Top Crop Manager

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Late soybean harvest may delay winter wheat planting


Sept. 18, 2014, Ontario – Grower desire to plant winter wheat remains high, but with a late soybean harvest, Peter Johnson notes that many producers are struggling to plant wheat in a timely fashion. 

Spring cereals
Harvest drags on with frequent showers and rainfall, according to Peter Johnson. Yields remain well above average in many cases, despite the extremely late planting dates of the crop, a tribute to the cool summer that has plagued the corn and soybean crop. Quality has been excellent in many cases, with the exception of Fusarium-damaged spring wheat, which has been very severe in some areas. Barley straw yields have been extremely disappointing in many fields, especially frustrating where growers chose barley for the quality of the straw.

Winter cereals
Grower desire to plant wheat remains high, Johnson adds. However, with a late soybean harvest, many growers are struggling to find places to get wheat planted in a timely fashion. Wheat after wheat is not a good option. Take-all is the main concern, although barley yellow dwarf virus and Fusarium could be additional issues. Note that you give up the rotational benefit to corn (~15 bu/ac increase) and soybeans (~5 bu/ac increase), as well as take a 10 per cent yield hit to the wheat crop even without Take-all. This is a $150/ac lost opportunity from growing wheat on wheat. If you still decide to grow wheat on wheat, use 55 kg/ha (50 lbs/ac) of muriate of potash, 0-0-60 in furrow with the wheat, along with the starter phosphorus. The chloride in the potash will give some suppression of take-all, and is the best management recommendation we can provide. Wheat after wheat is not covered by crop insurance.

Wheat after silage has but one concern: Fusarium! This is the rotation with by far the highest risk of Fusarium issues, so be sure to plant a variety with a MR rating for Fusarium (see Agricorp requires both an MR variety, and the use of a Fusarium fungicide at the proper timing next spring, to be eligible for crop insurance coverage in this situation.

Wheat after hay suffers the same Take-all issues as wheat after wheat, if there is a significant amount of grass in the hay. If planting wheat after a stand of pure alfalfa, there should be no issues.

Broadcasting wheat into standing soybeans is fraught with issues, but there has been some success in the past. Slugs, wind injury and frost heave can all damage the crop. This year, wet, cool conditions have given rise to very high slug populations. Slugs can decimate broadcast wheat, by “popping” the germ end out of the kernel as it germinates. Look for slug feeding injury on the soybeans: slime trails on the leaves. If broadcast seeding is undertaken, seed two to 2.5 million seeds per acre just as leaf drop begins. Agricorp must see the field this fall and evaluate if the stand is acceptable for these acres to be eligible for crop insurance.

Corn crop development in some parts of the province or in early planted corn arrived at the half milk line stage this week and is on track for black layer by the end of September. However, Greg Stewart reports that in many areas the crop is in the early dent stage and still needs three more weeks of frost free weather. There were only a few isolated reports of frost this past week and virtually no crop damage.

A killing frost (stems and leaves) that occurs at the one-half milk line will reduce yields by about 10 per cent; alternatively, a killing frost at the early dent stage will reduce yields by approximately 25 per cent.

Silage harvest has started in some areas over the past week. Be sure to monitor whole plant moistures. Milk line targets (i.e. one-half to two-thirds) are reasonable tools to estimate silage moisture; however data over many years show a range in whole plant moisture at one-half milk line of 52 per cent to 72 per cent, with an average of 63 per cent.

The recommendation is to determine whole plant moisture shortly after denting when the milk line is about 20 per cent. Experience shows that in a typical year, corn silage at this stage dries approximately 0.5 per cent per day. Therefore, if the sample was 70 per cent moisture, and 65 per cent moisture is the target, harvest should be done about 10 days after the corn was sampled.

Fall pasture growth has remained reasonable with adequate moisture but cool temperatures, reports Jack Kyle. During the fall period both the legume and grass plants need the opportunity to increase root reserves of energy to prepare for the winter dormant period. Do not graze pastures short during this fall period, leaving a significant amount of green leaf material will allow the plants to properly prepare for the coming winter.

The one exception would be on fields that you want to frost seed next spring: these fields should be grazed short this fall to weaken the established plants so that they are slower to start growing next spring. This will give the seedlings from the broadcast seeds a fighting chance against the competition. The highest success rate with frost seeding comes with the clovers and trefoil; alfalfa and the grass species are generally not very successful at getting establishing this way.

Consider grazing corn stover and or cover crops this fall. These are excellent low cost sources of feed and the grazing animals leave all the nutrients in the field for the next crop.


September 18, 2014  By Top Crop Manager


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