Wheat Streak Mosaic Virus infections in Southern Alberta, 2023

Jul 04, 2023

Wheat streak mosaic (WSM) is a disease caused by the Wheat streak mosaic virus (WSMV). The virus is
vectored by the movement and feeding of the wheat curl mite (Aceria tosichella). Infected plants are
usually stunted and produce fewer seeds, which are often badly shriveled. The earlier the infection, the
greater is the effect on the plant. Plants may die, fail to set seed, be stunted or show little effect
depending on when they were infected.

Most years the virus and vector do not survive winter, so we do not often see early season symptoms in
Alberta wheat fields. The most recent epidemic in Alberta was in 2017. In 2022, more than ten fields
were confirmed in southern Alberta. As of the end of June 2023, close to twenty fields are confirmed.
The area currently reporting symptoms is south of the Red Deer River.
Scout for symptoms

Producers, agronomists, and crop scouts are encouraged to watch for symptoms of WSMV on wheat
(winter, spring, durum), barley, corn and all other cereals and grasses. Wheat is by far the most
susceptible host, followed by barley, so these crops are most likely to have symptoms. Once wheat or
barley becomes infected, symptoms may appear within a few days.

Video: Dicamba Returns for Georgia Farmers: What the New EPA Ruling Means for Cotton Growers

After being unavailable in 2024 due to registration issues, dicamba products are returning for Georgia farmers this growing season — but under strict new conditions.

In this report from Tifton, Extension Weed Specialist Stanley Culpepper explains the updated EPA ruling, including new application limits, mandatory training requirements, and the need for a restricted use pesticide license. Among the key changes: a cap of two ½-pound applications per year and the required use of an approved volatility reduction agent with every application.

For Georgia cotton producers, the ruling is significant. According to Taylor Sills with the Georgia Cotton Commission, the vast majority of cotton planted in the state carries the dicamba-tolerant trait — meaning farmers had been paying for technology they couldn’t use.

While environmental groups have expressed concerns over spray drift, Georgia growers have reduced off-target pesticide movement by more than 91% over the past decade. Still, this two-year registration period will come with increased scrutiny, making stewardship and compliance more important than ever.