Search

Wheat is an important staple crop not only in Pakistan but all over the globe. Although the area dedicated to wheat cultivation expands annually, the quantity of wheat harvested is declining due to various biotic and abiotic factors. Global wheat production and output have suffered as a result of the drought, which is largely driven by a lack of water and environmental factors. Organic fertilizers have been shown to reduce the severity of drought. The current research was conducted in semi-arid climates to mitigate the negative effects of drought on wheat during its critical tillering (DTS), flowering (DFS), and grain filling (DGFS) stages through the application of three different abscisic acid treatments: ABA0 (0 mgL−1) control, ABA1 (100 mgL−1) and ABA2 (200 mgL−1). Wheat growth and yield characteristics were severely harmed by drought stress across all critical development stages, with the DGFS stage being particularly vulnerable and leading to a considerable loss in yield. Plant height was increased by 24.25%, the number of fertile tillers by 25.66%, spike length by 17.24%, the number of spikelets per spike by 16.68%, grain count per spike by 11.98%, thousand-grain weight by 14.34%, grain yield by 26.93% and biological yield by 14.55% when abscisic acid (ABA) was applied instead of the control treatment. Moreover, ABA2 increased the more physiological indices (water use efficiency (36.12%), stomatal conductance (44.23%), chlorophyll a (24.5%), chlorophyll b (29.8%), transpiration rate (23.03%), photosynthetic rate (24.84%), electrolyte leakage (− 38.76%) hydrogen peroxide (− 18.09%) superoxide dismutase (15.3%), catalase (20.8%), peroxidase (− 18.09%), and malondialdehyde (− 13.7%)) of drought-stressed wheat as compared to other treatments. In the case of N, P, and K contents in grain were maximally improved with the application of ABA2. Through the use of principal component analysis, we were able to correlate our results across scales and provide an explanation for the observed effects of ABA on wheat growth and production under arid conditions. Overall, ABA application at a rate of 200 mgL−1 is an effective technique to boost wheat grain output by mitigating the negative effects of drought stress. [ABSTRACT FROM AUTHOR]

High temperature stress during reproductive stages of wheat is a leading constraint in achieving food security. The objectives of study were to investigate heat sensitivity of terminal stages of wheat, to optimize foliar selenium dose, to boost nonenzymatic antioxidants and to determine correlation of these nonenzymatic antioxidants with yield and quality attributes of wheat crop. The field experiment was conducted for two consecutive years at agronomic research area, University of Agriculture Faisalabad, Pakistan. It was laid out in a randomized complete block design under split arrangement, and treatments were replicated thrice. Main plot factor comprised of heat imposition treatments; H0 = Control; H1 = Heat from spike to grain filling; H2 = Heat from flowering to grain filling while in subplots doses of foliar selenium were maintained; Se0 = Control (water spray); Se25 = 25 mg L−1; Se50 = 50 mg L−1; Se75 = 75 mg L−1 and Se100 = 100 mg L−1. Impact of H1 was more damaging compared to H2 and H0 for all response variables. Higher levels of proline, phenolics and leaf selenium were recorded with foliar spray of selenium either at 75 or at 100 mg L−1 under H0, whereas under H1 and H2, significantly higher responses were observed with 100 mg L−1 selenium for these traits. Increases in leaf chlorophyll and grain protein contents were statistically alike with 75 and 100 mg L−1 selenium; while in case of 1000-grain weight, harvest index and grain yield three levels of foliar selenium (50, 75 and 100 mg L−1) performed equally well under all the three heat stress treatments. Moreover, strong positive and significant associations of proline, phenolics, leaf selenium and chlorophyll were measured with yield of wheat. Conclusively, more harmful impacts were recorded under H1 compared to H2 and H0; while 75 mg L−1 Se proved more beneficial under H0 and 100 mg L−1 Se under H1 and H2. Strong associations of biochemical and agronomic traits were observed. [ABSTRACT FROM AUTHOR]

Wheat crops are highly sensitive to high temperatures during reproductive and grain filling phases. This study explored how hydrogen peroxide (H2O2) protects grain yield formation in wheat crops exposed to heat during different developmental phases. Two wheat genotypes, Ujala-16 and Anaj-17, of varying heat tolerances, were subjected to heat stress (32 °C/20 °C) at pre-anthesis, anthesis, and post-anthesis stages under glasshouse and field conditions. Before heat stress treatment, the plants were sprayed with 60-ppm hydrogen peroxide (H2O2). Post-stress changes in leaf physiology were studied to understand the heat recovery mechanism. Despite significant genotypic variations, high temperature damaged leaf physiology and grain yield of both studied wheat genotypes. On average, high temperatures during any developmental phase caused more damage to Anaj-17 than to Ujala-16. Compared with the control, the plants heated during pre-anthesis, anthesis, and post-anthesis produced 44%, 35%, and 25% lesser grains yield per spike (averaged across genotypes and experiments), respectively. In contrast, post-anthesis-stressed plants produced the smallest grains compared to those heated during pre-anthesis or at anthesis. Compared with the control, H2O2-treated plants sustained significantly higher leaf chlorophyll and net photosynthetic rate by protecting cellular membranes from heat injury. Under hot conditions, hydrogen peroxide-treated plants yielded 17% more grains (averaged across the developmental phases and genotypes) than control plants. Our study suggests wheat performance can be improved through exogenous H2O2 application, particularly during terminal heat stress. [ABSTRACT FROM AUTHOR]

This study aimed to optimize methods for identifying heat-tolerant and heat-susceptible cotton plants by examining the relationship between leaf physiology and cotton yield. Cotton accessions were exposed to elevated temperatures through staggered sowing and controlled growth conditions in a glasshouse. Based on their yield performance, leaf physiology, cell biochemistry, and pollen germination, the accessions were categorized as heat-tolerant, moderately tolerant, or susceptible. High temperatures had a significant impact on various leaf physiological and biochemical factors, such as cell injury, photosynthetic rate, stomatal conductance, transpiration rate, leaf temperature, chlorophyll fluorescence, and enzyme activities. The germination of flower pollen and seed cotton yield was also affected. The study demonstrated that there was a genetic variability for heat tolerance among the tested cotton accessions, as indicated by the interaction between accession and environment. Leaf gas exchange, cell biochemistry, pollen germination, and cotton yield were strongly associated with heat-sensitive accessions, but this association was negligible in tolerant accessions. Principal component analysis was used to classify the accessions based on their performance under heat stress conditions. The findings suggest that leaf physiological traits, cell biochemistry, pollen germination, and cotton yield can be effective indicators for selecting heat-tolerant cotton lines. Future research could explore additional genetic traits for improved selection and development of heat-tolerant accessions. [ABSTRACT FROM AUTHOR]

Different environmental conditions affect the phenology and insect/disease incidence in cotton crop. Studies on modulatory role of plant growth stimulants on cotton phenology, insect/disease incidence, and the bolls opening under various thermal regimes/sowing dates under field conditions are lacking. In this study, different growth stimulants, e.g., hydrogen peroxide (H2O2-30 ppm), salicylic acid (SA-50 ppm), moringa leaf extract (MLE-30 times diluted), and ascorbic acid (AsA-70 ppm), were applied at squaring, flowering, and boll formation. June/late thermal regime showed higher incidence of CLCV, insect-infected bolls, and unopened bolls than April/early and May/normal sowing dates. Among the biostimulants, foliar spray of H2O2 and SA (averaged across) reduced the incidence of CLCV, cotton boll worms, and unopened bolls by 25%, 30%, and 29% in June thermal regime than water-treated plants of respective sowing date. April thermal regime took more days for the accumulation of required growing degree days for all phenological components, i.e., days to squaring, flowering, boll splition, boll maturation period, and node number for first fruiting branch, while June thermal regime took less days to initiate these phenological stages. Foliar spray of H2O2 and SA (averaged across) increased earliness at squaring and flowering by 12% and 7%, respectively under April thermal regime while MLE and AsA delayed earliness. The results indicate that exogenous application of SA and H2O2 could improve cotton phenology but reduce the insect and disease incidence under field conditions. [ABSTRACT FROM AUTHOR]

Studies based on the use and role of alligator weed compost mulch in vegetable production are lacking in the literature. Mulches conserve the soil moisture, enhance the nutrient status of soil, and suppress the weeds in crop plants. In the present study, alligator compost mulch was applied in okra under field conditions with the objectives to suppress weed population and to reduce nutrient uptake in weeds to get better crop yield and quality. Alligator compost mulch was applied in furrows 2 days after sowing at 4 t/ha, 6 t/ha, 8 t/ha, and 10 t/ha. Weeds data were collected 20, 27, and 34 days after sowing as well as yield data collected at maturity. Results delineated that alligator compost mulch at 10 t/ha reduced Cyperus rotundus population by 1.07 folds, 0.73 folds, and 0.54 folds for 20, 27, and 34 days after sowing as compared to control, whereas alligator compost mulch also reduced fresh and dry biomass by 0.91 folds and 0.74 folds as compared to control. Similarly, the population and biomass of Trianthema portulacastrum and Alternanthera philoxeroides were also reduced with the application of alligator compost mulch at 10 t/ha. Furthermore, suppression of weed population and biomass by alligator compost mulch (10 t/ha) reduced the uptake of nitrogen (N), phosphorous (P), and potassium (K) in weeds by 1.3 folds, 1.6 folds, and 0.62 folds, respectively, as compared to control. Likewise, okra pod yield, pod K, ascorbic acid (AsA), and ash contents were increased by 53%, 58%, 91%, and 24%, respectively, with the application of alligator compost mulch (10 t/ha) as compared to control plants. The findings of this study stated that alligator compost mulch suppressed weed population, reduced nutrient uptake in weeds, and improved okra yield and quality, and thereby, it would be an emerging source of organic vegetable production. [ABSTRACT FROM AUTHOR]

Abiotic stresses are the prime coercion to sustainable crop production in changing climate scenario. Heat and drought stresses at reproductive as well as vegetative stages of rice cause extensive reduction in its yield. Being a multifunctional amino acid, proline is being used to diminish numerous biotic and abiotic stresses of plants. A pot experiment was conducted in summer season 2018, to check the effectiveness of foliar applied proline in mitigating the concurrent effects of heat and drought stresses on rice, at greenhouse/screenhouse of Faculty of Agriculture, University of Agriculture, Faisalabad, Pakistan. Experiment was carried out under completely randomized design with split arrangement having three replications. Stress was imposed at anthesis with treatments viz. drought stress, heat stress and heat plus drought stress as a main factor, and various levels of exogenously applied proline viz. no proline/water spray, 10, 20 and 30 mM concentrations were maintained as subfactor. A control (no stress imposed) was upheld for comparison. Stress treatments: drought, heat and heat plus drought stress at anthesis stage depressed the production of antioxidants, osmoprotectants and chlorophyll contents while causing overproduction of malondialdehyde content. Exogenous proline application upregulated activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), total soluble proteins (TSP), leaf proline and glycine betaine contents and diminution in lipid peroxidation resulting into improvement in chlorophyll contents and eventually yield per plant. Concurrent heat and drought stresses were more perilous as compared to individually applied heat or drought stress and 30 mM proline application gave maximum alleviation against stress. [ABSTRACT FROM AUTHOR]

Rapid industrialization and urbanization have resulted in elevated global temperature over the years consequently disturbing the balance of agro-ecological systems worldwide. Therefore, new eco-friendly agricultural practices for sustainable food production are needed. Mulching could potentially serve the purpose by reducing soil evaporation, conserving moisture, controlling soil temperature, reducing weed growth, and improving microbial activities. Additionally, mulches could provide economical, aesthetic, and environmental advantages to agriculture and landscape. Moreover, in the restoration sites, mulches are widely used for the plantation of trees which need no significant care. Mulches combat with different stress conditions in agricultural lands as well as in landscapes. This review paper focuses on multiple significant impacts of mulches for the production and establishment of different crops in nature. Mulches conserve the soil moisture, enhance the nutrients status of soil, control the erosion losses, suppress the weeds in crop plants, and remove the residual effects of pesticides, fertilizers, and heavy metals. Mulches improve the aesthetic value of landscapes and economic value of crops. This paper also describes some problems associated with various mulch materials. There are contradictions about mulching materials as some researchers favor mulches and others have denoted some concerns. The selection of mulching material is important with respect to crop type, management practices, and climatic conditions. The appropriate mulching technique could provide the aforementioned benefits to the agro-ecological systems. Therefore, the impacts of low-cost, eco-friendly, and biodegradable mulching materials on soil microbes, nutrient balance, plant growth, and soil erosion should be explored in the future. [ABSTRACT FROM AUTHOR]

Poultry manure (PM), a rich source for crop nutrients, is produced in ample quantities worldwide. It provides necessary nutrient to soil and has a potential to improve plant water holding availability under semiarid environment. The effect of composted poultry manure (CPM) and irrigation regimes on morpho-physiology of selective maize (Zea mays L.) hybrids (H1 = drought tolerant, H2 = drought sensitive) was investigated in this study. Two field experiments were conducted during 2010 and 2011 under randomized complete block design with split split-plot arrangements and three replications of each treatment. Irrigation regimes (I1 = 300, I2 = 450, I3 = 600 mm) were kept in main plots; the two maize hybrids (H1 and H2) in sub-plots and nutrient levels (L1 = recommended rate of NPK (control), L2 = 8 t ha−1 CPM, L3 = 10 t ha−1 CPM, and L4 = 12 t ha−1 CPM) were arranged in sub sub-plots. The drought tolerant hybrid showed best growth under all treatments. Results revealed that maximum leaf area index (LAI) was recorded with the application of the recommended dose of NPK. Low irrigation regimes (I1 and I2) highly significantly (P < 0.01) reduced the photosynthesis and transpiration rate in both hybrids while application of 12 t ha−1 CPM was able to partially alleviate the effect of water stress on these parameters. Resultantly, the application of 12 t ha−1 CPM enhanced the plant growth and increased grain yield (21%; 4.17 vs 5.27) under limited water availability (I2L4) as compared to the recommended dose of NPK (I2L1). However, the nutrient application under control treatment had maximum grain yield. Therefore, shortage of water for maize production might be partially alleviated by the application of 12 t ha−1 CPM. [ABSTRACT FROM AUTHOR]

Growth, development, and economic yield of agricultural crops rely on moisture, temperature, light, and carbon dioxide concentration. However, the amount of these parameters is varying with time due to climate change. Climate change is factual and ongoing so, first principle of agronomy should be to identify climate change potential impacts and adaptation measures to manage the susceptibilities of agricultural sector. Crop models have ability to predict the crop’s yield under changing climatic conditions. We used OILCROP-SUN model to simulate the influence of elevated temperature and CO2 on crop growth duration, maximum leaf area index (LAI), total dry matter (TDM), and achene yield of sunflower under semi-arid conditions of Pakistan (Faisalabad, Punjab). The model was calibrated and validated with the experimental data of 2012 and 2013, respectively. The simulation results showed that phenological events of sunflower were not changed at higher concentration of CO2 (430 and 550 ppm). However LAI, achene yield, and TDM increased by 0.24, 2.41, and 4.67% at 430 ppm and by 0.48, 3.09, and 9.87% at 550 ppm, respectively. Increased temperature (1 and 2 °C) reduced the sunflower duration to remain green that finally led to less LAI, achene yield, and TDM as compared to present conditions. However, the drastic effects of increased temperature on sunflower were reduced to some extent at 550 ppm CO2 concentration. Evaluation of different adaptation options revealed that 21 days earlier (as compared to current sowing date) planting of sunflower crop with increased plant population (83,333 plants ha−1) could reduce the yield losses due to climate change. Flowering is the most critical stage of sunflower to water scarcity. We recommended skipping second irrigation or 10% (337.5 mm) less irrigation water application to conserve moisture under possible water scarce conditions of 2025 and 2050. [ABSTRACT FROM AUTHOR]

Coincidence of high temperature with terminal reproductive pheno-stages of cotton is chief constraint to achieve yield potential. This high temperature interfere plant defensive system, physiological process, water relations and lint yield production. In this study, we modulated the detrimental outcomes of heat stress on cotton through the foliar spray of nutrients. Cotton crop was exposed to sub-optimal and supra-optimal thermal regimes for a period of one week at squaring, flowering and boll formation stages under glass house and field conditions. Foliar spray of potassium (K-1.5%), zinc (Zn-0.2%) and boron (B-0.1%) were applied at three reproductive stages one day prior to expose high temperature regimes. High temperature increased lipid membrane damage through increased malondialdehyde (MDA) contents in cotton leaves. High temperature stress also reduced leaf chlorophyll contents, net photosynthetic rate, stomatal conductance, water potential, averaged boll weight (g) and seed cotton yield per plant. Various nutrients variably influenced growth and physiology of heat-stressed cotton plants. Zinc outclassed all other nutrients in increasing leaf SOD, CAT, POX, AsA, TPC activity, chlorophyll contents, net photosynthetic rate, stomatal conductance, water potential, boll weight and seed cotton yield per plant. For example, zinc improved seed cotton yield under supra-optimal thermal regime by 17% and under sub-optimal thermal regime by 12% of glasshouse study while 19% under high temperature sowing dates of field study than the water treated plants under the same temperatures. Conclusively, increasing intensities of temperature adversely affected the recorded responses of cotton and exogenous application of Zn efficaciously alleviated heat induced perturbations. Moreover, exogenous nutrients mediated upregulations in physiochemical attributes induced heat tolerance at morphological level. [ABSTRACT FROM AUTHOR]

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper. [ABSTRACT FROM AUTHOR]