Management of alternaria leaf spot (Aegle marmelos Correa) of bael

Abstract

The beal (Aegle marmelos Correa) is an important indigenous arid zone growing regions. To test the effect of fungicide alone and in combination against Alternaria leaf spot, a field experiment was conducted at Main Experimental Station Horticulture, Narendra Deva University of Agriculture and Technology, Faizabad during 2015-2016. Bael plants (Aegle marmelos Correa) grown in pot were inoculated with spore suspension of Alternaria alternata by hand sprayer during evening hours to prove the pathogenicity. After inoculation typical symptoms were appeared after 5-7 days on the leaves which was similar to the symptoms recorded under natural condition. Thus is Koch’s postulate was proved. At the time of appearance of disease weather parameters viz. temperature and relative humidity ranged between 27.2 to 31.5oC and 70.40 to 89.00 per cent, respectively, it was also recorded that disease increases very fast when seasonal rain occurs. Efficacy of fungicides in In vitro condition revealed that, up to 24 hrs growth Inhibition recorded in Carbendazim (83.31 Per cent). But up to 48 hrs growth inhibition was recorded in Mancozeb (87.05 per cent) and Carbendazim (79.76 Per cent) treated plates. In case of 72 hrs growth Inhibition recorded in Carbendazim and Mancozeb treatments (69.54 and 86.00 percent).Up to 96 hrs 100 percent growth inhibition recorded in the plates treated with Propiconazole, Difenconazole while growth inhibition was recorded in the plates treated with Carbendazim, Mancozeb and Copper oxychloride (65.00, 82.80 and 95.320 per cent) respectively. Out of six treatments that minimum disease intensity (16.05 per cent) observed with Propiconazole @ 0.1%. This treatment were statistically at par with the treatments Difenconazole @ 0.1%, Copper oxychloride @ 0.2%, and Mancozeb @ 0.2% which have per cent disease intensity 17.10, 18.47 and 19.18 per cent respectively.