Evaluation of fungicides against Alternaria leaf blight of mustard

A field trial was carried out for bioefficacy of three fungicides (iprodione, propiconazole, mancozeb) with four different doses (0.15.0.20, 0.25, 0.30% a.i.) on Alternaria blight of mustard during 2008–09 to 2009–10. All the three fungicides reduced the Alternaria blight of mustard in comparison to untreated control irrespective of their doses. The results showed that three sprayings at 15 days interval from 40 days after sowing showed minimum percent of leaf infection (13.0%), AUDPC (9.9), per cent of siliqua infection (9.9%), number of spots per siliqua (5.3) and increase in the number of siliqua per plant (106.0) and seed yield (kgha−1) in iprodione sprayed plots @0.25% (1682.6 kgha−1) similar as 0.3% a.i.of the same chemicals (1671.8 kgha−1) and followed by propiconazole @0.30% (1539.3 kgha−1) with maximum cost benefit ratio (1: 5.5, 1: 4.5 and 1: 3.5, respectively).