From OMAF Field Crop Report
Corn: Greg Stewart
Corn planting has come to an end in virtually all areas, with final plantings estimated to be down 10- 20% from last year.
Most corn moved through two leaf stages in the last week. Early corn is now at the 8th leaf stage and the growing point is at or slightly above the soil surface. Dry soils and seedbeds that are tight or have poor structure are limiting nodal root development in some areas.
Sidedressing is underway in many areas. A reminder that research has shown that UAN left uncovered in the bottom of a sidedress slot, especially if there is moisture present, can be susceptible to volatilization losses. When using pencil jet injectors be sure to adjust depths to provide soil cover. The Ontario Pre-Sidedress Nitrate (PSNT) Test Survey was conducted by OMAF Field Crop staff this week; see www.gocorn.net for the complete report.
Canola/Edible Beans: Brian Hall
Canola: Canola is growing rapidly and varies between 1 to 5 leaf stage. Emergence is acceptable but very uneven. For canola fields at or below 4-5 plants per square foot, consider lowering the action thresholds for insect and weeds. Flea beetle pressure is high in some areas. Spray if leaf loss exceeds 25%, paying particular attention to new growth. Sprays have no residual, scout several days later to evaluate flea beetle populations. Swede midge populations are increasing and at threshold in some areas. Northern Ontario has very high populations, and canola in this area that is between 2 leaf and early flowering should be protected with insecticide.
Edible Beans: Planting is 90% complete, emergence is uneven in some fields due to lack of soil moisture. A timely rotary hoe operation 7 – 10 days following planting will remove ‘hair size’ weeds while waiting on rain to activate soil applied herbicides, Scout emerged beans for leafhoppers.
Cereals: Peter Johnson
Winter wheat fusarium fungicides have been applied. Some growers opted out of fusarium fungicides, due to low fusarium risk and wheat crops that will be below crop insurance yield guarantees regardless. These crops are at risk of late season disease significantly impacting yields.
Armyworm, grass sawfly and cereal leaf beetle are all being found at low levels in wheat fields. Scout! While these pests are at low levels, somewhere there will be hotspots that are over threshold. See http://fieldcropnews.com/?p=8896. Cephalosporium stripe is showing at high levels in heavy clay soils that suffered from excess moisture in May. Irregular width yellow stripes the full length of leaves is diagnostic. Varietal differences are clearly evident; Branson looks to have resistance. Early spring cereal fields are at second node (GS 32). Timing is perfect for second nitrogen applications or first fungicide applications if 2 fungicides are planned. All weed control applications should be finished, even on late planted fields.
Forages/Pastures: Joel Bagg/Jack Kyle
Forages: With some dry weather and delayed alfalfa maturity, high quality 1st-cut hay, haylage and baleage has been made. Yields are quite variable, with some very disappointing yields being reported in western Ontario, but closer to normal yields in the east. Some alfalfa is showing the symptoms of uniform yellowing indicating sulphur deficiency. Tissue testing of alfalfa (bud to first-flower stage, top 6 inches, 35 stems) can be used to determine sulphur deficiencies. The critical level below which there may be an economic benefit from applying sulphur is 0.25% S. http://www.omafra.gov.on.ca/english/crops/field/news/croptalk/2014/ct-0314a3.htm Many new seedings were done later than optimum. Saturated soils often result in a higher risk of alfalfa seedling diseases, such as aphanomyces and phytophthora root rots. The risk of injury to alfalfa seedlings is significant when 2,4-DB application is made outside of the first- to the third-trifoliate stage. 2,4-DB can suppress alfalfa growth for a period of 2 – 3 weeks and severe injury can occur under drought or high temperatures. Field experience has demonstrated that reducing the rate of herbicide can reduce the risk of injury to alfalfa seedlings while providing acceptable control of weed seedlings. (Publication 75, Guide To Weed Control. http://www.omafra.gov.on.ca/english/crops/pub75/pub75ch10.pdf)
Pastures: Rotationally grazed pastures are now into their second rotation. Set stocked pastures are showing areas of over grazing which will result in reduced growth for the remainder of the grazing season. If mature plants with maturing seed heads or flowering weeds are plentiful in your pastures then consider clipping to stimulate new forage growth and stop the weeds from setting seed. Rotating pastures every 1-3 days and allowing sufficient rest and recovery time of 30-45 days, depending on growing conditions, will give the most productivity. Applying 40-50 kg/ha of nitrogen will stimulate good growth that will provide extra summer pasture.
Soybeans: Horst Bohner
Most regions have essentially finished planting, parts of the Niagara region and areas with excessive rainfall in southwestern Ontario have not finished. A late spring and relatively high soybean prices have pushed acreage to an all-time high. It’s expected that well over 3 million acres of soybeans will be seeded in Ontario this year. Tough soil conditions, crusting, and dry soils have caused plant stand issues and some re-seeding has taken place. When assessing a questionable plant stand it’s important to wait for all the seedlings to emerge. Do not rush when making a replant decision. Soybeans have the ability to adapt to thin stands. If there are 100 000 plants per acre the field should be left alone (120 000 on heavy clay). If plant stands are very thin the best approach is to seed right on top of the existing stand. Contact your seed supplier as soon as possible. Supply is tight. The final population should not exceed 225 000 plants per acre as a maximum so a supplemental seeding rate of 125 000 seeds per acre is usually adequate. Use the same variety if possible.