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The Cropwalker - Volume 4 Issue 27

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Crop Conditions

Weather -rain across the province has slowed down wheat harvest. Sporadic harvesting across the province as far east as Peterborough. Only field activities were spraying corn and beans for diseases. Winter wheat harvest continues. Essex/Kent started June 28 and now 3 weeks later they are 50% done. Grade is slipping. Test weight was off the board high but is dropping quickly. Some soft red fields have 1’sprouts. As you go further north quality and grade improves. Yields are still good. As of Monday morning, #2 is about $8.15 a bushel. Drying charges are about $.20-.30 a bushel. Feed grade wheat Monday morning was $7.35-7.70 in Essex/Kent. Take home GET THE WHEAT OFF AND PAY DRYING CHARGES One person said once it gets to 20% it doesn’t flow out of the wagons very good. Be extra careful pushing wheat. No going into the bins. Mildew, sprouts, are reasons for down grading. Some dwarf bunt showing up. (See below) Corn lots of fields in tassel. Scouting is occurring for Western Bean Cutworm. As of Monday July 19, numbers are low in traps reporting in Ontario. Surprisingly there are more WBC in the traps in edible bean fields than in the corn fields. Not sure if that means there are more WBC in edible bean fields or traps are catching a higher percentage in dry bean fields. Here is the website for up-to-date WBC numbers Western Bean Cutworm 2021 Tar spot has been found in Elgin County last week. It is at significant levels in parts of the US. (See below) Soybeans are looking amazing. White mould is starting to show up even in sandy soils. Current weather conditions are conducive to mould. Areas that have mould cannot be stopped now. However, there are so many other diseases in soybeans, you have to consider spraying for those diseases. We are getting pictures of powdery mildew and Septoria. (See Cropwalker Volume 4 Issue24 June 23 2021, for the various company’s strategies to control white mould.) (See Cropwalker Volume 4 Issue 25 June 29 for the various diseases that affect corn and soybeans.) Forages are doing amazing. There are a lot of bugs in these fields. Currently there are lots of leaf hoppers, spittle bug, the various sting bugs and probably some late alfalfa weevil adults. If you need feed, consider an insecticide. If you don’t then you can live with a lower yield. Edible beans are having a lot of insects (leaf hoppers and others) as well as being set up for mould.


Things to do this week

1.    Check fire extinguishers to make sure they are charged. Good idea to buy a couple more to leave in tractors or trucks that will be in fields.

2.   Instruct people how to use a fire extinguisher. Aim at the base of the fire, not just at the flames.

3.    If you have corn on corn start checking for corn rootworm.

4.   Check for evenness of tasseling during tassel emergence. This is the one time of year after crop emergence, you have for the best indication of uniformity of crop emergence. If tassel emergence is not uniform, emergence was not uniform.

5.    Check the perimeter of fields along bush lots and waterways for invasive weed species. These are typical spread by birds migrating north.

6.   If double cropping soybeans, do not wait to get them in. You lose 1 bu/day after July 1st as a rule of thumb. Solid seeding is best, keep populations in the 200 to 300,000 seeds/ac depending on soil type, soil moisture, and variety.

Operating a Fire Extinguisher PASS describes 4 basic steps

Pull the pin

Aim at the base of the flames

Squeeze the handle to discharge extinguishing agent

Sweep the nozzle from side to side as you approach the fire directing the extinguishing agent at the base of the flames.

Q  Is this fusarium and if not, will it hurt yield?

Ans This is alternaria. Alternaria is a secondary fungus that breaks down plant material. It grows on dead plant tissue when conditions are wet. While it is not a problem in itself it does indicate a bunch of things. First that the field is mature and should be harvested ASAP. Secondly, if there is any fusarium in the field it will start to grow. Third, once you see alternaria start, “black point” which causes the tips of wheat kernels to turn black can start. Black point is a reason to down grade wheat. The presence of alternaria means that the chances of combine fires have increased. The alternaria spores will build up everywhere and can start fires easily.

Picture 1 - Alternaria on Wheat Head

Field fires in wheat

Comment from reader “combine lit inside the rotor and threw fire out the back. Had enough extinguishers to save the machine but wind picked up and lost 5-6 ac of standing wheat. It cost me $15,000 to repair what was burnt in the combine, but could have lost a $215,000 combine. The first guy to see it was in the grain buggy and he did not have an extinguisher. (Now we have extinguishers in the tractor that is on the grain buggy)”

Picture 2 - Fire in Wheat Field due to Combine

Bunt in winter wheat Generally occurs when soil does not freeze cold enough and long enough. The traditional “snow belt” area is where dwarf bunt occurs. Dwarf bunt gives a fish like smell to wheat which can make that wheat unmarketable.

1.     Combine wind-blast set at maximum

Turning the wind-blast settings up will remove a large portion of the bunt balls. Minimal good grain will be lost at maximum wind.

2.    Harvest fence rows and bush areas separately

Infection is most severe where snow was the deepest and stayed the longest. Harvesting those areas separately from the rest of the field should minimize the number of bunt balls in the sample.

3.    Clean grain before storage

It is important to remove as many bunt balls as possible from the sample before storage. Bunt balls will rupture during grain handling or removal from the bin. Bunt balls are similar in size to wild buckwheat seed. Therefore, screens that remove wild buckwheat should remove many of the bunt balls in the sample.

4.    Put grain into the bin with full aeration

It will take an extended period of aeration to remove the odour from the sample.

Tar spot in corn

Last year tar spot was identified in Ontario. This year it was reported July 7 in Elgin County. There are significant reports in Michigan straight west of most of Ontario. Research SUGGESTS that the best time to spray is mid tasseling to silking. There are significant differences among hybrid susceptibility. Seed companies are still working to characterize their hybrids. Tar spot is favoured by weather that is 17-25 degrees C and at least 75% humidity. This pretty much describes current weather. Go to https://corn.ipmpipe.org/tarspot/ for up-to-date positive sites for Tar Spot 2021.

Summer seeding alfalfa

The two most important things. Control volunteer wheat and watch seeding depth.

If you do these two things correctly you have conquered summer alfalfa seeding. Other points.

1.     Seed should be in the ground by August 10-15th. Earlier seeding will work if you have good soil moisture.

2.     Spray with glyphosate to control volunteer wheat and weeds such as chickweed before you work the ground.

3.     Apply manure or fertilizer P and K. I like to have the P worked in. If field is testing low in P consider putting on more than will be removed in one year. P does not move through the soil as well as K does. A good crop of alfalfa grass will remove 65-70 lbs/ac of P2O5 yearly. If your soil test is low, consider a minimum of 100 lbs./ac P2O5

4.     Adding a companion crop such as oats or peas and or oats greatly reduces the chances of a good catch.

5.     You must have a fine seedbed. If you applied manure and worked it in, you must get rid of the lumps

6.     Spray volunteer wheat if it emerges after alfalfa emerges. This will mean you may need to reseed grasses.

7.     Consider using Harvxtra (glyphosate resistant variety) where you have hard to kill weeds such as heavy chickweed pressure. Harvxtra has the added benefit of higher feed quality as the crop advances in maturity. If you want grass in the mix seed grasses right after you spray glyphosate. We like to have alfalfa seeded by mid- August but grasses will generally establish if seeded by mid-September. Grasses do not require as early of establishment, due to not needing a crown to survive the winter.

Corn rootworm on second year corn fields

There are lots of reports in central Ontario of corn rootworm that is resistant to current corn rootworm resistant genes. It is fairly easy to check for rootworm feeding now. Dig up some corn roots and check for feeding on the main root system. I like to take a knife and cut the main root in half longitudinally or just use a thumb nail to split the root. Then check the outer layer of root tissues. Root worm tunneling is very obvious this time of year. If you cannot do it now, you can check for rootworm adults later in the season.

Picture 3 - Corn Rootworm Tunnelling

Tissue testing

Is still an art. The results of tissue testing are almost always frustrating. That is because 1) the nutrients are reported on a percentage basis. Thus, you could have a very poor plant but it may show high levels of the suspected nutrient deficiency because there is less plant. 2) The nutrient may be deficient to the plant but there is lots in the soil. The plant just cannot take it up (maybe due to soil conditions, i.e. standing water). 3) The plant comes from an area of very poor topsoil and many nutrients are deficient.

Tissue testing Procedures

1.     Check with the lab that you are using for the appropriate time to sample, which part of the plant to sample, how big a sample is needed, how to store and ship sample.

2.     Always sample poor plants and good plants that are as close as possible to the poor plants.

3.     Always take a soil sample from the good area and the poor area. For best results, these areas should be as close as possible hopefully within 50 feet or so from each other.

4.     Once you get the results talk to someone who has experience dealing with tissue tests.

BASF - Sefina

Sefina is registered on alfalfa for the control of Potato Leaf Hoppers. It has a pre-harvest interval of 0 days. So, if you are looking for an alternative to Lagon or Cygon (2 days PHI), Sefina maybe it.

Sefina™ Insecticide Powered by Inscalis: Aphid Time-Lapse

Corn Fungicides

Still on the fence on what product to use. Here is a summary of what is labelled for Ontario. One comment I will make, do not look at just yield when it comes to selecting a fungicide. If you are in an area where marketability of the crop can be a concern. Also consider quality, this means selecting a product with DON suppression. A 10-bushel yield bump might not mean much if you are dinged $50/MT for high DON. Also, this year’s corn is taller than most years. This can make lodging later an issue. Typically, fungicide sprayed corn stands better.

Figure 1 - Corn Fungicides

Fungicide Efficacy for Control of Corn Diseases

Wheat Seeding Width and Yields

Question - I’m looking at a modifying a drill, is there any advantage to going narrower than 7.5”?

Answer – It depends on the yield environment, with wheat in higher yielding environments (like Ontario) there is some data to support going narrower than 7.5”. A quick survey of the scientific literature suggests about 8% more yield (going from 7.5 or 8” to 4-5” spacing), mainly due to increased tillering, if left at the same seeding rate. Depending on drill setup, this may not be conducive to no-tilling in high residue fields.

You may have Corn Planter neglect syndrome…

Symptoms may include;

1)    Uneven plant to plant spacing, including double and triples, gaps in the stand

2)    Uneven plant height

3)    Open seed trenches

4)    Variable seeding rates

5)    Variable cob size

6)    And finally, the worst of all, uneven tassel emergence

To reduce the risks of having Corn Planter neglect syndrome, visit your local corn planter dealer or service provider for a planter health checkup and to take advantage of the respective early order parts/service program. Side-effects from the visit may include; lighter wallet, increased evenness at tassel timing, additional time to sleep during spring, and larger kitchen renovation budgets.

Soybean Fungicides – what to do now

If you no longer have flowers on the plant, spraying to hoping to control white mould is out at this point. Now you are looking at leaf diseases, this may mean using a different fungicide product or rate that what you have chosen if you were targeting white mould. Product list with labelled diseases listed below.

Figure 2 - Soybean Fungicides

SCN/SDS vs. Brown Stem Rot

If you are starting to see what looks like the leaf below. You may have sudden death syndrome, or brown stem rot. To confirm which one it is, cut the stem of the plant in half. If you do have sudden death syndrome, also inspect the roots for signs of Soybean Cyst Nematode, which act as host for Sudden Death Syndrome. If you are suspecting there is SCN present, I suggest soil sampling beside the impacted plants and sending the results away for a cyst count. This can determine the presence of SCN, and what future management should look for fields with SCN populations.

Picture 4 - Soybean Sudden Death Syndrome

For more information, check out the following flyer from the Crop Protection Network.

Scouting for Soybean Stem Diseases

Crop Protection Network

Diagnosing Interveinal Chlorosis in Soybeans — it’s not just SDS

Crop Protection Network

Management screams volumes

Your crop management leaves a thumb print, you might now always see it, but just like the mechanic checking over a piece of unmaintained equipment, the signs are there.

Alfalfa Management – 9 Possible Reasons for Low Yields not related to Weather

1.     Thin stand, not enough viable plants, time to retire it.

2.     Low phosphorus leaves, leading to poor thriftiness

3.     Low potassium levels, poor winter survival/brittle leaves

4.     Low sulphur levels, leading to stunting

5.     Boron deficiency, stunted plants with reddish leaves

6.     Insect feeding – could be leaf hoppers (damage can look like boron deficiency), alfalfa weevil feeding

7.     Magnesium deficiency – excessive potassium levels or low magnesium levels are causing reduced plant growth

8.     Root rots – Alfalfa variety in the field is susceptible to root rots

9.     Last but biggest is compaction. Numerous trips across a field with heavy equipment damages crowns and allows root rot diseases to start.

Potash Article – Crops and Soils

If you want one of the best articles I’ve read recently on potash recommendations, and the impact clay type has on potash response, you can find it here in the latest issue of Crops and Soils - https://acsess.onlinelibrary.wiley.com/doi/10.1002/crso.20114

My biggest take away from reading this article, is that you want to enact an aggressive potash build program, it may be worth the time to figure out what type of clay is in your soils and do a rate trial to see if you are getting a response. It might be different than the often spouted 120 ppm.

If you are a Certified Crop Advisor, you should be getting this magazine for free.

The article gives the name of a lab in Ontario that tells you what type of soil you have and how that affects K availability

White Mould – Disease Triangle

The most asked question last week was, “is it too late to spray for white mould?” and “Have you seen any mould yet?”

To answer the first question, it depends on if you still have flowers on the soybean plant, and to answer the second question, in my area locally, it is likely premature to see mould in the fields. But you may start to see it in areas that have had significantly more moisture.

For white mould to occur in soybeans, you need three things. 1) spores from the white mould Apothecia, 2) flowers to infect 3) environmental conditions conducive for the spores to survive on the flower and infect the stem.

For the spores to be present, you need a previous host plant on the field, could be soybeans, canola, edible beans, red clover or one of the other 400 plant species that can be a host for it., including a number of common weeds. To infect the soybean plant, you require an open flower for the spores to land on and then get caught on the stem. To cause the infection to start, you need a humid environment, but without a heavy rainstorm to wash the flowers off. The flowers provide a food source for the infection to occur.

“If we are all in agreement on the decision - then I propose we postpone further discussion of this matter until our next meeting to give ourselves time to develop disagreement and perhaps gain some understanding of what the decision is all about.”

— Alfred P. Sloan