Evaluation of Citrus Cultivars for Tolerance to Citrus Tristeza Virus (CTV), <i>Aphis gossypii</i> and Their Management by Limiting Vector Population

Abstract

Citrus tristeza virus (CTV) is one of the most destructive diseases affecting citrus and is a major cause of reductions in citrus yield. CTV epidemics have caused the death of millions of citrus trees globally. The present study aims to evaluate citrus cultivars against CTV and its vector (aphid) population. The highest levels of infection and vector population were recorded in Mangal Singh, whereas the lowest were found in the early fruiter (20%). Early fruiter had a maximum level of tolerance against Citrus tristeza virus. CTV is replicated in the phloem cells of plants and is transmitted by the aphid specie Aphis gossypii. Thus, the maximum vector population mirrors the highest infection. Chemical plant nutrients, including micro-mix (Zn, Fe, Cu, Mn), NPK, zinc, and the insecticide Lufenoron, were used to limit the impact of CTV and A.gossyii. Lufenuron caused maximum disease inhibition, followed by the plant nutrients zinc, NPK, and micro-mix, respectively. However, Lufenoron significantly decreased the population of Aphis gossypi. The results indicate that the early fruiter has the lowest percent disease index and vector population. Moreover, Lufenuron is the best solution for controlling vector population and disease inhibition.

Keywords

• citrus
• epidemics
• nutrients
• CTV
• <i>Aphis gossypii</i>
• lufenoron