Agronomist Notes

Blink. There goes three months of growing season. We’re on the down slope towards harvest and there’s nothing left now but to monitor canola for insects and wait for the right timing to start pre-harvest glyphosate treatments in a few weeks. Lygus bug pressure in canola has been low at one per sweep towards Calgary and zero in the east toward Drumheller. I haven’t found any Bertha Armyworms or Diamondback moths and hopefully won’t this year.

I hosted 50 local farmers at our place last week to view our equipment and CTF system as well and also attended the last CTFA field day at James Jackson’s near Westlock. After making my rounds, I did post-fungicide spray checks with a client and his custom aerial applicator. I’d suggest you also do post-fungicide checks and grab your product rep when you go to make sure the $10+ you spent is performing well.   

This week in Beyond Agronomy News, we’ll start with Bertha Armyworm identification and control in canola. Next, we’ll look at the future of unmanned grain carts. I’ll briefly outline my top two herbicide combinations for 2011 and discuss my observations on the use of PrePare as a wild oat control strategy. Last, I’ve listed some quick calculations you can use to estimate yield. We’ll finish with fundamental and technical grain market news.

Agronomy

Bertha Armyworm identification, monitoring and control

I haven’t found any bertha’s in my travels and moth trap counts have been low, but just in case I thought I would give you the low down on bertha armyworm monitoring, description and control.

Description: Mature larvae are green, brown or black with a light brown head and an orange stripe along each side. They are 1" to 1.5" long. The most damaging larval stages are when worms are 0.5" long and larger. Small larvae feed on the underside of leaves, but usually cause little economic damage even when population levels are high.

Threshold: At a canola price of $12 per bushel and application costs of $12 per acre, the economic threshold is 17 bertha armyworms per square metre. At that number, bertha armyworms can reduce canola yields by roughly one bushel per acre. Counts of 200 per square metre can reduce yields by 50%.

Insecticide Timing: It is important to ensure that the larvae are up on the middle to upper parts of the plant and feeding on the pods. If the larvae are still feeding on leaf material in the lower canopy or the leaf litter on the ground, there will be poorer control. Avoid spraying during high temperatures (above 250C), as the larvae are likely to be in the lower levels of the canopy. Use rates appropriate to the stage of the larvae. Most insecticides recommend a range of rates. Use higher rates when faced with high populations and/or larger stages. Also at the latest stage, ensure that the larvae are actively feeding. Larvae at the latest stage may be inactive on the ground as they prepare to pupate.

Registered Products:
Lorsban: 485 ml/ac: preharvest interval 21 days
Decis: 60 ml/ac: preharvest interval 7 days
Matador: 34 ml/ac:  preharvest interval 7 days

Provincial forecast map: http://www.agric.gov.ab.ca/app68/listings/bertha/bertha_map.jsp

Unmanned grain cart project: The future of autonomous equipment

I received a YouTube video on twitter recently which demonstrated an unmanned John Deere 8430 pulling a 1000 bushel grain cart from a standstill, move under a combine auger, take grain on the go and then move back to a staging area to be unloaded. Have a look at both videos. Very impressive! What next, touch tone phones?

YouTube video: http://youtu.be/YFy6ZAjbeew to view it action: To view it in detail http://youtu.be/k0Lj_5MBu8w

Steve’s top two herbicide combos for 2011

Each year I find myself experimenting with new combinations of herbicides that match both weed control with cost effectiveness. The farmer in me wants to save a few bucks but my agronomist side says spend the extra money and be satisfied with the results. This year I found three herbicide combinations that performed very well at a cost you can’t beat. Here they are:

Simplicity @ 106 ac/case + Prestige @ 27 ac/case: $20.50/ac after rebates

If your wild oats have less than two tillers, this combination offers excellent control of cleavers 8 whorls, wild buckwheat 8 leaf, kochia 10 inches tall plus season long control of Canada thistle and perennial sowthistle. All for $20.50/acre after rebates, which is very good value. It’s a little weak on large hemp nettle but that’s its only real weakness. Simplicity is synergistic with Prestige which makes it perform like a full rate of Prestige.

Axial iPak + 500 ml/ac AMS + 140 ml/ac MCPA Ester 600: $22.50/ac before rebates

There was a decent pre-buy opportunity last winter for Axial iPak from Syngenta which is a co-pack of Axial + Infinity. The cost ran most around $21.00/ac to start, then we added 500 ml/ac of AMS to boost cleaver control and 140 ml/ac of MCPA Ester 600 to help boost Canada thistle control for a total of $23.00/ac. The product is excellent on chickweed 6 leaf, hemp nettle 6 pairs (MCPA), round leaf mallow 6 leaf, wild buckwheat 6 leaf and not bad on cleavers up to 6 whorl plus kochia up to 5 inches tall when AMS added. Its biggest weakness is Canada thistle and cleavers above 6 whorls. With a group 27 and 6 in the Infinity plus a Group 4 with the MCPA, this brew is wonderful multi-action herbicide combination that targets a very broad spectrum of weeds for a decent price. SL

A great Pre-Pare strategy

I’ve reviewed the herbicide efficacy and wild oat control in the fields that received a Pre-Pare treatment prior to seeding this spring. PrePare is an 8.7 g/ac rate of flucarbazone-sodium (Everest) in a 696 gram bottle which is added to your 0.5-1.0 L/ac glyphosate equivalent prior to seeding wheat. The product is used to control early flushing wild oats before they grow too big to control in-crop. This year we compared the wild oat control using a follow up application of Simplicity (80ac/case) after PrePare with 9.5 g/ac rate of Everest after Prepare. We used Simplicity to stick with a non-residual Group 2 herbicide.

Based on my observations PrePare plus a full rate of Simplicity (80ac case) outperformed Prepare plus Everest at 9.5 g/ac rate. PrePare plus 9.5 g/ac Everest treatment has patches of short, spindly wild oats growing at canopy level verses no visual signs of wild oat escapes in the PrePare/Simplicity fields. We may have been off with our timing on the in-crop Everest as they recommend you apply Everest within 4 weeks of the PrePare treatment. Also, the heavy rains in June may have reduced the length of residual control the 9.5 g/ac rate of Everest could offer.    

Bottom line: I’m very pleased with the upfront control of flushing wild oats PrePare offers. If you don’t have time to apply Avadex this fall prior to wheat then a pre-burn application of Prepare is the ticket on those heavy wild oat populations. That being said, I’m not quite sold on the second application of Everest at a reduced rate of 8.7 g/ac. In hard to control wild oat fields, I’d recommend a follow up with a full rate of another wild oat herbicide like Axial, Simplicity, Traxios or Horizon. Yes, it’s an additional $8.00/ac but at least you have the best chance of controlling those nasty wild oats. I will definitely be using a lot more PrePare followed by Simplicity next year and no, I wasn’t paid to publish that. SL

Calculating yield potential

At this time of year many producers have an idea of what they think crops will yield. The number they come up with may vary by 20% which makes calculating grain storage and off combine movement difficult. To assist you this fall I've included some quick calculations to help you estimate yield. In my experience, the actual number is somewhere in between your own estimate and the calculated amount. Good luck! 

Wheat: Heads/ft/row × #seeds/head ÷ row width (inches) × 0.48 = bu/ac
Example: 60 heads/ft/row × 26 seeds/head ÷ 12 × 0.48 = 62.4 bu/ac

Barley: Heads/ft/row × #seeds/head ÷ row width (inches) × 0.60 = bu/ac
Example: 72 heads/ft/row × 22 seeds/head ÷ 12 × 0.60 = 79.2 bu/ac

Canola: plants/ft2 × pods/avg/plant × seeds/avg/pod × 10.7 ÷ 86,000 × 44.1 = bu/ac
Example: 8 plants ft2 × 60 pods/plant × 20 seeds/pod × 10.7 ÷ 86,000 × 44.1 = 52.6 bu/ac

Peas: Pods/ft2 × peas/pod × 4840 × 9 ÷ 3600 × 0.036744 = bu/ac
Example: 40 heads/ft2 × 4 peas/pod × 4840 × 9 ÷ 3600 × 0.036744 = 77.1 bu/ac

Oats: heads/ft2 × kernels/head × 10.7 ÷ 129 = bu/ac
Example: 40 heads/ft2 × 35 seeds/head × 10.7 ÷ 129 = 116 bu/ac

Flax: plants/ft2 × bolls/avg/plant × seeds/boll × 10.7 × 0.000023 × 39.368 = bu/ac
Example: 35 plants/ft2 × 15 bolls/plant × 8 seeds/boll × 10.7 × 0.000023 × 39.368 = 40.6 bu/ac