Effect of selected plant extracts against post-harvest rot fungi of Onion (Allium cepa L.)

Survey of fungi associated with post-harvest deterioration of onion bulbs in three major markets in Allahabad district was conducted. Rotten onion bulbs obtained from the three selected markets viz. Mundera sabji mandi, Naini sabji mandi and Khuldabad sabji mundi. Four different fungal genera viz. Aspergillus sp., Penicillium sp., Fusarium sp. and Colletotrichum sp. were isolated from the infected bulbs. The most frequently encountered fungus species was A. niger. Seven plant leaf extracts viz. Azadirachta indica, Psidium guajava, Aloe-vera, Ocimum basilicum, Eucalyptus camaldulensis, Carica papaya and Taraxacum officinale were tested on A. niger in vitro condition. All the leaf extracts significantly inhibited the radial mycelial growth of the test pathogen (A. niger). The highest percentage growth inhibition was achieved with Aloe-vera (65.5%) against A. niger followed by guava leaf (43.8%).