Abstract:
Grapevine leafroll disease (GLD) is the most common and economically destructive grapevine viral disease in South African vineyards and throughout the world. There are many GLD-associated virus variants with Grapevine leafroll-associated virus 3 (GLRaV-3) being the main causative agent of GLD. The vine mealybug, Planococcus ficus, is the most widespread and problematic vector of GLRaV-3. Roguing, pesticides and sanitary measures are common control strategies used in South African vineyards. In this paper, we propose an age-structured mathematical model for the transmission of (GLRaV-3) by Planococcus ficus in the South African context. The model is investigated in terms of the transmission thresholds and control strategies. A simplified model is used to shed light into the qualitative dynamics of transmission and assess the effectiveness of roguing as the main control strategy for GLRaV-3 spread.
