ASSESSMENT OF GUAVA WILT DISEASE (GWD) AND VARIETAL SUSCEPTIBILITY IN PUNJAB-PAKISTAN.

Guava cultivation is rapidly rising in the progressive farming community due to its early bearing habit, long harvesting span and meadow orchard culture. However, in the last 7-8 years, despite 25% increase in the area under cultivation, production has not increased accordingly and per hectare yield has decreased up to 13% mainly due to guava decline which is alarming situation. In this scenario, extensive surveys were conducted to estimate the damage caused by guava wilt disease which is badly affecting guava industry and farming community. Infected trees were found at a much higher proportion in cv. Pyriform (Surahi) in Lahore (52.92%) and Faisalabad (65.12%) regions compared with cv. Round (Gola). Most of the elite strains in both Pyriform and Round cultivars across different regions in central and southern Punjab were found infected with wilt disease. In Pyriform, strains viz. Large Surahi, Small Surahi and Sadabahar Surahi while in cv. Round, Large Gola and Sadabahar Gola strains were more susceptible to wilt compared with other strains. Cytological characterization of isolates recovered from infected roots collected during surveys showed frequent involvement of Fusarium species in guava decline. Further characterization and screening of elite guava strains for tolerance against wilt disease is in progress. Such studies will lead towards identification of guava strains tolerant to GWD for future breeding and biotechnology applications. [ABSTRACT FROM AUTHOR]