2009 Soybean Seasonal Summary

Table of Contents

  1. Summary
  2. Planting
  3. Growing Season
  4. No-till and Nodulation
  5. Soybean Pests
  6. Harvest
  7. Challenges and Opportunities for 2010

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.


A record acreage of 2.4 million acres was planted in 2009. Cool wet conditions were the norm for most of the growing season. Fortunately a warm dry September allowed for the crop to mature normally although a few areas were hit with a frost in late September. Timely planting due to wet conditions was the challenge in the spring and wet conditions in the fall made timely harvest difficult. Although much of the province had sufficient moisture during July and August for excellent seed set and pod fill the extreme southwest as well as a few other areas were actually too dry. 2009 will be remembered as producing an extremely variable crop both from field to field and within a given field. Yields ranged from 20 bu/ac to over 70 bu/ac. With approximately 40% of insured acres reported to Agricorp the provincial average so far is 41.9 bu/ac. The 5 year provincial average is 40.6 bu/ac. Due to excess rainfall weed control was a challenge especially in IP fields. Seed size and quality has generally been acceptable although green immature seed due to frost can be found where frost hit.


Soybean planting was delayed this year and the majority of the crop was planted after May 24th. Dryer conditions in eastern Ontario allowed for more average planting dates. By the end of May 95% of fields were planted. Fields planted from May 6-12 were challenged by cool, wet weather after planting resulting in emergence difficulties. Seed treatments used during this planting window showed an improvement in plant stands.

Growing Season

Precipitation was spotty and above average in many regions. For optimum yields soybeans need significant rainfall especially during July and August. Because rainfall occurred during this time of key plant development yields were above expectations considering how cool the year was. Conditions were cool in June and July but a warm dry September allowed the crop to mature normally.

Moist and cool conditions made ideal conditions for increased slug feeding. Some no-till fields were devastated from slug feeding. Cool conditions in May and June also reduced emergence. On average plant stand counts were down about 10% compared to normal this year. Cool moist soils also caused increased disease pressure such as sudden death syndrome. A lack of heat slowed nodulation causing slow growth and reductions in some no-till yields.

No-till and Nodulation

About two thirds of Ontario soybeans are grown under some form of minimal or no-till production system. Many research trials over the last 20 years have shown relatively small yield differences between conventional and no-till systems. The yield difference has usually been from 0-2 bu/ac in favour of tillage. This small yield advantage to tillage actually makes no-till more economical. Since the first half of the growing season was so cool along with higher than usual corn residue from the previous year yield reductions in no-till were higher than usual in 2009.

Soybean Pests

Soybean aphids were a significant problem in the central part of the province and many acres were sprayed. Although aphids were present in the southwest populations remained well below thresholds. Most fields southwest of London did not get sprayed. Eastern Ontario and parts of Quebec had larger numbers of aphids and many fields needed to be sprayed.

White mould was a problem again this year, depending on seeding rate, row width, variety, and region. Root rots including sudden death syndrome were more prevalent in the southwest this year than we've seen for a number of years.

Septoria brown spot was common on lower leaves. Yield losses from brown spot were negligible.

Weeds emerging through the soybean canopy were evident due to slow canopy closure, too much rainfall, and sufficient moisture for weed emergence.


Harvest progressed slowly with few good days for harvest. Only about 80% of the provincial crop was harvested by the end of October. Seed moisture was generally acceptable (13-15%) and quality reasonable. Two dry weeks in November allowed for the rest of the crop to be harvested without major difficulties.

Challenges and Opportunities for 2010

Poor Crop Rotations

A wet fall and commodity prices have pushed winter wheat acreage down this fall. This will likely result in high soybean acres next year. A good rotation is absolutely essential for maximum yields. Soybeans seeded once every three, or even better, every four years in the rotations is ideal. When considering crop budgets remember that a 10-15% yield reduction must be included for a crop following the same crop.(ie. soybeans following soybeans) In a field that had significant white mould pressure or soybean cyst levels in 2009 planting soybeans in 2010 could result in huge yield losses.

Diseases and Insects

If soybean acreage is high next year more insects and diseases can be expected. Careful consideration of the variety chosen (e.g. SCN, white mould tolerant) and monitoring of each field must be conducted.


Soybeans remove a large amount of P and K each year. (40 lbs/ac of P and 70 lbs/ac of K for a 50 bu/ac crop). In many Ontario fields these nutrients are not being returned to the soil and fertility levels are dropping. Soybeans cannot yield well if soil fertility is low. Soil tests should also be conducted to assure that fertility is not limiting yields.

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