Breakfast Sponsor: Thanks from the group to Greg Stewart – Maizex
Quote of the Week:
“The corn crop looks SO GOOD today, we are on track to set another new yield record!” Greg Stewart.
“You can draw an organic matter map based on emergence.” Alan McCallum.
Synopsis: This is the final meeting for spring 2018. A fall meeting was discussed: stay tuned. Most areas in Southwestern Ontario received some rain yesterday (Monday). Amounts varied widely, 2-80 mm, most areas receiving 10-20 mm. For most growers it was a critical boost, although not really enough. Parts of Niagara are the exception, and they got hammered again.
Soybean stands are extremely variable: beans that had swollen and moisture had disappeared should be able to emerge on this rainfall. Side dressing is winding down. Wheat was really hurt by high winds and high temperatures over the weekend. Harvest is moving earlier and earlier, with potential negative yield impacts.
Wheat: The continued lack of rainfall coupled with high temperatures and high winds over the weekend took a huge toll on the wheat crop. Wheat on heavy clay and drought prone sands changed colour dramatically, going from green to brown or white, with the Monday rain being too little, too late. Better soils held on, and the rain will be a huge benefit, but yield was impacted. Fields are short and straw will be at a premium. Some lodging occurred in areas with severe thunderstorms, but not widespread. Fusarium can be found, but at extremely low levels. Stripe rust has not exploded, and will not impact the crop.
Corn: Advanced corn is approaching waist high. Good fields look excellent. Fields planted tough are suffering badly, with poor root growth and delayed development. Some fields show extreme symptoms on heavy clay. Corn on soybean stubble is generally worse than corn following wheat (Alex Zelum). Lots of yellow corn in these situations: sulphur, manganese and magnesium deficiencies can all be identified, but in many cases it all comes back to poor root growth. Side dressing continues, but is in the final stages. Weed control has been “fair”, with resprays on-going.
Corn Nitrogen: A great discussion around corn nitrogen led by Greg Stewart and Dale Cowan. The new Field Apex program looks at rainfall 15 days before and 15 days after normal side dress time as the most important factor in N response. Soil clay content is another key factor. In areas with little or no rainfall, this approach results in significantly lower N recommendations. In one example, with 60N broadcast (affects soil N test recommendation), the corn calculator recommended an additional 94 lbs N, the N test only 12, and Field Apex 54 lbs N. In another example, Field Apex recommended 67 N (with 60 down). When 4” of rainfall was added to the scenario (1”/week, 4 weeks) the recommendation increased to 138 N, or double. Bill Deen’s research supports these conclusions, although 180 N (corn after corn, Elora) is within $10/ac of maximum economic yield 70% of the time. In general terms, growers in dry areas can reduce N rates slightly, while growers in rainfall zones should not.
Source : fieldcropnews