Ontario field activity picking up speed
Field activity has ramped up with the warmer temperatures and many areas receiving spotty rains allowing soils to dry up. There is tremendous capacity in the country side from the input suppliers to growers with the ability to plant a significant acreage in a day. If the weather holds what started out as a slow spring will finish up close to normal timing.
The winter wheat crop has put on significant growth in the last week with the warm temperatures. The most advanced wheat, in south Essex County, is at the flag leaf emerging stage (Z37). The wheat in the rest of the province ranges from Z30 to Z32. Almost all of the nitrogen has been applied to the crop. Herbicide applications have begun as annual weeds like common ragweed have emerged. Some early fungicide applications have been made. To date, disease pressure has been very low in Ontario although stripe rust has been confirmed in Kentucky and southern Illinois and this week has begun to increase in very susceptible varieties in those states. Storm fronts could move strip rust spores into Southern Ontario. In the past few years, stripe rust has been detected around the third week of May in southern Ontario so continue to scout susceptible varieties especially over the next two weeks.
Less than 10 per cent of wheat fields have not progressed in the last week and will need careful observation as to whether they should be terminated and planted to another crop. Generally, a stand of five healthy plants per foot of row will provide about 80 per cent of your anticipated yield potential.
The majority of the crop has been planted.
Pasture and hay fields have had a slow start, with very little grass growth until the recent warmer temperatures. Management is critical to minimize damaging wet pastures: daily moves can reduce pugging damage.
There are some concerns about alfalfa winter injury, particularly on fields that were cut late in the fall or had late manure application. Wet conditions and potato leafhopper damage also increased injury risk on new seedings. Poorer stands can be supplemented by adding Italian ryegrass and other grasses to maintain yields if the field must be kept.
Fertility is often a concern on forage fields. Generally, potash is the most limiting nutrient. Use a soil test to ensure the crop has adequate P and K before worrying about secondary nutrients like sulphur and boron. The window for producers applying Priaxor fungicide to alfalfa is rapidly closing, as preliminary research suggests the biggest yield boost when applied 21 days before harvest (PHI is 14 days), and when the crop is four to eight inches high.
A significant percentage of the corn planting on the lighter soils is complete. The spotty rains and warmer temperatures have allowed planting to begin on the loam and clay soils. As of May 10, about 20 per cent of the crop is planted. Planting date and yield potential research by Dave Hooker, U of G, Ridgetown Campus, found that one can expect 95 per cent of corn yield at Elora when planted May 20, Exeter at May 25 and Ridgetown at May 30.
A few soybean fields have been planted but it will likely be another week before soybean planting ramps up as growers complete corn planting.
Canada fleabane rosettes, with the increase in air temperatures, are beginning to grow quickly. Delays in controlling such weeds will increase the probability of poor control. The pre-plant tank-mix of glyphosate plus Sencor 75DF (220 g/ac) plus Eragon LQ plus Merge has been the most effective way to control glyphosate resistant populations of this weed (University of Guelph, Ridgetown Campus). If growing Xtend soybeans (dicamba and glyphosate resistant), pre-plant applications of Engenia or Xtendimax at their highest label rate are also effective.
Despite the slow start to spring, we are now accumulating growing degree days (GDDs) quickly, especially due to the warmer nights. Crops already growing are soon to see some insect activity. Locations in the southwest have accumulated enough GDDs to start experiencing alfalfa weevil larvae and cereal leaf beetle (both adults and young larvae) feeding. If temperatures continue as is, central and eastern locations will start to see activity in a week or so.
For crops like corn that are still being planted, the insects are getting the head start. Black cutworm moth migration in Ontario has increased due to the recent storm fronts. With GDDs accumulating quickly, larvae from their eggs will develop quickly. They will feed on weeds or cover crops until the corn plants start to emerge. Fields in southwestern Ontario could to see emerging corn plants being cut as early as later next week.
The increase in air and soil temperatures saw a significant amount of annual weeds emerge in the past week. Glyphosate should be applied to emerged weeds before they are 10 centimetres tall to maximize control. Most other post-emergence herbicides must be applied to emerged weeds prior to them reaching the eight-leaf stage of growth, otherwise control is significantly reduced.