Agronomist Notes

The second summer heat wave came through our area, increasing the total number of days above 300C to three! All kidding aside, there’s been no significant rainfall event over the past 10 days, yet I’m still finding a foot of soil moisture in most places. At the farm near Morrin, we haven’t been so fortunate but crops still look good and are maturing quickly. According to my weather source, Ray Garnett, he is calling for a dry August to October period. I hope he’s right as we’re going to need a pleasant fall to accommodate the late harvest.

Lygus bug populations have exploded in certain areas with the recent heat. Areas around Acme, Airdrie and Okotoks have recorded numbers of 4 to 10 per sweep. Numbers are very sporadic within the fields and also adjacent fields. For instance, I have fields well below threshold while fields next door have been sprayed due to lygus bug pressure. With that in mind, please be diligent to have your fields properly scouted.

For diseases, the stripe rust has been kept at bay with the warmer temperatures. I’m also seeing sclerotinia starting to show up in the late-April, early-May seeded fields. 

On the harvest front, I’ve heard a few producers are ready to start combining peas this week. Also, there are a canola fields in the countryside ready to be swathed in roughly 7 to 10 days time. The winter wheat fields have a touch of green left and perhaps a few producers may start by the end of the week. 

In this week’s newsletter, we’ll discuss how to properly stage a cereal crop for pre-harvest glyphosate and look at why staging is so important. I’ve also provided some straight cut harvesting canola experiences as well as a checklist to help you make the decision the pick up or straight cut your canola this year. International crop weather news will conclude the issue.

Agronomy

How to easily tell whether wheat is physiologically mature

Pre-harvest glyphosate applications are just around the corner and many producers struggle with correctly identifying when the crop has reached 30% moisture or physiological maturity. It turns out the old “leave a thumbnail imprint” on the kernel is not the best method to determine maturity. Here are a few helpful hints to identify the correct crop staging for applying pre-harvest glyphosate.

Physiological maturity is reached when the maximum amount of dry matter has accumulated in the developing kernel and dry down of the kernel is all that remains before harvest can commence. At this point, the kernel transitions from the soft dough to the hard dough stage. This is also the earliest time can you use glyphosate for pre-harvest weed control and as harvest aid. Kernel moisture can, however, vary greatly and is not a reliable way to determine the physiological maturity.

There are some visual indicators that are reliable and easy to use. The first indicator is the colour of the upper portion of the peduncle. The peduncle is the upper node of the stem. Just below the rachis the peduncle has a characteristic bend (Figure 1). When the green color is about to disappear from this bend, the crop has reached physiological maturity.

A second, slightly more laborious indicator is the appearance of pigment strands along the crease of the wheat kernel (Figure 2). To check for this pigment, simply cut kernel crosswise and check for the pigment strand. Understand that not all the kernels within each spikelet and across the spikelet within a head will reach physiological maturity at the same time.
Source: Cropping Issues in Northwest Minnesota

Why spray glyphosate at physiological maturity?

The reasons for applying glyphosate at physiological maturity are:

1. To prevent excessive herbicide residue in the seed. Prior to physiological maturity, the seed is actively taking in sugars and other compounds in the plant. During this time, glyphosate applied to the plant will also be moved into the seed, potentially raising residue levels in the grain. After physiological maturity has been reached, movement to the grain is minimized.
2. To maximize harvestable yield and minimize shriveled seed. Biological processes in the crop stop within a day or two after glyphosate application. If this occurs before the seed is mature, filling of the seed also stops. If seed filling is terminated prematurely, the proportion of shriveled seeds increases, and test weight and yield decline.

IMPORTANT: Glyphosate will not speed up seed fill. Glyphosate kills the plant and stops seed fill shortly after it is applied. Also, glyphosate application will not prevent frost damage to the seed. If applied prematurely, glyphosate can cause more damage and yield loss than the frost it was intended to protect against.
Source: Crop Production News, Saskatchewan Agriculture

Is straight cutting canola the answer?

Over the past few years I’ve been experimenting with straight cutting canola. Last September I decided to swath 70 acres and leave 90 acres to straight cut. Well, a hail storm ripped through on September 7th and caused 70% damage to the standing canola and 30% damage to the swathed. Lesson 1: standing canola does not like hail! In 2006, I helped harvest 400 acres of RR 9550 with a Gleaner R62 and a 25 ft rigid header. It worked really well, in spite of plugging, twice.

The end result in both years was a drastic increase in seed size, reduced green count and a darker, more uniform colour. On the flip side, the biggest risk was not the moisture content of the canola, but the small green pieces of stem and pods that collect along the sides of the bin during unloading. These small pockets of dockage can cause serious hot spots and spoil canola quickly. So, if you are deciding whether or not to straight cut, the handy checklist below may help with the decision.

Straight Cut Checklist:

Time of year – You should be making the decision whether to swath or straight cut around the second or third week in August. You should know by then if crop maturity will allow you to straight cut. Once September hits, crop maturity can slow down significantly with cooler nights and shorter days, something we forget during warm August weather.

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.
Canola variety – Choose an early maturing InVigor or RR hybrid. Stay away from open pollinated varieties like Clearfield canola or any of the specialty canola varieties. Open pollinated varieties tend to bloom for extended periods of time and stay greener longer. 

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 harvest.

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.

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.

Number of acres – Straight combining can be a finicky process with respect to threshing tough 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.
Reference: Canola Council of Canada

Growing days and predicting harvest start times

We’re now on the home stretch towards harvest. To date, growing degree days are 1,086 for the Three Hills-Drumheller area. At 15 GDD per day, the early-May seeded wheat should be ready for harvest around September 6th. The early seeded barley should be ready around the August 24. From what I’ve seen, the early-May seeded canola may be ready to swath in ten days time with some of the earlier maturing varieties. SL

What’s the deal with Pod Stik or Pod Ceal DC?

Two companies have launched a new product in Western Canada to help canola producers reduce shattering losses and allow them the option of straight cutting. Both UAP and Brett Young have introduced the anti-pod shattering products. Brett Young’s product called Pod Ceal uses a polymer coating containing cyclohene and UAP’s product contains synthetic latex with alcohol ethoxylates. The SRP on the Pod Stik is $9.76 an acre and comes in 2 x 10 L jugs and applied at 400 ml/acre. The Brett Young Product comes in 2 x 10 L jugs and is applied at 500 ml/acre.

I’m a little skeptical on the amount of pod coverage you would receive with these products. The labeled water volume rate is 20 gallons per acre by ground and 5 gallons by air. The product has to touch the pod to protect it and with half of the pods facing down, I wonder if you’d receive the coverage you desired.

Secondly, I’m concerned with the number of wheel tracks you’d have with a 20 gallon per acre rate. Even a sprayer with a 1,000 gallon tank can only apply 50 acres per fill. That’s three and half fills to complete 160 acres! I suspect with the right aerial applicator, applying this product by air may provide better coverage and more than pay for itself by eliminating wheel tracks if you choose to use this product. However, the jury’s still out on this one. SL

For more information on Pod Ceal click on: http://www.brettyoung.ca/podceal/docs/2008_brochure.pdf
For more information on Pod Stik click on: http://www.fwi.co.uk/Articles/2008/05/09/110431/new-product-helps-prevent-oilseed-rape-pod-shatter.html

Market News

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.