Ontario Field Crop Report
Soybean Seasonal Summary

Table of Contents

  1. Introduction
  2. Production Challenges for 2006


The present estimate is that over 80% of the soybean crop has been harvested. Areas with heavier textured soils in the west, and much of eastern Ontario have been slowed down by wet weather over the last 3 weeks.

Soybean growers faced numerous production challenges in 2005 including soybean aphids, spider mites, bean leaf beetles, soybean cyst nematode and adverse weather. Geography played a part in how much this impacted individuals. Some were forced to deal with a combination of challenges while others dealt with only one or escaped altogether. A lack of moisture was a problem for many areas while some parts of eastern Ontario suffered from excess rainfall in June. Despite these difficulties, yields have generally been at or above average. The range reported so far is from a low of 25 to a high of 75 bu/ac. Both Perth and Oxford counties had many fields yield in excess of 50 bu/ac. Much of the rest of the province achieved yields between 35-45 bu/ac. The provincial average is expected to be approximately 41 bu/ac.

Over 2.3 million acres of soybeans were planted in 2005, making soybeans the largest row crop in Ontario. A dry spring across much of the province allowed most soybeans to be planted under good conditions and during the ideal planting window. Many producers were able to complete soybean seeding by May 25th. In some areas, such as parts of Huron and Elgin counties, fields were so dry that soybean emergence was poor resulting in some replanting being required. Nevertheless, dry spring weather across most of the southwest resulted in excellent root establishment during the vegetative growth stage of the plant. This strong root development early in the season was important for the crop when moisture became limited later in the season.

Pod set was excellent this year in those areas that received timely showers during the flowering period in early July. The remainder of the season was dry across much of the province. As a result these extra pods did not necessarily result in higher yields since seed size was smaller than usual. Soybean aphids and/or spider mites also had an effect in those areas impacted.

Weed Control

Initial dry conditions made weed control challenging in 2005. Preemergence herbicides went unactivated resulting in respays and poor control. Access to product was also a challenge this spring. A late flush of weeds was triggered when rains finally came which resulted in very poor weed control. Herbicides could not be activated at this delayed time and emergence of weeds was not uniform which made timing post emergent weed control difficult. Timing of post applied herbicides was often late due to weather, weed staging, or too many acres to be sprayed within optimum timings.

Soybean plant injury from post-emergent tank mixes was also prevalent this year. The "bounce back" normally seen from these applications took longer this year due to hot dry conditions. Intense sunshine, high UV ratings and smog alerts resulted in environmental injury symptoms that were often confused with herbicide and disease symptoms.

Soybean Aphids

Small populations of soybean aphids were observed in early June in southwestern Ontario, and by the end of June soybean aphids could be found in almost every field right across the province. A significant number of acres were sprayed this year for aphid control. Yield response to spraying ranged from 0 - 10 bu/ac, depending on the health of the crop and the number of aphids present. On average, side-by-side comparisons showed a 3-5 bu/ac advantage to the application of control measures.

Soybean Cyst Nematode

The dry, hot conditions experienced this summer were ideal for soybean cyst nematode and as a result nematode injury was very apparent in many fields in southwestern Ontario. Under these conditions, the SCN soil population level needed for above ground plant damage is lower then would be observed in a "normal" or less stressed year. In other words it does not take as much SCN in the soil to cause damage. Yield losses due to SCN were related to the SCN soil population level, environmental conditions, crop rotation and variety. Yield losses ranged from minimal to significant (50%+).

Spider Mites

The dry, warm weather resulted in significant spider mite infestations, which were much larger and more widespread this year than is usual in Ontario. Infestations often started as hot spots along field edges, and rapidly moved into the whole field as the weather stayed dry. Significant acreage was sprayed this year to control spider mites.


With the tremendous heat and sunshine of 2005, soybeans matured rapidly this fall in many areas of the province. Harvest began during the first half of September and many producers were finished by October 1st. Some beans came off at moistures as low as 8%, but the majority of the crop was harvested at 12-15%. Some fields did not mature evenly and the large percentage of green stalks slowed combines and made harvest difficult.

Various seed quality issues became apparent as harvest got into full swing. A lack of moisture during seed development resulted in mature green seed problems for some producers. Late season feeding of bean leaf beetles and grasshoppers resulted in damaged seed in the southwest. Phomopsis seed decay caused significant damage to some seed lots.
Production Challenges for 2006

Production Challenges for 2006

Increased Acreage

Soybean acreage is expected to increase again in 2006. Planning a good crop rotation will become more challenging as more soybeans are grown. A good crop rotation is essential to minimize disease and insect damage and maintain good soil structure. The soybean plant does not do much for soil structure and returns very little organic matter to the soil.

SCN/Soybean Insects

Soybean Cyst Nematode (SCN) continues to be a major yield reducing pest in southwestern Ontario. SCN has now been found in counties as far east as Brant and Peel and as far north as Bruce. Growers in these areas will need to adjust their management practices to minimize the impact and spread of this pest. Growing susceptible varieties back to back can greatly increase SCN populations in the soil.

Soybean aphids were also a challenge to control in 2005. Every effort to attain good spray coverage within the canopy will be necessary in the future to achieve acceptable control of aphid populations. Scouting will remain an essential tool in determining the infestations of soybean insect pests and determining the optimal timing for applying control products to achieve economic benefit from these activities.

Soybean Rust

No soybean rust was found in Ontario in 2005. To date, South Carolina is the farthest north and east that the disease has been able to spread. Nevertheless, the industry in Ontario will need to be vigilant in 2006 to monitor the spread of rust, and be prepared to apply control measures if necessary. Emergency use and full registration for soybean fungicides will be pursued this winter by OMAFRA, OSG, fungicide companies in cooperation with the PMRA.

For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca