May 23, 2012

Agronomists Notes

Hello Reader,

We had another excellent week of weather allowing most producers to wrap up in the next day or two. I’d say we are 95% complete seeding and late-April seeded crops are well on their way. In-crop herbicide will begin the end of this week with peas and into next week with early seeded cereal crops.

On this insect and disease front all is calm for now but I’ll continue to monitor progress. Soils have been warm and moist which has some crop germinating within 24 hours of planting. Our wheat is 1-leaf and was planted 11 days ago and peas are emerged to 1 node after 14 days in the ground so progressing quickly.

This week we’ll start with a handy graminicide tank mix guide to help with herbicide tank mixing. Next, I’ve jotted down some notes to help you maximize the performance of some common herbicides. I’ve also included a little ditty on controlling wild oats early as well as my perspective on the packing systems of today’s precision air drills. I've also included a reminder about temperatures duing spraying. If you've been following the Monosem vacuum planter topic we have an update from a producer doing trials with one this spring.

Have a great week.

Picture: Wheat on canola stubble at three-leaf stage, near Morrin, AB.

Crop Staging

(Calgary to Drumheller to Three Hills)

Seeded    Apr 24-30        May 1-7        May 8-15
Wheat      early 3-leaf     2-leaf            1-leaf emerging
Canola     2-leaf              1-leaf             cotyledon emerging
Barley       early 3-leaf    2-leaf             1-leaf   emerging
Peas        3rd node        2nd node       1st node

Steve's tips and tricks 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

Graminicide Mixing Instructions

Quick Reference

Each year the list of wild oat herbicides gets longer and more difficult to know what order to mix each product. With that, I’ve compiled a list you can print off and keep in the water truck or sprayer to help you mix perfect cocktails this spring.

Graminicides tank mix guide

Tips on maximizing herbicide efficacy

Specifics not found on the labels

Group 1

Only 10 to 15% of Group 1 wild oat herbicides actually translocate within the plant. Most Group 1's rely on spray droplets to gravitate down the leaf to the growing point. That is one of the reasons water volumes are so important when dealing with heavy wild oat populations.

Liberty

The day after an application of Liberty is just as important as the application day. Warm and sunny weather the following day will dramatically improve control.
Spraying Liberty in the evening is fine so long as the temperature is warm enough during application and the following day is sunny and warm. Cloudy conditions following application reduces efficacy.
Be sure its 15 to 20 degrees Celsius with moderate sunshine. If the temperatures below 15 degrees and cloudy, Liberty will not work well.

Centurion

If you have more than 300 ppm of bicarbonates, add ammonium sulphate AMS at 1% v/v (1 litre AMS per 100 litres) to improve grassy weed control.

Assure II

If you’re struggling with foxtail barley or volunteer barley in your Liberty Link canola, Assure II is an excellent choice to add to Liberty. Apply 0.2 L/ac of Assure II for foxtail barley control or 0.15 L/ac for volunteer barley. Apply at temps above 8C.

Infinity

If you add AMS, you will get improved Canada thistle suppression, cleaver and kochia control. With the AMS added 6” tall kochia can be knocked down.
Infinity has three systemic modes of action with the Group 27 pyrasulfotole and one contact mode of action with the Group 6. This herbicide offers very little Group 1 wild oat antagonism.

Achieve Liquid

If you have bicarbonate levels above 400 ppm, add ammonium sulphate AMS at 0.5% v/v (0.5 litre AMS per 100 litres) to improve grassy wild oat and green foxtail control.
Non-tillered crops can be injured by Achieve Liquid if an application is followed by or prior to 5 degree Celsius air temperatures.
Tillered cereal crops can be injured if sprayed within 48 hours of freezing temperatures.

Avenge

This Group 8 wild oat herbicide has no activity on one or two leaf wild oats. The wild oats must be in the 3 to 5 leaf stage before Avenge will work effectively. Go figure!

Tank mixing fungicides

Do not tank mix fungicides containing strobilurin (Group 11) with herbicides unless registered. For example, a half rate of Stratego which contains trifloxystrobin combined with Inifinty herbicide can cause severe leaf burn. Check labels first! 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 plants 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 your 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

ConservaPak has it right for on-row packing

When it comes to packing systems on precision air drills like the Morris Contour, Bourgault PHD, JD 1870 CPak, CNH 800/ 2070, SeedMaster and SeedHawk there is one that stands out among its peers. The precision drill I’m speaking of is the JD 1870 Conserva Pak.

There are two significant issues when it comes to packer placement in todays precision air hoe drills. First, the distance between the seed shank and the packer wheel are sometimes too far apart. If the distance between the opener and packer wheel is 8 inches or more, there is opportunity for residue to flow back into the furrow. This is an issue because the residue which flows back into the furrow is compressed by the packer which keeps the furrow cooler, longer and traps frost longer. Allowing residue to flow back on to the furrow also leads to seedling toxicity issues with finely cut residue. The goal of any packing system should be to loosen up the residue on the ground, push it to the side of the furrow and place the seed firmly into the side of the furrow. This reduces frost risk in the furrow, allows air flow to warm up soil and reduces toxicity issues from highly concentrated finely cut residue sitting above the seed as it tries to emerge.

The second biggest issue with packing systems is where the packer presses the seed into the furrow. A packer wheel that follows over top of the seed creates a zone of resistance above. This is definitely an issue with canola and if there is any amount of clay or wet soil above, the problem is amplified. The goal of any packing system is to provide seed to soil contact without creating resistance points above or below the seed.

Now, I’ve noticed that on 2012 SeedMaster and Seed Hawk systems the packer wheels were moved closer to the seed shank. Other manufacturers may have done so too. Unfortunately, all but one packing system addresses the issues mentioned above and that’s the JD 1870 Conserva Pak. The packer wheel is just a short 7 inches from the seed shank which blocks most residue from falling back into the furrow. The packing wheel also presses seed into the side of the furrow which eliminates resistance points above and below the seed. The other precision drills on the market pack overtop of the seed which creates unnecessary stress, especialy in wet soil.

In the end, there is no perfect air drill. Dual shank machines like the Conserva Pak are not the pat answer for every farm. However, if the rest of the precision drills on the market could develop a packing system like the JD 1870, you’d have some serious competition in this space. I encourage you to look at your field finish and residue in the furrow and take a critical look at emergence rates behind the precision drills you pay a premium for. If they don't measure up, well, squeaky wheels get the grease. Let the manufacturer know. SL

Photo: The Conserva Pak shank has superior on-row packing in my opinion.

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”.

• Please 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

The Monosem vacuum planter experiment in canola

Producer Craig Shaw, who farms at Lacombe and Dr. Neil Harker from Lacombe Research Station are testing the use of a Monosem vacuum planter to seed canola this year. If you want accurate seed depth and seed spacing in the furrow then a vacuum planter is what you need. Up until now there has been no research on the use of vacuum planters in canola in Western Canada. I believe a combined one pass direct seeding system that involves vacuum planter technology is the future and will allow us to decrease seedling mortality and improve maturity and yield.

The following is Craig’s experience this spring with the Monosem vacuum planter in his own words.

Field scale trials will be used to compare 12, 18 and 24-inch row spacing. There will also be seeding rate comparisons at 2.5 lbs/ac versus 3.5 lbs/ac. There was also a seeding speed trial comparing 5mph versus 7.5mph.

Notes
The 12-inch row spacing makes the planter boxes tight side by side and that makes it more difficult to work on each unit. This is more of a problem in our situation where we were changing seed plates, locking out row units etc. The units have multiple adjustment, packing pressure, seed rate, vacuum pressure, striker plate adjustment, but it’s quite simple and straight forward to visually see what adjustments do to the planter. The inspection door allows you to see the seeds stuck on the holes on the plate and allows for adjustment to eliminate blanks and doubles.

The Monosem seems to have some latitude on settings (don’t need to be exact to get good results). A little seed in each box seems to go a long way and so with trial plots you don’t want to put too much in each box. Clean out is a bit of a pain and while there is a clean out door on each unit we found it best to use a shop vac to suck most out of the boxes first. Plate change is pretty straight forward although the knock off mechanism was a little tough to get off. We filed some of the holes and that should help. Closing of individual row units was straight forward and you can lock out by pulling pin on sprocket, shutoff vacuum to each unit and also lock unit out of ground.

Thoughts from the plots
Seed plates- from what we had heard we assumed more holes in the plate were better. That is not necessarily correct. You need to match plates to row spacing and intended seeding rates. The wider the row spacing the closer the seeds are in the row and then seed plates with more holes makes sense. On our 12-inch spacing a 120 hole plate max’s out at 1.8 inches between seeds and that gives you a higher seeding rate than you may want to run. The 72 hole plate with our current sprockets would only come down to about 2.5 lbs per acre.

Seed size
The original thought was that we wanted large seed size as it was insurance with low seeding rates and experience had suggested the planters worked better with bigger seed. The problem is that larger seed brings up your seeding rates (lbs per acre). In other words it costs more to maintain seed populations. After my short experience with the Monosem I am thinking that we need to go the other way a little bit. I am quite comfortable that the planter can easily handle all seed sizes. While larger seed may have a benefit with seed placement (depth) is an issue, when you can fine tune all seeds at a shallow depth then vigour maybe less of an issue. Just a note, our InVigour seed lot was 5.52 grams per thousand.

Seeding speed
With the Monoshox suspension system on the Monosem, I would be comfortable suggesting we could be seeding up to that 7 mph range.

Seed placement
The Monosem will give you the most uniform seed placement likely you will find. We were set at about ¾ inch and that’s where the seeds were. One issue we did see was behind the tractor tires and with our lighter sandy soil we were seeing seeds exposed in the lug imprints. We did discover one issue with the packing system and Monosem is going to rectify. With the narrow row spacing, they elected to go with more upright packers which meant there is a wider space between the packers than normal. In our sandy conditions if we pushed packing pressure to hard there was a tendency to actually push seeds up as the force was more beside the seed than over top. By moving the packers a little closer to the row we should help do and better job closing the furrow and allowing more lee way in packing pressure.

Seed singulation
With our light soils we did have some problems finding seeds in the row. You can tie the packer assembly up on a unit and in normal conditions that will keep the furrow open and then should be better able to see seeds in the row. For the most part we think it is doing a very good job and we will see with emergence.

Project
I think we have a huge capacity to increase our knowledge base on both the planter and canola. Kudos to Steve Larocque for getting us thinking about planters as an option. I’m hoping after the research station is done we can do a few more trials on the site we had originally intended to go on. If there is anything else we should include let me know. Hopefully we can all learn. Craig Shaw, Lacombe

Pictured above: Monosem built for plot work.