The influence of biofertilizer and sulphur on growth and yield of sunflower (Helianthus annus L.)

A precisely managed field experiment was carried out during the Zaid season of 2025 at the Crop Research Farm, Department of Agronomy, Naini Agriculture Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, to assess the "Effect of Biofertilizer and Sulphur on growth and yield of Sunflower." Characterization of the experimental plot's soil indicated a sandy loam texture and an approximately neutral pH. Additionally, it exhibited deficiencies in organic carbon, available nitrogen, available phosphorus, and available potassium, which necessitated the implementation of a precise nutrient management strategy. The study's methodology employed a Randomized Block Design, featuring ten treatments, each replicated three times. This approach was adopted to uphold statistical validity and diminish the impact of confounding variables on the observed results. The treatment combinations are T1: Azotobacter + Sulphur 15 kg/ha, T2: Azotobacter + Sulphur 20 kg/ha, T3: Azotobacter + Sulphur 25 kg/ha, T4: VAM + Sulphur 15 kg/ha, T5:VAM + Sulphur 20 kg/ha, T6: VAM + Sulphur 25 kg/ha, T7: Azotobacter + VAM + Sulphur 15 kg/ha, T8: Azotobacter + VAM + Sulphur 20 kg/ha, T9: Azotobacter + VAM + Sulphur 25 kg/ha, T10: Control (RDF)-N:P:K-80:60:40 kg/ha. The results indicated that the combined application of Azotobacter and Vesicular Arbuscular Mycorrhiza along with Sulphur 25 kg/ha (treatment 9) significantly increased plant height (169.22 cm), maximum plant dry weight (43.55 g/plant), seeds per capitulum (411.33), seed yield (1.53 t/ha), stover yield (2.23 t/ha) and harvest index (40.47%).