Transmission of Pelargonium Flower Break Virus (PFBV) in Irrigation Systems and by Thrips

Abstract

Pelargonium flower break virus (PFBV) has become an important disease in glasshouses in Western Europe. In studies of the spread of PFBV via recirculating nutrient solutions, PFBV was found in nutrient solutions used with PFBV-infected Pelargonium plants 2 wk after starting the culture. In previously uninfected plants, PFBV was detected after 6 wk in culture. By 14 wk, 100% of the plants were infected. When the nutrient solution was decontaminated by means of slow sand filtration, infection of the plants was delayed by 6 wk, and the final percentage of infected plants was reduced to about one third. PFBV was also transmitted by thrips (Frankliniella occidentalis), and 30% of plants became infected when thrips were caged with PFBV-infected and healthy Pelargonium plants. When pollen from PFBV-infected plants was dusted onto the leaves of plants that were then caged with about 15 F. occidentalis per plant, about 40% of the Pelargonium plants became infected. No infection occurred with thrips or pollen alone. Pollination and inoculation by rubbing with pollen from PFBV-infected Pelargonium plants also resulted in virus-infected plants