In vitro management of citrus melanose caused by Phomopsis citri through commercially available fungicides

摘要

Citrus melanose, caused by Phomopsis citri is a serious disease that can affect trees at any age. Symptoms include small, dark brown to black colored spots on the fruit, leaves and twigs. Though it does not affect internal fruit quality but market value of the citrus is reduced to a great extent. Samples were collected from an orchard of District Toba Tek Singh, Punjab during March-April 2018 and P. citri (PPS-114) was isolated and maintained. Five fungicides (i.e., Amistar Top 325 SC, Emesto Silver 240 FS %, Kocide? 3000, Nativo 75% WG and Score 250 EC) were tested using poison food technique each with 100, 200 and 300 PPM concentrations. Data was recorded on the basis of colony diameter and percent inhibition of mycelial growth. Results indicated that all the tested fungicides had significant antifungal potential against the test fungus and their inhibition is concentration dependent. Among the tested fungicides, Kocide exhibited 100 percent growth inhibition at the highest tested concentration i.e., 300 ppm followed by Nativo which was accounted for 94 per cent reduction of mycelial growth over control. Score and Emesto silver showed 84 and 82 percent growth inhibition respectively. The least growth inhibition over control was observed with Amistar top i,e., 74 percent. It was concluded that Kocide? 3000 is best for in vitro management of P. citri .