Chromium (Cr) is a toxic metal that exerts detrimental effects on plant growth, physiology and yield. The increasing prevalence of Cr contamination necessitates the development of effective mitigation strategies. Salicylic acid (SA), a key signaling molecule and zinc (Zn), an essential micronutrient, are known to enhance crop productivity and stress tolerance. However, their combined role in alleviating Cr toxicity remains unexplored. Therefore, this study aimed to determine the effects of SA and Zn on mitigating Cr-induced stress in barley cultivars. The experiment included two barley cultivars (Sultan-17 and Haider-93) and five treatments: control, Cr stress (40 mg kg⁻¹), Cr + Zn (50 mg kg⁻¹), Cr + SA (1 mM) and Cr + Zn + SA. Chromium stress markedly reduced growth and yield attributes by impairing chlorophyll content, relative water content (RWC) and nutrient uptake, while increasing oxidative damage, Cr accumulation and oxidized glutathione levels. The application of SA and Zn, particularly in combination, significantly mitigated Cr toxicity. The combined treatment considerably improved morphological traits and yield in both Sultan-17 and Haider-93 compared to Cr-stressed plants. These improvements were achieved through increased chlorophyll synthesis, RWC, antioxidant activities, and osmolyte production (including proline, soluble proteins [SP], free amino acids [FAA], glycine betaine [GB], soluble sugars [SS], reducing sugars [RS] and non-reducing sugars [NRS]), as well as enhanced nutrient uptake. Concurrently, the combined treatment reduced Cr accumulation and subsequently decreased electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) levels. Overall, SA and Zn alleviated Cr toxicity by enhancing antioxidant defense, improving physiological and biochemical functions and restoring yield performance in barley cultivars. These findings highlight the strong potential of SA and Zn as an integrated strategy to alleviate Cr toxicity and improve crop resilience in contaminated environments.
Iron deficiency is a major nutritional constraint limiting plant growth and crop productivity in many agricultural soils. In the present study, fifty rhizobacterial isolates obtained from diverse rhizosphere soils were screened for plant growth-promoting traits, including indole−3-acetic acid (IAA), ammonia, hydrogen cyanide (HCN), and siderophore production. Among the isolates, 29 exhibited siderophore-producing ability, and the most efficient strain was identified through 16S rRNA gene sequencing as Pseudomonas fluorescens MR8. Optimization studies showed the highest mean siderophore production of 72.77
Maize (Zea mays L.) productivity and kernel quality are frequently constrained by fungal rot diseases, particularly those affecting roots, stalks, and kernels. This study evaluated the interaction among root rot, stalk rot, and kernel rot in two maize hybrids with contrasting responses to stalk rot. The experiment was conducted during the 2019/2020 and 2020/2021 crop seasons in Chapecó, Santa Catarina, Brazil, using a randomized complete block design with six replicates. Two hybrids, Pioneer 32R22 and Pioneer 3456R, were evaluated at four phenological stages: V8, R1, R4, and R6. Root and stalk rot incidence and severity were assessed, fungal isolates were obtained from roots, internodes, and kernels, and yield, thousand-kernel weight, kernel rot, and fungal incidence in kernels were determined. Pioneer 32R22 showed greater root and stalk rot incidence and higher stalk rot severity, particularly at R4 and R6, whereas Pioneer 3456R maintained higher yield and thousand-kernel weight across both seasons. Kernel rot was positively correlated with root rot and basal internode rot, especially in 2020/2021. Isolates morphologically identified as Fusarium verticillioides, F. graminearum, and Cephalosporium sp. were associated with infected tissues and kernels. Multivariate analyses confirmed distinct disease patterns between hybrids and growth stages. These findings indicate that maize rot diseases are interconnected and that resistant hybrids are essential for reducing disease progression and preserving kernel yield and quality.
Climate change-driven water scarcity poses a major threat to sustainable crop production in arid and semi-arid regions. Exploiting drought-tolerant native crops together with efficient irrigation strategies may improve agricultural resilience under limited water availability through enhanced biochemical adaptation. Fonio (Digitaria exilis), an underutilized climate-resilient cereal, exhibits considerable biochemical adaptive potential under drought conditions. This experiment investigated drought-responsive biochemical signaling and physiological adaptation in three fonio varieties exposed to control irrigation (CK), partial root-zone drying (PRD), and deficit irrigation (DI), with particular emphasis on osmolyte biosynthesis, antioxidant enzyme regulation, oxidative stress mitigation, and water use efficiency under reduced irrigation. Maximum growth and yield occurred under control irrigation, but osmolyte accumulation, enzymatic antioxidant activity, and water use efficiency were greater under PRD. Compared with the other techniques, DI treatment resulted in weaker yield- and drought-responsive biochemical signals. Among the varieties, V1 outperformed the others in drought-responsive signaling, drought tolerance, internal water balance, and yield. Under reduced water availability, the V1–PRD combination produced the strongest drought-mitigating biochemical response, with higher mesophyll conductance (55.33 mmol CO 2 m− 2 s− 1), photosynthesis (11.40 µmol CO 2 m− 2 s− 1), proline content (5.83 mg g− 1), spermidine content (2.13 nmol g− 1 fresh weight), antioxidant enzyme activities (APX, GPX, and SOD), yield (0.16 g plant− 1), and water use efficiency (0.065 g 100ml− 1 H2O), alongside the lowest H₂O₂ (31.70 mmol g− 1 FW), MDA (1.23 µmol g− 1 FW), lipid peroxidation (0.43 µmol g− 1 FW), and methylglyoxal (12.23 umol g− 1 FW) contents. These findings demonstrate that PRD-mediated regulation of osmolyte biosynthesis and antioxidant enzyme signaling pathways underlies drought acclimation in fonio, positioning PRD as a promising irrigation strategy for improving drought resilience and water productivity in climate smart fonio production systems. Future research should focus on experiments under different soils and ecological conditions.
Although grain sorghum [Sorghum bicolor (L.) Moench] is recognized for its tolerance to water deficit, drought conditions can compromise crop growth and yield performance. In this context, bio-inputs based on Priestia aryabhattai emerge as a promising alternative to mitigate the effects of drought stress. However, studies evaluating the use of this rhizobacterium in sorghum are still scarce, especially regarding reinoculation strategies during reproductive stages. Thus, this study evaluated whether reinoculation with P. aryabhattai during flowering could enhance root development, grain production, and irrigation water productivity of grain sorghum under water limitation. The experiment was conducted in a greenhouse, using a randomized block design in a 3 × 3 factorial arrangement, consisting of three water regimes based on soil available water capacity (AWC) [85
