Asian Journal of Advances in Agricultural Research

Development And Evaluation of a Sargassum-based Biostimulant Formulation for Improving Maize Seedling Vigour

Mon, 31 Aug 2026 00:00:00 +0000

Aims: To develop an acid-hydrolysed Sargassum-based biostimulant formulation and evaluate its biochemical characteristics and effectiveness in improving seed germination and early seedling growth of maize.

Study Design: A laboratory seed germination experiment was conducted using a Completely Randomised Design (CRD), with four treatments and three replicates.

Place and Duration of Study: The study was conducted at the Department of Soil Science and Agricultural Chemistry, Anbil Dharmalingam Agricultural College and Research Institute, Tamil Nadu Agricultural University, Tiruchirappalli, Tamil Nadu, India, from April to July 2026.

Methodology: Sargassum biomass collected from Mandapam, Rameswaram, Tamil Nadu, was washed, shade-dried, powdered, and subjected to partial acid hydrolysis using 5% (v/v) nitric acid at a 1:10 solid-to-liquid ratio for 24 h at 30°C. The hydrolysed extract was characterised for phenolics, tannins, flavonoids, terpenoids, and phytosterols. Fourier-transform infrared spectroscopy (FTIR) and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) were used to characterise the hydrolysed extract. Maize CO(H)M8 hybrid seeds were treated with 1, 2, and 3% acid-hydrolysed Sargassum formulation and evaluated using the roll-towel method for germination and seedling growth.

Results: The acid-hydrolysed extract contained phenolics (5.92 ± 0.14 mg GAE mL⁻¹), tannins (4.15 ± 0.11 mg TAE mL⁻¹), flavonoids (3.84 ± 0.09 mg QE mL⁻¹), terpenoids (2.71 ± 0.07 mg LE mL⁻¹), and phytosterols (2.24 ± 0.05 mg CE mL⁻¹). FTIR analysis showed characteristic absorption bands at 3344, 1631, 1324, and 1041 cm⁻¹, indicating changes in functional groups following acid treatment. MALDI-TOF MS showed major peaks at m/z 2053, 4664, 7569, 9322, 11934, 13736, and 18475. The Sargassum-based treatments improved maize seed germination and seedling growth compared with the untreated control. The 3% formulation recorded the highest germination (95.2%), root length (12.6 cm), shoot length (13.4 cm), stem girth (3.8 mm), fresh weight (1.42 g seedling⁻¹), and dry weight (0.33 g seedling⁻¹).

Conclusion: The acid-hydrolysed Sargassum-based formulation enhanced maize seed germination and early seedling growth, with the 3% formulation showing the best overall performance. The developed formulation has potential as a sustainable seaweed-based biostimulant for improving maize seedling establishment.

Weather-based Epidemiological Analysis and Disease Progression Curve of Gray Mold (Botryotinia ricini) in Castor (Ricinus communis L.) under Different Sowing Dates

Mon, 31 Aug 2026 00:00:00 +0000

A field investigation was conducted at the Tapioca and Castor Research Station, Yethapur, Salem District, Tamil Nadu, India, to examine the relationship between prevailing weather conditions and progression of gray mold in castor sown in June and July 2025. Disease severity on primary and secondary spikes was recorded weekly and expressed as per cent disease index (PDI), while maximum and minimum temperature, relative humidity, rainfall, and rainy days were monitored concurrently. Gray mold symptoms first appeared during the 38th standard meteorological week, when the maximum temperature was 32.6°C, the minimum temperature was 24.2°C, and relative humidity was 76.7%. Disease severity subsequently increased, reaching peak PDI values of 60.4% in the June-sown crop and 60.9% in the July-sown crop during the 48th week. Maximum temperature was significantly and negatively correlated with disease incidence in the June- and July-sown crops (r = -0.8478 and -0.8544, respectively), as was minimum temperature (r = -0.7433 and -0.7407). Relative humidity showed significant positive correlations (r = 0.4904 and 0.5036), whereas rainfall and rainy days were not significantly associated with disease development. The observed disease progression indicates that moderate temperatures combined with elevated relative humidity favoured gray mold development. These relationships may support weather-based forewarning and the timely scheduling of protective disease-management measures.

Efficacy of Combined Herbicides on Weed Dynamics, Crop Quality, Nutrient Content and Uptake and Post-harvest Soil Nutrient Status in Summer Black Gram (Vigna mungo L.)

Wed, 02 Sep 2026 00:00:00 +0000

Weed infestation is a major constraint to summer black gram production because the crop exhibits relatively slow initial growth and limited early canopy development, allowing weeds to compete strongly for nutrients, moisture, light and space. Effective weed management is therefore important for reducing crop–weed competition and improving crop quality, nutrient uptake and post-harvest soil nutrient status. A field experiment was conducted during the summer season of 2019 at the Hill Millet Research Station, Rajendrapur farm, N. A. U., Waghai, to study the “Efficacy of combined herbicides in summer black gram (Vigna mungo L.)”. The study area was characterised by clayey soils low in available nitrogen, medium in available phosphorus and fairly rich in available potassium. The study comprised ten weed-management treatments, viz., T₁: Pendimethalin 900 g ha^-1 as pre-emergence + 1 HW at 30 DAS, T₂: Sodium acifluorfen + clodinafop-propargyl _(RM) 250 g ha^-1 as post-emergence at 20 DAS, T₃: Imazethapyr + pendimethalin _(RM) 750 g ha^-1 as pre-emergence, T₄: Imazethapyr + imazamox _(RM) 70 g ha^-1 as pre-emergence, T₅: Imazethapyr + propaquizafop _(RM) 125 g ha^-1 as post-emergence at 20 DAS, T₆: Quizalofop-p-ethyl 100 g ha^-1 post-emergence at 20 DAS, T₇: Fenoxaprop-p-ethyl 100 g ha^-1 post-emergence at 20 DAS, T₈: 2 HW at 20 and 40 DAS, T₉: Unweeded control, T₁₀: Weed-free. The treatments were evaluated on black gram cv. GU-1 and arranged in a randomised block design (RBD) with three replications. The results indicated that the highest protein content (24.17%) and protein yield (261.92 kg ha⁻¹) were recorded under the weed-free treatment (T₁₀), followed by treatments T₁, T₂ and T₈. The lowest weed population and weed dry weight at harvest (326.67 kg ha⁻¹) were recorded with two hand weedings at 20 and 40 DAS (T₈). The maximum weed control efficiency (83.20%) and the lowest weed index (7.98%) were also observed under the same treatment. The residual N, P₂O₅ and K₂O contents in the soil after crop harvest were significantly higher under the weed-free treatment, T₁₀ (277.67, 61.33 and 423.00 kg ha⁻¹, respectively), and were statistically at par with those recorded under treatments T₁, T₂ and T₈. Significantly higher N (3.87 and 1.12 %), P₂O₅ (0.49 and 0.29 %) and K₂O (2.03 and 1.03 %) contents were registered under the weed-free condition (T₁₀) in seed and haulm, respectively. The highest N, P₂O₅ and K₂O uptake by seed (41.91, 5.30 and 21.94 kg ha^-1, respectively) and haulm (27.53, 7.22 and 25.19 kg ha^-1 respectively) were registered under treatment T₁₀, in which the plot was kept weed-free.