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The Cropwalker - Volume 3 Issue 32

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Crop Conditions

Most areas things are growing well. Except the Niagara peninsula where things are dry. Winter wheat harvest is dragging on in lower heat unit areas. Some issues with elevators discounting wheat with low falling numbers. Once falling numbers fall below 250, it is feed wheat. In a year where there are plenty wheat millers can be choosy. Corn is motoring on. Field checks are showing fewer ears because of some cold soils at planting. Cobs have compensated by having more kernels per cob and will probably have a heavier kernel weight. No reports of moulds. Our August Twitter survey came up with an Ontario average yield of 166.7 and a range of 145 t0 188. There is some Western Bean Cutworm (WBC) feeding. Growers are a bit frustrated because there were very few egg masses found. Some acres have been sprayed for WBC. There are some reports that contrary to what researchers have said, WBC larva do come out of the ear and could be controlled by a spray. Silage Corn is drying earlier than last year. Do not let it get too dry. See table below.  Soybeans Our August Twitter survey came up with an average yield of 46.5 with a range of 39.5 to 52. There is still some spider mite activity. Not sure if there will be an economic response by spraying. Lots of fields where leaves are turning. Some interest in broadcasting cereal rye into standing soybeans for a cover crop. OMAFRA is doing a demonstration at COFS site. This will be part of the Canada’s Digital Farm Show which you can view later at ­­­­­­­­­­­https://register.outdoorfarmshow.com/. We also did a Planting Soybeans into Corn Stalks Demonstration. This too will be available at ­­­­­­­­­­­­­https://register.outdoorfarmshow.com/. Forages Fourth cut is looking good. Second cut is mostly finished on this year’s direct seeding. Yields were very low. Good soil moisture should give us a good cut in September for those who need it. Cover crop oats seems to be the crop of choice. In the US cereal rye is the crop of choice. You need to protect oats from rust. One strategy is to figure when you are going to harvest your oats and apply the fungicide 2 ½-3 weeks before that date or when you see rust.


Top Things for This Week

1.     Check all corn fields for Northern Corn Leaf Blight and note any hybrids. Check stage of corn maturity.

2.    Clip red clover to get it to grow better

3.    Spend a few hours cleaning the shop, throwing stuff out, and selling any equipment not used in 6-8 years.

4.    Finalize wheat seed requirements for fall.

5.    Check to see which soybean fields will need pre harvest glyphosate.

6.    Sample for SCN if you are seeing symptoms and relatively new to the pest, send away to soil lab.

Corn for Silage – this table shows that corn at early dent is around 75% moisture. Black layer is 55-65% moisture. For some bunk silos you want 65-75%. The exact % depends on size of bunker, speed of fill and how well you can pack it. Main point is it is about 30 days from early dent to black layer. If you are making silage now is a good time to start watching how your corn is maturing. There will be differences in dry down from hybrid to hybrid, so the table is an approximate rule of thumb.

Figure 1 - Corn Stage, Approximate Date and Moisture

Northern Corn Leaf Blight is starting to be more visible. One CCA suggested that it appears to be worse if corn is under a bit of stress. It seems that once the corn plant starts to move nutrients to the ear, and the leaf is stressed, the disease starts to show worse. It is too late to spray to control. If you applied a fungicide earlier check your results. This year it is the worst disease in corn. The lesions are described as being “cigar shaped”.

Picture 1 - Northern Corn Leaf Blight

Corn Rootworm (CR) Showing Resistance to Genetics we use hybrids with CR genetic resistance. But now there are reports of this resistance being overcome by CR. If you planted a hybrid with CR resistance check your fields now. Check for root tunneling as shown at the knife tip. If you find adults, then check the roots for tunneling. Adults may still be clipping silks but more apt to have laid eggs and be gone. To check for root feeding dig up the corn roots. Pick a good-sized root. Cut the end off and split it in two and look along the edge of the root for tunneling. Very easy to see.

Picture 2 - Corn Root Worm Damage
Picture 3 - Corn Rootworm Beetle

Red Clover for Plough down

Lots of great looking fields. This field is uniform enough that you can easily credit it 50 pounds of actual “N”. The low areas have killed out, but they are traditionally higher in residual nitrogen. There is a strip around the outside you might want to put some extra “N” on. If you have areas in fields with significant kill out, you can spread manure to even out “N” credit. Alternatively, you should be able to see the areas of no red clover next spring and add extra nitrogen there. This red clover also does a good job of reducing the weed seed bank. It would be easy to fly a drone over a field in late fall and make a NDVI map of kill outs/good areas and adjust if you have VR capable equipment.

Picture 3 - Red Clover Stand - Note minimal plants on headlands

Farm Budget – you do not have to sell at crazy high prices to make money…

The reason I state this is that some areas are shaping up to what looks like above trendline yields. When it comes selling or marketing, I find that producers get caught up in a target price that they must sell at to be profitable, but gross revenue is yield times price, not just price. Here are a few example calculations.

Figure 2 - Corn Yield by Price

If you are really into excel, you can run a What-If Analysis or a heat map to figure out what price you have to sell at various levels to achieve your target revenue per acre, example below.

Figure 3 - Corn Price x Yield Heat Map

Pre-Harvest on Alfalfa

Last year a few fields that had been burnt off later in the season did not have proper control due to lack of growing degree days and the size of alfalfa at the time of termination. My preference would be to terminate the alfalfa pre-harvest, allowing a better kill due to more top-growth, and then enabling the spreading of manure or field work immediately following harvest.

From the Roundup Transorb HC Label;

“For forage crops, apply this product at 1.67 to 3.33 liters per hectare (0.67 to 1.33 L/ac) 3 to 7 days prior to the last cut before rotation or forage renovation.

Apply only during the period 7 to 14 days (or 3 to 7 days for forage applications) before harvest to ensure best weed control and to maximize harvest management benefits. Earlier application may reduce crop yield and/or quality and may lead to excess glyphosate residues in the crop.”

Soybean Staging

Majority of fields I have been in are either just coming into R6 or just past R6.

R6 = Full seed at top of the plant

R7 = 1 Brown pod on the stem

R8 = full maturity

Figure 4 - Soybean Stage and Length of Time

Pre-Harvest on Soybeans/Edible Beans

Really only two, maybe three options. And the end user has the ultimate say, please check prior to application. Glyphosate at 0.67 L/ac, glyphosate @ 0.67 L/ac plus Eragon at 30 to 60 mL/ac plus Merge, lastly the use of Reglone.

Eragon – When, Where and How Much?

Eragon is a desiccant. The use rate of 1X rate is 29 ml/ac. Use the 1X rate for desiccation. Use the 2X rate before winter wheat for desiccation and to provide residue control of fleabane and chickweed. Always use Merge and glyphosate. The rate of glyphosate is dependent on weeds present. Watch glyphosate rate and days before harvest if spraying pre-harvest. If you have a field mainly with perennial weeds, such as dandelion or sow-thistle, I recommend only using glyphosate, and leaving out the Eragon, for better translocation.

Figure 5 - Eragon Rate and Weed Species

Eragon Pre-Harvest Timing Guide

Can be found at this link: https://agro.basf.ca/basf/agprocan/agsolutions/solutions.nsf/Images/PDC-AFRV-AJ8NCD/$File/Eragon_Staging_Guide.pdf

Pre-Harvest Interval for Insecticides on Corn, Soybeans and Edible Beans

Figure 6 - PHI and Common Field Crop Insecticides

Do you have sudden death syndrome?

If you are starting to see plants show up in your fields that look like this (see picture below), you may have sudden death syndrome. Brown stem rot looks similar, but the pith (stem of the plant), will have a brown discoloration with brown stem rot. About 70-80% of the time when you have SDS, you will also have soybean cyst nematode. Soybean cyst nematode is a host for infection of SDS. More on the differences between SDS and Brown Stem Rot here.

Brown Stem Rot of Soybean | Crop Protection Network

Crop Protection Network

Sudden Death Syndrome of Soybean | Crop Protection Network

Crop Protection Network

Soybean Cyst Nematode of Soybean | Crop Protection Network

Crop Protection Network

Picture 5 - SCN (White balls) on Root Hairs
Picture 6 - Sudden Death Syndrome Symptoms

Forage Fertility Pictures and Expected Yield Response – Volume 1/3

I recently completed a presentation on forage fertility, specifically around alfalfa, and felt this is a good spot to share it. Will have 2 nutrients each week for the next 3 weeks. First up, phosphate and potassium.

One of the biggest differences between forages and grain crops is the sheer amount of potassium removed, we have written about this extensively in the newsletter but to reinforce the point.

Figure 7 - P&K Crop Removal for Alfalfa, Corn and Soybeans


Research done by Agriculture and Agri-food Canada in Manitoba found that you could double your forage yields by applying MAP at planting if your alfalfa were seeded into a field of 12 ppm phosphorus (Olsen). The size of the response was visible over the 4-year trial.

Up to 20-30% of broadcast phosphorus can be taken up through the roots on a field that has already been established.

Picture 7 - Phosphorus Deficiency in Alfalfa (left)


The most critical time to apply potassium in an alfalfa’s life cycle is in the fall, to provided adequate K to survive winter conditions.  Applying large quantities of potassium at once, especially prior to first cut, can lead to luxury consumption of potassium, and possibly causing issues with early-lactating dairy cattle. My preference is to limit total product applied to 150 lbs. of Red Potash (90 lbs./ac actual K2O) and feed the alfalfa crop two or three times over the growing season, if using commercial fertilizer.

Picture 8 - Potassium Deficiency in Alfalfa

Soil pH and Alfalfa Yield

If you have fields going to alfalfa, and have not soil sampled lately, might be time to check your soil pH. Chart from University of Wisconsin Alfalfa Management Guide.

Figure 8 - Impact of soil pH on Alfalfa yields

Open Access Plant Diagnostic Images – American Phytopathological Society

Looking for images to help diagnosis crop issues? Check out the APS image data base, once of the most extensive I have found. Please note these images are copyrighted if you plan on using them in literature.


“Closing time

Every new beginning comes from some other beginning's end."

- Semisonic