Top Crop Manager

Features Agronomy Soybeans
Ontario soybean acreage at an all-time high

June 12, 2014, Ontario – A late spring and relatively high soybean prices have pushed soybean acreage to an all-time high: more than three million acres of soybeans are expected to be seeded in Ontario this year, according to Horst Bohner in the latest field crop report from OMAF. 

Canola
Canola is growing rapidly and varies between 1 to 5 leaf stage, reports Brian Hall. Emergence is acceptable but very uneven. For canola fields at or below four to five 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 per cent, 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 per cent complete, emergence is uneven in some fields due to lack of soil moisture. A timely rotary hoe operation seven to 10 days following planting will remove hair size weeds while waiting on rain to activate soil applied herbicides. Scout emerged beans for leafhoppers.

Cereals
Winter wheat fusarium fungicides have been applied, reports Peter Johnson. 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. 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 two fungicides are planned. All weed control applications should be finished, even on late planted fields.

Corn
Corn planting has come to an end in virtually all areas, with final plantings estimated to be down from 10 to 20 per cent from last year, according to Greg Stewart.

Most corn moved through two leaf stages in the last week. Early corn is now at the eighth 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.

Forages
With some dry weather and delayed alfalfa maturity, high quality first-cut hay, haylage and baleage has been made, according to Joel Bagg. 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 six 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 per cent S. 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 two to three 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)

Pastures
Rotationally grazed pastures are now into their second rotation, reports Jack Kyle. 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 one to three days and allowing sufficient rest and recovery time of 30 to 45 days, depending on growing conditions, will give the most productivity. Applying 40 to 50 kg/ha of nitrogen will stimulate good growth that will provide extra summer pasture.

Soybeans
Most regions have essentially finished planting, reports Horst Bohner, but 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 three 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.


June 12, 2014
By Top Crop Manager

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