Controlling Penicillium Fruit Rot of Citrus Using Wood Vinegar and Some Medicinal Plant Extracts

Abstract

Fifteen strains of Penicillium sp., caused citrus fruit rot disease, were isolated from citrus sold in Chiang Mai. The pathogenicity test showed that POF-2 was the most virulent isolate for citrus rot disease. Efficacy of five different wood vinegar, namely wood vinegar from coconut shell, bamboo, rubber tree, eucalyptus, longan and efficacy of two plant extracts of neem and turmeric were determined for inhibition of growth and development of POF-2 isolate. Each wood vinegar and medicinal plant extract was separately mixed into potato dextrose agar (PDA) at final concentration of 1, 2, 3, 4 and 5 %. The results showed that wood vinegar from bamboo and rubber tree at 2 % (v/v) could inhibit 100% of mycelia growth and sporulation of POF-2 isolate. The minimum inhibition concentration (MIC) of wood vinegar from rubber tree and bamboo were 1.4 and 1.5 % (v/v), respectively. Afterward, wood vinegar of bamboo and rubber tree were tested for disease control on citrus fruits. Citrus fruits were separately soaked into 1.4% (v/v) wood vinegar from rubber tree and 1.5 % (v/v) bamboo wood vinegar for 1 minutes. The results showed that rubber tree wood vinegar had the efficacy to control the disease at 0 and 12 h after soaking for 66.67 and 56.56% whereas bamboo wood vinegar could control the disease by 57.50 and 46.67%, respectively.