Browsing by Person "Nawaz, Fahim"

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Biochar and slow-releasing nitrogen fertilizers improved growth, nitrogen use, yield, and fiber quality of cotton under arid climatic conditions
(2021) Manzoor, Sobia; Habib-ur-Rahman, Muhammad; Haider, Ghulam; Ghafoor, Iqra; Ahmad, Saeed; Afzal, Muhammad; Nawaz, Fahim; Iqbal, Rashid; Yasin, Mubashra; ul Haq, Tanveer; Danish, Subhan; Ghaffar, Abdul
The efficiency of nitrogenous fertilizers in South Asia is on a declining trajectory due to increased losses. Biochar (BC) and slow-releasing nitrogen fertilizers (SRNF) have been found to improve nitrogen use efficiency (NUE) in certain cases. However, field-scale studies to explore the potential of BC and SRNF in south Asian arid climate are lacking. Here we conducted a field experiment in the arid environment to demonstrate the response of BC and SRNF on cotton growth and yield quality. The treatments were comprised of two factors, (A) nitrogen sources, (i) simple urea, (ii)neem-coated urea, (iii)sulfur-coated urea, (iv) bacterial coated urea, and cotton stalks biochar impregnated with simple urea, and (B) nitrogen application rates, N1=160 kg ha-1, N2 = 120 kg ha-1, and N3 = 80 kg ha-1. Different SRNF differentially affected cotton growth, morphological and physiological attributes, and seed cotton yield (SCY). The bacterial coated urea at the highest rate of N application (160 kg ha-1) resulted in a higher net leaf photosynthetic rate (32.8 μmol m-2 s-1), leaf transpiration rate (8.10 mmol s-1), and stomatal conductance (0.502 mol m-2 s-1), while leaf area index (LAI), crop growth rate (CGR), and seed cotton yield (4513 kg ha-1) were increased by bacterial coated urea at 120 kg ha-1 than simple urea. However, low rate N application (80 kg ha-1) of bacterial coated urea showed higher nitrogen use efficiency (39.6 kg SCY kg-1 N). The fiber quality (fiber length, fiber strength, ginning outturn, fiber index, and seed index) was also increased with the high N application rates than N2 and N3 application. To summarize, the bacterial coated urea with recommended N (160 kg ha-1) and 75% of recommended N application (120 kg ha-1) may be recommended for farmers in the arid climatic conditions of Punjab to enhance the seed cotton yield, thereby reducing nitrogen losses.
Combination of silicate-based soil conditioners with plant growth-promoting microorganisms to improve drought stress resilience in potato
(2024) Mamun, Abdullah Al; Neumann, Günter; Moradtalab, Narges; Ahmed, Aneesh; Nawaz, Fahim; Tenbohlen, Timotheus; Feng, Jingyu; Zhang, Yongbin; Xie, Xiaochan; Zhifang, Li; Ludewig, Uwe; Bradáčová, Klára; Weinmann, Markus; Mamun, Abdullah Al; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Neumann, Günter; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Moradtalab, Narges; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Ahmed, Aneesh; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Nawaz, Fahim; Research School of Biology, Australian National University, Canberra 2901, Australia;; Tenbohlen, Timotheus; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Feng, Jingyu; Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, College of Horticulture, China Agricultural University (CAU), Haidian District, Yuanmingyuanxilu 2, Beijing 100193, China; (J.F.); (Y.Z.); (X.X.); (L.Z.); Zhang, Yongbin; Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, College of Horticulture, China Agricultural University (CAU), Haidian District, Yuanmingyuanxilu 2, Beijing 100193, China; (J.F.); (Y.Z.); (X.X.); (L.Z.); Xie, Xiaochan; Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, College of Horticulture, China Agricultural University (CAU), Haidian District, Yuanmingyuanxilu 2, Beijing 100193, China; (J.F.); (Y.Z.); (X.X.); (L.Z.); Zhifang, Li; Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, College of Horticulture, China Agricultural University (CAU), Haidian District, Yuanmingyuanxilu 2, Beijing 100193, China; (J.F.); (Y.Z.); (X.X.); (L.Z.); Ludewig, Uwe; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Bradáčová, Klára; Department of Fertilization and Soil Matter Dynamics, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany;; Weinmann, Markus; Department of Nutritional Crop Physiology, Institute of Crop Science, University of Hohenheim, 70599 Stuttgart, Germany; (A.A.M.); (N.M.); (A.A.); (U.L.); (M.W.); Li, Huixin
Due to shallow root systems, potato is a particularly drought-sensitive crop. To counteract these limitations, the application of plant growth-promoting microorganisms (PGPMs) is discussed as a strategy to improve nutrient acquisition and biotic and abiotic stress resilience. However, initial root colonization by PGPMs, in particular, can be affected by stress factors that negatively impact root growth and activity or the survival of PGPMs in the rhizosphere. In this study, perspectives for the use of commercial silicate-based soil conditioners (SCs) supposed to improve soil water retention were investigated. The SC products were based on combinations with lignocellulose polysaccharides (Sanoplant® = SP) or polyacrylate (Geohumus® = GH). It was hypothesized that SC applications would support beneficial plant–inoculant interactions (arbuscular mycorrhiza, AM: Rhizophagus irregularis MUCL41833, and Pseudomonas brassicacearum 3Re2-7) on a silty loam soil–sand mixture under water-deficit conditions (6–12 weeks at 15–20% substrate water-holding capacity, WHC). Although no significant SC effects on WHC and total plant biomass were detectable, the SC-inoculant combinations increased the proportion of leaf biomass not affected by drought stress symptoms (chlorosis, necrosis) by 66% (SP) and 91% (GH). Accordingly, osmotic adjustment (proline, glycine betaine accumulation) and ROS detoxification (ascorbate peroxidase, total antioxidants) were increased. This was associated with elevated levels of phytohormones involved in stress adaptations (abscisic, jasmonic, salicylic acids, IAA) and reduced ROS (H2O2) accumulation in the leaf tissue. In contrast to GH, the SP treatments additionally stimulated AM root colonization. Finally, the SP-inoculant combination significantly increased tuber biomass (82%) under well-watered conditions, and a similar trend was observed under drought stress, reaching 81% of the well-watered control. The P status was sufficient for all treatments, and no treatment differences were observed for stress-protective nutrients, such as Zn, Mn, or Si. By contrast, GH treatments had negative effects on tuber biomass, associated with excess accumulation of Mn and Fe in the leaf tissue close to toxicity levels. The findings suggest that inoculation with the PGPMs in combination with SC products (SP) can promote physiological stress adaptations and AM colonization to improve potato tuber yield, independent of effects on soil water retention. However, this does not apply to SC products in general.
Foliar humic acid and salicylic acid application stimulates physiological responses and antioxidant systems to improve maize yield under water limitations
(2023) Altaf, Adnan; Nawaz, Fahim; Majeed, Sadia; Ahsan, Muhammad; Ahmad, Khawaja Shafique; Akhtar, Gulzar; Shehzad, Muhammad Asif; Javeed, Hafiz Muhammad Rashad; Farman, Muhammad
Background: Humic acid (HA) is an organic acid that is naturally present in soil organic matter and improves nutrient availability and the mechanisms involved in plant growth and development. Likewise, salicylic acid (SA) is an important plant hormone involved in the regulation of plant growth and development. A pot experiment was carried out to determine the effects of individual or combined HA and SA application on growth and yield of maize (Zea mays L.) under drought stress conditions. Two maize hybrids, namely, 30T60 (drought tolerant) and 75S75 (drought sensitive), were grown in semi-controlled conditions and foliar applied with SA (1 mM), HA (100 mg L 1 ) and their combination (HA + SA). The plants were exposed to drought stress at the tasseling stage (R1, 60 days after sowing) for 2 weeks, while control plants were given normal irrigation. Results: The results showed that HA and SA applications significantly enhanced the gas exchange characteristics (photosynthetic rate, transpiration rate, and stomatal conductance), and antioxidant activity (catalase, guaiacol peroxidase, and superoxide dismutase) of water stressed maize plants. Foliar SA spray significantly increased the photosynthetic efficiency and activity of enzymatic antioxidants closely followed by HA + SA application that ultimately improved the yield and net benefit cost ratio of maize under water deficit conditions. Conclusion: Our findings suggest that foliar spraying of SA at the initiation of the reproductive stage is a cost-effective strategy to obtain a high maize yield under limited water conditions.
Microbial consortia versus single-strain inoculants as drought stress protectants in potato affected by the form of N supply
(2024) Mamun, Abdullah Al; Neumann, Günter; Moradtalab, Narges; Ahmed, Aneesh; Dupuis, Brice; Darbon, Geoffrey; Nawaz, Fahim; Declerck, Stephane; Mai, Karin; Vogt, Wolfgang; Ludewig, Uwe; Weinmann, Markus
This study investigated the drought protection effects of six fungal and bacterial inoculants and ten consortia thereof on vegetative growth, nutritional status, and tuberization of potato under controlled and field conditions. It was hypothesized that microbial consortia offer improved drought protection as compared with single strains, due to complementary or synergistic effects, with differential impacts also of N fertilization management. Under NO3− fertilization, a 70% reduction in water supply over six weeks reduced shoot and tuber biomass of non-inoculated plants by 30% and 50%, respectively, and induced phosphate (P) limitation compared to the well-watered control. The P nutritional status was significantly increased above the deficiency threshold by three single-strain inoculants and eight consortia. This was associated with the presence of the arbuscular mycorrhizal fungus (AMF) inoculant Rhizophagus irregularis MUCL41833 (five cases) and stimulation of root growth (five cases). Additionally, Bacillus amyloliquefaciens FZB42 and AMF + Pseudomonas brassicacearum 3Re2-7 significantly reduced irreversible drought-induced leaf damage after recovery to well-watered conditions. However, the microbial inoculants did not mitigate drought-induced reductions in tuber biomass, neither in greenhouse nor in field experiments. By contrast, NH4+-dominated fertilization significantly increased tuber biomass under drought stress (534%), which was further increased by additional AMF inoculation (951%). This coincided with (i) improved enzymatic detoxification of drought-induced reactive oxygen species (ROS), (ii) improved osmotic adjustment in the shoot tissue (glycine betaine accumulation), (iii) increased shoot concentrations of ABA, jasmonic acid, and indole acetic acid, involved in drought stress signaling and tuberization, and (iv) reduced irreversible drought-induced leaf damage. Additional application of bacterial inoculants further improved ROS detoxification by increasing the production of antioxidants but stimulated biomass allocation towards shoot growth at the expense of tuber development. The results demonstrated that microbial consortia could increase the probability of drought protection effects influenced by the form of N supply. However, protective effects on vegetative growth do not necessarily translate into yield benefits, which can be achieved by adequate combination of inoculants and fertilizers.
Physiological insights into sulfate and selenium interaction to improve drought tolerance in mung bean
(2021) Aqib, Muhammad; Nawaz, Fahim; Majeed, Sadia; Ghaffar, Abdul; Ahmad, Khawaja Shafique; Shehzad, Muhammad Asif; Tahir, Muhammad Naeem; Aurangzaib, Muhammad; Javeed, Hafiz Muhammad Rashad; Habib-ur-Rahman, Muhammad; Usmani, Muhammad Munir
The present study involved two pot experiments to investigate the response of mung bean to the individual or combined SO42− and selenate application under drought stress. A marked increment in biomass and NPK accumulation was recorded in mung bean seedlings fertilized with various SO42− sources, except for CuSO4. Compared to other SO42− fertilizers, ZnSO4 application resulted in the highest increase in growth attributes and shoot nutrient content. Further, the combined S and Se application (S + Se) significantly enhanced relative water content (16%), SPAD value (72%), photosynthetic rate (80%) and activities of catalase (79%), guaiacol peroxidase (53%) and superoxide dismutase (58%) in the leaves of water-stressed mung bean plants. Consequently, the grain yield of mung bean was markedly increased by 105% under water stress conditions. Furthermore, S + Se application considerably increased the concentrations of P (47%), K (75%), S (80%), Zn (160%), and Fe (15%) in mung bean seeds under drought stress conditions. These findings indicate that S + Se application potentially increases the nutritional quality of grain legumes by stimulating photosynthetic apparatus and antioxidative machinery under water deficit conditions. Our results could provide the basis for further experiments on cross-talk between S and Se regulatory pathways to improve the nutritional quality of food crops.
Silicon seed priming combined with foliar spray of sulfur regulates photosynthetic and antioxidant systems to confer drought tolerance in maize (Zea mays L.)
(2021) Farman, Muhammad; Nawaz, Fahim; Majeed, Sadia; Javeed, Hafiz Muhammad Rashad; Ahsan, Muhammad; Ahmad, Khawaja Shafique; Aurangzaib, Muhammad; Bukhari, Muhammad Adnan; Shehzad, Muhammad Asif; Hussain, Muhammad Baqir
The present study evaluated the effect of silicon (Si) seed priming and sulfur (S) foliar spray on drought tolerance of two contrasting maize hybrids viz. drought tolerant Hi-Corn 11 and susceptible P-1574. The maize seeds were primed with (3 mM Na2SiO3) or without Si (hydropriming) and later sown in pots filled with sandy loam soil. Drought stress (25–30% water holding capacity or WHC) was initiated at cob development stage (V5) for two weeks, whereas the well-watered plants were grown at 65–70% WHC. On appearance of drought symptoms, foliar spray of S was done using 0.5% and 1.0% (NH4)2SO4, whereas water spray was used as a control. The drought-stressed plants were grown for further two weeks at 25–30% WHC before the final harvest. The results showed a marked effect of Si seed priming and foliar S spray on biomass, physiological and enzymatic processes as well as macronutrient concentrations of maize. In comparison to control, the highest increase in leaf relative water content (25%), chlorophyll a content (56%), carotenoids (26%), photosynthetic rate (64%), stomatal conductance (56%) and intercellular CO2 concentration (48%) was observed by Si seed priming + S foliar spray (Si + S) under water deficit conditions. Also, Si + S application stimulated the activity of catalase (45%), guaiacol peroxidase (38%) and superoxide dismutase (55%), and improved NPK concentrations (40–63%) under water limitations. Our results suggest that Si seed priming + foliar spray of S is more effective than the individual application of these nutrients to enhance drought tolerance in maize.
Sulfate-based fertilizers regulate nutrient uptake, photosynthetic gas exchange, and enzymatic antioxidants to increase sunflower growth and yield under drought stress
(2021) Shafiq, Bilal Ahamid; Nawaz, Fahim; Majeed, Sadia; Aurangzaib, Muhammad; Al Mamun, Abdullah; Ahsan, Muhammad; Ahmad, Khawaja Shafique; Shehzad, Muhammad Asif; Ali, Muqarrab; Hashim, Sarfraz; ul Haq, Tanveer
The challenging impact of drought to agricultural productivity requires the adoption of mitigation strategies with a better understanding of underlying mechanisms responsible for drought tolerance. The present study aimed at investigating the effects of sulfur-based fertilizers on mitigation of drought stress in sunflower. Sulfate-containing fertilizers, viz., ammonium sulfate, zinc sulfate, magnesium sulfate, potassium sulfate, and gypsum, were initially evaluated at two different rates (10 and 20 mg kg−1 soil equivalent to 20 and 40 kg ha−1, respectively) for nutrient uptake and growth-promoting traits in sunflower seedlings (cv. Hysun-33). The best performing fertilizer (gypsum) was then selected to evaluate the response of sunflower under drought stress imposed at flowering stage for three weeks (25–30% water holding capacity). Results indicated significant amelioration of drought stress with higher activity of photosynthetic apparatus, upregulation of antioxidative enzymes, and increased achene yield by gypsum application. In comparison to control, gypsum-treated plants (20 mg kg−1 soil) exhibited higher water status (32%), leaf photosynthetic rate (29%), transpiration rate (67%), and stomatal conductance (118%) under drought stress. The antioxidant enzyme activities of catalase, guaiacol peroxidase, and superoxide dismutase were also increased by 67%, 62%, and 126%, respectively, resulting in higher achene yield (19%) under water-deficit conditions. This study indicates that the application of sulfur-based fertilizers (gypsum) can be used to induce drought tolerance and obtain high sunflower yields under drought stress, and furthermore, it is a cost-effective strategy resulting in high benefit–cost ratio with respect to no gypsum application.