Beyond Agronomy News: August 19th, 2008

Agronomy

Crop Staging Area (Calgary to Drumheller to Three Hills)

This Week in Scouting

• Start swath timing 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.

Controlling late season lygus bugs a tough decision

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: Alberta Agriculture

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

Choose 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. SL



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

Source: wintercereals.ca

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: fertilizerworks.net

International Crop Weather News

• United States: On the Plains, the threat of heavy rain and flash flooding continues across the southern half of the region, including drought-affected areas from eastern Colorado and western Kansas southward into Texas. In the Corn Belt, warm, dry weather and generally adequate soil moisture reserves are maintaining nearly ideal growing conditions for the majority of summer crops. Dry weather elsewhere in the South favors fieldwork and crop development.
• Europe: Drier than normal weather persists in northeastern Germany and northwestern Poland, reducing soil moisture for filling spring grains and reproductive summer crops. Locally heavy showers slow small grain harvesting across the rest of northern Europe. However, the wet weather maintains favorable soil moisture supplies for reproductive to filling summer crops. Dry, warm weather in the Balkans causes some stress on reproductive corn and sunflowers.
• Former Soviet Union: Light showers cause only brief delays in small grain harvesting in Ukraine and most of western Russia. Additional rain would still benefit summer crops in the filling stage. Rain boosts soil moisture for filling spring wheat in the Urals District in Russia, while highly variable weather prevails over crop areas in Kazakhstan and Siberia, Russia.
• East Asia: Showers boost soil moisture for reproductive corn and soybeans in western Heilongjiang.
• Southeast Asia: Tropical Cyclone Kammuri causes more flooding in corn and rice areas in the northwestern Philippians.
• South Asia: Heavy rain in northern and western India boosts soil moisture for cotton and soybeans.
• Australia: In southeastern Australia, scattered showers further benefit vegetative winter wheat and barley. Drier weather overspreads Western Australia, favoring fieldwork and winter grain development.
• South America: In Argentina, planting delays continue in drought-affected wheat areas of Cordoba and Santa Fe. Very heavy rain covers Parana, Brazil, raising concern for the quality of ripening winter wheat.
• Canada: Warm, sunny weather promotes development of reproductive to filling spring grains and oilseeds.
• Mexico: Rain benefits corn and other rain-fed summer crops in key southern growing areas, including the southern plateau.