OMAFRA Field Crop Report

Table of Contents

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

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 at www.ontario.ca/crops and Crop Pest Ontario at www.omafra.gov.on.ca/croppest. 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.

Winter Cereals

Harvest continues at a somewhat slower pace than expected. Green straw and a flush of late, short tiller heads are hampering progress, particularly in late planted or winter injured fields. Yields remain variable, from 40 to135 bu/ac. Drainage, planting date and seed placed phosphorus fertilizer are the three key elements responsible for these yield disparities. Most yields are 5-10 bu/ac below long term averages.

Quality remains good in the bulk of the crop, but there are definite hot spots of problems. The white wheat crop has again had major challenges with sprouting. Red wheat has sprouted in an area from south of Brantford through to Burgessville. Fusarium hotspots also exist, with samples at 1.8 to 3% fusarium. Fortunately these are small areas and not the majority of the crop.

Test weights drop as wheat left in the field experiences shrinking and swelling due to rains. Be careful not to wait on green straw or late tiller heads to the point that the good wheat in the field ends up with low test weight from delayed harvest.

Spring Cereals

Spring cereal harvest has just begun in the deep southwest. The bulk of the crop is one to three weeks from harvest. Rust has hit the oat crop significantly, as has fusarium in the spring wheat crop. High levels of loose smut continue to be reported in barley. Where fusarium concerns exist, use the combine best management techniques of increased wind blast, slightly slower forward speed and early harvest. Where loose smut is an issue, do not retain this crop as seed. Where rust is a problem, expect that low test weight will result.

Corn

Sixty - seventy five percent of the corn crop is now in, or through, the pollination window. The estimated 10-20 percent of the crop which tassels after August 10th is at serious risk of not reaching physiological maturity (black layer) before killing frost. Although there are notable exceptions most of the province has received adequate rainfall to move through the flowering period without much moisture stress.

Crop Heat Units (CHU) accumulation for July was consistently behind the thirty year normal. However, the range across the province was significant. In July, Windsor was 6% behind normal, London: 10%, Waterloo: 14%, Hamilton: 10% and Barrie: 21% behind the 30 year normal for the month. On average CHU accumulation from May 1 to July 31 is about 10% behind normal. Hence, the April planted corn although lagging somewhat is developmentally not far behind normal. The real concern exists for the corn that was planted mid-May or later. Corn planted at the Elora Research Station in this time period is still two-four leaves from tassel emergence.

Once corn has pollinated it moves to the blister stage. In these fields successful kernel development is identified by small fluid blisters. Detecting successful pollination without waiting for the blisters to appear can be done by carefully removing the husks and turn the ear upside down and shaking it, silks will only remain attached to those parts of the ear which have not been pollinated. Those fields which experienced tough planting conditions, heavy rainfall events, or poor drainage are showing up with very uneven tassel emergence.

Forages

Alfalfa winterkill has resulted in many farmers altering rotations to accommodate additional reseeding. Summer seeding of alfalfa forage mixtures can be a viable alternative to spring seeding. Fields seeded this summer can be treated as established stands next year with full yield potential. Summer seeding of alfalfa can be successful, although it is seldom as reliable as a spring seeding. Summer seedings present a higher risk on heavier soils, and works best on light to medium textured, well-drained soils. Alfalfa needs about six weeks of growth after germination to develop a crown before killing frost to survive the winter. The summer seeding window is approaching for much of the province. Recommended summer seeding dates are:

" > 2900 CHU areas - August 10th - 20th
" 2500 - 2900 CHU areas - August 1st - 10th
" < 2500 CHU areas- July 20th - 30th.

Lack of moisture for timely germination is a significant risk. If soil conditions are extremely dry and no rain is in the forecast, abandon your plans for summer seeding. Conserving soil moisture is critical, so use as little tillage as possible to create a fine, firm seedbed, drill the seed rather than broadcasting it, and follow with a press wheel or packer to ensure good seed-soil contact. Do not use companion crops with summer seedings, as they compete too strongly for available soil moisture and will reduce stand establishment. Seeding alfalfa after alfalfa is not usually recommended because of autotoxicity and disease. If following cereals, control of volunteer grain is essential to reduce competition. Summer seeding trefoil is usually not successful, since it is slower to establish and needs the entire season to produce a plant that will survive the winter. Refer to "Summer Seeding Forages" www.omafra.gov.on.ca/english/crops/facts/summer_forages.htm.

Pasture

Mid-summer is a difficult time to manage rotational grazing, since forage growth tends to be slow and the livestock can get ahead of the forage supply. It is often tempting to rotate onto fresh paddocks before there is sufficient growth. The total supply of forage for the season will be much greater if the livestock are held back, and given supplemental feed, until there is eight inches of top growth for cattle, or four inches for sheep, in the paddocks they are to be rotated to. Over-grazing during the summer reduces the length of time the pasture will support grazing in the fall, and result in the requirement for more supplemental feed.

Clipping during the summer does little to increase pasture productivity, since the grasses that have gone to seed will not quickly resume vegetative growth. It does, however, reduce the growth and seed set of many perennial and biennial weeds, like thistles, curled dock and burdocks.

Soybeans

The majority of the soybean crop is between the R2 (full bloom) and R4 (full pod) plant stage. Warmer weather over the last two weeks has been favourable for growth, flowering, and pod set. Slow growth during July has meant that some fields have just now reached full canopy. Plants are generally shorter than average but plant height is not a good indication of final yield. Growing conditions over the next four weeks will be critical in determining yields.

Soybean aphid populations have increased slowly in southwestern Ontario but numbers remain low except for a few areas. In eastern Ontario many fields are above threshold and have been sprayed. Careful scouting is important at this time of year. Some populations have actually decreased and levels have fallen below threshold.

Septoria brown spot is common on the lower leaves. Yield losses from brown spot are negligible. Conditions have been favorable for white mould especially in eastern Ontario. Some white mould is already evident in affected fields. Foliar fungicides are not effective in controlling white mould in soybeans.

Weeds emerging through the soybean canopy are evident in many fields due to slow canopy closure and sufficient moisture for weed emergence. These weeds will not have a great impact on yield. A pre-harvest herbicide application to aid harvest and preserve seed quality should be considered in weedy fields.

Spring Canola

Cool weather and lack of moisture stress have been ideal for pod fill in spring canola. Most canola stands are podding well, although areas of Bruce County have received very little rainfall. A considerable amount of swede midge injury is evident in some fields of late planted canola. Swede midge has been found as far north as the North Bay area. Scout fields during late flower - early pod fill stage for alternaria black spot. Significant black spot infection during early green pod stage increases the amount of green seed, shriveled seed, and increases premature pod shatter. Black spot is favoured by cool temperatures (10 - 250C), and days when rainy, windy weather spreads spores through canopy. Early lodged stands of canola will be most at risk. The most serious loss is from premature pod shatter. A Western Canada trial shows a yield increase of 9 - 35% where a fungicide was applied at late flowering when significant alternaria occurred.

Edible Beans

The majority of the edible bean crop looks good, but is behind in development. White mould is evident in fields with a dense crop canopy. Scout white and black beans for anthracnose. In some fields, anthracnose can be spotted in areas with stunted and yellow plants, and advanced pod infection. High day time temperatures above 280 C will slow development of the disease, but moderate temperatures at night and heavy dews will allow the disease to develop. Water movement spreads the disease. Rain storms with gusting winds can spread spores short distances (up to 12 ft). Movement of animals, people, or equipment through fields will easily spread the disease especially when foliage is wet. Optimum disease control is obtained when a protectant fungicide is applied at early-bloom stage. Fungicides are very effective in stopping further development of anthracnose and provide up to 14 days protection. If wet and windy weather persists, a second application has proven effective in protecting seed quality if the disease is present.

Low levels of bacterial blight infection are evident in many edible bean fields. High humidity and rain favours the spread of the disease. Copper based fungicides have proven inconsistent in controlling the spread of blight because inoculants levels are often high by the time blight becomes evident. Fungicides are not effective against blight.

Tarnished plant bug populations appear to be increasing. Plant bugs pierce pods to feed on individual seeds, causing shriveled or blemished seed. Damage reduces yield and increases the amount of beans graded as pick. The insect can affect all bean types, but visual damage will be most notable on light coloured bean types. Tarnished plant bugs often migrate into edible bean fields from nearby orchards or recently harvest alfalfa stands. Control plant bugs when one or more bugs per plant are found during flowering to green pod stage.