Agronomist Notes

The 14-day forecast calls for temperatures to rise to the mid-teens with sunny skies but turning to scattered showers next week. Three quarters of my clients have started seeding and managed to get 10-15% of their crop in the ground in just a few days. If the weather holds, we could easily see a 30% jump in planted acres this week. The biggest challenge will be juggling spraying and planting and trying to dodge the hidden sink holes.

This issue of Beyond Agronomy News will look at a few post-seed herbicide options for cereals, peas and canola. Next, I’ve included a handy glyphosate chart of over 20 glyphosate products to help you chose which glyphosates can be mixed with each other. We’ll look at how to narrow down nutrient deficiencies across our fields with a new service called SSG. Last, we’ll run the numbers to look at the opportunity cost of hiring a custom applicator to do you pre-burn this spring should you get behind. We’ll finish with fundamental and technical grain market news. 

Agronomy

Steve's tips of the week

• I've seen a jump in weed germination over the past week. Be sure to scout fields that didn't show signs of weed growth a week ago so you don't get caught off guard.
• Watch your seeding speed. The mellow soil conditions are causing openers to throw more soil at higher speeds causing fluctuations in seeding depth. Remember, speed kills!
• Volunteer canola is starting to emerge, especially under the residue. If your fields look clean, take a look at what's hiding under the residue to be sure you don't need a pre-seed herbicide.
• Soil temperatures are hovering around 8C so shallow seeding will help you get that crop out of the ground fast if conditions are moist. It can buy you maturity. 

Post-seed herbicide options for cereals, canola and peas

Many producers will be forced to choose between seeding and spraying this week. With the late start to spring I suspect some fields will see a post-seed herbicide application rather than a pre-seed burndown. Should you find yourself applying a post-seed herbicide application, here are a few tips I’ve used to help you that you won’t find in the Blue Book:

1. PrePass http://msdssearch.dow.com/PublishedLiteratureDAS/dh_0611/0901b8038061113e.pdf?filepath=ca/pdfs/noreg/010-21406.pdf&fromPage=GetDoc Apply up to 3 to 4 days post-seed in wheat, barley, oats. Ideally, you want to apply PrePass within 3 days after seeding to avoid any risk of injury. RISK: Florasulam can be washed into the root zone if an inch +/- of rain occurs after application when the crop is nearing ground crack. Sandier soils are at higher risk of florasulam leaching into the root zone and causing stunting and yellowing.
2. Express Pro http://www2.dupont.com/Crop_Protection/en_CA/products-services/herbicides/express-pro.html Do not apply Express Pro post-seed period!
3. Heat https://agro.basf.ca/West/Products/HEAT.html Apply Heat prior to ground crack in wheat, barley, oats and peas.
4. Express SG http://www2.dupont.com/Crop_Protection/en_CA/products-services/herbicides/express-SG.html You can apply Express SG in wheat, barley and oats up until ground crack. I’ve applied Express SG with surfactant at the 1 and 2 leaf stage in wheat and barley safely. RISK: DO NOT apply a post-seed application of Express SG when planting peas. Express SG cannot be used pre or post-seed when planting canola. 
5. 2,4-D Ester Apply up to 200 ml/ac of 2,4-D Ester 700, 3 to 4 days post-seed in wheat and barley. RISK: Applying 2,4-D when the crop has begun to emerge can cause twisting and bending of the heads in wheat and barley.

Can I mix different brands of glyphosate together in the tank?

Not all glyphosates can be mixed together and not all surfactants can be safely used with others. From my experience, Vantage PlusMax and Touchdown IQ have had problems with compatibility in the past. The safe rule of thumb if you have to change brands and you have a couple hundred gallons left in the tank is to fill the tank three quarters full with water and then add the next brand of glyphosate. This should help reduce any compatibility issues.

If you do decide to mix different glyphosates together be sure to stick to glyphosates of the same salt formulations. There are three common salt formulations of glyphosate: isopropylamine salt, potassium salt and diammonium salt. See the accompanying table or a quick list of glyphosate product names and their salt formulations. SL

Insert pdf of glyphosate.

Narrowing down nutrient deficiencies with SSG technology

This season I’m involved in an exciting project- managing the agronomy on 4,000 acres of high yield trials. In an effort to zone in on nutrient deficiencies across each field, we intensified the soil sampling by taking five acre grid samples made possible through Trevor Thornton of Soil Stewardship Group (SSG) West in Manitoba. He helps growers and agronomists build nutrient base maps with proprietary software based on one to five acre grid samples. Each nutrient and soil quality parameter is outlined in a separate map like the one you see here. For our purposes, we used 5 acres grid samples taken in the 0-6 inch depth.

Response rates to nutrients like phosphorus or potassium can be sporadic at times, especially micronutrients like zinc, copper and boron. How many times have we treated a micronutrient deficiency based on a soil test and been disappointed with the results? My guess is fairly often. The reason we don’t often see a response is because deficiencies rarely occur across an entire field yet we apply blanket rates expecting a result. With the use of SSG grid sampling we can begin to discover where the deficiencies occur in the field. From there we can focus on nutrient applications on select areas of the field which is a lot more cost effective than the standard blanket rate approach.

To give you an example, take this base map of copper levels in the SSG map above. This map shows copper levels ranging from 0.4 ppm to 1.4 ppm across the field. Each point represents 5.88 acres. The critical soil test level for copper in wheat and barley is 0.4 ppm and 0.3 ppm for canola and flax. Now, what if your benchmark soil sample fell in the top right corner of this map where soil test copper levels are 0.4ppm? You would assume that this soil is deficient and recommend an application of copper.  But unfortunately, you would be disappointed with the results because 95% of the field is unlikely to see a response. 

The cost to do a complete macro and micronutrient package through SSG West is $14.00 acre for the first year and $5.50 acre for the next few years. The $5.50 acre package includes macro and micro nutrient analysis on four grid points per 160 acres. You can modify the number of soil sample points you take depending on your philosophy. I’ve done 4,000 acres this season and the results so far have been tremendous. We now a clearer understanding of nutrient variability across each field and can count the number of acres we’re likely to see a response to nutrients. From here we can start to fine tune our fertility program to match the right nutrients in the right place. If you want to learn more about the SSG program just respond to this email and I’ll point you in the right direction. SL

Should I hire a custom applicator to help with pre-burn?

Many of you who've been delayed on seeding will be deciding whether to stop the drill to spray or leave the application until after you've seeded. In a perfect world where no yield loss would occur from a delay in seeding, the drill would be parked and we'd be off spraying. But considering the tight timeframe we're in this spring, I think you might be money ahead to continue seeding and hire the custom applicator to do a pre-seed or post seed burn off on a few fields.

In my analysis here I'll assume the custom applicator costs $6.00 an acre. Yield loss in wheat, barley and canola is 1% per day after May 7th in canola and May 15th in wheat and barley. Wheat, barley and canola are valued at $6.50/bu, $4.00/bu and $11.00/bu, respectively. Average yields are 60 bu/ac wheat, 90 bu/ac barley and 50 bu/ac canola.

Steve's quick math

Custom applicator: $6.00/ac
Yield loss wheat: 1% x 60 bu/ac x $6.50/bu = $3.90/ac
Yield loss barley: 1% x 90 bu/ac x $4.00/bu = $3.60/ac  
Yield loss canola: 1% x 50 bu/ac x $11.00/bu = $5.50/ac

If you were to lose one day seeding because you had to stop the drill and go spraying it would cost you:
Wheat: $6.00/ac custom app - $3.90/ac yield loss = $2.10/ac
Barley: $6.00/ac custom app - $3.60/ac yield loss = $2.40/ac
Canola: $6.00/ac custom app -$5.50/ac yield loss = $0.50/ac

Therefore, in this example, it would cost between $0.50 to $2.40/ac to hire a custom applicator when you factor in the potential yield loss by delaying seeding and spraying it yourself. I realize the $6.00 or $7.00 price tag for custom app seems high but when you look at the opportunity cost of spending your time seeding instead of spraying, hiring it out may be your best option. If anything, it can get you through in a pinch. SL