Efficacy of Neem, Garlic and Aloe Extracts in the Management of Postharvest Potato Soft Rot Caused by Erwinia carotovora

Abstract

Potato (Solanum tuberosum L.) production in Kenya is limited by soil borne diseases especially soft rot bacteria caused by Erwinia carotovora. Although the use of synthetic pesticides has significantly contributed in the management of E. carotovora, their use is often associated with environmental pollution and loss of beneficial soil biodiversity. Here, we investigated the efficacy of neem (Azadirachta indica M.), garlic (Allium sativum M.) and aloe (Aloe secundiflora Engl.) extracts, on the development of soft rot bacteria in three potato varieties; Kenya Mpya, Sherekea and Purple Gold. The treatments were laid out in a completely randomized design with five replicates. Interestingly, all the extracts significantly (p˂0.05) reduced the extent of rot on the treated compared to the untreated tubers. Garlic recorded the highest antimicrobial effect as seen from the extent of rot (6.50±0.59%), while aloe (29.00±1.54%) gave the least antimicrobial effect.  Sherekea potato variety showed the highest tolerance to E. carotovora among the studied potato varieties. These results demonstrate potential use of plant extracts in the future development of low cost and environmental friendly biopesticides; a key step towards achieving sustainable global food production