While there wasn’t a great amount of pea leaf weevils in the area last year, farmers are recommended to keep an eye out.
“It appears that there are not significant risks projected for the area this year but it would be good to keep an eye out for pea leaf weevil,” explained Justin Babcock, Ponoka County manager of agricultural services in an email.
Producers in the eastern portion of Ponoka County will want to monitor plants. “The numbers were generally down last year but there were a couple hot spots around the east end of the county that could see damaging levels if conditions are right,” said Babcock.
A 2018 spring survey conducted in May and early June by Alberta Agriculture and Forestry (AF) found evidence that feeding occurred over a wider area than in previous years.
A total of 203 fields in 46 municipalities from as far north as Peace River region and Barrhead County to the southern portion of the province were surveyed. “Feeding damage in the spring of 2018 remains low in the Peace but reports of high numbers of adults in August may indicate a change to that situation.”
Farms along Highway 2 may need to keep an eye out, but not all the news is bad, the data shows pea leaf weevil feeding damage was the lowest in the past eight years.
“For any producers south of Highway 9 and along Highway 2 up to Edmonton there is a risk of damaging levels of pea leaf weevil in 2019,” states AF.
“Research has shown that seed treatment is much more effective in reducing losses from pea leaf weevil than foliar treatments.”
Something the ministry pointed out about the survey is that it isn’t strictly a forecast but more of a survey of the province in 2018. What it does tell surveyors is that activity levels greater than nine notches per plant may be enough to cause further damage if the conditions are favourable.
“When warm conditions (>20 C) persist for more than a few days in late April or early May the weevils arrive in fields early,” states the website.
In each field the total notches per plant are counted on 50 plants (10 plants in 5 locations near the field margin). The damage rating for a particular field is the average number of notches per plant. It is important to note that although this survey concentrates on adult damage, yield losses are caused by the larval damage to the nitrogen fixing root nodules.