July 23, 2013

Agronomist Notes

Hello Reader

Cooler temperatures coupled with rain and hail dominated the week. We’re now topping 12 inches of rain at the farm; most areas have had over 10 inches since mid-May. Fungicides have been applied across the board and for the first time in three months I think we can take a breather before insect sweeping begins.

Just a quick note on fertilizer- there have been a few quotes for urea floating around at $480 tonne paid now with delivery in August. Also, $500 urea paid September and delivered October.

This week we’ll look at applying urea on canola at early podding. Next, we’ll look at the idea of fortifying wheat with zinc at milky dough. We’ll follow with split applying fungicide in peas and some great reader comments on water volumes after last weeks article on spray myths. We’ll finish with technical grain market news.

Photo: Our Spray Coupe applying Folicur in wheat at flowering, near Michichi, AB. S. Larocque

Crop Staging

(Calgary to Drumheller to Three Hills)

Seeded May 1-7 May 8-15 May 15-22
Wheat Watery ripe Watery ripe Flowering
Canola Early pod 90% bloom 80% bloom
Barley Milky dough Watery ripe Heads emerged
Peas Early pod Late flower Mid flower

Steve's tips & tricks of the week

Follow me on Twitter for in-season updates @BeyondAgronomy

It’s time to start sweeping for lygus bugs in early seeded canola just coming out of bloom.
Check disease pressure in peas even if you applied a fungicide. Disease pressure can be high and a second app of fungicide may be warranted.
Wheat planted the last week of May could be susceptible to wheat midge damage. Check fields in the evenings to monitor midge levels.

Liquid urea at early pod stage in canola boosts yield

We’re coming to the end of flowering in canola and nearing an opportunity to add yield with foliar nitrogen. Producers in the UK apply liquid urea at the early pod stage to generate higher oil content and yield. The results have been mixed but in some cases they’ve found a 7 to 9 bu/ac yield increase from a 25 lb/N/ac application using liquid urea solution. I think a quick tissue test for nitrogen at the end of flowering could show you whether nitrogen is limiting in the plant. If there is adequate moisture in the soil profile, a liquid top dress of urea might be a new avenue to explore in our canola production systems.

The majority of producers are using liquid urea instead of liquid UAN (28-0-0) for its lower cost, increased uptake efficiency and reduction in leaf burn. That’s not to say that liquid urea doesn’t burn because it will under high light intensity or temperatures above 18 degrees C. The key to reducing scorch is water volume.

Here's a list of tips used by my UK friend Nick Ward to give you some ideas.

You can use any 46% urea and tip it into the water tank and circulate it using a pump. 'Distressed' urea is usually used (ie. sweepings out of a shed) as it is cheaper and doesn't need to have spreading quality.
We spray on 150-200 litres of 20% nitrogen solution per hectare at the end of flowering. (That works out to 25 lbs/N per 15-20 US gallons/ac.)
If temperatures are hot, apply in the evening. We don't dilute it, but if you were concerned about heat, dilute it with the same amount of water. I've applied the urea solution up to 23 degrees C and didn't have any problems with leaf burn.
20% is the max strength that you will get. I think granular urea may be the better option as prilled has an oily coating that leaves a film on the liquid.
For our main liquid fertilizer solutions we would use an ammonium nitrate/urea mix in solution to get the concentration up to 37%. But for this job a urea solution is a lot gentler and will cause way less scorch even in warmer conditions.

And I've added a couple of points of my own:

Add 3.6 lbs of urea per gallon of water to give you 25 lbs/N per acre and apply solution at 15 gal/ac.
You can delay maturity with a late season nitrogen application so those who've finished flowering by late July, early August might be able to afford a slight delay in maturity.

Steve's quick math
Let's see what this nitrogen boost could pay back.

25 lbs/ac × $0.69 lb/N: $17.25 ac + $3.50 application = $20.75/ac
50 bu/ac canola yield × 8% × $12.00 bu = $48.00/ac
ROI: 2.3 to1

In theory, if we were to see the same response as some have in the UK, the additional $20.75 ac investment in top dress nitrogen may net you a 230% return on your investment. I believe there is value in spreading out your nitrogen applications in canola and this might be a way to generate better nitrogen use efficiency rather than applying all of our nitrogen up front which by now is almost 90 days ago. Even a 5% yield increase at today's prices makes this option viable. SL

Fortifying wheat with zinc

Is it relevant in Western Canada?

There is a project called HarvestZinc aimed at reducing zinc deficiency in cereals globally. The Bill & Melinda Gates foundation along with private companies like Omex, ATP Nutrition, Bayer Crop Science and a few others sponsor it. The project aims to reduce zinc deficiency in wheat and rice as it relates to malnutrition worldwide. I see three opportunities from results so far: 1) zinc content can be increased in wheat seed almost three-fold through late season foliar applications, 2) Western Canada has zinc deficient soils, and 3) marketing opportunity may exist for the sale of wheat fortified with zinc.

Zinc deficiencies typically occur on soils with high pH (over 7), soils with high clay content, high soil phosphorus levels from manuring or heavy fertilizer applications, high iron and aluminum levels or high calcium carbonate levels. According to Alberta Ag research, soils with zinc levels between 0-0.5 ppm are considered deficient, 0.6-1.0ppm are marginal and soil with over 1.0ppm have adequate levels. That being said, zinc deficiencies could be induced by cool, wet conditions and after Group 1 herbicide applications. Signs of zinc deficiency in wheat are stunted plants, reduced leaf area, poor vigor and chlorotic lesions along the leaves (see photo).

Now, the agronomic benefits from wheat seed containing high zinc concentrations are increased seedling vigor, reduced mortality, improved disease resistance, greater stress tolerance and higher yields in zinc deficient soils. The best time to apply foliar zinc to increase zinc content in wheat seed is at milky dough stage, which is just around the corner in early-planted wheat. Studies suggest application rates of 2 to 9 lbs/ac of zinc sulphate (ZnSO4) as a foliar will help increase zinc content in seed. To increase yield in zinc deficient soils (<0.6ppm) applications of 9 to 90 lbs of granular zinc sulphate are used.

It is well documented that seeds containing high levels of zinc do show improvements in germination, vigour and stress tolerance over seeds with low zinc levels. There are numerous areas around Alberta and Western Canada that have high pH, heavy clay soils with zinc levels down around 0.5ppm, which is borderline deficient. Fortifying wheat or barley fields you plan to keep for seed with late season zinc applications may be a great way to produce high quality seed, especially when grown on soil with low zinc levels.

In a post-CWB open market there may be an opportunity to develop a market for zinc fortified wheat and barley. I understand that maltsters sometimes have to add zinc to improve the malting process. I think the concept warrants some further investigation. Cereals and breads marketed in the grocery store are fortified with zinc, iron, or Vitamin A. There is no reason we can't help produce a fortified wheat product and capture some of the value chain on farm.

In the end, if you farm in a region with low zinc levels or the conditions suitable for low zinc uptake, fortifying wheat you're keeping for seed might be a viable option to improve emergence, maturity, yield and stress tolerance. For the researchers and funding bodies out there, perhaps we can look at ways of value adding our cereal grains through nutrient fortification in-season. I think it's a really interesting concept worth exploring. SL

Source, Source

Photo Source: harvestzinc.org

Split applying fungicide in peas

As the season progresses and field peas finish blooming, it’s a good time to recheck disease pressure under the canopy, even if you’ve already sprayed a fungicide. I’ve seen a few heavy canopies with ascochyta/mychosperalla complex developing on leaves and stems due to the constant wet, humid conditions. This disease is well known for destroying stems at the soil surface and reducing yield and harvestability. The leaf lesions tend to spread on to the pods and rot seeds inside the pods. Yield losses can range from 5 to 15% when humid conditions continue throughout pod fill.

The products registered to protect against asco/mycho complex are Quilt (azoxystrobin + propiconazole), Headline (pyraclostrobin), Bravo 500 (chlorothalonil), Acapela (picoxystrobin), Priaxor DS (fluxapyroxad + pyclastrobin) and Quadris (azoxystrobin). Syngenta recommends an application of Quilt at 500 ml/ac under moderate-high disease pressure. Headline is registered at 160 ml ml/ac, Bravo at 1.2 L/ac and Acapela at 350 ml/ac. The products will run approximately $15.00/ac plus application.

When applying two fungicides in one season it’s good management to mix up fungicide groups. For that reason, if you applied a Group 11 (Strobi), which is contained in all but one fungicide I listed, try Bravo (a Group M) or Priaxor DS (Group 7 and 11).

If you consistently grow peas in your rotation and have been relying on one fungicide group I would take a second look at the disease pressure in your canopy. You may warrant a second fungicide application in this above average rainfall year. To give you some perspective let’s crunch the numbers beginning with one small seed.

Steve’s quick math
If you could save one seed on each plant on every acre, what would that add up to in the big picture?

10 plants ft2 x 43,560 ft2 = 435,600 plants/ac
435,600 plants x 1 seed/plant = 435,600 seeds
435,600 seeds x 0.23 grams/seed (230 g/tkw÷1000) = 100,188 grams
100,188 grams = 100 kg/ac or 220 lbs/ac
220 lbs/ac ÷ 60 lbs/bu = 3.67 bu/ac
3.67 bu/ac x $8.50 bu = $31.20/ac

In this example we have a $31.20/ac return on a $23.00/ac fungicide investment including $8.00/ac for application. If you have moderate disease pressure under the canopy, humid or wet conditions you could easily double the amount of seed lost to disease. If you have excellent yield potential in peas with 10 inches of rain or more and find moderate disease pressure under the canopy, a second fungicide will likely net you a handy return this year. SL

To read more on this disease visit .

Photo: Aschochyta/ mycosperalla complex is showing up on peas, even after fungicide treatment; canopy conditions are just right for disease. S. Larocque

Reader comments

re: Spray Myths by Tom Wolf

We do all our glyphosate work at 10 L/ha (2.65 US gal) total volume by air now and recently did some trials using glyphosate alone at 1 L/ac REL. The results were excellent- no drift as glyphosate is 30% heavier than water- and the only problem due to low drift was that we needed to narrow our swath. This was all done with Micronair's Micromax rotary atomizer at 200 micron.

I am planning on putting Micronair’s controlled droplet units on our boom, only about $5,000 USD for 27 meters, then we can start using 10 L/ha (2.65 gal/ac) by ground. For the same volume of spray, you get 8 times the number of 200 micron droplets. Coverage is not just about liters per hectare, it’s about droplets per hectare. To get serious drift you need to be getting sub 150 micron droplets. Flat fan nozzles usually put out some really big droplets >400 and some driftable and evaporatable fines. Average means very little with droplet size.

Application accuracy is the next frontier in precision ag. We are carting tonnes of water all over our fields with the resulting loss of massive efficiencies. Using supper low water volumes rates we can piggyback applications in one pass much earlier, like the side dress/ planting cover crop in one pass or fungicide/ side dress nitrogen.

I suggest that we all have a line in our mind with high water rates per ha. The system has grown up from "flat fan" thinking. Now all anyone can talk about is changing our droplet spectrum to throwing basketball-sized droplets so we don't get drift, whatever the cost in efficacy. It’s not the only way to control drift.
Stuart Barden, Athi River, Kenya