Management of leaf spot disease complex of betelvine by bioagents and plant extracts

In vitro screening of four bioagents viz., Trichoderma harzianum, Aspergillus terreus, Bacillus subtilis and Pseudomonas fluorescens and extracts of four plant species viz., Chromolaena odorata, Ageratum houstonianum, Polygoum hydropiper and Tagetes erecta was done against Colletotrichum capsici, Xanthomonas axonopodis pv. betlicola and complex of C. capsici + X. axonopodis pv. betlicola. B. subtilis significantly inhibited the growth of C. capsici (79.5%) and X. axonopodis pv. betlicola (68.1%) and their complex (76.4%). Among the phytoextracts, P. hydropiper was the best in restricting the growths of both pathogens (72.3 and 72.2%) and their complex (70.4%) respectively over control. Under field condition, sanitation + B. subtilis provided best control strategy of leaf spot complex showing 9.7 percent disease index (PDI), followed by 11.1% PDI in sanitation alone and sanitation + P. hydropiper. Highest fresh leaf yield and cost: benefit ratio were obtained in sanitation + B. subtilis with 33.5 lakh/ha/year and 1:1.29, respectively.