BBTV-infected plants are infectious earlier than previously thought!

Abstract

Banana bunchy top virus (BBTV) is spread in infected planting material and over shorter distances by aphid vectors (Pentalonia sp). Disease control in a plantation relies on a program incorporating the use of clean planting material, regular inspection, and eradication of infected plants before they can act as a source of further infection. Transmission is thought to occur only from symptomatic leaves. Usually, an infected plant produces two or more asymptomatic leaves before the first symptoms appear on the newly emerging leaf. Only this and subsequently formed leaves will be symptomatic. The timing of newly infected plants becoming infectious determines the allowable interval between inspections to limit disease spread. However, using data from a farm with a recalcitrant BBTV epidemic, computer modelling suggested that virus transmission was occurring earlier than assumed.