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.

Background: Drought stress is the most harmful one among other abiotic stresses with negative impacts on crop growth and development. Drought-hardening is a feasible and widely used method in tobacco seedlings cultivation. It has gained extensive interests due to its role in improving drought tolerance. This research aimed to investigate the role of drought-hardening and to unravel the multiple mechanisms underlying tobacco drought tolerance and adaptation. Results: This study was designed in which various drought-hardening treatments (CK (no drought-hardening), T1 (drought-hardening for 24 h), T2 (drought-hardening for 48 h), and T3 (drought-hardening for 72 h)) were applied to two tobacco varieties namely HongHuaDaJinYuan (H) and Yun Yan-100 (Y). The findings presented a complete framework of drought-hardening effect at physiological, biochemical, and gene expression levels of the two tobacco varieties under drought stress. The results showed that T2 and T3 significantly reduced the growth of the two varieties under drought stress. Similarly, among the various drought-hardening treatments, T3 improved both the enzymatic (POD, CAT, APX) and non-enzymatic (AsA) defense systems along with the elevated levels of proline and soluble sugar to mitigate the negative effects of oxidative damage and bringing osmoregulation in tobacco plants. Finally, the various drought-hardening treatments (T1, T2, and T3) showed differential regulation of genes expressed in the two varieties, while, particularly T3 drought-hardening treatment-induced drought tolerance via the expression of various stress-responsive genes by triggering the biosynthesis pathways of proline (P5CS1), polyamines (ADC2), ABA-dependent (SnRK2, AREB1), and independent pathways (DREB2B), and antioxidant defense-related genes (CAT, APX1, GR2) in response to drought stress. Conclusions: Drought-hardening made significant contributions to drought tolerance and adaptation in two tobacco variety seedlings by reducing its growth and, on the other hand, by activating various defense mechanisms at biochemical and molecular levels. The findings of the study pointed out that drought-hardening is a fruitful strategy for conferring drought tolerance and adaptations in tobacco. It will be served as a useful method in the future to understand the drought tolerance and adaptation mechanisms of other plant species. Graphical Drought-hardening improved drought tolerance and adaptation of the two tobacco varieties. T1 indicates drought-hardening for 24 h, T2 indicates drought-hardening for 48 h, T3 indicates drought-hardening for 72 h

Drought stress is a major abiotic stress that hinders plant growth and development. Brassinosteroids (BR), including 2,4-epibrassinolide (EBR), play important roles in plant growth, development, and responses to abiotic stresses, including drought stress. This work investigates exogenous EBR application roles in improving drought tolerance in tobacco. Tobacco plants were divided into three groups: WW (well-watered), DS (drought stress), and DSB (drought stress + 0.05 mM EBR). The results revealed that DS decreased the leaf thickness (LT), whereas EBR application upregulated genes related to cell expansion, which were induced by the BR (DWF4, HERK2, and BZR1) and IAA (ARF9, ARF6, PIN1, SAUR19, and ABP1) signaling pathway. This promoted LT by 28%, increasing plant adaptation. Furthermore, EBR application improved SOD (22%), POD (11%), and CAT (5%) enzyme activities and their related genes expression (FeSOD, POD, and CAT) along with a higher accumulation of osmoregulatory substances such as proline (29%) and soluble sugars (14%) under DS and conferred drought tolerance. Finally, EBR application augmented the auxin (IAA) (21%) and brassinolide (131%) contents and upregulated genes related to drought tolerance induced by the BR (BRL3 and BZR2) and IAA (YUCCA6, SAUR32, and IAA26) signaling pathways. These results suggest that it could play an important role in improving mechanisms of drought tolerance in tobacco.

Rendimento e índices fenológicos do trigo afetados pela fertilização exógena de zinco e ferro - DOI:10.5039/agraria.v15i1a7730

Balanced nutrition is the key to higher quality crop production. Micronutrients, especially boron (B) have an important role in various physiological processes and stress tolerance while its deficiency could affect the yield and quality of crop plants. In this context, this study investigated the significance of foliar B application at various growth stages on maize yield components, yield, and grain B content. The treatments consisted of boron foliar application levels (0, 0.5, 1, 1.5 and 2%) at different growth stages (V4 = fourth leaf stage, V8 = eighth leaf stage and VT = tasseling stage) during summer 2021 and 2022. The results revealed that plant height, leaf area plant-1, leaf area index, plants at harvest, ear length, grains ear-1, thousand grains weight, shelling percentage, biological yield, grain yield and harvest index were increased with 1 % B foliar spray compared to other levels. In addition, ear length, grains ear-1, thousand grains weight, shelling percentage, biological yield, grain yield and harvest index were increased with B foliar application at VT (tasseling stage) compared to other stages. It was concluded that the application of 1% foliar boron (1.28 kg B ha-1) i.e. 7.32 kg H3BO3 at tasseling stage improved growth, yield and yield components of maize.

| Management of nutrients has a great impact over the yield and quality of crops as well as soil health. An experiment was performed to investigate the impact of nutrients management and application time over the yield and yielding attributes of wheat at the Agronomy Research Farm in the University of Agriculture, Peshawar, Pakistan during winter 2014-15. The experiment was designed in RCBD with split plots arrangement, replicated four times. Three levels of nitrogen (N) (90, 120, 150 kg ha -1 ) were allotted to main plots, while combination of sulfur (S) levels (15, 30, 45 kg ha -1 ) and application timings (100% at sowing, 100% at tillering and 50% at sowing + 50% at tillering) along with a control were allotted to the sub plots. Data regarding number of productive and unproductive tillers m -2 , thousand grain weight, grains spike -1 , biomass yield and value cost ratio (VCR) of wheat were significantly affected by N and S. Sulfur and its application time prominently influenced the productive tillers m -2 and biomass yield. Nitrogen at 150 kg ha -1 resulted in more number of productive tillers m -2 , less un-productive tillers m -2 and higher thousand grain weight, biological yield and higher value cost ratio. Sulfur at 45 kg produced higher productive tillers m -2 , thousand grain weight, grains spike -1 and biomass yield. Sulfur applied 50% at sowing and 50% at tillering significantly influenced number of productive tillers m -2 and biological yield (9704 kg ha -1 ). It was concluded from the analysis of data that nitrogen at the rate of 150 kg ha -1 with sulfur at the rate of 45 kg ha -1 applied 50% at sowing + 50% at tillering significantly contributed towards the economics and reproductive traits of wheat.