Evaluation of Citrus Cultivars for tolerance to Citrus Tristeza Virus (CTV) and their Management by limiting vector Population

Citrus tristeza virus (CTV) is the most emerging damaging disease of citrus and is the major cause of reduction in citrus yield particularly in Punjab and KPK provinces of Pakistan. It is the most challenging virus due to efficient (vector) transmission system and unavailability of resistant cultivars. Thus, present investigations were carried out to find the source of resistance against CTV. In this regards, fourteen citrus cultivars were evaluated against CTV. Among all the cultivars highest infection was recorded in Mangal Singh i.e 85.90% and lowest in early fruiter i.e., 20%. Early fruiter has a maximum level of tolerance against Citrus tristeza virus. For the management of Citrus tristeza virus disease four chemical (nutrients) i.e., micro mix (Zn, Fe, Cu, Mn), NPK, Zinc and Leufenoron at three concentrations (3, 5, 7g/liter of water) were used. Among all the chemicals micro mix showed maximum disease control 42%. CTV is one of the most challenging viruses to handle and as it is transmitted by Aphid (Aphis gossypi). Thus, in present study chemicals were also tested against the population of Aphis gossypi. It was found that Leufenoron showed maximum inhibition of vector population. These results are helpful for farmers, researchers and scientist for the management of citrus tristeza virus disease to save their citrus field from the harms of CTV.