in 0.15 cm, but all were low at 15–30 and 30–45 cm depths. Iron (Fe) and zinc (Zn) were low at depths of 0–15, 15–30, and 30–45 cm. Most citrus leaves were deficient in N (94%), Fe (76%), Zn (67%), and B (67%). In conclusion, soil fertilization is not sufficient for optimum citrus yield because of alkaline pH and slight calcareous soil conditions in this region. Foliar application of nutrients is suggested instead of only soil fertilization, for better nutrient management in citrus orchards. [ABSTRACT FROM AUTHOR]

This research intends to offer a scientific foundation for environmental monitoring and early warning which will aid in the environmental protection management of Qaroun Lake. Qaroun Lake is increasingly influenced by untreated wastewater discharge from many anthropogenic activities, making it vulnerable to pollution. For that, six environmental pollution indices, namely contamination factor (Cf), enrichment factor (EF), geo-accumulation index (Igeo), degree of contamination (Dc), pollution load index (PLI), and potential ecological risk index (RI), were utilized to assess the bottom sediment and to determine the different geo-environmental variables affecting the lake system. Cluster analysis (CA), and principal component analysis (PCA) were used to explore the potential pollution sources of heavy metal. Moreover, the efficiency of partial least-square regression (PLSR) and multiple linear regression (MLR) were tested to assess the Dc, PLI, and RI depending on the selected elements. The sediment samples were carefully collected from 16 locations of Qaroun Lake in two investigated years in 2018 and 2019. Total concentrations of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Ga, Hf, Li, Mg, Mn, Mo, Ni, P, Pb, Sb, Se, Zn, and Zr were quantified using inductively coupled plasma mass spectra (ICP-MS). According to the Cf, EF, and Igeo results, As, Cd, Ga, Hf, P, Sb, Se, and Zr demonstrated significant enrichment in sediment and were derived from anthropogenic sources. According to Dc results, all collected samples were categorized under a very high degree of contamination. Further, the results of RI showed that the lake is at very high ecological risk. Meanwhile, the PLI data indicated 59% of lake was polluted and 41% had PLI < 1. The PLSR and MLR models based on studied elements presented the highest efficiency as alternative approaches to assess the Dc, PLI, and RI of sediments. For examples, the validation (Val.) models presented the best performance of these indices, with R2val = 0.948–0.989 and with model accuracy ACCv = 0.984–0.999 for PLSR, and with R2val = 0.760–0.979 and with ACCv = 0.867–0.984 for MLR. Both models for Dc, PLI, and RI showed that there was no clear overfitting or underfitting between measuring, calibrating, and validating datasets. Finally, the combinations of Cf, EF, Igeo, PLI, Dc, RI, CA, PCA, PLSR, and MLR approaches represent valuable and applicable methods for assessing the risk of potentially harmful elemental contamination in the sediment of Qaroun Lake. [ABSTRACT FROM AUTHOR]

Zinc (Zn) is an important micronutrient for plants, whose deficiency in alkaline soils creates hurdles in the achievement of optimum crop growth. Moreover, overuse of phosphorus (P) fertilizers often causes Zn immobilization in the soil. The employment of arbuscular mycorrhizal fungi (AMF) could be potentially environmentally friendly technology in this regard. Therefore, a pot experiment was conducted to assess the beneficial role of AMF (Glomus species) on maize under low and high P and Zn levels. Seven levels of Zn (0, 20, 40, 60, 80, 100 and 120 mg Zn kg−1 soil ZnSO4·7H2O) and three levels of P (0, 14.5, 29 and 58 kg ac−1 as single superphosphate) were applied with (M+) and without AMF (M−). The results showed that a high application rate of Zn (100 and 120 mg Zn kg−1 soil) restricted P translocation in plants and vice versa. Moreover, the nutritional status of mycorrhizal plants (AM) was better than non-mycorrhizal (NM) plants. AM plants showed a maximum positive response at 20 mg Zn kg−1 soil, or 29 kg P ac−1. In response to 20 mg Zn kg−1 soil, root colonization was maximum, which enhanced the maize nutrient concentration in shoots. In conclusion, AMF inoculation (M+) with P (29 kg ac−1) and Zn (20 mg kg−1) is efficacious for improving maize's growth and nutrition. More investigations are suggested at the field level under different agroclimatic zones to ascertain whether P (29 kg ac−1) or Zn (20 mg kg−1) with AMF is the best treatment for maize growth optimization. [ABSTRACT FROM AUTHOR]

Abiotic stresses varyingly affect the grain composition and quality of food legumes. This paper is aimed at discussing the impact of abiotic stresses on the grain composition and quality of food legumes. As protein is the main grain constituent of food legumes for which it is being consumed by humans as a cheap protein source, abiotic stresses such as heat, cold, drought, salinity and heavy metals alter this grain protein content in different dimensions for different food legumes. Moreover, other valuable constituents such as starch, soluble sugar, oil, fatty acid and fiber content are affected differently by the abiotic stresses. The diverse impact of these abiotic stresses ultimately declines the grain quality and yield of food legumes. As food legumes play a vital role in the nutritional diet of millions of people in the world and are occasionally denoted as the meat of poor people, it is important to recognize that the sustainable production of food legumes, even under various environmental stresses, has the potential to ensure protein security for people globally. Therefore, it has become a necessity to improve the productivity and quality of food legumes under abiotic stresses through proper crop management and improved breeding strategies, thus enhancing food and economic security to the farmers, particularly in the developing countries of the world. [ABSTRACT FROM AUTHOR]

Monitoring and managing water quality parameters (WQPs) in water bodies (e.g., lakes) on a large scale using sampling-point techniques is tedious, laborious, and not highly representative. Hyperspectral and data-driven technology have provided a potentially valuable tool for the precise measurement of WQPs. Therefore, the objective of this work was to integrate WQPs, derived spectral reflectance indices (published spectral reflectance indices (PSRIs)), newly two-band spectral reflectance indices (NSRIs-2b) and newly three-band spectral indices (NSRIs-3b), and artificial neural networks (ANNs) for estimating WQPs in Lake Qaroun. Shipboard cruises were conducted to collect surface water samples at 16 different sites throughout Lake Qaroun throughout a two-year study (2018 and 2019). Different WQPs, such as total nitrogen (TN), ammonium (NH4+), orthophosphate (PO43−), and chemical oxygen demand (COD), were evaluated for aquatic use. The results showed that the highest determination coefficients were recorded with the NSRIs-3b, followed by the NSRIs-2b, and then followed by the PSRIs, which produced lower R2 with all tested WQPs. The majority of NSRIs-3bs demonstrated strong significant relationships with three WQPs (TN, NH4+, and PO43−) with (R2 = 0.70 to 0.77), and a moderate relationship with COD (R2 = 0.52 to 0.64). The SRIs integrated with ANNs would be an efficient tool for estimating the investigated four WQPs in both calibration and validation datasets with acceptable accuracy. For examples, the five features of the SRIs involved in this model are of great significance for predicting TN. Its outputs showed high R2 values of 0.92 and 0.84 for calibration and validation, respectively. The ANN-PO43−VI-17 was the highest accuracy model for predicting PO43− with R2 = 0.98 and 0.89 for calibration and validation, respectively. In conclusion, this research study demonstrated that NSRIs-3b, alongside a combined approach of ANNs models and SRIs, would be an effective tool for assessing WQPs of Lake Qaroun. [ABSTRACT FROM AUTHOR]

Drought stress and poor zinc (Zn) are major constraints for commercial agriculture. Their detrimental effects significantly decrease crop's growth and yield. Less water uptake disturbs the metabolic processes in plants. However, the deficiency of Zn leads to the inactivation of many enzymes. It is well documented that cereal crops, especially wheat, are susceptible to drought and Zn deficiency. Scientists suggest the supplementation of Zn along bio-fertilizers for the sustainable management of these issues. That is why the current experiment was conducted to explore the best combination of Zn and bio-fertilizer for wheat. There were two different recommended concentrations of Zn sulfate (Zinc level 1 (Zn1) = 20 and Zinc level 2 (Zn2) = 40 kg ha−1) applied under normal irrigation (75% field capacity = FC) and severe drought stress (40% FC). Sole and combined inoculation of arbuscular mycorrhizal fungi (AM) with Zn1 and Zn2 was also performed. Osmotic stress (40% FC) significantly decreased the examined growth parameters. It also significantly enhanced antioxidant and oxidative indicators in wheat. A significant increase in root fresh weight, root dry weight, and shoot length while a significant decrease in EL, SOD, POD over the control validated the efficacious role of Zn2 + AM. It is concluded that Zn2 + AM can improve wheat root fresh weight and root length wheat under 40% FC. Under different climatic zones, wheat varieties, and soil types, more investigations are recommended to declare Zn2 + AM as the best amendment for improving wheat growth attributes under osmotic stress. [ABSTRACT FROM AUTHOR]

Allelopathy is an ecological phenomenon that involves the production and release of biomolecules from different crops, cultivated plants, and bacteria or fungi into the soil rhizosphere and impacts other organisms in the vicinity. Sorghum possesses vital allelopathic characteristics due to which it produces and releases different biomolecules from its root hairs, stems, and grains. Several studies have reported that sorghum acts as an allelopathic crop, decreasing the growth and eco-physiological attributes of surrounding plants and weeds growing simultaneously or subsequently in the field. Sorghum allelopathy has been exploited in the context of green manure, crop rotations, cover crops, and intercropping or mulching, whereas plant aqueous extracts or powder might be an alternate method of weed control. A diverse group of allelochemicals, including benzoic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, chlorogenic acid, m-coumaric acid, p-coumaric acid, gallic acid, caffeic acid, p-hydroxibenzaldehyde, dhurrin, sorgoleone, m-hydroxybenzoic acid and protocatechuic acid, have been isolated and identified from different plant tissues of sorghum and root exudates. These allelochemicals, especially sorgoleone, have been investigated in terms of their mode(s) of action, specific activity and selectivity, release in the rhizosphere and uptake and translocation in sensitive species. The present review describes the importance of sorghum allelopathy as an ecological tool in managing weeds, highlighting the most recent advances in the allelochemicals present in sorghum, their modes of action, and their fate in the ecosystem. Further research should focus on the evaluation and selection of sorghum cultivars with high allelopathic potential, so that sorghum allelopathy can be better utilized for weed control and yield enhancement. [ABSTRACT FROM AUTHOR]

Drought and low amounts of mineral nutrients in the soil are the two leading global constraints in arid and semiarid regions. Their detrimental effects on soils and crops can be alleviated by applying controlled release and biodegradable fertilizers to better and sustain the crops. On a global scale, spinach (Spinacia oleracea L.) is an essential leafy green vegetable that is biologically considered a reliable source of essential nutrients and minerals for human health. A comprehensive approach is needed to manage water stress to mitigate the impacts of stress-caused damage and to examine this for better and increased plant production. An experiment was conducted using potassium-nitrate-containing chitosan/montmorillonite microparticles (150 mg) under mild and severe drought stress (MDS: 50% and SDS: 35% FC, respectively). The treatments include control (no KNO3 and 70% FC as normal irrigation (NI)), KNO3 + NI, 50% FC as mild drought stress (MDS), KNO3 + MDS, 35% FC as severe drought stress (SDS) and KNO3 + SDS. Results revealed that drought stress decreased all studied physiological parameters and increased oxidative stress indicators in spinach. Applying KN significantly increased root (122%) and shoot length (4%), shoot fresh weight (32%) and shoot dry weight (71%), chlorophyll a (88%), carotenoids (39%), total soluble proteins (50%), soluble sugars (51%), potassium (80%), and phosphorous (32%) concentrations over No KN at severe drought. While stress indicators, like glycine betaine, malondialdehyde, hydrogen peroxide, electrolyte leakage, peroxidase, superoxide dismutase, and ascorbic acid levels, were increased in stress. Treatment KN was proved efficient and effective in improving spinach physiological status in both MDS and SDS. [ABSTRACT FROM AUTHOR]

Lentil (Lens culinaris Medik) is an important component of the human diet due to its high mineral and protein contents. Abiotic stresses, i.e., drought, decreases plant growth and yield. Drought causes the synthesis of reactive oxygen species, which decrease a plant's starch contents and growth. However, ACC-deaminase (1-aminocyclopropane-1-carboxylate deaminase) producing rhizobacteria can alleviate drought stress by decreasing ethylene levels. On the other hand, caffeic acid (CA) can also positively affect cell expansion and turgor pressure maintenance under drought stress. Therefore, the current study was planned with an aim to assess the effect of CA (0, 20, 50 and 100 ppm) and ACC-deaminase rhizobacteria (Lysinibacillus fusiform, Bacillus amyloliquefaciens) on lentils under drought stress. The combined application of CA and ACC-deaminase containing rhizobacteria significantly improved plant height (55%), number of pods per plant (51%), 1000-grain weight (45%), nitrogen concentration (56%), phosphorus concentration (19%), potassium concentration (21%), chlorophyll (54%), relative water contents RWC (60%) and protein contents (55%). A significant decrease in electrolyte leakage (30%), proline contents (44%), and hydrogen peroxide contents (54%), along with an improvement in cell membrane stability (34% over control) validated the combined use of CA and rhizobacteria. In conclusion, co-application of CA (20 ppm) and ACC-deaminase producing rhizobacteria can significantly improve plant growth and yield for farmers under drought stress. More investigations are suggested at the field level to select the best rhizobacteria and CA level for lentils under drought. [ABSTRACT FROM AUTHOR]

An experiment was carried out to investigate the effects of different mineral fertilizers on mineral contents in turmeric rhizomes and soil enzyme activities and soil properties under field conditions in Uzbekistan. The present study is the first report on the impact of mineral fertilizers in turmeric rhizomes and soil enzymes and soil properties in Uzbekistan. The experiment was carried out with four treatments: T1—Control, T2—N75P50K50 kg/ha, T3—N125P100K100 kg/ha, and T4—N100P75K75 + B3Zn6Fe6 kg/ha. Turmeric rhizomes and soil samples were collected from field experiments at the Surkhandarya scientific experimental station of the vegetable, melon crops and potato research institute, Surkhandarya, Uzbekistan. The data showed that T3—the NPK (125:100:100 kg/ha) and T4—the NPK + BZnFe (100:75:75:3:6:6 kg/ha) treatments significantly enhanced K content by 27–21%, Ca content by 43–38%, and P content by 54–17% in turmeric rhizomes as compared to control without fertilizer. A maximum of turmeric rhizome microelements content was recorded with T4, which also resulted in improved Fe, Zn, Cu, Cr, and Mo contents in turmeric rhizomes and mineral contents of soil compared to other treatments. This treatment significantly enhanced active P content by 34%, active K content by 25%, total P content by 62%, total K content by 14%, and the activities of soil urease, invertase, catalase, and phosphatase over those in the control. The present study results suggest that the application of NPK + BZnFe (100:75:75:3:6:6 kg/ha) improves macro and micronutrient contents in turmeric rhizomes and activities of soil enzymes and physicochemical properties of soil. [ABSTRACT FROM AUTHOR]

Biochar, prepared from organic waste materials, can improve the quality of contaminated soil areas. Biochar can be used as an economic centerpiece over other available resources and can properly utilize large amounts of waste. Soil contaminated with cadmium (Cd) is a worldwide problem that poses potential agricultural and human health hazards. Moreover, Cd toxicity causes serious problems for sustainable food production, especially in food crops like barley. High cadmium concentration in soil is phytotoxic and decreases plant growth and ultimately yields. Biochar and ascorbic acid in ameliorating Cd stress are economically compatible and consistent approaches in agriculture. The present study aimed to evaluate biochar's and foliar-applied ascorbic acid's influence on some growth and biochemical characteristics of barley (Hordeum vulgare L.) to Cd stress. The soil was supplemented with biochar 2% w/w and 20 mg Cd kg−1. The foliar application of 30 mM ascorbic acid was done on plants. The results revealed that Cd stress decreased chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids. It also increased oxidative stress indicators, i.e., APX, COD, POD, flavonoids, anthocyanin, phenolics, and electrolyte leakage, in barley with Cd-contamination. A significant enhancement in root and shoot length, gas exchange attributes, and chlorophyll contents validated the effectiveness of Bio + Asa treatments over all other treatments under Cd contamination. In conclusion, the sole applications of biochar and Asa in Cd contamination are also effective, but Bio + Asa is a better amendment for Cd stress alleviation in barley plants. [ABSTRACT FROM AUTHOR]

Advances in proteome research have opened the gateway to understanding numerous metabolic pathways and fundamental mechanisms involved in abiotic stress tolerance. In the present study, the antioxidant capacity of four tomato genotypes i.e., Kashi Amrit, Kashi Anupam, EC-317-6-1, and WIR-4360 was determined under drought stress to ascertain the scavenging potential for reactive oxygen species (ROS). A significant increase in the superoxide dismutase (SOD), Ascorbate peroxidase (APX), and catalase (CAT) activities in all the four genotypes under drought stress was observed, which seemed to be associated with a protective role against ROS (p < 0.001). Based on the antioxidant enzyme activities, a proteomic approach was applied to study differential protein expression in two selected genotypes from different species i.e., EC-317-6-1 (Solanum pimpinellifolium) and Kashi Amrit (Solanum lycopersicum) grown under irrigated, drought, and re-watering conditions. To reveal the protein network regulated under these conditions, two-dimensional gel electrophoresis was employed to identify and quantify the number of proteins in drought-sensitive (Kashi Amrit) and tolerant (EC-317-6-1) genotypes. Matrix-assisted laser desorption/ionization-time of flight analysis (MALDI-TOF) revealed a total of 453 spots after fine-tuning factors i.e., smoothness, saliency, and minimum area that responded to drought. Out of 453 total spots, 93 spots were identified in Kashi Amrit and 154 in EC-317-6-1 under irrigated conditions, whereas 4 spots were identified in Kashi Amrit and 77 spots in EC-317-6-1 under drought conditions. Furthermore, differentially expressed proteins were distinguished according to the fold change of their expression. Information provided in this report will be useful for the selection of proteins or genes in analyzing or improving drought tolerance in tomato cultivars. These findings may assist in the construction of a complete proteome database encompassing various divergent species which could be a valuable source for the improvement of crops under drought-stress conditions in the future. [ABSTRACT FROM AUTHOR]

A good understanding of nutrient release from manure or compost after application through mineralization is important to assure meeting the nutrient demand of crops, to secure timely fertilizer application and to enhance nutrient use efficiency. The current study was done to evaluate phosphorus (P) and sulphur (S) release patterns from different types of manures viz. cow dung, cow dung slurry, tricho-compost, vermicompost, poultry manure, poultry manure slurry and mungbean residues. The mineralization study was performed under aerobic (field capacity) and anaerobic (waterlogging) conditions for 180 days at 25 ± 1 °C in the laboratory. The release of P and S showed the highest values within 75–180 and 75–150 days, respectively, and was always higher in aerobic conditions than in anaerobic conditions. The first-order kinetic cumulative model was a good fit for mineralization, which was significantly influenced by manure type, soil moisture level and incubation period. Poultry manure slurry exerted the highest P and S release under both moisture conditions. Both slurries showed higher potential mineralization, with a lower rate constant for these elements compared to that in their manure states. Hence, appropriate manures should be chosen and applied in the proper quantity to provide exact amounts of nutrients, to increase crops nutrient use efficiency and to formulate correct fertilizer recommendations. [ABSTRACT FROM AUTHOR]

Mineralization of carbon (C) is a burning issue that is regulated by soil attributes. It has direct impacts on crop productivity and quantification of organic residue addition in soil. For better understanding and achievement of potential tillage benefits, a comprehensive scientific understanding of C mineralization is very important. Therefore, a laboratory incubation experiment was conducted to investigate the C mineralization rates and kinetics of crop residues (rice and maize) when applied on the surface (as zero-tillage, ZT) and incorporation (as conventional tillage, CT) in four different soil types (S1 and S2 of Entisol; S3 and S4 of Inceptisols) of West Bengal state, India. Results showed that after 7 days of incubation, there was a rapid phase of decrease in CO2-C fluxes. It continued up to day 14 followed by a sluggish nature of CO2 emission up to day-42, and after that almost levelling off in all subsequent periods up to the end of 126 days of incubation. There was a progressive release of cumulative total C from the soils with an increase in time till the last day of incubation. For every 10% increase in C loss, there was about 0.376 mg/g C mineralization from the applied residue C. It was evident from the kinetic models that C mineralization from the residues followed the exponential model: C = Co(1 − e−kt). Similar rate constant (k) values were recorded in both placement methods, but the rate of maximum potential mineralizable (C0k) residue C was higher under residue incorporation treatments for both rice and maize residue. However, the rice and maize residues showed almost similar amounts of C mineralized over time when applied on the surface. The future prediction analysis using the equation C = Co(1 − e−kt) suggested that the residues incorporated into the soil releases a maximum C irrespective of residue type. We conclude that the residues when incorporated into the soil significantly increases the C footprints through maximum C mineralization; leaving the crop residue on the soil surface reduces the C footprints which helps in achieving sustainability from an environmental perspective. [ABSTRACT FROM AUTHOR]

Accumulation of heavy metals (HMs) by ornamental plants (OPs) from contaminated agriculture soils is a unique technique that can efficiently reduce the metal load in the food chain. Amaranthus tricolor L. has attractive characteristics acquiring a higher growth rate and large biomass when grown at heavy metal contaminated soils. Site-specific detailed information is not available on the use of A. tricolor plant in metal phytoremediation from the polluted sites. The study aimed to enhance the uptake of HMs (Pb, Zn, and Cu) via amending poultry litter extract (PLE), vinasse sugarcane (VSC), and humic acid (HA) as natural mobilized organic materials compared to ethylene diamine tetraacetic acid (EDTA), as a common mobilized chemical agent by A. tricolor plant. The studied soils collected from Helwan, El-Gabal El-Asfar (Cairo Governorate), Arab El-Madabeg (Assiut Governorate), Egypt, and study have been conducted under pot condition. Our results revealed all organic materials in all studied soils, except EDTA in EL-Gabal El-Asfar soil, significantly increased the dry weight of the A. tricolor plant compared to the control treatment. The uptake of Pb and Zn significantly (p > 0.05) increased due to applying all organic materials to the studied soils. HA application caused the highest uptake as shown in Pb concentration by more than 5 times in Helwan soil and EDTA by 65% in El-Gabal El-Asfar soil while VSC increased it by 110% in El-Madabeg soil. Also, an increase in Zn concentration due to EDTA application was 58, 42, and 56% for Helwan, El-Gabal El-Asfar, and El-Madabeg soil, respectively. In all studied soils, the application of organic materials increased the remediation factor (RF) than the control. El-Madabeg soil treated with vinasse sugarcane gave the highest RF values; 6.40, 3.26, and 4.02% for Pb, Zn, and Cu, respectively, than the control. Thus, we identified A. tricolor as a successful ornamental candidate that, along with organic mobilization amendments, most efficiently develop soil health, reduce metal toxicity, and recommend remediation of heavy metal-contaminated soils. Additionally, long-term application of organic mobilization amendments and continued growth of A. tricolor under field conditions could be recommended for future directions to confirm the results. [ABSTRACT FROM AUTHOR]

Nitrogen (N) losses are prevalent under South East Asia's due to high N fertilizer inputs, but low N fertilizer use efficiency. This leaves a large quantity of reactive N at risk of loss to the environment. Biochar has been found to reduce N losses across a variety of soil types, however, there is limited data available for semi-arid climates, particularly at a field-scale. Herein we present an exploration of the biological and chemical enhancement effects observed of a cotton stalk-based biochar on wheat growth and yield under arid field conditions. The biochar was treated with urea-N and biofertilizer (bio-power) in different treatment setups. The six experimental treatments included; (i) a full N dose "recommended for wheat crops in the region" (104 kg N ha−1) as a positive control; (ii) a half N dose (52 kg N ha−1); (iii) a half N dose + biofertilizer (4.94 kg ha−1) as a soil mixture; (iv) a half N dose + biofertilizer as a seed inoculation; (v) a full N dose as broadcast + biochar (5 t ha−1) inoculated with biofertilizer; and (vi) a full N dose loaded on biochar + biofertilizer applied as a soil mixture. The half dose N application or biofertilizer addition as soil mix/seed inoculated/biochar inoculation with biofertilizer caused reduced wheat growth and yield compared to the control (conventional N fertilization). However, co-application of chemically enhanced biochar (loaded with a full N dose) and biofertilizer as soil mixture significantly increased the crop growth rate (CGR) and leaf area index (LAI). A significantly higher crop growth and canopy development led to a higher light interception and radiation use efficiency (RUE) for total dry matter (TDM) and grain yield (11% greater than control) production compared to the control. A greater grain yield, observed for the full N dose loaded on biochar + biofertilizer applied as a soil mixture, is attributed to prolonged N availability as indicated by greater plant and soil N content at harvest and different crop growth stages, respectively. The present study has improved our understanding of how the application of nitrogen loaded biochar and biofertilizer as soil mixtures can synergize to positively affect wheat growth and soil-nitrogen retention under arid environmental conditions. [ABSTRACT FROM AUTHOR]

The present study was aimed to test cholesterol reduction and vitamin B12 production abilities of the isolated lactic acid bacteria (LAB). Three LAB isolates, namely, Enterococcus faecium (EF), Enterococcus faecium (Chole1), and Lactobacillus pentosus (7MP), having probiotic potential, were isolated from yoghurt. These isolates were screened for bile salt hydrolase (BSH) activity, cholesterol reduction property in MRS broth, and the production of vitamin B12. The present study revealed that the isolate 7MP possesses the highest potential of (48%) cholesterol reduction compared to the other isolates. The isolates EF and Chole1 produced a good amount of (1 ng/mL) vitamin B12. These isolates were identified by 16S rRNA gene sequencing and confirmed by MALD_TOF analysis. Thus, the use of these LAB isolates for yoghurt-making can offer the value addition of lowering cholesterol and vitamin B12 fortification in fermented food. [ABSTRACT FROM AUTHOR]

Amylase (EC 3.2.1.1) enzyme has gained tremendous demand in various industries, including wastewater treatment, bioremediation and nano-biotechnology. This compels the availability of enzyme in greater yields that can be achieved by employing potential amylase-producing cultures and statistical optimization. The use of Plackett–Burman design (PBD) that evaluates various medium components and having two-level factorial designs help to determine the factor and its level to increase the yield of product. In the present work, we are reporting the screening of amylase-producing marine bacterial strain identified as Bacillus sp. H7 by 16S rRNA. The use of two-stage statistical optimization, i.e., PBD and response surface methodology (RSM), using central composite design (CCD) further improved the production of amylase. A 1.31-fold increase in amylase production was evident using a 5.0 L laboratory-scale bioreactor. Statistical optimization gives the exact idea of variables that influence the production of enzymes, and hence, the statistical approach offers the best way to optimize the bioprocess. The high catalytic efficiency (kcat/Km) of amylase from Bacillus sp. H7 on soluble starch was estimated to be 13.73 mL/s/mg. [ABSTRACT FROM AUTHOR]

Soil salinity disrupts the physiological and biochemical processes of crop plants and ultimately leads to compromising future food security. Sodium nitroprusside (SNP), a contributor to nitric oxide (NO), holds the potential to alleviate abiotic stress effects and boost tolerance in plants, whereas less information is available on its role in salt-stressed lentils. We examined the effect of exogenously applied SNP on salt-stressed lentil plants by monitoring plant growth and yield-related attributes, biochemistry of enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) amassing of leaf malondialdehyde (MDA) and hydrogen peroxide (H2O2). Salinity stress was induced by NaCl application at concentrations of 50 mM (moderate salinity) and 100 mM (severe salinity), while it was alleviated by SNP application at concentrations of 50 µM and 100 µM. Salinity stress severely inhibited the length of roots and shoots, the relative water content, and the chlorophyll content of the leaves, the number of branches, pods, seeds, seed yield, and biomass per plant. In addition, MDA, H2O2 as well as SOD, CAT, and POD activities were increased with increasing salinity levels. Plants supplemented with SNP (100 µM) showed a significant improvement in the growth- and yield-contributing parameters, especially in plants grown under moderate salinity (50 mM NaCl). Essentially, the application of 100 µM SNP remained effective to rescue lentil plants under moderate salinity by regulating plant growth and biochemical pathways. Thus, the exogenous application of SNP could be developed as a useful strategy for improving the performance of lentil plants in salinity-prone environments. [ABSTRACT FROM AUTHOR]

The deficiency of micronutrients and low organic matter (OM) status of soils are major hurdles in the optimum crop yield achievements. Humic substances can play an imperative role in the micronutrient bioavailability and improved crop yield by ameliorating the physicochemical soil properties. consumed as fresh food and in processed form. However, its susceptibility towards micronutrient deficiency causes a significant reduction in yield. That is why a current study was done to examine the influence of different potassium humate (KH) levels, i.e., 0, 5, 10, and 15 kg ha−1 with micronutrients mixture (MC), i.e., 0, 50 (Zn = 2.50, B = 0.75, Fe = 2.50 kg ha−1), 75 (Zn = 3.75, B = 1.125, Fe = 3.75 kg ha−1) and 100% (Zn = 5.0, B = 1.5, Fe = 5.0 kg ha−1) on the yield, biomass, harvesting index and uptake of the micronutrients in tomato. The results showed that increasing the level of K-humate significantly improved the yield (7.4 and 7.17%), total biomass (6.38 and 6.59%), and harvesting the index (0.46 and 0.76%) of tomato. It also enhanced Fe uptake but did not affect B and Zn concentrations in the tomato fruit at 100% MC + 15 kg ha−1 KH over control in the autumn and spring seasons. In conclusion, both levels of K-humate 10 and 15 kg ha−1 and MC 75 and 100% effectively enhance the yield, biomass, harvesting the index, and micronutrients (B, Zn, and Fe) uptake in tomatoes. [ABSTRACT FROM AUTHOR]

Zinc (Zn) concentration in soil varies from deficient to toxic. Its deficiency, as well as toxicity, through imbalanced application and cropping in industrial sites can reduce maize growth and yield. Therefore, balanced Zn application is necessary to save resources and achieve optimum growth and yield in maize. Arbuscular mycorrhizal fungi (AMF) can provide tolerance to the host plant against Zn-induced stress. Inoculation with AMF helps in regulating the uptake of Zn and enhances the growth and yield of crops. Different application rates of Zn (0, 20, 40, 60, 80, 100, and 120 mg Zn kg−1) were applied with inoculation with AMF (AM) and without AMF (NM). Results showed that root colonization was 45% higher in AMF-inoculated plants than non-inoculated plants. A significant increase in plant height (15%), number of leaves (35.4%), cob weight (4.39%), 1000-grain weight (10.5%), and biological yield (42.2%) signified the efficacious functioning of Zn20 + AM over sole inoculation with AM. We also observed that AMF inoculation with Zn20 helped to improve photosynthesis, transpiration, and stomatal conductance. Furthermore, both Zn20 + AM and Zn20 + AM significantly increased total soluble protein compared with AM. Higher application rates of zinc, i.e., Zn80 and Zn120, induced Zn toxicity with (AM) and without (NM) AMF. In conclusion, Zn20 + AM is an effective treatment to achieve better growth and maize yield without Zn deficiency or toxicity. [ABSTRACT FROM AUTHOR]

Due to the scarcity of water, raw sewage effluents are often used to irrigate arable suburban soils in developing countries, which causes soil contamination with toxic metals. Soil microorganisms involved in biochemical transformations are sensitive to heavy metals contamination. The study was designed to investigate the effect of organic amendments on the microbial activity of cadmium (Cd), lead (Pb) and zinc (Zn) fractions and their bioavailability in soils contaminated with wastewater irrigation. Three metal contaminated soils under wastewater irrigation were collected, ground, sieved and added to incubation jars. Two organic amendments: wheat straw and chickpea straw, were applied (1% w/w) to the soil before incubation for 84 days at 25 °C. The CO2-C evolution after 1, 2, 3, 5, 7, 10 and 14 days was measured and thereafter was also measured weekly. Soil samples collected at 0, 14, 28, 42, 56, 70 and 84 days after incubation were analyzed for microbial biomass carbon (MBC). Sequential extraction for metal fractionation of samples was carried out collected at 0, 28, 56 and 84 days. Three soils differed significantly in evolved MBC and ∑CO2-C. Chickpea straw addition significantly increased soil MBC as compared to the wheat straw. Organic amendments significantly increased ∑CO2-C evolution from the soils, which was higher from chickpea straw. The addition of crop residues did not affect total Pb, Cd and Zn contents in soils. The concentration of exchangeable, carbonate bound and residual fractions of Pb, Cd and Zn decreased (6–27%), while the organic matter bound fraction increased (4–75%) with straw addition. Overall, the organic amendments improved microbial activity and reduce the bioavailability of toxic metals in wastewater irrigated soils. Furthermore, organic amendments not only reduce economic losses as they are cheap to produce but also minimize human health risks from heavy metals by hindering their entry into the food chain. [ABSTRACT FROM AUTHOR]

Linseed is an important industrial crop cultivated for its edible seeds and fiber linen. Organic fertilizers have beneficial effects on soil properties and quality of crops. Therefore, we conducted two field experiments during 2018–2019 and 2019–2020 to determine the effect of organic fertilizers on soil fertility, yield and fiber quality of linseed varieties Roshni, BL1 and Chandni under low soil moisture conditions. We prepared organic fertilizers from seed cake of Eruca sativa, leaves of Moringa oleifera and chicken peat in various combinations by composting method. The various formulations of organic fertilizers included OF1(1 kg seed cake of Eruca sativa), OF2 (1 kg seed cake of Eruca sativa + 1 kg chicken peat), OF3 (1 kg seed cake of Eruca sativa + 0.5 kg chicken peat + 0.25 kg Moringa oliefera leaves) and OF4 (1 kg seed cake of Eruca sativa + 0.250 kg chicken peat + 0.5 kg Moringa oliefera leaves). Compositional analysis of organic fertilizers indicated that OF3 and OF4 had higher and may potentially sufficient quantities of NPK and organic matter. Both of these fertilizers significantly improved soil total N, available P, K, Zn and Fe contents. Growth response of linseed varieties to organic fertilizers was evaluated under water deficit stress (40% field capacity of soil) at tillering stage for one month. Water stress had significantly adverse effects on plant height, production of tillers per plant, leaf relative water content (LRWC), number of capsules per plant, thousand seed weight, total seed yield, straw yield, fiber length and fiber weight of linseed varieties. However, the application of OF3 and OF4 significantly enhanced plant height, tillers production, LRWC, seed yield, straw yield, fiber length and fiber weight under water deficit stress. Water deficit stress also resulted in a significant increase in the content of phenolics of both the leaves and roots. For each measured quality parameter of linseed varieties, organic fertilizer treatments resulted in higher values than untreated and irrigated control. We concluded that organic fertilizers particularly OF3 and OF4 significantly improved soil fertility and minimized negative effect of water deficit stress on plant height, tillers production, LRWC, seed yield, straw yield, fiber length and fiber weight of linseed varieties. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) is one of the major fiber crops. Its production is under threat due to scarcity of water resources under a changing climatic scenario. Limited water availability also decreases the uptake of phosphorus, and less uptake of phosphorus can deteriorate the quality attributes of cotton fiber. There is a need to introduce bio-organic amendments which can mitigate osmotic stress on a sustainable basis. Inoculation of rhizobacteria can play an imperative role in this regard. Rhizobacteria can not only improve the growth of roots but also enhance the availability of immobile phosphorus in soil. That is why the current experiment was conducted to explore and compare the efficacy of sole application of diammonium phosphate (DAP) over plant growth-promoting rhizobacteria (PGPR) and phosphorus solubilizing bacteria (PSB) coated DAP on growth and quality attributes of cotton under artificially induced osmotic stress at flowering stage. The impact of phosphorus levels was found to be significant on the plant height, leaf area, average boll weight, stomatal conductance, net photosynthetic rate, and seed cotton yield, while the irrigation effect was significant on all the parameters. The PGPR coated phosphorus performed better as compared to other treatments under normal irrigation and osmotic stress. Results showed that PGPR coated phosphorus increased by 29.47%, 21.01%, 41.11%, 32.73%, 15.63% and 22.89% plant height, average boll weight, stomatal conductance, net photosynthetic rate, fiber length, and seed cotton yield respectively. In conclusion, PGPR coated DAP can be helpful to get higher cotton productivity as compared to control and sole application of DAP under normal irrigation and osmotic stress. [ABSTRACT FROM AUTHOR]

Plant growth-promoting bacteria (PGPB) and putrescine (Put) have shown a promising role in the mitigation of abiotic stresses in plants. The present study was anticipated to elucidate the potential of Bacillus thuringiensis IAGS 199 and Put in mitigation of cadmium (Cd)-induced toxicity in Capsicum annum. Cadmium toxicity decreased growth, photosynthetic rate, gas exchange attributes and activity of antioxidant enzymes in C. annum seedlings. Moreover, higher levels of protein and non-protein bound thiols besides increased Cd contents were also observed in Cd-stressed plants. B. thuringiensis IAGS 199 and Put, alone or in combination, reduced electrolyte leakage (EL), hydrogen peroxide (H2O2) and malondialdehyde (MDA) level in treated plants. Synergistic effect of B. thuringiensis IAGS 199 and Put significantly enhanced the activity of stress-responsive enzymes including peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD). Furthermore, Put and microbial interaction enhanced the amount of proline, soluble sugars, and total soluble proteins in C. annum plants grown in Cd-contaminated soil. Data obtained during the current study advocates that application of B. thuringiensis IAGS 199 and Put establish a synergistic role in the mitigation of Cd-induced stress through modulating physiochemical features of C. annum plants. [ABSTRACT FROM AUTHOR]

Humus is the stable form of added crop and animal residues. The organic matter after a long-term decomposition process converts into humic substances. The naturally occurring humus is present in less amount in soils of the arid and semi-arid regions. The addition of commercially available humic acid can, therefore, contribute to improving soil health and crop yields. The present study was conducted to evaluate the effect of potassium humate, applied through soil seed dressing, on cotton productivity and fiber quality attributes. Seed dressing with potassium humate was done at the rate of 0, 100, 150 and 200 mL kg−1 seed while in soil potassium humate was applied at the rate of 0, 10, 20 and 30 L ha−1. Results showed that the combined application of potassium humate by seed dressing and through soil application improved the soil properties, productivity and fiber quality traits of cotton. All levels of soil applied potassium humate (10, 20 and 30 L ha−1) performed better over seed dressing in terms of cotton productivity and fiber quality attributes. Among the soil application rates, 20 L ha−1 potassium humate proved better as compared to other rates (0, 10 and 30 L ha−1). Higher soil application of potassium humate (30 L ha−1) showed depressing effects on all the traits studied like the reduction of 12.4% and 6.6% in Ginning out turn and fiber length, respectively, at a seeding dressing of 200 mL kg−1. In conclusion, potassium humate seed dressing and soil application at the rate of 200 mL kg−1 and 20 L ha−1, respectively, is a better approach to improve cotton productivity. Soil potassium humate should not exceed a rate of 20 L ha−1 when the seed dressing of potassium is also practiced. [ABSTRACT FROM AUTHOR]

Management of inorganic fertilizer is very important to obtain maximum crop yield and improved nutrient use efficiency in cereal crops. Fixation of phosphatic fertilizers in alkaline soils due to calcareousness is one of the major hurdles. It induces phosphorus nutritional stress that can decrease the yield of maize and wheat. Selection of a suitable application method and proper stage of crop for phosphorus (P) fertilizer has prime importance in better uptake of P and crop production. Among different application methods, soil and foliar application are widely adopted. In wheat and maize, knee height + tasseling and stem elongation + booting are critical stages towards P deficiency. That is why field trials were conducted to evaluate the supplemental effect of foliar P on maize and wheat yields. For that, 144 mM KH2PO4 was applied as foliar at knee height + tasseling and stem elongation + boot stages in maize and wheat, respectively. Soil application of 0, 20, 40 and 60 kg P ha−1 was done through broadcast and band methods. Results showed that foliar spray of 144 mM KH2PO4 at knee height + tasseling and stem elongation + boot stages in wheat and maize significantly enhanced grains yield and phosphorus use efficiency (PUE) where P was applied as banding or broadcast at the time of sowing. A significant decreasing trend in response to increasing soil P levels validated the efficacious role and suitability of foliar P. In conclusion, the use of P as foliar at knee height + tasseling and stem elongation + boot stages is an efficacious way to manage P fertilizer. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is one of the heavy metals that negatively affects the growth of plants. High solubilization in water leads Cd to enter into plants quite easily, thus decreasing seed germination, photosynthesis, and transpiration. It also shows an antagonistic effect with many of the plants' nutrients like Mn, Ca, K, Mg and Fe. Nowadays, inoculation of plants with ACC deaminase (ACCD) rhizobacteria to mitigate Cd's adverse effects has drawn the attention of environmental microbiologists. The rhizobacteria secrete organic compounds that can immobilize Cd in soil. Therefore, this study was accomplished to investigate the effect of ACCD plant growth promoting rhizobacteria (PGPR) on the bitter gourd under Cd stress. There were six treatments consisting of two ACCD PGPR (Stenotrophomonas maltophilia and Agrobacterium fabrum) strains and inorganic fertilizers at two levels of Cd, i.e., 2 (Cd2) and 5 mg kg−1 soil (Cd5). The results showed A. fabrum with the recommended NPK fertilizer (RNPKF) significantly increased the vine length (48 and 55%), fresh weight (24 and 22%), and contents of chlorophyll a (79 and 50%), chlorophyll b (30 and 33%) and total chlorophyll (61 and 36%), over control at the two Cd levels i.e., Cd2 and Cd5, respectively. In conclusion, the recommended NPK fertilizer + A. fabrum combination is a very effective treatment with which to immobilize Cd in soil for the improvement of bitter gourd growth. [ABSTRACT FROM AUTHOR]

In calcareous soil, the significant portion of applied phosphorus (P) fertilizers is adsorbed on the calcite surface and becomes unavailable to plants. Addition of organic amendments with chemical fertilizers can be helpful in releasing the absorbed nutrients from these surfaces. To check out this problem, a field experiment was conducted for two years to determine the effect of P fertilizers and humic acid (HA) in enhancing P availability in soil and their ultimate effect on growth, yield and P uptake of wheat in calcareous soils. The experiment was comprised of five levels of P (0, 45, 67.5, 90 and 112.5 kg P2O5 ha−1) as a single superphosphate (SSP) and 2 levels of locally produced humic acid (with and without HA) arranged in a two factorial randomized complete block design (RCBD) with three replications. Wheat plant height, spike length, number of grains per spike, 1000-grain weight, grain, straw and biological yield were significantly improved by the addition of HA with SSP. Very often, the performance of 67.5 kg P2O5 ha−1 with HA were either similar or better than 90 or even 112.5 kg P2O5 ha−1 applied without HA. Post-harvest soil organic matter, AB-DTPA extractable and water-soluble P, plant P concentration and its uptake were also significantly improved by the addition of HA with SSP compared to sole SSP application. It was evident that P efficiency could be increased with HA addition and it has the potential to improve crop yield and plants P uptake in calcareous soils. [ABSTRACT FROM AUTHOR]

The high consumption of water in industries, domestic areas and increasing earth temperature are major hurdles for the optimization of maize yield. Being the third most widely cultivated cereal crop, improvement in maize yield is a big challenge under the limited availability of irrigation. As the water requirement for maize cultivation is high, it is time to introduce technologies that can mitigate drought stress and are environmentally friendly. The inoculation of rhizobacteria with '1-aminocyclopropane-1-carboxylate deaminase' (ACCD) can play an imperative role in that regard by decreasing stress ethylene in plants. Biochar (BC) can also alleviate drought stress. Therefore, a field study was conducted, to examine the single and combined application of drought-tolerant plant-growth-promoting rhizobacteria (PGPRs) Achromobacter xylosoxidans and Enterobacter cloacae, with 15 Mg ha−1 of timber waste biochar (TWBC) at normal irrigation = 16 irrigations, mild drought = 14 irrigations and severe drought = 12 irrigation for maize cultivation. A significant improvement in shoot dry weight (28%), 1000-grains weight (19%), grain yield (27%), concentrations of N (43%), P (92%) and K (71%) in grains, rate of photosynthesis (33%), transpiration rate (55%), stomatal conductance (104%), chlorophyll A (33%), chlorophyll B (62%) and total chlorophyll (45%) of maize was noted under drought stress where E. cloacae + TWBC was applied. Likewise, the application of A. xylosoxidans + TWBC also significantly enhanced the plant height (24%) and cob length (9%) of maize under drought stress. In conclusion, E. cloacae is more effective than A. xylosoxidans, with 15 Mg ha−1 TWBC to increase maize yield under drought stress, due to the potential of higher '1-aminocyclopropane-1-carboxylate' (ACC)-deaminase synthesis, better nutrient solubilization and indole acetic acid (IAA) production. [ABSTRACT FROM AUTHOR]

Low availability of phosphorus (P) in calcareous soils is a major problem for sustainable improvement in cereals crops yield. A higher amount of calcium in soils precipitates the P, thus making it immobile in soil. Inoculation of arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) could be helpful in the sustainable management of immobile P in soil. However, their combined use in releasing P from rock phosphate (RP) in alkaline calcareous soils have been little investigated. In this regard, two successive field experiments were conducted to assess the interactive inoculation potential of AMF and PSB strain Bacillus sp. PIS7 with RP on the yield and P uptake of maize (Zea mays L.) and wheat (Triticum aestivum L.) crops in alkaline calcareous soil. The first field experiment was conducted in a complete randomized block design with 10 treatments and three replications by inoculating maize seeds with AMF and Bacillus sp. PIS7 inoculum alone and in combination with RP. Their performance was compared with single super phosphate (SSP) inorganic fertilizer. Afterward, the residual effects of inoculated AMF and Bacillus sp. PIS7 were investigated on wheat as a subsequent crop. Maize and wheat yield parameters, P uptake, AMF root colonization, and PSB population was measured. The results of both trials indicated the beneficial effects of AMF and Bacillus sp. PIS7 with RP in increasing the plants grain yield and P uptake until the second season after inoculation, as compared to controls. Likewise, maize and wheat roots colonization, PSB population density, and post-harvest soil properties were also improved by the combined inoculation of AMF and Bacillus sp. PIS7 with RP. It is concluded that PSB solubilizes the unavailable forms of P in combination with RP fertilizers in soil, and AMF ultimately transfers it to plants for growth promotion. Moreover, the combined inoculation of AMF and PSB with ground RP had more potential to improve maize-wheat yields and P uptake comparable to those obtained by using expensive phosphatic fertilizers in P deficient calcareous pH soils. [ABSTRACT FROM AUTHOR]

Global warming promotes soil calcification and salinization processes. As a result, soil phosphorus (P) is becoming deficient in arid and semiarid areas throughout the world. In this pot study, we evaluated the potential of phosphate-solubilizing bacteria (PSB) for enhancing the growth and P uptake in maize under varying levels of lime (4.8%, 10%, 15% and 20%) and additional P supplements (farmyard manure, poultry manure, single super phosphate and rock phosphate) added at the rate of 45 mg P2O5 kg−1. Inoculation and application of P as organic manures (Poultry and farm yard manures) improved maize growth and P uptake compared to the control and soils with P applied from mineral sources. Liming adversely affected crop growth, but the use of PSB and organic manure significantly neutralized this harmful effect. Mineral P sources combined with PSB were as effective as the organic sources alone. Furthermore, while single supper phosphate showed better results than Rock phosphate, the latter performed comparably upon PSB inoculation. Thus, PSB plus P application as organic manures is an eco-friendly option to improve crop growth and P nutrition in a calcareous soil under changing climate. [ABSTRACT FROM AUTHOR]

Drought stress retards wheat plant's vegetative growth and physiological processes and results in low productivity. A stressed plant synthesizes ethylene which inhibits root elongation; however, the enzyme 1-Aminocyclopropane-1-Carboxylate (ACC) deaminase catabolizes ethylene produced under water stress. Therefore, the ACC deaminase producing plant growth promoting rhizobacteria (PGPR) can be used to enhance crop productivity under drought stress. Biochar (BC) is an organically active and potentially nutrient-rich amendment that, when applied to the soil, can increase pore volume, cation exchange capacity and nutrient retention and bioavailability. We conducted a field experiment to study the effect of drought tolerant, ACC deaminase producing PGPR (with and without timber waste BC) on plant growth and yield parameters under drought stress. Two PGPR strains, Agrobacterium fabrum or Bacillus amyloliquefaciens were applied individually and in combination with 30 Mg ha−1 BC under three levels of irrigation, i.e., recommended four irrigations (4I), three irrigations (3I) and two irrigations (2I). Combined application of B. amyloliquefaciens and 30 Mg ha−1 BC under 3I, significantly increased growth and yield traits of wheat: grain yield (36%), straw yield (50%), biological yield (40%). The same soil application under 2I resulted in greater increases in several of the growth and yield traits: grain yield (77%), straw yield (75%), above- and below-ground biomasses (77%), as compared to control; however, no significant increases in chlorophyll a, b or total, and photosynthetic rate and stomatal conductance in response to individual inoculation of a PGPR strain (without BC) were observed. Therefore, we suggest that the combined soil application of B. amyloliquefaciens and BC more effectively mitigates drought stress and improves wheat productivity as compared to any of the individual soil applications tested in this study. [ABSTRACT FROM AUTHOR]

Pea (Pisum sativum L.) leaf chlorophyll and pigments syntheses are retarded under nutritional stress. Biochar has the potential to regulate soil nutrient supplies and optimize plant nutrient uptakes. We examine the role of Pongamia pinnata L. waste leaf biochar (PLB) in improving vegetative growth and leaf chlorophyll and accessory pigments of pea exposed to nutritional stress. Three PLB application rates (0, 1, and 2%) crossed with half (HF), and full NPK fertilizer (FF) recommended doses were applied to sandy soil field-pots (arranged in a completely randomized design). There were significant or maximum increases in plant vegetative or physiological traits, including the fresh or dry, above- and below-ground biomass weights, and photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and anthocyanin) in response to a 2%PLB + FF application (p = 0.002). Trait values also responded to 2%PLB + HF, which signified the nutrient regulatory character of PLB (p = 0.038). The PLB-driven reduction in nutritional stress resulted in diminished lycopene (antioxidant) content (p = 0.041). Therefore, we suggest that the soil application of 2%PLB + FF has the greatest impact on pea vegetative growth and leaf chlorophyll, carotenoids, anthocyanin, and lycopene contents in Pisum sativum L. Further research is recommended to investigate the relationship of PLB with soil nutrient availabilities and plant nutrient concentrations. [ABSTRACT FROM AUTHOR]