2015 Corn Seasonal Summary

Table of Contents

  1. Summary

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.


Spring was slow to start in April, but arrived quickly in May. Field operations and planting progressed quickly at the start of the month as warm, dry conditions prevailed with few rainfall events to stop the progress except in the extreme SW of the province (Essex) where repeated heavy rainfalls resulted in as much as 2 times the normal monthly precipitation. Showers were limited in many parts of the province until the last week of May, resulting in a large number of workable days. OMAFRA estimates total 2.3 million acres of grain and silage corn was planted in 2015. Given the lack of rainfall after planting, seeding into moisture was important for quick, uniform emergence. A widespread frost occurred throughout most of the province on the night of May 22, with the coldest temperatures of -3?C centred in the northern Perth/Wellington County areas. A majority of corn was emerged but was immature enough for growing points to still be protected in the soil. Replanting was performed in some more advanced fields.

Soil nitrate samples were collected during the first week of June as part of the Pre-Sidedress-Nitrate-Test (PSNT) survey, and results indicated that soil nitrates were on average 4-5 ppm higher than previous surveys. This suggested greater soil N supply than average, likely influenced by good mineralization potential and reduced loss potential through the warm and dry spring experienced to that point. Regular rainfalls occurred throughout the month of June for most corn growing areas in the province, with total amounts ranging from 1.5 to 2.0 or more times normal June rainfall. Wet soil conditions made sidedressing nitrogen and any other field work a challenge.

July and August were cooler and slightly drier than normal in Southern and Central Ontario, while near normal precipitation fell in Eastern Ontario. Pollination progressed as normal. September was also dry but much warmer than normal, with most areas experiencing 100-140 more CHU than normal for the month. Warm temperatures hastened development which in conjunction with timely planting for most of the province resulted in little concern about crop maturing on time. No early frost concerns arose. Final May 1 to September 30 crop heat unit accumulation ranged from normal to 100 CHU above normal in Southern Ontario, to 100 or 200 CHU above normal in Central and Eastern Ontario.

An annual vomitoxin survey was conducted across the province during the last two weeks of October. Visually, samples appeared clean. Vomitoxin lab results were in line with previous "normal" years with 76% of samples testing <0.5 ppm, 20% testing between 0.5 and 1.9 ppm, and 5% testing 2.0 ppm or above. There was evidence of larvae feeding (ie. Western Bean Cutworm) on ears at many locations in Southern Ontario, but very little visual mould or Vomitoxin present on these ears, suggesting that in a dry year like 2015 insect damage does not guarantee an increase vomitoxin risk. Overall, elevated samples were relatively uniformly distributed across the survey, no with "hot-spots" were observed.

Harvest was timely with a warm fall and the crop reached maturity before any killing frost. Harvest conditions remained good, and moved along quickly once started. Many reports of good crop moistures and reasonable test weights and excellent yields. As of the beginning of December, early reported acres by Agricorp report an average yield of 180 bu/ac, which is well above the previous provincial record of 165 bu/ac (2010) and well above the 5 year average of 158 bu/ac.

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