Degree days for root, bulb and leafy vegetable pests – 12 June 2012

Thresholds for first generation emergence of onion maggot flies and emergence of tarnished plant bug have been reached for all areas. Cabbage maggot adults are probably past peak flights based on degree days for London, Wellington, Windsor, Thedford and Delhi. Carrot rust fly counts on sticky traps have increased over the last week at the Muck Crops Research Station in the Holland Marsh (where resident populations are present, degree days have indicated emergence of adults in all areas). In Wellington, if resident populations are present, carrot weevil have likely started to lay eggs. In the Holland Marsh, Thedford and Delhi, 90% oviposition by carrot weevil will be completed in ~5 days. The threshold for emergence of local adult leafhoppers has been reached in Windsor and is expected to be reached in other areas over the next 4-5 days.

Here are the degree days accumulated from April 1st until June 12th, 2012.

(These values are provided as guidelines only. Local environments, soil type, field history, etc. may influence activity of these pests.)

Degree day model information for pests 

* Data provided by Muck Crops Research Station, University of Guelph.