Synopsis: The week of May 9 to 14, with sudden summer temperatures and good drying conditions, saw a flurry of field activity that came to an end with sporadic rain events over the weekend. Rainfall amounts ranged from less than 8 mm to 90 mm (NW of London) with thunderstorms also generating some localized hail. A significant number of planted fields in areas that received substantial rainfall will emerge without herbicide application resulting in some alternative control strategies. Corn acres are over 50 percent planted with acres on lighter soils completed and heaviest soils at 10 percent. Soybean acres are estimated at about 15 percent planted. At Chatham, 106 crop heat units were recorded just in the past week for a total of 233 since May 1st (111 CHU at the same point in 2021). Crop inputs moved as quickly as logistics allowed. Emergence has been rapid with crops emerging within a week of planting. September planted wheat is approaching flag leaf emergence in the southwest.
Field preparation: Drying conditions were good over the entire area. Seedbeds were drying out too quickly in some cases resulting in need for deeper planting to place seed to moisture. Planting depth for soybeans is ideally between 1 to 1.5 inches into moisture. When moisture is below the 2-inch depth it may be better to wait for rain or plant into dry soil. Planting into the transitions zone or planting at 3-inch depth is not recommended. Placing soybean seed below 2-inch depth will result in some stand reduction.
Finding the right balance between number of passes and depth of tillage can be difficult in the quest for garden type seedbeds. One pass with vertical tillage is often enough for proper seedbed but the appeal for finer seedbed often leads to additional passes that can leave soils more prone to crusting in the event of thunderstorms. Heavier soils went from ideal to crusted within 24 hours and some sidewall smearing occurred that could result in reduced emergence. These fields will benefit from light rains that occurred over the past few days and forecasted later in the week.
Wheat: Warm temperatures have advanced wheat growth. Earliest planted wheat is at flag leaf stage with most September planted wheat approaching growth stage 37 – flag leaf emerging. Late-planted wheat is at growth stage 32. Light powdery mildew infection reported in a few early planted thick canopy wheat fields but overall the disease pressure continues to be low. Those considering a T2 flag leaf fungicide application should scout individual fields to determine disease levels. A lot of herbicide, fungicide and plant growth regulators were applied, some during cool conditions on May 6-7th. Syngenta is working with C&M seeds on a replicated field trial (based on a similar trial last year) with 1 to 5-way tank mixes applied with 10 gallons water. Fields were rated after application into cool conditions followed by warm conditions. There was little negative impact observed from the 5-way tank mix with less than 2 percent phytotoxicity observed. This field trial will be followed up with yield data at harvest. It appears that when growing conditions are good growers can get away with multiple tank mixes applied at the proper timing. Where herbicide, fungicide or PGR application is still being considered, a tip to determine if the crop is at flag leaf is to identify the leaf arising from the 1st node, call that leaf #1 and count upward. The flag leaf will be leaf #4.
Horticulture Crops: Sugar beet planting is completed, and plants are emerging with no crusting or disease issues to date. 35 percent of tomato acres are planted with early maturing varieties with average stands. Mid-season varieties are currently being planted as soil conditions allow with 50 percent of tomato acreage expected to be seeded by the weekend.
Weed Control: Herbicide application in wheat largely done with good crop safety and only the odd field with some tip burn. Large perennial grasses are difficult to control and take a long time to die with glyphosate. If anyone is seeing perennial grasses such as fescue, ryegrass and bluegrass species that they are unsure of or would like positively identified at the lab, please contact Mike Cowbrough (mike.cowbrough@ontario.ca )
Burndowns applied up to 10 days ago are slow to die and this is normal. Dandelions and other tougher to control weeds take up to 3 weeks when only glyphosate is applied. Patience is required. Separating glyphosate from other herbicides to prevent antagonism takes additional time and is most beneficial when trying to eradicate especially tough-to-control weeds.
Crop Insurance: Leon Walczak (Agricorp) provided the winter wheat status with 570 damage reports for the South West Region, South Central and Niagara Region representing approximately 34,500 acres; an increase of 130 reports and 6,600 acres from 2 weeks ago with the predominate peril being excessive rainfall (water) followed by winter kill. This represents 17.25 percent of the acres planted in the these 3 regions.
The May 16th deadline has passed for application for crop insurance or to report changes. Risk Management program renewals have been sent out to growers. Please visit www.agricorp.com to obtain up-to-date information.
Staffing Announcements: Colin Elgie has joined the OMAFRA Field Crop Team starting May 16th as the Soil Fertility Specialist based in Ridgetown. His contact information is colin.elgie@ontario.ca and cell 548-388-3496
Doug Young is retiring at the end of May after a 38-year career as a researcher and instructor at U of Guelph, Ridgetown campus. We wish him well in his new endeavors.