Canola Seasonal Summary 2019

Spring canola acreage in Ontario declined 25 per cent in 2019 compared to the previous year. Insured acres totaled just over 30,000 compared to approximately 40,000 in 2018. Five counties that grew canola in 2018 did not appear in the insured acreage statistics this year.  Some producers were unable to plant all their intended canola acres because of cold, wet weather through April and May. Export trade instability likely contributed to the reduction in canola acres as well.

 

It is likely an understatement to say that spring planting conditions were challenging. Wet weather as well as cool conditions that prevented drying caused planting delays across most regions in the province. Floods and rainfall warnings took place in Eastern Ontario and Nipissing District in the first two weeks of May, along with snow and rain in Temiskaming and further north. Few if any producers found a planting window in April or early May. Rain continued to fall every few days in most regions through to mid-June. Most of the crop was planted towards the end of May and into the first week of June. Planting in June is generally not recommended because of the increased risk of swede midge damage and late harvest, but in some regions later planted fields had better moisture during pod fill in August and September.

 

Temperatures were much lower overall than in 2018. Heat unit accumulation was very slow through May and June, and even in July temperatures dipped below 10°C some mornings in “southern” spring canola regions. Simcoe County and northeastern Ontario were drier than normal through July and August and may have had shallow root systems because of plentiful moisture earlier on. Some soils moved from too wet to baked dry causing significant stress and abortion of flowers and pods.

 

 

Flea beetles were abundant in spring based on numerous reports, and many fields were sprayed. In some areas, particularly Wellington County, flea beetle activity continued through to the end of the season. There are no established thresholds for controlling late season flea beetle. Pre-harvest intervals for insecticide application may limit late season options. Flea beetle can strip pods and contribute to green seed and shatter losses but varieties with pod shatter resistance appeared to hold up well.

 

While swede midge was present and emerged around the first of June as usual, reports from Bruce, Grey and Dufferin Counties indicated similar or lower pressure compared to last year. Some fields did not see an insecticide application at all this year. However, swede midge significantly reduced yields in some fields, particularly in Nipissing and Temiskaming Districts.

 

Fields that had very high flea beetle or swede midge damage were those that had inadequate fertility and grew slowly, leaving plants susceptible to insect damage for a longer period of time. Overly wet fields or any other causes of slow growth can also lead to higher levels of early season insect damage. In a fertility trial at the Elora Research Station in 2019, canola plots that did not receive pre-plant sulphur grew slowly and had significant plant damage and stand loss from flea beetle feeding, even with a well-timed insecticide application (Figure 1). Ensuring you have a good fertility program is an important part of integrated pest management.

 

 

Figure 1. The canola plot at center did not receive pre-plant sulphur, resulting in slow growth and significant flea beetle damage causing a reduced plant population. Neighbouring plots had adequate fertilizer. All plots had one application of insecticide for flea beetle control.

There were no reports of significant incidences of canola disease in 2019. White mould was limited due to dry conditions during susceptible stages. Clubroot spores are present on many fields and in most canola growing regions but many producers have selected clubroot resistant varieties and there were no reports of significant damage this year.

 

 

Harvest was stretched out over a few months because of late planting and wet conditions at harvest. Most of the crop was harvested in September through to mid-October. Many producers battled significant regrowth, particularly in Temiskaming on fields that had moisture stress during the summer months. A greater number of fields saw pre-harvest herbicide applications this year to attempt to harvest ahead of forecasted rains. There may be some fields left unharvested, particularly in northern regions. There were no reports of poor quality.

 

 

 

About 2500 acres of winter canola were planted in Renfrew, Bruce, Grey, Hamilton-Wentworth, Chatham-Kent and Essex Counties. The prolonged, wet spring led to “winter kill” of about half of the fields planted in 2018. The healthiest fields were on sandier soils, had 5 or 6 leaves heading into winter, and were not planted too thick. Dense stands cause canola seedlings to compete and set crowns (growing points) about an inch above the soil surface increasing the risk of winter kill or poor plant health (Figure 2), whereas crowns snug to the soil surface are more protected and survival is improved.  The wet spring also made it very difficult for producers in southern Ontario to get into the field and apply fertilizer and fungicide, so inputs were delayed or missed in some cases.

 

 

Figure 2. In spring, cut plants at the soil surface to check for hollow stems caused by heaving; the plants pictured here have very low yield potential even though the field appears to have an adequate number of green, growing plants.

Cabbage seedpod weevil (CSW) can be a significant challenge in winter canola but was not an issue this year. Producers are reminded to scout for CSW in 2020 as the crop is bolting and moving into reproductive stages. More information on CSW can be found at FieldCropNews.com.

 

The winter canola was nearly 6 feet tall in some fields, particularly where fertility levels were high. Lodging of the tall crop presented harvest challenges as well as difficulty in getting good spray coverage with pre-harvest herbicides. Many opted to spray prior to harvest, although this is not a requirement and fields can be left to dry down naturally. The majority of fields were harvested in mid to late July, which is later than what some were expecting in the southern counties. In at least one case in Wellington county, harvest occurred in September because of the extremely late start in spring.