In the spring and summer of 2024, Cucurbit Aphid-Borne Yellows Virus (CABYV) was noticed in several cucumber growers in the western part of the Netherlands. After suspecting an association with substrate slab reuse, this was investigated.
The virus was detected in both the first and second crops of cucumbers. Earlier, in 2021 and 2022, CABYV was mainly present in the south of the Netherlands. The year 2023 had relatively few outbreaks of the virus.
CABYV is transmitted by aphids, with cotton aphids as the most efficient vector. Studies in years 2021 and 2022 showed that whitefly transmission of the virus was not demonstrated and that the offspring of cotton aphids cannot transmit the virus.
However, cotton aphids can infect cucumber plants for three weeks after the virus is acquired. Moreover, flying cotton aphids can transmit the virus from plant to plant.
Reuse mats
This year, growers noticed that in their second crop, on rockwool slabs that had previously been used for infected cucumber plants, infestation occurred again. As early as 2-3 weeks after planting, the cucumber plants showed yellow leaves, indicating a new infection with CABYV.
The growers had infected plants in their first crop and quickly switched cultivation, disinfecting the greenhouse and controlling aphids. Nevertheless, they continued to wonder if the virus could infect new plants via infected roots in the old rockwool slabs.
A new study took a closer look at this issue. A greenhouse trial investigated whether transmission of CABYV via substrate with infected root residues is possible. The results of this study may help growers take additional measures to prevent infections from old crops from spreading to new plants via the substrate. The findings will help cucumber growers control the virus and improve crop protection.
This project was carried out by the Control in Food & Flowers Foundation and funded and coordinated by the innovation program The New Doing in Plant Health of Kennis in je Kas (KijK). Made possible in part by the Crop Cooperative Cucumber. The trial was supervised by growers.
View the research report here.
Index photos: infection CABY virus, photos Bayer