Agronomist Notes

I made a snide comment last week about the three days of heat we had all summer and now I’m eating my words. The 300C degree heat has turned on over the last four days and may continue until Wednesday. This heat will definitely reduce some yield potential on the late seeded crops, but in the end, it will speed up maturity. At this point, I’ll take the maturity. 

I had a young farmer from Hussar named Owen join me last week to give me a hand checking canola. While sweeping for insects we noticed an Invigor 8440 canola plant with a main stem holding 67 pods! There aren’t many 60 bushel canola crops out there but this is one in the making as you can see from the photo. 

Producers in the area have begun swathing canola lately. I’ve actually recommended a few producers stop to let the heat wave pass by. I suspect a lot of canola acres start to get cut down by the end of the week. The winter wheat looks just about ready and pea harvest is just under way and yields look to be excellent.

On the insect front, this will be my last week of sweeping as the majority of the fields are ready for swathing in short time. Lygus bug levels have stabilized and 90% of the fields I manage have not reached threshold. Diamondback moths and Bertha Armyworms have stayed away thus far, though bird damage has occurred in some places.  As for disease pressure, you should start to see signs of sclerotinia if the disease is present.

In this newsletter, we’ll touch on some important considerations when assessing the risk of lygus bug damage close to swathing.  We’ll also discuss canola swath timing and the effect of high temperatures during and right after swathing and finish up with international crop weather news.

Crop Staging Area (Calgary to Drumheller to Three Hills)

Date Seeded:     April 23-31          May 1-7                 May 8-15
Wheat                Hard dough          Medium dough      Medium dough
Canola                Maturing              Maturing               Late-pod
Barley                 Hard dough          Medium dough      Medium dough
Peas                   Ripe                   Ripening               Late-pod

This Week in Scouting

Start swath timing in canola.
Decide which canola fields are candidates for straight cutting.
Line up cereal fields for pre-harvest glyphosate.
Continue scouting for lygus bugs, diamondback moths and bertha armyworms.

Agronomy

Lygus bug assessments
Many canola fields are roughly two weeks away from swathing and lygus bug counts have climbed into the 4 to 6 per sweep range or higher in some fields. The decision to control lygus becomes cloudier the closer we get to swathing. With that, I’ve put together a few points to help you make the decision of whether or not to spray.

First: Identify the maturity of the lygus bugs. If you’re two weeks away from swathing, you should be most concerned with the number of fifth instar and adult lygus bugs, shown in the picture above. I’m not concerned with the young lygus bugs because the seeds will firm up before they can do any harm. During your next scout, count the number of fifth instar and adult lygus bugs there are per sweep. If you count more than 3 to 4 mature lygus bugs per sweep then move on to the second step. Remember, the pre-harvest interval for insecticide is 7 days.

Second: Identify the firmness in the seeds. Lygus bugs have piercing sucking mouth parts, but they cannot pierce through firm seeds or pods. Select a few plants at each stop and open up the pods to see how firm the seeds are inside. Then, estimate the percentage of watery or translucent seeds in the plant.

Last: If the mature lygus bug counts have reached  3 to 4 per sweep, not including young lygus bugs and more than 1/3 of the seeds in the pods are watery or translucent, then control is necessary. Reversely, if more than 2/3 of the seeds are firm and the threshold level has just been reached, you’re likely out of the danger zone and don’t need to spray. It’s such a specific judgment call so I wish you the best.

Just to point out why we’re chasing lygus bugs, they will typically damage 7% of the seed at the 3 to 4 per sweep threshold. That’s 2 bushels damage on a 30 bushel crop, 2.8 bushels on a 40 bushel crop and 3.5 bushels on a 50 bushel crop. Under heavy infestations, yield loss estimates have been as high as 40%. SL

Source: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex741?opendocument

Reconsider swathing canola during hot weather
I’ve received a few calls on swathing canola during hot weather. In the end, my recommendation was to shut down and let this hot weather pass and perhaps start cutting Tuesday night. It looks like cooler weather is forecasted for the end of the week. Swathing during hot weather can force the crop to dry down to quickly and destroy precious chlorophyll clearing enzymes.

The enzymes that clear chlorophyll from the seed stop functioning at a moisture content of 20% or less. If canola is swathed during hot, windy weather that rapidly dries the immature seed to less than 20% moisture, the green color will not clear. Rainfall and rewetting in the swath may reactivate these enzymes but this cannot be counted on or results may be inconsistent. In hot weather the optimal time to swath may be at 50 – 60% seed color change on the whole plant to minimize the risk of fixing green seed.
Source: Alberta Agriculture

Choosing the optimum swath timing in canola
The optimum stage to swath for both yield and quality is up to 60% seed colour change. This enables many growers to start swathing at 30% to 40% seed colour change without sacrificing significant yield or quality. It widens the swathing window for all growers, including those with large canola acreages.

Canola should be swathed when the average seed moisture content is 30-35% which corresponds to 30-60% of seeds will have some color change. Swathing decisions should be based on observations of seed color change on the plant’s main stem. At the optimal time for swathing, seed in the middle third of the main stem will have at least some color change, the most mature seed in the bottom third of the stem will have complete color change, and the seed in top pods will be green but firm and not squish when rolled between fingers.
Source: Canola council of Canada

Growing winter wheat as a reclamation tool
Winter wheat has grown in popularity over the last two years, sometimes being sown into fallow areas that were too wet to seed in the spring. Those of you looking to do something with your lighter, less productive ground may want to give winter wheat a try. I’ve found winter wheat to be the best reclamation tool on sandy ground, low in organic matter. The root mass and straw production increases dramatically over spring seeded cereals and the yield bump is worth the effort. 

Back in 2005, I took on a sandy field that was just a mat of kochia and flixweed and grew only 9 bushels of wheat in 2004, a wet year! For the first time in my life, I recommended chem fallowing this field to clean up the weedy mess in 2006. That fall we planted winter wheat and thankfully the kochia and flixweed carcasses were tall enough to catch the snow. In 2007, we harvested a 65 bushel crop of winter wheat on that sandy light land and noticed a marked improvement in soil structure. I was also impressed with the amount of residue we were leaving on the field. In fact, I was so impressed I threw logic out the window and planted the field to winter wheat again.

Today, the crop looks healthy, although yield may have dropped a touch. The volunteer wheat was a little over my tolerance level but I’ve accepted it, knowing that we’re improving soil structure and organic matter. I’m almost tempted to plant canola in this field next year. We’ll see.

If you are thinking of growing winter wheat, now is the time to get things ready before harvest is in full swing. Below is a list of the top ten tips for growing winter wheat successfully.

Ten Tips for Successful Winter Wheat Production

1. A pre-seed burn off may be required to keep weed competition minimal during early establishment of winter wheat.
2. Leave as much standing stubble as possible. Set the swather as high as possible.
3. Direct seed into standing stubble. Best results have been obtained when winter cereals are direct seeded into the standing stubble of an early maturing crop such as early seeded barley or canola.
4. Seed winter wheat between Aug 22 and September 15. Earlier seeding within this window has given most consistent results.
5. Seeding rates should be targeted to achieving fall winter wheat populations of 30 plants per square foot. Generally, seeding rates of 1.5 to 2.5 bushels per acre of a recommended variety should accomplish this goal.
6. Seed shallow (less than 2 cm or 1 inch) with on row packing to ensure good seed to soil contact.
7. Apply phosphorous fertilizer with the seed and nitrogen away from the seed.
8. You can apply all the required nitrogen in one pass in the fall. However, in higher moisture areas you may want to split apply nitrogen to reduce lodging.
9. Assess need for winter annual weed control in late September to early October. An application of 2, 4-D or MCPA is the best option to combat winter annual weeds.
10. In the spring, when you assess the winter wheat, the plants may look as if all the leaves and roots are dead. This appearance does not mean the plants cannot recover. Dig up a few plants in the early spring, take them into the house and try to grow them for 7 to 10 days. If new roots develop, the plants are alive.

Source: http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/agdex94
Source: http://www.wintercereals.ca/tools/index.html

Market News

Update on International Urea Prices
Latest indications from China are that the State Council could approve the proposal to raise export taxes on urea as early as August 20th. Whether this happens or not, traders are very cautious about buying any more Chinese urea and exports are likely to be minimal for the balance of the year. In the absence of Chinese urea, the world market is short of urea and the current slight correction in price is unlikely to endure. In the US, granular barges have traded at $765-770/short ton FOB Nola for second half August loading. That works back to a delivered price to Alberta of roughly $935 a metric tonne. 
Source: http://www.fertilizerworks.net/

International Crop Weather News
United States: In the West, dry weather prevails, except for scattered showers in southern and eastern New Mexico. Fieldwork, including Northwestern small grain harvesting, is proceeding with few delays. On the Plains, scattered showers sweeping across Montana and the Dakotas are easing drought but causing brief small grain harvest delays. Elsewhere, the central Plains are getting a break from recent downpours, while heavy showers and thunderstorms on the southern Plains are slowing fieldwork but aiding drought-stressed pastures and immature summer crops. In the Corn Belt, mild, dry weather remains nearly ideal for reproductive to filling summer crops. In the South, locally heavy showers and thunderstorms are spreading eastward. Rain is arriving too late for drought-stressed corn, but remains favorable for pastures and immature summer crops.

Europe: Drier than normal weather persists in northeastern Europe, reducing soil moisture for filling spring grains and vegetative to reproductive summer crops. Showers slow small grain harvesting in England, France, and Germany. However, the wet weather maintains favorable soil moisture supplies for filling summer crops.

Former Soviet Union: In western Ukraine, dry weather follows in the wake of last week’s heavy rainfall, allowing flood waters to recede and improving conditions for small grain harvesting. In eastern Ukraine and southern Russia, showers and cooler weather improve growing conditions for summer crops in the reproductive to filling stages of development. In major spring wheat producing areas, showers accompany a cooling trend in the Urals District in Russia and north-central Kazakhstan, while hot, dry weather stresses filling crops in Siberia, Russia.

East Asia: Dry weather reduces soil moisture for reproductive corn and soybeans in western Heilonjiang.

Southeast Asia: Seasonal showers bring favorable moisture to corn in Thailand. Tropical showers cause flooding in the northern Philippines, likely necessitating some replanting of corn.

South Asia: Heavy rain in central and western India boosts soil moisture for cotton, soybeans, and groundnuts. Showers reach southern Pakistan more than a month later than normal, easing irrigation requirements for cotton and rice but likely arriving too late for rain-fed summer crops.

Australia: In Western Australia, soaking rain sustains favorable growing conditions for winter wheat and barley. Elsewhere in the Australia wheat belt, scattered showers continue to benefit vegetative winter grains.

South America: Rain maintains generally favorable conditions for winter wheat in southern Brazil. Following last week’s rain, winter grain planting continues in Buenos Aires, Argentina’s largest producer of wheat. Drought-related planting delays continue, however, in Cordoba and Santa Fe.

Canada: Moderate to heavy rain increases moisture for spring grains and oilseeds in many previously dry locations of the northern and eastern Prairies.

Mexico: Summer showers boost moisture for corn and other rain-fed summer crops after a brief drying trend.