Enhancing Fibre Yield and Economic Sustainable Returns of Mesta (Hibiscus sabdariffa L.) through Integrated Multi Stage Management of Foot and Stem Rot (Phytophthora parasitica var. sabdariffae)

Foot and stem rot is an important disease constraint in fibre-producing roselle or mesta (Hibiscus sabdariffa L.). An on-farm assessment in Vizianagaram district, Andhra Pradesh, compared three disease-management programmes during the 2023 and 2024 kharif seasons. The reported treatments were farmer practice without fungicide application (T1), metalaxyl seed treatment followed by mancozeb foliar applications (T2), and metalaxyl seed treatment followed by foliar and root-zone applications (T3). Three participating farms were described for each season. Annual treatment-level mean fibre yields were available for both seasons, whereas treatment-level disease percentages were available for 2023. Arithmetic two-year means for fibre yield were 1,762.5, 2,013.5 and 2,231.5 kg/ha for T1, T2 and T3, respectively. The T3 mean exceeded T1 by 469.0 kg/ha (26.61%), with year-specific differences of 12.63% in 2023 and 42.68% in 2024. Reported disease percentages in 2023 were 6.60% (T1), 3.76% (T2) and 2.40% (T3). Treatment-level pooled financial summaries gave net returns of ₹38,530.5, ₹42,858.5 and ₹57,272.5/ha, respectively; gross-return-to-cost ratios calculated from those summaries were 2.20, 2.29 and 2.72. Although T3 showed the highest descriptive yield and return, missing farm-level data, uncertainty estimates and treatment-allocation details preclude statistical claims about treatment superiority. Further replicated investigation and verification of formulation-specific, legally permitted application protocols are necessary before extension recommendations are made.