OMAFRA Field Crop Report

Table of Contents

• Corn
• Forages
• Pasture
• Winter Cereals
• Spring Cereals
• Soybeans
• Edible Beans
• Spring Canola

For emerging issues, questions or to provide feedback on this report, contact the CropLine at 1-888-449-0937. Technical information can also be obtained at the OMAFRA Field Crops Webpage and Crop Pest Ontario. Referenced OMAFRA Publications include the new edition of Publication 811 Agronomy Guide for Field Crops, 812 Field Crop Protection Guide, 75 Guide to Weed Control, and 505 Ontario Weeds. These can be obtained from your OMAFRA Resource Centre, or by calling 1-800-668-9938.

Corn

The hot weather and adequate soil moisture the last couple of weeks have helped to improve the corn crop. The remainder of the crop has tasseled by mid-August. For the most part, there was adequate moisture for pollination. The weather will have to continue to be favourable well into early October for the later-planted corn to reach maturity.

The hot weather the last couple of weeks has improved the crop heat unit (CHU) accumulations across the province. As of mid-August, Windsor was at the 30 year CHU normal. Hamilton narrowed the gap to 6% behind normal from 10% behind normal at the end of July. Ottawa is now only 5% behind normal.

Now is a good time to scout fields to see if insect and disease problems are present. The excess moisture in some areas may result in plants showing symptoms of nitrogen deficiency, with corn plants showing a paler green colour, bottom leaves firing at the tips and continuing down the middle of the leaf. By the end of August, it is quite normal to see some of this happening, especially on the bottom few leaves. Yield reductions associated with these symptoms are insignificant, unless firing is already extending up to and including the ear leaf. Corn diseases have been minimal.
Western Bean Cutworm (WBC) trap sites have accumulated from zero to thirty moths so far, with a site near Appin at over 50 moths. However, scouting has not yet detected WBC egg masses and larvae feeding damage in either corn or edible beans. Michigan has experienced high enough WBC levels to warrant spraying this year, so it may not be too many more growing seasons before we have to manage for the pest in Ontario as well.

Forages

The critical fall harvest period for alfalfa begins over the next couple of weeks in the major forage growing areas of southern Ontario. The critical period is approximately six weeks prior to a killing frost. Cutting and subsequent re-growth during this period reduces the alfalfa root reserves going into winter and increases the risk of winterkill. This was very evident last spring, with increased damage in fields that had been harvested during the critical period last fall. If possible, farmers should be scheduling their last harvest to avoid cutting during this period to reduce the risk of winterkill. Any additional stress on the alfalfa stand increases the risk of damage from inappropriate cutting schedules, so fields with low fertility, low soil pH, poor drainage, insect or disease pressure or short cutting rotations are not good candidates for harvesting during the critical period. Refer to OMAFRA Factsheet "Risk of Alfalfa Winterkill" www.omafra.gov.on.ca/english/crops/facts/91-072.htm.

Pasture

With advance planning, grazers can extend the grazing season well into winter by stockpiling forages for deferred grazing. This will result in improved animal health, reduced manure storage and handling costs, and reduced stored feed requirements. Stockpiling simply means leaving perennial forages unharvested during the late-summer and fall, for grazing during the period from October to December. As with hay fields, the longer the pasture has to grow, the higher the yield of forage but the lower the quality. Any grass species is suitable for stockpile grazing, but plants with an erect stem, such as tall fescue, will be easier for the livestock to access when there is snow on the ground. Refer to www.omafra.gov.on.ca/english/livestock/beef/facts/99-009.htm .

Winter Cereals

Winter wheat harvest is wrapping up in the latest harvest areas. Quality is predominantly good, although the late-heading, highly susceptible to fusarium winter wheats are being downgraded. Yields are quite variable, but more disappointing in some northerly areas, including Wellington, Dufferin, Simcoe and east-central counties.

The 2009 Winter Wheat Variety Performance Trial information will be available at www.gocereals.ca. Research shows a 1.1 bu/ac (0.07 t/ha) decrease in yield for each day planting is delayed past an optimum date. For optimum dates to seed winter wheat, refer to Figure 4-4, (p. 93) OMAFRA Publication 811, Agronomy Guide.

"Ultra-early" seeding winter wheat (ie seeding ten or more days before the optimum date) has been successful for some growers on heavy clay soils where there is concern that rain may delay planting past the optimum seeding date. Growers using this approach should use Cruiser® seed treatment to control cereal aphids in order to reduce the spread of Barley Yellow Dwarf Virus, and reduce seeding rates by 20%.

Dwarf bunt is a soil borne disease that affects the snow-belt zones of Ontario. In snow-belt areas, it is essential to plant seed treated with Dividend XL for control of soil-borne Dwarf bunt, or plant a resistant variety.

Spring Cereals

Spring cereal harvest continues to be delayed in many areas due to frequent rain showers. Spring wheat yields to date range from average to above-average in the early planted fields. Quality remains extremely variable, but generally better than expected. Some fields have high levels of fusarium and reduced test weights. Secondary cleaning over a gravity table has shown some success in improving grade in past years. To reduce the risk of fusarium mould growth and toxin production, harvest as soon as possible, and if necessary, dry the grain. Freshly stored wheat needs to be properly conditioned and monitored for heating. If possible, store wheat graded as "feed", because better marketing opportunities may arise as the harvest rush subsides.

Crown rust has had a major impact on oat yields this year, with up to 50% yield loss in fields that were not sprayed with fungicide.

Soybeans

The majority of the soybean crop is between the R4 (full pod) and R6 (full seed) plant stage. Although stressful conditions that occur between the R4 and R6 stage can result in significant yield loss, the current stretch of warm weather has been helpful for soybean growth and development. Hopefully this trend will continue for a few more weeks. Continue to monitor soybean aphid populations up to and including the R5 (beginning seed) stage of soybeans. Initiate control if aphid populations are actively increasing above 250 aphids per plant. Once soybeans are beyond the R6 stage, insecticide applications are unlikely to provide an economic return. If storing soybeans on farm, now is an excellent opportunity to make sure that storage bins are clean, free of insects and that all aeration units are operational. For more information on insect management strategies for farm stored grain, refer to page 185 in OMAFRA Publication 811, Agronomy Guide for Field Crops.

Edible Beans

Most of the edible bean crop is in good condition. Since late-July, bean plants have displayed a good flush of growth, flowers, and pod set. The earliest planted cranberry beans are beginning to turn colour, with harvest likely by September 1st.

Scout white and black bean fields for anthracnose. Over the August 1st weekend, anthracnose advanced significantly up in the canopy. Infection is currently confined to pockets of stunted, dying plants. Early fungicide applications appear to be controlling anthracnose. Fungicides provide 10-14 days protection. A late application may be warranted if disease spreading wet and windy weather persists. Animals, people or machinery going through fields when they are wet, can easily spread anthracnose spores. Disinfect machinery with bleach between fields.

Plan whether your fields will require a pre-harvest treatment. The Ontario Bean Dealers are recommending that on Otebo beans, only Ignite be used where a pre-harvest treatment is required. In all other bean types, only glyphosate plus AIM is permitted. Check with your dealer for further details.

Spring Canola

Early planted canola is maturing quickly with the heat, and harvest is expected to begin the last week of August. Sclerotinia infection is now becoming evident with premature ripening of plants.

Scout fields that are in the green pod stage for the development of Alternaria. Alternaria is favoured by cool, damp weather or heavy dews. The disease appears as black soot on pods and leaves, reducing seed fill and leading to increased pod shatter. Consider swathing infected fields to minimize losses due to pod shatter. Evaluate fields that are to be direct harvested for the need for pre-harvest herbicide. Pre-harvest treatment facilitates even dry down of weeds and canola, allowing for timely harvest. Delays in harvest caused by green stalks or field unevenness can lead to unacceptable shattering losses.