News Fruit Production
2023 strawberry virus survey

Ontario strawberry growers have been managing viruses for almost a decade now. Strawberry viruses, including strawberry mottle (SMoV), strawberry vein banding (SVBV), strawberry mild yellow edge (SMYEV), strawberry pallidosis-associated virus (SPaV), and strawberry polerovirus 1 (SPV1) cause plant decline, stunted plants, and reduced yields. Symptoms can include leaf cupping, asymmetrical leaves, chlorotic foliage, and leaf mottling. Typically, symptoms develop when two or more viruses are present. Unfortunately, symptoms can be easily confused with herbicide damage, cyclamen mite injury, or nutrient deficiency, and to make diagnosis more challenging symptoms cannot always be associated with a particular virus. The combinations of different viruses and the cultivars affected may result in different symptoms.

Most strawberry viruses are vectored by aphids, so growers have been vigilant with aphid management over the last 10 years. Over the last few years growers are finding their fields are lasting longer and vigour has improved, compared to previous years where viruses were reducing yields and vigour, and fields were only lasting for 1 or 2 harvests.

In Ontario we have done multiple virus surveys over the years to determine the incidence and frequency of strawberry viruses, with the most recent surveys in 2017 and 2023. The 2017 survey determined the level of strawberry viruses in Ontario after 4 years of virus vector management. Results indicated virus levels had decreased, but not as much as anticipated. Further decrease was anticipated following the 2017 survey if growers obtained virus free transplants and continued to effectively manage virus vectors.

In 2023 we collected 6 samples from 16 farms across the province, including the same farms that were involved in previous surveys. Results from the 2023 survey showed the trend of decreasing incidence of viruses continued for most of the viruses included in the survey (Fig. 1). | READ MORE