by Horst Bohner
Summary: Soybeans were the largest row crop in Ontario in 2012 with a record 2.65 million acres being seeded. Acreage could again increase significantly in 2013 if soybean prices remain high. Relatively early seeding was achieved due to the mild winter, dry soil conditions and favourable temperatures. Most of the crop was seeded during the first two weeks of May with a few acres being seeded in April. Short periods of rain during May delayed planting for some growers, but these delays were not long. Soil moisture levels however were limited in certain areas of the province leading to poor seed germination and emergence problems in these dry regions. Rainfall was sporadic and in certain areas rainfall levels were significantly below normal resulting in a premature harvest and unfortunately low yields (less than 20 bu/ac in the most affected fields). For those areas that did receive timely showers yields were better than expected and some growers reported record high yields. In a few cases yields over 80 bu/ac were reported. 2012 will likely turn out to be the highest yielding soybean year on record for the province. With 30% of acres being reported to date to Agricrop the average yield across the province is 49 bu/ac. Early planting into dry conditions, a relatively long summer along with warm night time temperatures, and timely showers in late summer contributed to these exceptional yields. Soybean genetics continue to improve as well as increased use of SCN resistant varieties continues and should be given some credit for the exceptional yields. Visit www.gosoy.ca for the 2012 soybean performance trial information. Foliar diseases were minimal and white mould levels were very low. No significant soybean aphid populations developed but two spotted spider mites were widespread and reduced yield potential in heavily infected fields.
The 2012 season will be remembered as the best soybean year the province has ever experienced. The largest acreage planted along with record yields and exceptional prices all contributed to the most profitable soybean growing season in memory for those growers that were able to catch a few timely showers.
Planting: The early spring of 2012 was dry so a few fields were seeded by mid-April, although the majority of the crop was planted during the more traditional May planting window. Seeding very early with short season varieties reduced yields compared to seeding longer day varieties. A few replants were necessary on heavy soils or where partially germinated seed dried out.
Because winter wheat harvest was earlier than normal considerable soybean double cropping was attempted in 2012. Double crop success was variable and dependent as expected on rainfall and planting date with some fields not making any seed while others yielded as high as 40 bu/ac in the southwest.
Growing Season: Emergence of the crop was affected by dry conditions. Planter units
outperformed drills in this regard, mostly because of deeper seed placement. During much of July the province experienced high temperatures in conjunction with near record low precipitation. This lack of moisture and high temperature coincided with the plant’s vegetative growth and early reproductive development. However, significant yield losses do not generally occur unless moisture stress continued into the R4 (full pod) growth stage. The majority of soybean yield is set during the last week of July and during the month of August in Ontario.
Growing conditions during that time have more impact on yield than growing conditions during the early stages of plant development. By the end of July many fields, especially in the central region appeared to be in tough shape. August and September had better weather conditions. As this period of time coincided with the plant’s reproductive growth stages, much of the soybean crop was able to make a recovery. In some ways this was similar to what happened in 2011. This growing season again showed how the indeterminate growth habit of soybeans allows the crop to take advantage of favourable environmental conditions late in the season.
Soybean Pest/Diseases: Most soybean pest and disease levels were lower than normal for the bulk of the province with the exception of spider mites. Severe stippling causing yellowing, curling and bronzing of leaves could be seen in affected areas during the summer. Some fields were left unchecked reducing yields. Root diseases such as Fusarium wilt, brown stem rot, and charcoal rot were more prominent this year than usual due to the dry conditions and high temperatures.
Aphid pressure was low in 2012. Red headed fleabeetle were widespread but only a handful of fields reached threshold levels. Japanese Beetle caused some defoliation problems that required action in a few fields.
White mould was not a significant problem this summer. A lack of moisture during early
flowering reduced the incidence of white mould. Soybean Vein Necrosis Virus was confirmed for the first time in much of southwestern Ontario.
Sudden Death Syndrome was reported in areas in the south, as well as sandier soils, because of dry conditions and traditionally higher levels of Soybean Cyst Nematode (SCN). Population levels of new SCN types continue to increase but to date resistance sources PI88788 and Peking are performing well.
Harvest: Harvest started early but was then interrupted by about three weeks of wet weather. Yields were reported to be as low as 8 bu/ac in dry areas and as high as 80 bu/ac in areas with good moisture and growing conditions. Mature green seed was an issue for some of the earliest harvested fields but the majority of the crop had good seed quality with little disease.
Challenges and Opportunities for 2013: Relatively high prices and good yields in 2012 is expected to push acreage higher again in 2013. Shorter crop rotations will mean soybean growers have to be vigilant in selecting disease resistant varieties, scouting their crop, and applying inputs when required. Low soil tests for potash continue to be a significant concern for high yield potential. Excessive tillage resulting in soil erosion and spring tillage compaction are also issues that could become a problem in 2013.