April 30, 2014

Agronomist Notes

Hello Reader

We’re days away from a full on start to seeding with many waiting just a few more days for the soil to firm up. Soil moisture levels are sitting around 60% in the top two feet so we are sitting nicely this spring. Now, if only the weather would cooperate and give us a stretch of warm weather.

This week we’ll look at post seed herbicide options followed by practical questions on glyphosate use in the spring. I’ll outline my top three podcasts to listen to while you spend time in the cab. Last, I’ve got some handy online tools to help calculate machinery costs, fertilizer, seeding rates and crop budgeting. We’ll finish with technical grain market news.

Have a great week.

Photo: The old Steiger on singles and Concord air drill are days away from hitting the field. This is our fifth year in CTF and we're still excited about this system and how it performs.

Agronomy

Post-seed herbicide options

Many producers will be forced to choose between seeding and spraying next week. With fields not quite dry enough to plant, I suspect some fields will see a post-seed herbicide application rather than a pre-seed burn down. 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:

PrePass (Glyphosate + florasulam) 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.
Heat (Saflufenacil) Apply Heat with Merge and glyphosate prior to ground crack in wheat, barley, oats and peas.
Express SG (Tribenuron-methyl) 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. This is a favourite!
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.
Express Pro (Tribenuron-methyl + metsulfuron-methyl) DO NOT apply Express Pro post-seed period! The metsulfuron-methyl component can leach into the root zone and stunt wheat or barley.

Photo: Weeds showing symptoms of Group 2 damage from a post seed application of Express SG with Agral 90 surfactant.

Practical questions on glyphosate use

How long do I have to wait to seed after I spray Glyphosate?

If you are targeting annual weeds like stinkweed, volunteer canola, cleavers, flixweed, kochia and wild buckwheat then seeding the same day is fine. Does that mean seeding 1 hour or 12 hours after you spray? Remember that annual weeds have very small root systems so it doesn't take very long to get the glyphosate into the plant. Spraying early afternoon and seeding early evening is fine.

If you are targeting perennial weeds like dandelion, quackgrass and Canada thistle then, ideally, you should wait 3 days before seeding. If weather conditions are good (no frost) and 15-20°C days then you can push the envelope to 2 days before seeding while understanding the risk and guarantees that are foregone by spraying earlier than recommended. The longer you wait the better.

If a frost occurs, can I still spray Glyphosate?
Frost is always a problem in the early part of spring. Often temperatures will reach a low of -2 to -3°C, and then peak the following day to 13-20°C.

Hard Frost (roughly -2 to -3°C for an extended period of time, window scraping in the morning)
Perennials: wait until the warm part of the next day to spray. Wait 24 hours.
Annuals: wait until the warm part of the same day to spray. Wait until daytime temps have reached 10°C for at least 2 hours before spaying. If frost damage is suspected wait 1-2 days to ensure that the weeds recover (they need to be at least 60% green).

Light Frost (temperatures dip briefly below 0°C overnight)
Perennials and annuals: wait until the warm part of the same day to spray. Minimum daytime temperatures should be at least 10°C.

Weeds in order of frost tolerance:
1. Dandelion
2. Winter annuals
3. Quack grass
4. Perennial Sow Thistle
5. Canada Thistle
6. Toadflax
7. Annuals

Source: Syngenta and Monsanto

Popular Ag Podcasts

There are a few ag podcasts that I listen to and I thought I would highlight them just before you start spending countless hours in the tractor cab during seeding. Here are my top three picks:

GRDC Driving Agronomy This is an excellent weekly podcast out of Australia that focusing on agronomy issues, which almost parallel those in Western Canada. Clickhere

Precision Ag
This is an excellent bi-weekly podcast hosted by Tim Neale and David Cusssons from Australia. They focus on all things precision ag and provide tips and tricks when using precision technology. Click here

Growing with Canola
This is a weekly podcast that focuses on canola agronomy, markets and research put on by the Alberta Canola Producers Commission. Click here

Helpful online calculators

I thought I would pass on a few handy online calculators that help with fertilizer, seeding rates, crop budgets and machinery costs.

Machinery cost calculator. This is one of the best machinery cost calculators there is online. It breaks machinery costs down to the hr, ac/hr and cost per acre. Very handy! Click here

Crop budgeting. This is a handy online crop budgeting tool that comes pre-populated to give you rough estimates on crop input costs or you can enter your own. You can print off the results but you can’t save your info or download it as a file. Click here. You can take it up a notch and have a downloadable spreadsheet here.

Fertilizer rate calculator. This online tool allows you to enter your fertilizer cost per tonne, fertilizer blends and will calculate your application rate, bulk density, cost per tonne and cost per acre. Click here.

Seeding rate calculator. This online tool is by Alberta Ag and is a great tool for determining plant densities and calculating seeding rates. Click here.

Reader Comments

Mini-strip till article

"On our 30-inch strip-till, the strips were a good 4 degrees cooler than the non-stripped rows, when measured around 6 or 7 am. By 10 or 11 am on a sunny morning, they were even. Beyond that, the strips would gain warmth and be about 4-6 degrees warmer than un-stripped at sunset. I assume the strips then lost more heat during the night than un-stripped, but the difference was less in the mornings as time moved from +/- 20 April to 10 May. This experiment was carried out on Timothy hay stubble so there wasn’t much stubble left to stop the wind from carrying the warm air away at night."
Gary MacLagan, Rolling Hills, AB

Beyond Agronomy Apps

Tank Mix & Rainfastness Guide

This tank mix app, built for Western Canadian farmers, answers the everyday questions about herbicide rainfastness and the proper order to tank mix herbicides.

Apple or Android

Seeding Rate Calculator

An app designed to help you calculate how much seed is needed to produce a desired plant population when calibrating your seeder.

Apple or Android

Air Cart Maximizer

The air cart maximizer quickly calculates the maximum number of acres per fill based the size of each compartment in your air cart and the desired fertilizer and seeding rates. The app indicates which compartments should be dedicated to seed or fertilizer and how much product to deliver out of each to achieve the greatest number of acres per fill every time.

Apple or Android