Ontario Field Crop Report
2008 Soybean Seasonal Summary

Table of Contents

  1. Summary
  2. Challenges and Opportunities for 2009

Technical information can also be obtained at the OMAFRA Field Crops Webpage and Crop Pest Ontario. Referenced OMAFRA Publications include the Agronomy Guide for Field Crops (Publication 811), the Field Crop Protection Guide (Publication 812), Guide to Weed Control (Publication 75), and Ontario Weeds (Publication 505). These can be obtained from your OMAFRA Resource Centre, or by calling 1-800-668-9938.


The 2008 growing season was characterized by above average rainfall and a warm September. Lots of moisture and a lack of major stress factors resulted in above average yields. With 41% of reported yields submitted to Agricorp, the provincial average to date stands at 43 bu/ac. The 10 year average farm yield on those same acres is 37.6 bu/ac. Some producers harvested fields above 65 bu/ac. It now looks like 2008 soybean crop will be the second highest yielding year on record, with the largest yield ever reported was in 2006 with 46 bu/ac. Approximately 2.1 million acres were seeded this year. Seed size and quality has generally been excellent.

Unfortunately, many fields suffered from excess rainfall which resulted in white mould disease pressure. White mould was a particular problem in Eastern Ontario. In the extreme southwest, conditions were quite dry during the summer resulting in below average yields in some areas.


Soybean planting progressed slowly during the first half of May due to wet conditions. Only about 25% of Ontario soybeans were planted by May 15th. By the end of May, 90% of fields were planted. Fields planted from May 9-11 were challenged by cool, wet weather after planting resulting in emergence difficulties. Seed treatments used during this planting window resulted in a marked improvement in plant stands. Although some fields were planted into wet soil conditions, rainfall throughout the season helped prevent major root development problems.

Growing Season

The 2008 growing season was below last years' Crop Heat Units (CHU's) but not far off the 30 year average. From May 1 to September 30, London reported 3,152 CHU's in 2008 compared to 3,262 CHU's in 2007. The 30 year average for London is 3,106 CHU's for that time period. Precipitation was spotty and above average in many regions. Soybeans need significant rainfall, especially during July and August for optimum yields. Since rainfall occurred during this time of key plant developmental phases of the plant, yields were above average.

A few areas in the southwest suffered hail damage. Fields that were hailed on early in the growing season recovered well with some yielding over 50 bu/ac. Those fields were severely damaged in late July and during August suffered significant yield losses, including 100% in a few cases.

Soybean Pests

Soybean aphids were not a problem in 2008. Although aphids were present in the southwest, populations remained well below threshold levels. Eastern Ontario and parts of Quebec had larger numbers but only a few fields required spraying.

Bean leaf beetle pressure was a concern during late summer in affected fields. A few regions within Essex and Kent counties had populations high enough to warrant spraying, although the number of fields affected was low. Leaf feeding at below economic thresholds was evident in fields west of Toronto.

Spider mites and soybean cyst nematode caused yield losses in the southwest especially where conditions were dry.

Some fields were hit hard with white mould this year depending on seeding rate, row width, variety and region. In western Ontario where conditions have been dry the last few years, inoculant levels were quite low going into the season. Due to these low levels of inoculant, disease pressure was much lower than expected considering the moist weather conditions. Take note of which fields had white mould in order to plan for future susceptible crops such as soybeans, edible beans and canola. Disease inoculant levels will be high next year so that favourable weather conditions for disease could result in substantial damage.


Harvest progressed relatively smoothly except where beans were planted very late or harvest was delayed due to excess moisture. About 3-5% of the crop was not harvested by November 20th. Snow and excess moisture could make harvest a challenge for the remainder of the crop. Seed moisture was generally excellent and quality was good.

Challenges and Opportunities for 2009

Poor Crop Rotations

Increased input costs may lead to more acres being planted back into soybeans in 2009. A good rotation is absolutely essential for maximum yields. Soybeans seeded once every three, or even better every four years in the rotation is ideal. When considering crop budgets, remember that a 10-15% yield reduction must be included for a crop following the same crop (i.e. soybeans following soybeans) In a field that had significant white mould pressure in 2008, planting soybeans in 2009 could result in significant yield losses.

Soybean Rust

Soybean rust spores were detected in Ontario for the first time in 2007. Spores were again found in the province this year, although no disease symptoms were found on plants. Soybean rust continued to move into new areas of the United States. Close monitoring of this disease continues to be essential. Ontario will need to be vigilant in 2009 to monitor the spread of rust, and be prepared to apply control measures as necessary.

IP Production

A strong demand for IP soybeans has meant higher IP premiums for producers. Growers may want to investigate possible IP varieties for the 2009 growing season.

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