May 22, 2013

Agronomist Notes

Hello Reader

Producers are wrapping up seeding in the west and are about 85% complete in the east. The 14-day trend calls for showers starting Thursday with temperatures in the low 20’s and no risk of frost. It’ll be a mad dash to the finish.

This week we’ll look at wild oat control strategies, spray temperatures and timing and follow with inter-row seeding tips when using the ‘nudge’ method. We’ll finish with technical grain market news.

Have a great week.

Pictured above: Gridley Farms seeding canola across from us near Morrin. Tom Anderson was the pilot on this 70-foot Flexi-coil drill.

Crop Staging

(Calgary to Drumheller to Three Hills)

Seeded    May 1-7        May 8-15
Wheat      2-leaf            1-leaf
Canola     1-leaf             cotyledon
Barley      2-leaf             1-leaf
Peas        2nd node       1st node

Steve's tips of the week

Follow me on Twitter for in-season updates @BeyondAgronomy

Now is the time to look for emergence patterns. Is residue management causing emergence delays? Is seeding depth highly variable? What is causing crop emergence variability?
Continue checking for wireworm damage and look out for cutworm and flea beetle damage as well. Look closer at fields that don’t seem to be advancing as fast as others.
Watch your overnight temperatures when spraying. To avoid crop damage do not spray herbicides when temperatures are dipping down to 5 degrees over night.
Do not spray ‘imi’ herbicides a like Odyssey, Viper or Solo (common active ingredient imazamox) during cold weather as their effectiveness is dramatically reduced.
Monitor volunteer canola in wheat and barley fields. It can get out of control fast with warm temperatures.
Be sure to measure plant stand densities during weed scouting this week. This will help you understand seedling mortality and help fine tune seeding rates next year. SL

Check problem fields now to control wild oats early

There were a few fields with patchy wild oat pressure in my travels last week and it prompted some spot spraying in a few areas. The wild oats were at the one-leaf stage, a perfect time to catch them before they start to rob yield. Leaving those areas for 10 days to reach the normal in-crop herbicide timing could have created a small disaster.

Research from Alberta Agriculture suggests that when wild oats exceed 20 plants per ft2, tillering in wheat can be reduced by 50%. Remember that tillers account for 50% of yield in spring wheat. Research by Arysta LifeScience pegs nitrogen loss at 1.2 lbs/ac when wild oats are at the 1-leaf stage. If you wait until the 6-leaf stage to control wild oats, you’re looking at a nitrogen loss of 16 lbs/ac in the affected areas.

There are several grassy herbicides on the market that can be used at the 1-leaf stage in wheat, barley, canola or peas.

Wheat- Axial, Achieve Liquid, Traxos, Horizon, Everest, Assert, Velocity, Varro
Barley- Axial, Achieve Liquid, Puma Advance, Assert
Peas and canola- Centurion, Poast Ultra, Assure II, Select

NOTE: Be sure that temperatures don’t fall below 5 degrees Celsius the night before spraying any herbicide to avoid crop injury. SL

In-crop spray temperature recommendation

As we transition from pre-seed burn off to in-crop spraying, consider the following recommended temperatures:

Optimal temperatures for most herbicides are overnight temperatures of +5 C or greater and at time of application of +10 C or greater (the 5-10 rule).
Keep in mind the overnight temperatures apply to before spraying application and after spraying application.
The +5 C or greater overnight temperature and +10 C or greater at application represents the ideal temperatures for best results. One should avoid spraying when overnight temperatures are below +3 C and application temperatures are below +8 C.
If a frost event occurs, wait 2-3 days or more of frost free nights before spraying.

The minimum temperature for biological activity to occur (actively growing plant) is +5 C or greater overnight. Weeds need to be actively growing so that they are susceptible to the herbicide and the crop needs to be actively growing so that it can metabolize the herbicide to prevent injury.

Source: Dow AgroSciences

Liquid Avadex (triallate) is in

Success in 2013

One of the wild oat management strategies we’ve been toying with this spring is liquid Avadex. We’ve been using granular applications in the fall for several years but it takes logistics, the right weather for heavy harrowing and can be pricey when you add in custom application. Adding liquid Avadex to your pre or post seed burn-off is a really simple, cost effective option that works surprisingly well in a no-till system.

My partner in crime, Daryl Chubb, sent me these photos of wild oats showing Group 8 symptoms today after an application of Liquid Avadex 17 days ago. The patches of wild oats are stunted, yellow, have pinched stems and are starting to swell around the roots. In this case, the field did have a late fall application of NH3 to expose soil. Here are the details:

NH3 applied fall 2012
Planted AC Harvest on May 2nd
Applied ½ L/ac REL Glyphosate, 40 ml/ac florasulam, 1 L/ac Liquid Avadex
Organic matter 3-4%

If you are battling wild oats, I strongly suggest you look at adding Liquid Avadex to your program. Relying on Group 1’s and 2’s to control wild oats is a dead end road.

Here’s what you need to know to make Liquid Avadex work properly

Apply as a post-seed burn down with glyphosate only if the seedbed is left with a great deal of soil exposed. Excellent on canola or pea stubble.
Liquid Avadex must contact soil in order to activate. Lumps or clods of trash or uneven residue cover can leave strips of uncontrolled wild oats.
Increase water volumes to 7.5 gal/ac to ensure better soil coverage.
Apply at 1.2 L/ac in soils with over 4% organic matter.
Apply at 1.0 L/ac in soils with less than 4% organic matter.

If you have fields that you typically spray twice for wild oats, Liquid Avadex is great at controlling the first flush. At $13.20 ac for a 1 L/ac application, you could give your crop the time it needs to establish without being robbed of nitrogen and moisture from heavy wild oat patches. SL

Pictured above: Wild oat seedlings buckle after liquid Avadex treatment 17 days ago. Photo source: Daryl Chubb

Inter-row seeding successfully using the ‘nudge’

Lessons learned

Inter-row seeding is now all the rage with producers trying to figure out how to make it work properly. Many are frustrated they cannot inter-row successfully even though they have RTK or seed in the same direction. There is one major aspect to consider when using the nudge method.

The key to inter-rowing successfully by simply nudging side to side each year is to keep track of the direction of travel down each swath. For example, if you’re heading north down swath #20 (even) and south down swath #21 (odd) you must record that for each field. Each time you travel north you must be on an even numbered swath and the opposite or odd when going south. The reason is due to the unequal shank spacing on across each drill. Most have a shank offset in the middle and space shanks accordingly out to the wing.

When you travel the opposite direction the following year even though you nudged a few inches, you may have shanks plowing into last years row. In a way, the drill has a natural offset in the shanks. If the offset in shank spacing is a few inches to the right and you shift a few inches to the left the next year and seed in the opposite direction, you’ll end up plowing right through last year’s stubble.

Inter-row seeding is a simple concept but can be a challenge to implement. If you own John Deere or CNH drills, you can pull swath number and travel direction from the monitors. Bourgault, not so much. Write down those travel directions and keep them in the cab for next year. You’ll avoid some serious frustration! SL

Photo source: Steve Larocque