A 3250 heat unit corn hybrid planted in the last week of May in Chatham reached silking (R1) at Ist week of August. Our phenology model also predicted that silking would occur during the same period of time in Chatham field plot. The model predicted the silk emergence during the last week of July to the Ist week of August across corn growing belts of Ontario (Table 1). Corn CHU hybrids used in the model ranged 2700 to 3250, which is usually recommended across locations in Ontario. The planting dates of those locations were assumed the last week of May (May 27th).
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During silking to grain filling periods, corn plants are at a higher risk of infestation from economically important pests including western bean cutworm, European corn borer, corn ear worm. These pests cause significant damage on corn foliage and ear. Corn root worm and Japanese beetles also emerge during vegetative stages and the pest activities continue until grain filling stages. Japanese beetles were observed in Chatham during the first week of July and the WIN corn pest forecasting model predicted the first emergence of the pest during the same week (Table 1). The corn pest model also predicted western bean cutworm emergence during the first week of August in Bothwell and Rodney areas, where the pest scouting reported to reach the economic threshold close to that period (http://fieldcropnews.com/2014/07/western-bean-cutworm-reaching-threshold-in-some-fields).
The detail prediction of corn pest emergence and peak flight across corn growing areas of Ontario are presented in Table 1.
To get your site-specific corn pest advisory and management guidelines, we encourage corn growers to login and register your fields at www.weathercentral.ca.
If you have any questions, please feel free to contact Dr. Rishi Burlakoti, Research Lead (rburlakoti@weatherinnovations.com) or Karla Jackson, Client Service Manager (kjackson@weatherinnovations.com).
Table 1: Estimated corn growth stages and GDD-based predicted dates of five economically important corn pests across Ontario
Source: weathercentral