Agronomist Notes

A break in the weather has finally given us insect chasers a few days rest. The beginning of the week was filled with good news as I discovered a significant drop in diamondback moth populations. The diamondback moths have begun to pupate (cocoon) signaling the end of another generation. I would hope we’ll be swathing by the time the next generation arrives, if there is another. Lygus bugs have dropped off a touch since the rain and Bertha’s have not shown up to any significant degree. I’m still finding one or two Bertha’s in each of my fields.

The season is winding down for cereals and as I walk through some near ripe barley and wheat fields, I can see many late green tillers underneath the canopy. This is something to start looking for now to help you decide whether a pre-harvest burn down is required. If your crop maturity is behind and the fall turns a touch wet, the money may be well spent if you can save yourself a grade.

This week’s newsletter will focus on estimating sclerotinia damage and the economics of a fungicide to help you in future years. Also, we will touch on swath timing and tips for straight cutting canola.

Agronomy

Estimating Sclerotinia Damage – Should We Have Sprayed A Fungicide

Last weeks newsletter pointed out the number of canola fields showing pre-maturely ripened heads standing above the crop. Diseases like sclerotinia stand out like a sore thumb this time of year but how do you know if a fungicide would have paid off? To avoid the guesswork involved in estimating the risk of sclerotinia, I use the sclerotinia checklist. This year, at the beginning of flowering, I discovered that 90% of my fields scored a 35 or less out of a possible 75. That being said, if a field scored 40 or more, a fungicide application would likely be beneficial. Some fields scoring 35 are showing signs of a mild sclerotinia infection, however the question is always, would it have paid to spray a fungicide?  

Let’s do the math on how to determine whether we should have sprayed a fungicide or not. For this example, we will assume the infected plants contribute nothing to yield. The fact is the infected plants have decent seed size this year but may be lost due to shattering.

Steve Math:

1. Estimate the number of plants in an acre. Ex: 8 plants/ ft2 x 43,560 ft2 in an acre.
2. Count the number of infected plants in 10 ft2 and divide by 10.76.
3. Multiply the number of infected plants per ft2 x 43,560 ft2 per acre.
4. Divide the number of infected plants per acre by the total number of plants per acre.
5. Multiply that number by 100 and you have the percentage yield loss.  
6. Multiply your estimated yield (40bu/ac) by the percentage yield loss.
7. Multiply the bu/ac yield loss by the estimated price of canola.

Example

8 plants ft2 x 43,560 ft2 acre = 348,480 plants/acre
5 infected plants per 10ft2 ÷10.76 = 0.46 plants ft2
0.46 plants ft2 x 43,560 ft2 = 20,241 infected plants/acre
20,241 plants/acre  ÷ 348,480 plants/acre x 100 = 5.8 %
5.8 % x 40 bu/ac = 2.32 bu/ac
2.32 bu/ac x $9.00/bu = $20.88

Therefore, we have lost $20.88 per acre from disease, but it would have cost us $26.00 an acre to apply a fungicide. So we have spent $26.00 to save $20.88, which is a loss of $5.12 per acre conservatively. Again, that’s assuming we lose all yield in the infected plants.

Sclerotinia Checklist – Excellent Tool

The sclerotinia checklist is a fantastic tool for estimating the risk of sclerotinia in canola. A great example is the fact that most of my fields that scored a 35 out of 75, which is just under the threshold level of 40 show small signs of sclerotinia infection. If we had scored a 40 or higher you can bet the level of disease infection would have pushed above 10%, which begins to make a fungicide a worthy investment. The checklist takes the guesswork out of the decision making process. It removes some of the emotion from spending $26.00 an acre on a disease you can’t see or predict. That’s until this checklist came along. SL

Sclerotinia checklist: http://www.canola-council.org/PDF/canola_plant_disease_risk.pdf#page=1

Bertha Armyworm 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 25 degrees C), because 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.

For further information regarding bertha armyworm, please refer to the following link: http://www.directfocus.com/canolamanual/chapter10b.html#ch10b_sec6a

Source: Canola Council of Canada

Swath Timing In Canola

Recent research indicates that 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.
Canola Time of Swathing Guide: http://www.canola-council.org/pub_swathing.html

Source: Canola Council of Canada

Straight Cutting Canola

To be successful at straight cutting canola you need to evaluate a few things to help you decide. The biggest argument to straight combining is what if a heavy wind comes along and shells the pods. My response, what if a heavy wind comes along and you now have 14 swaths piled up in one row along a fence line? You are at risk from wind whether you swath or straight cut.

Myself, I helped straight cut 400 acres of Proven 9550 in 2006 using a Gleaner combine with a 25 ft rigid header and had excellent results. I found very little volunteer canola last fall or this spring compared to those who swathed and combined. I believe the reason is because swathing leads to many small but viable seeds thrown out the back of the combine and left to germinate. There is some obvious shelling at the side of the header when straight cutting, but it was insignificant. We harvested a 37 bushel crop, gained up to 30% in seed size and the colour was black as coal. We did plug twice because the stems stay quite green and can catch you by surprise. Two hours of unplugging compared to 20 hours of swathing sounds like a good trade-off to me.

Straight Cutting Check List

1. What time of year is it? You should be making the decision whether to swath or leave it to straight cut within the first two weeks of August. If the crop maturity has you asking this question in the last two weeks of August, the risk of the crop maturing under cooler August-September weather may be too high. Cooler nights and shorter days can really slow down crop maturity and push your harvest window out to mid-October.   
2. Crop canopy – The crop should be well knitted and slightly lodged to reduce the chance of pod shelling and pod drop. Remember that pod integrity can be affected by frost, drought and weathering caused by dry/wet conditions. 
3. Uniform Maturity – the crop should be relatively uniform to ensure over-ripe areas do not weather and shell before the rest of the crop is ready to combine.
4. Disease – the crop should be relatively free from diseases including blackleg, fusarium wilt, sclerotinia and alternaria. These diseases can cause premature ripening, which can in turn cause pod shattering.
5. Hail - Crops affected by hail are poor candidates for straight cutting due to the probability of greater disease infection through damaged tissue and reduced pod integrity from physical damage. Also, any late season hail often causes greater levels of damage to standing crops than swathed crops.
6. How many acres of canola do you have? – Straight combining can be a finicky process with respect to combining green straw, which can slow the process down. If you have a large number of acres to cover, and you seeded those acres in a short time span, I would suggest allocating only a portion to straight cutting.   

Market News

Wheat Supply Shortage to Cause Increased Exports, Prices

The USDA World Agricultural Supply and Demand Estimates (WASDE) released Friday morning showed further reductions in global production as poor growing conditions around the world undermine harvests and further reduce global stocks, already at the lowest level seen in 36 years. Adverse weather has hurt quality in parts of the U.S. HRW region and the EU, further tightening availability of milling quality grain. Reduced exportable supplies are keeping import demand for U.S. supplies very strong despite the highest export values in 11 years. As a result, USDA increased U.S. export and farm-gate price estimates from already historically high levels.

Source: http://www.wheatworld.org/html/news.cfm?ID=1255

Canola Market Update

With current price levels, you may want to start looking further down the line for the canola crop we intend to grow in 2008. Looking at November 2008 canola futures, which closed at $432.50 per tonne on Aug. 7 – it is certainly is tapping into the very upper end of the 20-year historical price range for canola. Perhaps you should consider forward-pricing for the far away canola crop to be harvested next fall.
Take $432.50 per tonne minus a $15 to $30 per tonne basis, it results in $9.10 to $9.50 per bushel. A hedge on 2008 production shorting November 2008 futures is making some sense. Perhaps we are not prepared to act today, but we must keep this opportunity very much in mind.

Full Story: http://www.fcc-fac.ca/newsletters/en/express/articles/20070810_e.asp#7

Source: Mike Jubinville – ProFarmer Canada

Alberta & Saskatchewan Weather Forecast.

According to Ray Garnett and his climate models, nearly all of Alberta and parts of Western Saskatchewan have a 50-80% chance of exceeding the median rainfall during August to October. Not good news for our harvest. SL

USDA Bullish Wheat, Corn & Beans Report

The U.S. Department of Agriculture maintained its bullish stance on the domestic cash grain market Friday, issuing a monthly crop report that predicts further tightening in global corn/wheat/soybean supplies, and even stronger farm-gate prices for wheat, which already reside within sight of record-high levels.

Full story: http://westernfarmerstockman.com/index.aspx?ascxID=dowJones&category=1&djid=21208

Canadian Feed & Edible Peas Outlook

For 2007-08, production and supply are forecast to increase because of a 17% rise in seeded area and higher yields. Carryout stocks are forecast to remain low, with a stocks-to-use ratio (s/u) of 5%. World supply is forecast to decrease slightly to 10.6 Mt, as higher production, mainly in Canada and Australia, is more than offset by lower carry-in stocks. The average price, over all types, grades, and food and feed markets, is expected to increase slightly from 2006-07 due to the lower world supply.

Source: Agriculture & Agri-Food Canada

Japan's to Wean Off US Corn Imports – Makes Room For Canada

Japan's largest corn buyer, will cut U.S. feed grain imports by 6 percent this year as it diversifies supply to avoid shortages as farmers sell more of their crops for use as biofuel. The reduction in purchases from the U.S., the supplier of more than 95 percent of Japan's total corn imports, opens the door to increased feed grain shipments from other nations, including corn from Argentina and wheat and barley from Australia and Canada.

Source: http://www.bloomberg.com/apps/news?pid=20601087&sid=aVag9xYDfuKc&refer=home

Weekly USDA Global Crop Highlights

Full Story: http://www.agweb.com/get_article.aspx?src=gennews&pageid=137402

USDA Monthly World Weather Highlights

Full article: http://www.agweb.com/get_article.aspx?src=gennews&pageid=137479