Ontario Field Crop Report
September 24, 2008
by OMAFRA Field Crop Specialists
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 Publication 811 Agronomy Guide for Field Crops ($20), 812 Field Crop Protection Guide ($15), 75 Guide to Weed Control ($15), and 505 Ontario Weeds ($15). These can be obtained from your OMAFRA Resource Centre, or by calling 1-800-668-9938.
Corn
Corn crop maturity is most advanced in the southwest where accumulated heat units are normal and much of the corn is at or approaching black layer. The crop is increasingly behind normal development as you move to lower heat unit areas. In the tour of Corn Performance Trials conducted the week of September 15, the majority of plots were in the one-third milk line stage. With the good weather conditions of the last two weeks, they should now be near one-half milk line. At one-half milk line, 95% of the yield potential is already in the kernel. If the crop does not finish from this point, test weights could be reduced. However, experience from 2002 suggests that feed value is not impacted. From one-half milk line, it normally takes 10-14 days to reach black layer.
Corn plants dying back from both the bottom and top at the same time have been reported. Plants normally die back from the bottom first, progressing upward. Die back at both ends can be caused by normal physiological responses (especially warm conditions during grain fill), hybrid differences, environmental stresses and anthracnose infestation. Anthracnose tends to be in a more random field pattern. Normal physiological or stress related die back tends to be widespread across fields. Anthracnose can be identified by visible black lesions on the outer stalk tissue behind leaf sheaths. It shortens the grain fill period available to move sugars from the stalks to the kernels limiting yield. Corn borer damage, where feeding occurs in both the upper and lower canopy, can also result in die back. Scout to determine the cause of any die back. Expect lodging associated with weakened stalks and prioritize fields for harvest.
In the Corn Performance Trials tour, plant health was generally good, with little evidence of disease or stalk cannibalization detected. However, others have reported stalk problems, so fields should be monitored to assess priority for harvest schedule. With energy prices and the high moisture of much of the corn crop, target harvest as late as feasible to enhance field dry down. Be aware of declining stalk quality and lodging as harvest begins.
Corn root worm and ear worm infestations have been reported in different pockets of the province. Initial field scouting has provided evidence to suggest some concerns with ear moulds in the south west and that these declined as you moved east. Increased ear moulds tend to be correlated with physical damage to ears and husks caused by hail, insects and birds. Fields with extensive ear moulds should be tested for mycotoxins. Farmers harvesting grain corn for on farm feeding should prioritize fields to keep for feed. Where extension mould concerns are evident consideration should be given to retaining 2007 corn.
Corn silage harvest is underway. Harvesting corn silage at the correct moisture is critical for good fermentation and feed quality. The best silage fermentation and livestock performance usually occurs when whole plant moisture is 65-70%. This corresponds well to horizontal silos, but silage may have to be a bit drier in tower silos to prevent seepage. Recommended moisture contents for corn silage are as follows:
The traditional recommendation has been to harvest corn silage from one-half to two-thirds milk line, but this may not be accurate enough. The range in whole plant moisture when plants are at one-half to two-thirds milk line can be very large. Weather and hybrid differences cause significant variation. Many silage-only hybrids have less stay-green, so that the grain will have higher moisture relative to the whole plant. Check whole plant moisture by chopping a sample and using a microwave, Koster tester, or laboratory. Silage moisture typically falls by 0.5% per day approaching harvest, but this rate may be higher in drier years or lower in wetter years. Watch for variability between and within the fields. Refer to “Harvesting Corn Silage at the Right Moisture”
www.omafra.gov.on.ca/english/crops/facts/07-047.htm .
Soybeans
Maturity of the soybean crop is variable throughout the province. This reflects the variability in planting dates, precipitation levels and variety selection. A small percentage of fields have been harvested, mainly in the southwest and the area north of London. Harvest should be in full swing by the week of September 29. Central and eastern Ontario are further behind. Early soybean yield reports are average to above average, except where conditions were very dry in late summer. Yields in the mid 30’s (bu/ac) are being reported in the extreme southwest. Yields in south-central Ontario are above average (45- 60 bu/ac). Overall, seed quality is good with average seed size.
Some fields were hit hard with white mould this year, depending on planting date, variety, and region. Take note of which fields have white mould in order to aid in planning for future susceptible crops such as soybeans, edible beans, and canola. Foliar fungicide sprays have not proven to be very effective for white mould control in soybeans. In fields that have a history of white mould, use wider rows (at least 38 cm or 15 inches), lower plant populations, and more tolerant varieties.
There have only been a few reports of overly dry soybean seed moisture levels (e.g: 9-10%). Monitor fields to minimize harvesting beans at seed moisture content lower than 13%.
If storing soybeans, have the grain bin ready. Ensure it is completely free of debris, the fan and ventilation system are in working order, and that any possible points of moisture entry are sealed. Roofing tar is often effective for sealing. Refer to www.omafra.gov.on.ca/english/crops/pub811/4harves.htm.
Forages
Although most of southern Ontario is in the middle of the six week “Critical Fall Harvest Period for Alfalfa”, there is considerable forage being harvested. The risk of alfalfa winterkill increases by harvesting during the critical period because the alfalfa re-growth uses up root energy reserves required for winter survival. This can lead to a Loss of vigour and reduced yield next spring, so cutting should be weighed against the immediate need for forage. Cutting in the middle of the critical period is a higher risk than cutting at the beginning or end. Risk can be reduced by cutting towards the end of alfalfa growth, which occurs when killing frost temperatures reach -4°C for several hours. The critical period is based on long term historical temperature data. After a killing frost, alfalfa feed value will decline as leaf loss occurs and rain leaches nutrients quickly. Leaving a six inch stubble will help trap snow to insulate the alfalfa crowns during cold weather. Stubble will also protrude through winter ice sheeting, should that occur. Assess the risk of winterkill for your farm. Parts of Ontario, such as the Ottawa Valley, are at higher risk of alfalfa winterkill. Older stands with less disease resistance, low potassium soil tests, and poor soil drainage also increase the risk. Cutting intervals of less than 35 days between cuts increases the risk of winterkill, while an interval of over 40 days allowing fill flowering reduces the risk. Refer to “Risk Of Alfalfa Winterkill” at www.omafra.gov.on.ca/english/crops/facts/91-072.htm
Heavy stands of grasses or red clover can sometimes smother over the winter because the top growth forms a dense, leafy mat. In contrast, alfalfa loses most of its leaves as soon as there is a hard frost, and the remaining stems do not pose any risk of smothering. Cool, dry, late-fall conditions encourage good alfalfa winter hardening.
Winter Cereals
Winter wheat planting is right on the heals of the soybean harvest. In most areas, the soil conditions for planting are excellent. With good soil moisture, optimum seeding depth is 2.5 cm (1 inch). This encourages early emergence and rapid development of an extensive secondary root system. Winter wheat plantings should target the optimum number of seeds per acre, which is 1.5 million seeds per acre on loam, and 1.8 million seeds per acre on clay soils.
Due to multiple disease concerns, do not seed winter wheat following winter wheat. Where rotation dictates that wheat follows corn or other cereals, consider additional management practices, including selection of fusarium tolerant varieties, proper residue management, and the use of fungicide for fusarium head blight control.
No-till fields should have a glyphosate burn-down applied pre-plant to control winter annuals (ie.chickweed), biennials (ie. wild carrot) and seedling perennial weeds such as dandelions. Where wild carrot is a concern, Refine Extra will provide excellent control. Do not spray hormone type herbicides (i.e. dicamba, 2,4-D) in the fall as serious crop injury can occur. Refer to OMAFRA Publication 75 “Guide To Weed Control”.
The “2008 Ontario Winter Wheat Performance Trials” are on-line at
http://www.omafra.gov.on.ca/english/crops/facts/wwperf-08.htm
Spring Cereals
The last of the spring wheat harvest is finishing up in southern Ontario. In northern Ontario, the spring wheat crop is about 50% harvested. Yields have been about average with good quality reported.
Edible Beans
Dry weather has allowed excellent harvest progress of a high quality edible bean crop. Yields have ranged from 15 to over 25 cwt/acre with moistures in the 16-20% range. Harvest is 30-40% complete.
If warm dry weather persists, seed moistures below 16% increase the risk of cracked seed coats. Seed moisture content and checked seed coat damage should be monitored throughout the day to make adjustments to combine operations. Ensure that trucks and handling equipment are clean of other crops including corn or soybeans. Contamination with corn or soybeans may be assumed to be genetically enhanced seed and result in load rejection.