Abstract
Citrus tristeza clostervirus (CTV) is one of the most damaging fruit viruses playing havoc in citrus orchards around the world. Here, we report, an ELISA-based indexing of citrus trees over a period of eight years (2002 to 2010) in Northwest Pakistan, revealing that the incidence of CTV is increasing mainly with the distribution of infected rootstocks, putting citrus industry at the verge of complete annihilation. The surveys revealed that the average incidence of CTV in 10 major citrus growing districts in the Northwest of Pakistan has steadily increased from 24% (in 2002) to 31, 35, 39 and 44 in 2004, 2006, 2008, 2010, respectively. Maximum per cent increase of CTV was in citrus orchards in district Haripur, that is, 27.50% and followed by 26% increase of the virus incidence in district Swat during 2002 to 2010. The incidence of the virus was correlated with use of sour orange as root stock with rough lemon. In orchards, where rough lemon was used as root stock; the incidence of CTV was comparatively low. A comparative study of the virus incidence conducted during 2006 to 2012 in sweet orange trees grafted on sour orange and rough lemon in Northwest indicated an average per cent incidence 43 and 37, respectively. This is the first comprehensive study on citrus fruits to determine an increasing trend of CTV in Northwest of Pakistan where citrus industry has been a major source of income for local farmers. An extensive rescue plan needs to be placed to avoid complete destruction of this exportbased industry. Keywords: Citrus, Tristeza, Citrus Tristeza Clostervirus (CTV), ELISA, Incidence, Pakistan
Highlights
Citrus fruits represent approximately 40% of all fruit crops growing in Pakistan and mainly concentrated in Punjab and Khyber Pakhtunkhwa (KP) Province (Catara, 1987; Catara et al, 1988)
A comparative study of the virus incidence conducted during 2006 to 2012 in sweet orange trees grafted on sour orange and rough lemon in Northwest indicated an average per cent incidence 43 and 37, respectively
In a preliminary survey conducted by a group of Italian and Pakistani experts in 1988 with the co-operation of Ministry of Foreign Affairs and Pakistan Agricultural Research Council (PARC), citrus was reported to be infected by a number of virus and virus-like diseases in KP and Punjab, regions Pakistan and only CTV was confirmed by enzyme-linked immuno-sorbent assay (ELISA) and electron microscopy (Catara et al, 1988)
Summary
Citrus fruits represent approximately 40% of all fruit crops growing in Pakistan and mainly concentrated in Punjab and Khyber Pakhtunkhwa (KP) Province (Catara, 1987; Catara et al, 1988). The major virus and virus-like diseases of citrus trees reported in Pakistan are tristeza, infectious variegation, exocortis, cachexia-xyloporosis, greening and stubborn (Catara, 1987; Catara et al, 1988; Bove, 1995; Arif et al, 2005a; Iftikhar et al, 2009). Most of these diseases are wide spread in new plantations due to un-certified infected bud wood being used as scion. New plantation would be un-successful until pathogen-free bud wood is provided to the citrus growers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
