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The Cropwalker - Volume 2 Issue 25

Always read and follow label directions.

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Crop Conditions

Winter wheat – You can really see a turn in the colour of some early panted wheat fields. Historically it is 6 weeks from FHB spraying to harvest. Wheat, like other crops, is 2 weeks behind. Expect earliest wheat harvest to start by July 14th. Corn is growing really fast, from just emerging to 9-10 leaf stage of early planted.  Soybeans just emerging to pre flower. Expect to see flowers this week. Be cautious about spraying soybeans in flower, Spring cereals – earliest fields are at late boot stage to just heading. Rust has been identified on oats. All oat fields whether for forage or seed should be sprayed for rust control. A good fungicide for this is Folicur. It combines good rust control at a good price.  Forages Some growers are working away at first cut as weather allows. The quality of this feed is low. Second cut looks good. We have had good moisture and temperatures to produce a good second cut.


Reader Feedback

One of the readers tried applying 28% UAN with Chafer bars on his corn at the 3-leaf stage. He applied it at 4 pm in the afternoon, and then at 10 pm had a rain event. He said that the corn had essentially no burn and was quite happy with the result.

Picture 1 - 3 leaf corn with UAN applied via Chafer Bar

About Always Reading the Label

Last week we wrote about an agronomist watching a field sprayed post emergent with 28% and a herbicide. Then watched the field struggle. The reality is this is off label. I have received pictures of very “affected” crops. Maybe even dead plants. Problem - off label use. We are now entering into IP soybean spraying, as well as, post emergent spraying of corn. There are only certain things you can spray on these crops at these stages. The crop protection companies have spent millions of dollars to come up with how to apply their products. In the last 20 years many products come with a surfactant. Use of this surfactant allows a lower rate of the active ingredient. This is good. But then if two products have surfactants, the result of when you mix them are unpredictable. I know growers want to mix many products along with a micronutrient, and, sometimes a plant stimulator. If you do mixes like these, you are on your own. The problem is that sometimes they work. It is a bit of Russian Roulette though. It is generally better to make two trips. Final point, whoever sprays the mixture is ultimately responsible. It does not matter who recommends what. The person in charge of the sprayer is responsible.

Prioritizing your Problem weeds

So, you have a field with 4 or 5 weeds and you need 3 different products to control the weeds. There are no registered tank mixes with the 3 products. What do you do? Control the worst first. They may be the worst because they are hardest to kill or there are so many, or they are something like nightshade in IP soybeans. Sometimes the mix has activity on the other weeds. And sometimes the weeds are there, but not a big deal such as dandelions at a low pressure. If you have to make two trip 4 days apart, that is better than damaging a crop. Especially this year when a lot of crops are already under stress.

Maximum leaf stage for most corn herbicides?

Once you are past the 4-leaf stage, it is considered late post emerge. The number of herbicide options decreases. The Roundup Transorb HC label states that you can apply the high rate (1.33 L/ac) up to the 6-leaf stage. After this stage, the maximum rate is 0.67 L/ac up to the 8-leaf stage. What happens if I do not follow the label? Biggest risk is yield loss; Pioneer figures theoretical yield loss is 25% depending on the plant stage and rate. Replicated plot data in Ontario and Michigan has averaged 10%.

Can I just increase Nitrogen the rate?

I’ve heard it multiple times, why don’t I just increase the rate to make up for my N losses, instead of using a nitrogen inhibitor like Agrotain Advanced? Using Agrotain Advanced is about $0.10/lb N, to protect Urea or the Urea portion of 28% UAN. If you have purchased nitrogen for $0.50/lb N, you could theoretically increase your Urea rate by 20%, and still have the same amount cost as adding Agrotain. But it doesn’t work that way. Now you have doubled down at the blackjack table with a losing hand. If you are under conditions that increase the risk of volatilization, you are now losing a larger amount, rather than protecting the original rate. See the chart below, assuming the grower was going to top-dress with 60 units of N.

Table 1 - N Loss Chart due to Gas Off of Urea

What to do with Unseeded Acres?

Oats is the number one choice. It is generally reasonably priced. However, the shortage of oats has greatly increased the price of oats. One retailer is selling it for 40-50 cents a pound. This equates to $800-900 / tonne. I am sure there is a lot of oats around the country in bins. Check around. Oats is a logical first choice, since it does not add diseases if you are planning to plant wheat. You can spray with MCPA to control annual broadleaf weeds. It should give enough top growth that would allow you to sell some forage. It builds soil structure and suppresses weeds. Most of the other choices, such as, millet, sorghum or sorghum sudan, and a lot of other annuals are sold out. I would not seed an annual grass since they will not all germinate and some could be a problem in winter wheat. I would harvest the oats before planting winter wheat, since this will give a better seedbed. Most of the benefit of oats is in the roots, compared to the top growth.

Spraying Soybeans in Flower

Soybeans set more flowers than they use. But the first ones they set are critical to high yields. You do not want to damage them. There are some products you can spray when soybeans are in flower. These include Engenia (label says up to first flower, however weather conditions at that time mean spraying soybeans at first flower is very dangerous because of off target movement), and Roundup. There are a number of other products you can spray while soybeans are flowering but some like Classic and Pinnacle, you must not spray while soybeans are flowering,

Putting a Positive Spin on 2019 Crops

If you are farming you have to look at the positive things. Here are some about 2019. We are clearly 2 weeks behind. 1)The last number of years the growing season lasted well beyond the normal “first frost” date, by at least 2 weeks. Worst case we get an early frost and corn will brown layer. At current corn prices that is not a disaster. We know corn that brown layers has great feed quality. Lower in sugars, but higher in protein. And if we get an early frost the soybeans will be harvested early and we will get wheat in on time. Last two years the lack of frost was a major factor in soybeans not being harvested in time to plant wheat. 2) A big issue with weeds reducing yield is because they take much needed moisture. Not an issue this year. 3) There has been a lot of discussion about planting green. Many fields were planted green this year even though that was not the intent. We will see how that turns out. 4) We have learnt a lot this year. Things were done this year on a wide scale that will be done more often. One was using 3-streamer nozzles or chafer bars to apply 28% to 3-5 leaf corn. A lot of forage acres were inter seeded with annual ryegrass. This worked well. 5) The last 2-3 years planting went pretty smoothly. This year not so much. This year pointed out where the limiting factor is in your planting plant. 6) Inability to get manure out before planting obligated growers too try different methods. One of our readers used a drag hose after corn emergence and when last contacted he was pleased with the process. 7) Next year will be better.

Corn with jointed leaves

I have been seeing 1 to 2,000 (or more) plants per acre of joined leaves in corn. At first, I was unsure on the cause, and it appeared to be due to temperature swings. Then after walking a few thousand acres of corn, my conclusion is that it’s due to soil crusting, and corn trying to push through to the soil surface. When it is below a soil crust, it continues to leaf out. When it finally pushes through, the leaves are jointed together from trying to push through. While I don’t think there is a yield impact from the fact the leaves are joined together, these plants do have a delay in emergence, so expect a lesser % of normal yield on these plants compared to those neighbours that didn’t suffer from crusting.

Picture 2 - Corn seedling unable to make through the crust
Picture 3 - Corn seedling struggling to push through the crust
Picture 4 - Emerged Corn with Jointed Leaves; significantly delayed

What fungicide should I spray on my spring grain?

You are relatively new or have been away from growing spring grain for several years. You have applied your weed control, and possibly an early fungicide. I’m done for the year until harvest, right? WAIT… no, the most important fungicide pass for yield, and possibly quality, is yet to come. For spring wheat, applying a fusarium head blight product at flowering, such as Prosaro or Caramba is critical to maintaining milling quality wheat, along with a nice yield bump. For Oats, and Barley (if fusarium isn’t a concern), a flag fully emerged timing maximizes yield response. Almost any fungicide registered on cereals could work, or if the boot has started to split, use Folicur, or if your retailer doesn’t carry it, Prosaro/Caramba. You cannot apply a strobi fungicide once the boot has started to crack, or the head has started to emerge. I typically put Folicur in the crop plan, then if the boot does split prior to application, the grower doesn’t have to make a product switch. Folicur is rated very strong on rusts.

What can I spray post-emerge in RR/RR2Y soybeans?

Really only a hand of products that you would consider. In no particular order;

1.     Glyphosate – still the best value for many of the weeds you need to control. Plus consider one of the following below.

2.    Classic (Guardian) – for residual control of broadleaves and enhanced activity on dandelions and nutsedge.

3.    Pursuit – for residual grass and broadleaf control.

4.    FirstRate – for glyphosate resistant fleabane (provide it is also not group 2 resistant)

5.    Flexstar GT – a pre-mix of glyphosate and Reflex, for control of waterhemp and giant ragweed, volunteer RR canola, suppression of field horsetail, and residual activity on common ragweed and redroot pigweed.

6.    Grass herbicides for volunteer corn – such as Assure, Statue, and Venture L

Do not make your own Flexstar GT

Past experience suggests making your own Flexstar GT by mixing glyphosate and Reflex, runs the risk of making a unsprayable solution. If available, buy the pre-formulated product. Otherwise make two trips.

Which grass herbicide should I use in soybeans for Volunteer Corn?

Three main products on the market. Assure II, Statue and Venture L.

Assure II – labelled until the 6-leaf stage. Label states 0.15 L/ac, you may hear 0.1 L/ac from some in the industry. From experience, at the 0.1 L/ac rate you may see reduction in efficacy depending on plant stage/water volume. Ensure the proper surfactant ratio is maintained at 0.5% v/v.

Statue – new for 2019, it is clethodim with a new and improved surfactant. 6-leaf is listed as the maximum size. Carrier (MSO/non-ionic surfactant), must be used with this product.

Venture L – can be used on vol. corn until the 4-leaf stage. One advantage of Venture L is that there is some limited residual activity, which can control later flushes. If used on its own at higher water volumes, consider adding Turbocharge to maintain the surfactant rate.

My corn is at the 8-leaf to 10-leaf stage, can I use my 7-hole streamer nozzles to apply UAN?

Data from Iowa State and University of Minnesota suggests you would be better to use a side-dresser or hire a sprayer with y-drops.

"As time goes on, you'll understand. What lasts, lasts; what doesn't, doesn't. Time solves most things. And what time can't solve, you have to solve yourself." - Haruki Murakami