Biology subjects

Joshi, H. C.

Publications and source records attributed to Joshi, H. C..

3 recordsLinked to original sources

bioRxiv2026

Physiological Characterization under the Influence of Drought Stress and Salicylic Acid in Valeriana wallichii DC

Valeriana wallichii DC, a high-altitude medicinal plant, is highly sensitive to drought stress, which adversely impacts its physiological functions and root biomass. This study aimed to evaluate salicylic acids role in mitigating drought stress by assessing physiological and biochemical responses in V. wallichii. Plants were treated with foliar applications of SA at concentrations of 0.25, 0.50, 0.75, and 1.0 mM during vegetative and flowering stages. Physiological parameters such as photosynthetic rate, stomatal conductance, water use efficiency (WUE), intrinsic WUE (iWUE), carboxylation efficiency, and biochemical traits including chlorophyll and carotenoid content were measured, alongside fresh and dry root biomass.Drought stress significantly reduced photosynthetic performance (Pn) (3.95 mol CO2m{square}2s{square}1 at 25% FC), stomatal conductance, relative water content, and root yield. SA application notably improved these traits. At 25% FC, 1.0 mM SA enhanced WUE (28.78), iWUE (642.37 mol/mol), and fresh root weight (8.41 g). Under moderate drought (50% FC), 0.50 mM SA improved net photosynthesis (12.5 mol CO2 m{square}2s{square}1), dry root weight (2.31 g), and chlorophyll content. SA treatments also stabilized membrane integrity and maintained higher chlorophyll fluorescence efficiency (Fv/Fm).These findings demonstrate that foliar application of SA enhances drought tolerance in V. wallichii by improving photosynthetic efficiency, water relations, and root biomass. The study supports the strategic use of SA to improve the resilience and productivity of medicinal plants under drought stress conditions. Highlights of the studyO_LIDrought lowers growth and yield by reducing photosynthesis and water use. C_LIO_LISalicylic acid reduces drought effects and improves plant performance. C_LIO_LIAt severe drought, 1- 0.50 mM SA raised WUE, conductance, and root yield. C_LIO_LIUnder mild drought, 0.75- 0.50 mM SA improved gas exchange and yield. C_LIO_LISA doses 0.25-1 mM differ in effectiveness across drought stress stages. C_LI

plant biology↗

bioRxiv2025

Improvement in Orchard Nutrient Status and Productivity Through Integrated Nutrient Management in Mango (Mangifera indica L.) Under Medium-Density Planting

AbstractBalanced nutrient management is essential for sustaining productivity and soil health in perennial fruit crops. A two-year field study (2022-2024) was conducted to evaluate the effects of integrating soil and foliar micronutrient applications with reduced recommended doses of fertilizers (RDF) on vegetative growth, nutrient status, yield, fruit quality, and economic performance of mango (Mangifera indica L.) cv. Dashehari under medium-density planting. Nine nutrient modules combining 25-100% RDF with soil- and foliar-applied Fe, Zn, B, Cu, and Ca were compared using ANOVA, PCA, and PLS-SEM. Integrated treatments significantly enhanced canopy height, spread, and volume, with the 75% RDF + two foliar micronutrient sprays producing the greatest vegetative growth. Yield attributes, fruit size, retention, and shelf life improved markedly under micronutrient-enriched treatments. The highest fruit yield and benefit-cost ratio was obtained with 75% RDF + two foliar sprays, outperforming the conventional 100% RDF. Soil pH and EC were moderated, and organic carbon improved slightly under integrated nutrient management. Soil and leaf macro- and micronutrient concentrations were consistently higher with combined soil-foliar approaches. PCA clustered high-performing nutrient modules with yield and canopy variables, while PLS-SEM identified plant nutrient status as the strongest predictor of fruit yield. Overall, integrating micronutrient supplementation with 75% RDF improved nutrient-use efficiency, productivity, and economic returns while reducing dependence on full-dose fertilizers. The study highlights 75% RDF + foliar micronutrient sprays as an effective and sustainable nutrient management strategy for enhancing yield and orchard performance in mango. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/697138v2_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@227e25org.highwire.dtl.DTLVardef@87b769org.highwire.dtl.DTLVardef@1a73b2org.highwire.dtl.DTLVardef@a1cf12_HPS_FORMAT_FIGEXP M_FIG C_FIG

plant biology↗

bioRxiv2025

Comparative Evaluation of Conventional Inorganic Fertilization and Sesbania rostrata Green Manuring on Soil Properties and the Growth and Development of Oryza sativa L. Pant Basmati 1

To assess the impacts of conventional and organic nutrient management techniques on growth, productivity, sustainability, and soil health in the Basmati rice (Oryza sativa L.) cultivar Pant Basmati 1, a two-year field experiment was carried out during the Kharif seasons of 2023 and 2024. Crop duration remained stable across management methods, as illustrated by phenological variables such as panicle initiation (58-62 days), blooming (84-88 days), and maturity (106-111 days) that were not significantly affected by fertilizer source. Conventional fertilizer supported superior growth at later stages, while organic management produced greater plant height at early growth phases. While the leaf area index and dry matter accumulation were consistently higher under conventional management because of the quick availability of nutrients, tiller density remained similar across treatments (363-411 m-{superscript 2}). Despite statistically significant variations, chlorophyll a and b quantities peaked under organic inputs at 60 DAT. Higher biological and grain yields were obtained with conventional fertilization; however, yield variations between systems were generally insignificant over time. As soil fertility stabilized, organic management notably increased the harvest index in the second year, indicating improved assimilate partitioning. The findings show that organic nutrient management can provide benefits in terms of resource efficiency and environmental sustainability while maintaining yield parity with conventional systems during the early conversion phase. Organic management techniques improve soil quality. Compared with to conventional methods, organic management practices were found to have higher soil macro and micronutrient status, water-holding capacity, aggregate stability, and soil enzyme activity (DHA and acid & alkaline phosphatase). These results show that organic Basmati rice cultivation is a feasible and sustainable alternative to traditional nutrient management, even though it may take longer to reach maximum yield.

plant biology↗