2015 Soybean Seasonal Summary

Table of Contents

  1. Summary
  2. Spring Frost
  3. Double Cropped Soybeans
  4. Weeds, Pests, and Diseases
  5. Harvest
  6. Challenges and Opportunities for 2016

Technical information can also be obtained at the OMAFRA Field Crops Webpage. 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.


Excessive rainfall in June, a frost in late May, and a dry August were some of the challenges faced by growers in 2015. Despite these problems the provincial average yield reported is 45 bu/ac for 2015. This is based on 28% of insured acres reported to AgriCorp to date. The five year average for Ontario is 46 bu/ac. The 2015 crop was the second largest ever grown in Ontario at 2.9 million acres. The largest was in 2014 with over 3 million acres being seeded. One of the main complaints in 2015 is that corn yields were exceptional for many growers (200 bu/ac) while soybean yields were only average. There is no one single issue that held soybeans back but rather a number of factors that contribute to yield. The key factors that contribute to high soybean yields remain the weather in July and August, pest and disease pressure, a good crop rotation, and a lack of soil compaction. One of the issues this year was the large amount of corn residue left over from the 2014 corn crop in no-till production. A late corn harvest in 2014, a cold winter, followed by a dry spring resulted in a large amount of corn stalks left over this spring. Excessive crop residue on the soil surface slows growth and also increased the amount of damage from the May 23rd frost. In many counties more tillage is now being conducted by soybean growers due to the issues associated with corn residue.

Spring Frost

A frost on May 23rd reduced plant stands across a wide geography in southwestern Ontario. Many fields had to be reseeded. No-till fields suffered more than conventional tillage. Side by side comparisons went from being completely unaffected in areas with no residue to completely dead in no-till. It should be noted that frost damage was worse due to residue on the surface not because of the form of tillage. Even fields that were worked but had considerable residue suffered damage. The residue acted like a blanked over the soil to keep in the radiating heat from the soil during the frost event. The soil type, slope, elevation, and residue cover all played a factor on which parts of the field were impacted.

Double Cropped Soybeans

Double cropped soybeans were successful this year especially for those growers seeding directly after winter barley harvest. Aggressive growers have been able to make double cropping work the last few years with some very impressive yields. One of the reasons double copping is more successful now than 20 years ago is due to higher yielding short season varieties. Plant breeding efforts for northern climates, especially western Canada have resulted in better short season varieties that can be seeded later in the growing season.

Weeds, Pests, and Diseases

Glyphosate resistant Canada fleabane has now been found all the way from Essex County to Glengarry County. It has spread 800 km in 4 years. Control in soybeans is the real challenge and results have been variable from field to field. Glyphosate plus Eragon plus metribuzin have given more consistent control compared to just Glyphosate plus Eragon. There are no in-season herbicide control options that work in soybeans for resistant fleabane. This weed must be controlled before the crop emerges. Tillage must be very aggressive to do anything on fleabane but fall herbicide application on the corn stalks can go a long way to reduce pressure.

White mould was not as significant an issue this year as expected. Although May and June were wet in many areas August was actually very dry so conditions were not that favourable for disease development. There were severely impacted fields in Eastern Ontario but generally speaking disease pressure was not as bad as it could have been. No-till fields were less impacted than tilled fields. Foliar fungicide application to reduce the impact of white mould in soybeans is becoming more common. Take note of fields with white mould to make future management decisions. Fields with white mould should not be seeded to soybeans next year. Do not keep seed from severely infected fields as the sclerotia (overwintering bodies) of the mould are about the same size as soybean seed and can infect next year's crop.

Soybean aphids were an issue in a few central counties but did not spread widely across the province. Spider mites were actually a larger issue in many areas than soybean aphids.


This harvest season was one of the best experienced in recent memory. Dry weather allowed many growers to finish harvest two or three weeks earlier than usual this year. This allowed for more winter wheat acres.

Challenges and Opportunities for 2016

A good crop rotation continues to be fundamental to achieve high soybean yields. With such a large Ontario soybean acreage over the last few years keeping a good crop rotation has been a challenge. In a normal year yield losses of 10-15% can be expected from a crop of soybeans following soybeans. An additional 10% yield loss can be expected if soybeans are grown for 3 years in a row. In subsequent year's yields will plateau. If a lot of soybeans are grown in the rotation the following management practices can help with yields; seed treatments, tillage, and foliar fungicides. None of these practices are a replacement for a good crop rotation. Too many soybeans in the rotation will result in lower yields and soil degradation. If a field has a history of white mould or Soybean Cyst Nematodes soybean should not be grown two years in a row.

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