Epidemiological aspects of the transmission and management of cowpea aphid-borne mosaic virus in a passion fruit orchard

Abstract

Brazil is the world’s main passion fruit (Passiflora edulis Sims) producer. The high incidence of passion fruit woodiness (PFW) induced by Cowpea aphid-borne mosaic virus (CABMV) from the genus Potyvirus,which is transmitted non-persistently by several aphid species,has caused constant and significant production losses,prompting producers to abandon or renew orchards once a year. The present study evaluated the effects of agricultural and ecological conditions on the abundance and composition of aphid populations and the influence thereof on CABMV spread in a passion fruit orchard established with young (30 cm tall) and advanced (80 cm tall) seedlings. The ecological and agricultural characteristics of the region negatively influenced the local aphid population,while aphid swarms and population dynamic were not affected by rainfall,temperature and season. However,when considered together these factors negatively influenced the local aphid population,manifested as low abundance and species diversity,with Aphis gossypii Glover as the most constant and abundant species. Although the virus was introduced simultaneously in both young and advanced seedlings,a longer virus latency period in the latter seedlings resulted in delayed expression of symptoms.