Assessing the Effectiveness of Integrated Treatments against Alternaria alternata in Stevia rebaudiana under Prayagraj Condition of India
Jyoti Jhirwal
*
Department of Plant Pathology, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh– 211007, India.
Sobita Simon
Department of Plant Pathology, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh– 211007, India.
Rahul Choudhary
Department of Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh– 211007, India.
Chandan Kumar Panigrahi
*
Department of Entomology, Faculty of Agricultural Sciences, Siksha ‘O’ Anusandhan, Deemed to be University, Bhubaneswar-751029, Odisha, India.
Rohit Kumar
Department of Plant Pathology, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh– 211007, India.
*Author to whom correspondence should be addressed.
Abstract
A field experiment was conducted during the Rabi season of 2022–23 at the Central Research Field of SHUATS, Prayagraj, to evaluate the integrated efficacy of organic manures (FYM @ 4.5 kg/m² and neem cake @ 40 g/m²), a bioagent (Pseudomonas fluorescens @ 2 g/m²), and biomix, applied at two different intervals, in managing Alternaria leaf spot of Stevia rebaudiana caused by Alternaria alternata. This disease poses a significant challenge in stevia cultivation, leading to considerable losses in both yield and leaf quality due to necrotic lessions and premature leaf drop. The experiment was laid out in a Randomized Block Design (RBD) with eight treatments replicated three times. Disease severity was assessed using a standardized 0–5 rating scale, and data were statistically analyzed with significance determined at p ≤ 0.05. The results demonstrated that the combined application of FYM + neem cake + Pseudomonas fluorescens + biomix (Treatment T7) was the most effective, resulting in the lowest disease intensity of 18.56% at 90 days after transplanting (DAT). This treatment also recorded the lowest disease severity at 45 DAT (10.98%), indicating its potential in early disease suppression. The next most effective treatment was the combination of neem cake + Pseudomonas fluorescens + biomix, which showed a disease intensity of 21.85%. These findings highlight the synergistic effect of integrating organic amendments with biocontrol agents in enhancing plant health and managing foliar fungal diseases in stevia. The use of eco-friendly and sustainable disease management strategies like these can play a pivotal role in organic stevia production and improving crop resilience.
Keywords: Alternaria leaf spot, organic manures, bioagent, biomix, Alternaria alternata, Stevia