June 26, 2012

Agronomists Notes

Hello Reader,

Crops are coming along nicely with more rainfall last week and 20C+ temperatures. Late-April wheat is now full flag leaf with some heading out as well as barley. Peas are just coming into flower and canola is bolting. The early seeded crops are well on their way and for the most part look fantastic.

I am finding issues with weed control on crops sprayed during the first week of June. I’ve found escape issues on wild oats and even some broadleaves, especially with the Group 2 wild oat products. So if you sprayed during that cool, wet weather in early June, best go check the fields to see what may be lurking under the canopy.

Reports of stripe rust moving north are more common so be ready to apply fungicide soon. There is no sign of canola insect pressure so far but canola is just starting to bolt so we’ll keep an eye out for cabbage seedpod weevil and diamondback moth.

This week we’ll look at some 24-inch wide row spacing trials in canola. Next, some quick tips on stripe rust and fungicide use. I’ll give some brief tips on what to expect if you get hail on canola and some tips on controlling flushing weeds and escapes at flag leaf in wheat and barley. Last, a brief overview of cabbage seedpod weevil thresholds and ID and some great tips on applying fungicides. We’ll end with technical grain market news.

Have a great week.

Crop Staging

(Calgary to Drumheller to Three Hills)

Seeded    Apr 24-30         May 1-7             May 8-15
Wheat      flag leaf           1st node             6 leaf 2 tiller
Canola     5% bloom         bolting               bud stage
Barley      flag leaf            2nd node           6 leaf 2 tiller
Peas        1% bloom        12th node          10th node

Steve's tips and tricks for the week

Follow me on Twitter for in-season updates @BeyondAgronomy

Stripe rust reports have been more frequent in our area. Try to allow all flag leaves to emerge before you spray fungicide if possible.
Be sure to do your post-herbicide spray checks to make sure products worked well. If herbicides didn’t perform, you have time to re-spray and correct the issue before it’s too late.
Start sweeping early flowering canola for cabbage seedpod weevils.
Continue timing flag leaf emergence in wheat and barley to properly time fungicides.
Look for late flushing weeds in cereal crops and peas.

Wide row canola seeding trials showing promise

Producers everywhere are trying to push canola yields by developing agronomic systems that produce greater yields with ideally lower costs. We’ve focused on the use of vacuum planters to help provide accurate seed placement while dropping seeding rates in previous issues of Beyond Agronomy News. Some producers are thinking row-spacing could be part of the package and Justin Nanninga from Barrhead is one of those guys giving it a shot. Justin is in his second year of trialing 24-inch versus 12-inch row spacing using a John Deere 1870 Conserva Pak.

This year Justin applied 1.5 lbs/ac of Liberty Link 5440 with a tkw of 5.13 and 98% germ. As you can see by the photos, the establishment is excellent even at 1.5 lbs of seed. He managed to achieve 9 plants per ft of row which equates to 4.5 plants per ft2.

To achieve 24-inch spacing on the Conserva Pak, every second run on the distributor was blocked with a shop towel. Shut off valves were installed on the NH3 and liquid starter lines and hooks were built to keep the fertilizer knives out of the ground. Lastly, lock out bolts were used to hold the seed boots out of the ground.

The goal of using wider row spacing is to achieve maximum solar capture, reduce disease pressure, and generate higher yields with less seed. Between precision drills like the JD Conserva Pak and vacuum planters, I know many producers will find the right row spacing to fit their farming system.

We don’t have to do Steve’s quick math to realize that saving $30.00 an acre on seed while achieving the same plant densities as those who spent $50.00 acre is phenomenal. The next step for Justin will be to tweak the air system on the drill to improve the spacing of each seed within the furrow. Thanks, Justin, for sharing the progress. SL

Pictured above: 24-inch canola rowsat 1.5lbs/ac seeding rate are looking awesome, near Barrhead, AB. Photos: J. Nanninga

The quick facts on stripe rust and fungicides

There have been reports of stripe rust showing up in our area lately which is once again earlier than normal. Those who sprayed a fungicide last year enjoyed an 8-15 bu/ac response from adequate leaf disease protection. This year more producers are on alert asking questions so I thought I’d give you a quick update on stripe rust and fungicide applications:

With ground application, the boom must be high enough so that the spray fans overlap on the uppermost leaves.
Choose a speed and pessure that provides you with a medium droplet size to ensure they penetrate the crop canopy.
Fungicides will only move from the droplet on the leaf surface towards the leaf tips, they do not move from lower leaves to upper leaves or the head.
Try to allow the majority of flag leaves to emerge. Portions of leaves, whole leaves and heads that develop after spraying will not be protected.
Tilt (propiconazole) moves towards the leaf tips quickly so the concentration drops and stops protecting after about 3 weeks.
Folicur (tebuconazole) and Prosaro (tebuconazole + prothioconazole) move more slowly toward the leaf tip and give 4 weeks protection.
The strobi portion of Quilt (azoxystrobin + propiconazole) is more immobile in the plant and can give up to 5 weeks protection.
Triazoles (Folicur, Twinline, Prosaro) are the only products that can cure an early infection of stripe rust (less than 7 days old).
If you have stripe rust already, a triazole is preferable because of its curative properties. Again, so long as the infection is less than 7 days old.
A stripe rust infection can restart once the fungicide applied breaks down. This is called ‘kick back’.
Fungicides containing strobi’s ( Quilt, Twinline, Headline, Stratego) can only be applied up to heads half emerged versus triazoles (Folicur, Prosaro) which can be applied from flag and up through flowering.
Once the effectiveness of the fungicides declines after 3 to 5 weeks depending on the product, stripe rust will start developing again from the ends of old stripes and from new infections. A second application of fungicide may then be needed. SL

Reference: NSW DPI

Hail damage in canola

What have you lost?

Yield loss in canola is always difficult to estimate when hail hits during flowering, especially when you're trying to come up with a fair estimate with the hail adjuster. Here are some facts to give you an idea of what to expect for crop loss after hail:

Any leaf area destroyed will result in yield loss.
Seed yield losses in canola are approximately 25% of leaf area lost. If leaf defoliation is 50%, then yield loss would be approximately 12.5%.
Seed yield loss will depend on both percent leaves and branches lost. For example, if canola has 60% lost branches 7 days into flowering, seed yield loss is estimated at 18%, whereas 21 days into flowering, yield loss would be an estimated 60%.
If hail strikes late, such as during pod filling or ripening, plant recovery is not possible. The time needed to develop new growth, flowers and mature is limited before a killing frost.
If injury occurs at the ripening stage then it depends directly on the loss of branches, individual pods and seed knocked out of pods. Severe hail losses have occurred in canola swaths.

Source: Canola Council of Canada

Tips and tricks for controlling weeds at flag leaf

As part of my field scouting package, I scout fields roughly 10-14 days after herbicide application. In some cases the herbicide didn’t work as it should or a hidden flush of weeds emerged after spraying. For some fields this means an herbicide application is necessary but the crop is hitting flag leaf. Here are some products I use as a rescue treatment or to control late flushing weeds at flag leaf timing:

Trophy at ¾ rate: (fluroxypyr + MCPA Ester) I’ve used this to control wild buckwheat, kochia, cleavers and annual sowthistle, sometimes combined with fungicides. If cleavers are larger than 4 whorl, go full rate. If you are only targeting cleavers then just go with straight fluroxypyr. The fluroxypyr is fantastic on cleavers but not as good on volunteer canola bigger than 4 leaves.
Express SG at 4-6 grams/ac: (tribenuron-methyl) Controls volunteer canola, annual sowthistle, narrowleaf hawksbeard, wild buckwheat and small dandelions.
Buctril M at ¾ rate: (bromoxynil + MCPA Ester) Excellent on annual sowthistle and wild buckwheat but not as great on larger volunteer canola.
Momentum at ¾ rate: (fluroxypyr + cloypyralid) This combination is only sold by Viterra and is a fantastic brew for late flushing wild buckwheat, annual sowthistle and cleavers. It won’t do a thing for volunteer canola but it will hammer Canada thistle, Perennial sowthistle, stork’s bill and scentless chamomile. If targeting scentless chamomile, then be sure to add at least 5 oz of MCPA.
Ally at 1 ½ grams/ac: (metsulfuron-methyl) This option will provide control of the same target weeds as Express SG but it also gets suppression of stork’s bill and scentless chamomile. Wach for recropping restrictions if canola is followed the next year.

Cabbage Seedpod Weevil

The majority of canola is starting to bolt with the early seeded canola now at 5% bloom. This is the time to begin scouting for cabbage seedpod weevils. The adult weevils are an ashy, charcoal gray colour approximately 3 mm long with a pronounced snout. The adults feed on buds, flowers, stems and pods. The adult weevils lay their eggs inside developing pods where the eggs hatch and larvae begin to feed on the seeds. Each larva can consume up to 5 seeds during its development, which can equate to a 15-20 % yield loss. The tiny exit holes left in the pods after the weevils emerge cause early shattering and provide an entry point for disease.

The threshold for cabbage seedpod weevil is 3 to 4 weevils per sweep. The proper technique to sweep for weevils is to do ten 180-degree sweeps in ten locations. Be sure to move away from the headlands and pick areas that are representative of the field. Weevils are typically higher in number along field edges. Sweeping should take place from bud stage through flowering. The best time to apply an insecticide is the 10-20 % bloom stage if possible to avoid harming the beneficial insects in canola.

Source: Alberta Agriculture

Photo source: Canola Council of Canada

Top 10 tips for fungicide application

In order to get the volume, method and speed of fungicide application right to get the most out of each spray application, here are some simple guidelines:

Have an understanding of how the fungicide you’re going to apply works on the plant. Most fungicides have limited translocation potential or move upwards and outwards only, meaning sprayers need to target the spray to hit the plant exactly where it’s needed. If the source of the infection is lower in the plant, more water may be required if the product has curative properties.
Ensure adequate volume (e.g. 7.5-10 US/gallons per acre for cereals and 10-15 gallons/US acre for pulses).
Try to limit application speeds to less than 12mph— any faster and chances most of the droplets will hit only one side of the plant.
Select a nozzle to give medium spray quality. Fine droplets won’t penetrate dense crop canopies and coarse ones may not give enough retention on waxy surfaces or when using an oil-based wetter.
Select nozzle sizes and volumes that will run the nozzle with adequate pressure (e.g. more than 35 psi for fan type and low drift and more than 50 psi for low-pressure air induction) and don’t use air induction with oil-based products.
Consider using narrower nozzle spacing such as 10 inches if you can. For those on wider spacing (e.g. 20 inch) twin jets or twin caps may improve coverage but should only be used at ground speeds of up to 10 mph.
Use the minimum hold setting on the controller to ensure you don’t lose pressure and under-dose or increase droplet size when you slow down at the end of rows.
Run the controller with total flow (gallons per minute for the whole boom) on the display when spraying and know what the pressure and flow rate should be when delivering the correct number of gallons per acre so that checks can be made as you go. For example, if pressure increases and flow remains the same, check for blockages. If flow increases or pressure drops check for leaks, if flow reduces and pressure stays the same, check that all sections are engaged.
Wind speeds should always be above 3-4 km/h and less than 20 km/h for in-crop spraying unless the label specifies otherwise.

These tips were taken from trusted consultant Bill Gordon from NSW, Australia in a GRDC news update.