Number of Times to Spray Canola

It can sometimes be tricky to decide whether there is a need to go in for a application of Glyphosate or Liberty on your canola crop. There are a number of things that must be considered before pulling the trigger on another application.

The first is simply is there a need for it? Lots of growers use canola as a way to clean up their field so they automatically go in a second time no matter what. This isn’t always the approach to take. You must go out into your field and check to see if there are any weeds actively growing. If there are more than a few here or there then you can assume that going in again is a possibility, but consider the second question.

How big is the canola crop? This question must be answered for a couple of reasons. The first is that if you are spraying a chemical such as Liberty which is a contact herbicide, coverage is key to killing the target plants. If your crop canopy is large enough that getting enough contact for the herbicide to be effective is a very low chance then automatically scrap going back in. Even with glyphosate you must be able to get adequate coverage of the target weeds. The second reason you must consider the size of the crop is because canola is a very competitive crop and if it is much larger than the target weeds then there is a very good chance it will out compete it causing no yield loss to you and even the potential for the crop to choke the weeds out.

The third thing to be considered is how big are the weeds? As stated before if the crop can out compete the weed then it probably isn’t worth getting going back in. But some growers may be concerned about the potential of the weed feeding the weed seed bank in their field. For example if it is already June and you are simply concerned about a large number of 1 leaf wild buckwheat in your field and don’t want to have to worry about them going to seed then you probably aren’t in a position to worry. The likeliness of those seedling wild buckwheat making it to the point where they produce viable seed probably isn’t a big enough concern to force you back into the field for another herbicide application.

Even if you have a thin plant stand and think you can get good weed coverage, spraying a herbicide to late can have a negative impact on your crop. I have personally witnessed Liberty sprayed on a thin Invigor stand at flowering set back the canola crop significantly. With that said I have also witnessed glyphosate sprayed on RoundUp Ready canola at flowering and not noticed a significant loss in plant health. When making your first application  Invigor canola is registered to take a shot of Liberty at the cotyledon stage. This is typically ok with glyphosate resistant varieties as well, however, it is generally considered to be a little safer to wait until the 1 leaf stage in glyphosate resistant crops. I have always heard that the farther down the line a Roundup Ready crop is in terms of its breeding lineage, the better it is at standing early or heavy doses of glyphosate.

Taking into account all of these considerations should allow you to decide whether a second herbicide application is warranted.

Seedling Frost Susceptibility

With the forecast in Southern Alberta calling for frost, I thought I would weigh in some of my experiences on frost and what to expect.

Our crops each have their own susceptibility to frost. Wheat and barley are very good at withstanding frost because in the early stages of their life their growing point is located below the ground. Peas and lentils have their growing points below ground as well making them fairly tolerant to frost as well. Crops with growing points above ground such as canola, flax and beans are much more susceptible to frost damage, but it goes much deeper than this.

 Another factor that affects a plants ability to withstand frost are the climactic conditions before and after frost. If the conditions leading up to the frost are consistently cool then the plants will be more tolerant to the below freezing temperatures. For example canola that has not been exposed to cooler temperatures and the temperature was a rapid drop then, -3 degrees celcius would cause damage to the plant. If canola has been experiencing cooler temperatures then even a drop to close to -9 degrees celcius has been shown to be tolerated. If after a frost the temperatures rapidly increase then this can also cause more significant damage to your crop as the rapid increase in temperature can cause frozen cells to burst whereas a gradual temperature increase would allow them to simply thaw out. The bigger a crop is generally the more frost tolerant it gets (1 leaf canola is more susceptible to frost than 4 leaf canola). Time below freezing is another factor that must be considered, if the time below 0 is only a couple hours you shouldn’t see the kind of damage you will see as when the temperature is that low for 8 hours for example. To take things even further, low spots in fields tend to have higher frost damage as frost "settles" in the lower areas. One more factor to consider is soil texture/type. A sandy soil in the brown soil zone with less than adequate moisture and a clay soil in the black zone with good moisture will affect how much damage there will be. The black soil with moisture will tend to hold more heat than the sandy brown soil will, potentially protecting the growing point. On top of this, if a field is covered in straw or has more "trash", then there may be more damage. Straw does not act as an insulator for small plants, rather it hinders the soils ability to absorb sunlight and warm up.

            One thing that a cereal crop may be subjected to due to cold temperatures is temperature banding. Temperature banding is due to a difference between air and soil temperature. The difference can cause cause yellow, chlorotic stripes on your cereal crops. Typically this is not yield damaging and the bands eventually go back to green in 10 days depending on further weather conditions.

Identifying frost damaged canola can be difficult, but generally speaking you must look at the growing point. If the growing point is green and healthy looking then it probably hasn’t been hurt to badly by frost. If the growing point is black, brown or purple then you may need to look into reseeding or other options. Another sign in canola can be curled or cupping margins (outside of cotyledon). Excessively dark plants or excessively yellow plants can also be a sign. Remember, you cannot see damage the following day typically. It is best to wait atleast 2-4 days before scouting to evaluate damage.

Temperatures Causing Damage or Death to Seedlings

                         Crop                                                              Temperature

Spring Wheat	-3 to -5.5
Barley	-2.5 to -4
Canola	-3 <
Flax	-3 to -4.5
Soybeans/Dry Beans/Corn	0 to -1
Peas	-4 to -5
Lentils	-4 to -5
Sunflower	-4 to -5.5

Note: Temps can vary based on prior and after temps, stage, soil texture and time below 0

Seed Treatment Actives

With farmers beginning to get antsy to get in the field there is always the question about what seed treatment is going to work best. This is a good question to be asking, especially with the sudden large rainfalls being seen across parts of the prairies. Cool, wet conditions are when you are going to see seed treatments getting the most bang for your buck. Atleast soils should be heating up now.

I cannot stress enough how before even thinking about seed treatment you purchase clean, certified seed where possible. Putting low quality seed in the ground cant be saved by any amount or any kind of seed treatment. Ensure you get your seed tested so you are aware of the levels of specific diseases with the seed, this can be a starting point for your fungicide choice. Remember disease can be in the soil as well, so from being out and actively digging up your  plants every year and inspecting the roots you can have an idea of what species of disease are present (distinguishing can be tough, ask an agronomist or do some research online). Even ask your local agronomist or sales reps what disease species tend to be high in your soils. I am not going to touch on insecticidal seed treatments here, but remember that there are options for insecticides with seed treatments as well.

There are a number of seed treatments out there, some with similar active ingredients. I am mainly going to focus on the actives and then give some examples of what seed treatments you can find them in.

Metalaxyl (gr. 4) is a systemic active that tends to be very effective on Pythium species (soil borne disease) of diseases. If you have heard of neighbours or local specialists talk about Pythium in your area, then products with this active may be some to consider. Secondly, metalaxyl is effective on Botrytis. Products that contain this active include Trilex AL, Apronn Maxx, Raxil MD and Dividend XL RTA.

Next up I will touch on the active known as Thiram (group M). Thiram’s claim to fame is its activity on smut type of diseases. Anyone that uses a lot of bin ran barley may want to consider a product with this active (however, there are other actives with good activity on smuts as well). Products with Thiram in them include Raxil T, Gemini, and Vitaflo.

Fusarium is a disease species that tends to cause some losses every year, especially in wet soils. For control of this disease there are a number of options in seed treatments since the triazole family of fungicides (gr 3) is so prevalent in western Canadian seed treatments. Youll notice that foliar fungicides for Fusarium Head Blight in cereals tend to be triazole fungicides as well. Here is a list of seed treatments with triazole family fungicides and good activity on fusarium; Raxil MD and Raxil T (tebuconazole), Gemini (Triticonazole), Dividend (Difenoconazole) and Rancona Apex (ipconazole). There are some other ones out there as well to I believe.

As of right now seed treatments that are exceptional on Rhizoctonia are difficult to find. There are products out there with activity on it including Trilex AL and Apronn Maxx (probably others, but not sure off the top of my head). Next year is going to be exciting for seed treatments when it comes to rhizoctonia products. Syngenta has a new product being released up here known as Sedaxane which has very good effectiveness on the disease. On top of this, Bayers new canola seed treatment called EverGol (all Invigor seed will come pre treated with it) with the active Penflufen (gr 7). Penflufen has great activity on rhizoctonia as well.

The tendency with these diseases is that they are all present in every soil, it is determining the one that tends to be more of a concern to you when choosing a seed treatment. Using products with more than one active ingredient is an effective strategy to help with this.

Distinguishing these diseases can be difficult, potential for another blog on them alone.

If any of this info seems to be wrong on anything I write please let me know, I have zero desire to be spreading incorrect information.

Weed Resistance

Weed resistance to herbicides has been around for a number of years now. With glyphosate resistance being confirmed in Alberta it seems a lot more people are starting to really take notice. I hope to see a lot more guys throwing in some extra groups with their pre burn, putting down a soil applied herbicide or alternating groups between years. We have already lost a lot of control with our group 2 products due to resistance, would hate to see group 9 be lost in Canada on more problem weeds such as wild oats or cleavers.

A lot of the time simply upping the rate of glyphosate may be the most economical and most effective way to control those target weeds in a pre burn, but we have to take a pro active approach and spend a few extra dollars an acre now rather than lose glyphosate as an effective chemical all together. In front of canola for example the only registered option to add to glyphosate is a group 14 product known as AIM (in Cleanstart). While this product is not the most potent and in a lot of cases it may be cheaper and more effective to add another 0.5L equiv. to get those tougher to kill weeds, adding Aim can help fight resistance. Especially if that field is going into Round Up Ready Canola. If a producer uses glyphosate pre burn, 2 in crops apps and then a fall applied glyphosate app, that’s 4 straight applications with ONLY glyphosate, not to mention probably using glyphosate again the following growing season as a pre burn. It is scenarios like that where you begin to increase your resistance risk significantly.

When it comes to group 1 wild oat resistance it should be approached the same, you know you are going to spray a grassy herbicide essentially every year. To help combat resistance there are a number of options from applying granular herbicides with activity on wild oats (Avadex or Edge) or alternating between group 2 and group 1 grassy herbicides. Bayer just released their gr2 grassy herbicide as stand alone product giving you another option for the 2012 growing season. Dow’s Simplicity, Arysta and Syngenta’s flucarbazone products have been around for a number of years now giving you options in your cereal fields. If you want to go even farther you can begin to recognize different chemical families within the group 1 chemical classification and begin to alternate between the ‘dim’, ‘den’ and ‘fop’ families (the actives will end in one of those three 3 letter words. Axial is in the ‘den’ classification with its active being pinoxaDEN). There has been research from AAFC’s Dr. Hugh Beckie showing that different families within group 1 have different levels of resistance to a wild oats resistance mutation.

Pulses rely heavily on group 2 herbicides, one reason there may such high levels of gr 2 resistance in some areas across the prairies. With the registration of a gr 14 in Authority in front of peas, there is another option in your weed control arsenal. The group 3 product of Edge is also something that has been used effectively for a while in front of pulses. On top of this using a product such as Reglone (gr 22) or Heat (gr 14) as a desiccant can further diversify the chemical spectrum on a pulse field in a given season.

Acknowledging the problem at hand starting now will allow us to lengthen the life time of many different chemicals, ensuring high efficacy weed control well into the future.

Big Yields Start With Seeding

            I was talking to a farmer the other day about plant stands in wheat. He wasn’t concerned at all because he has had crops with thin plant stands yield well. I do understand where he was coming from because he has observed a wheat crops ability to make up for a thin stand by throwing out more tillers.  At the same time it concerns me because seeding rate is very important when it comes to growing good crops, for a number of reasons. The wheat’s ability to compensate shouldn’t be an indication to just throw random amounts of seed down, it should be a last resort, after doing everything possible to achieve a solid plant stand that is going to maximize yield, decrease weed competition and speed up maturity.

            Right from seeding things like disease, insects, negative environmental conditions (flooding, drought, heat etc), weeds  and more are doing everything to keep you from achieving your target yield. Putting in place the right practices can fend off these pressures and ensure a profitable yield for your farm.

            Starting with clean, certified seed is one of the best investments you can make. This may sound repetitive, but certified seed consistently out yields bin ran seed time and time again, the extra cost is worth it.

            Once you have your certified seed, be sure to have the vigour and germ tested and use those numbers to calculate your seeding rate based on the seeds thousand kernel weight (TKW). To calculate this count out 1000 seeds and weigh those seeds (in grams).

The formula looks like this:

target plant population/ft square X TKW (in grams) / seedling survival (decimal) / 10.4

= lbs/ac

EX: 32 plt/ft sq, 35grams for TKW, .90 (90%) seedling mortality in wheat looks like:

32 X 35 / .90 / 10.4 = 119.65lb/ac                120lb/ac or 2bu/ac seeding rate

I have been reading a few good tweets about this on Twitter lately from a few guys and its good to see more trying to spread the word on just how important this formula is to use. But now what does using this formula and extra work do for you?

Guys used to aim for that 24plts/ft sq, and for dryland guys sometimes that is more realistic as in some areas the lack of moisture is going to allow those thinner plant stands to do better than a higher target of 30plts/ft sq, but upping your target can speed up and even maturity. The majority of yield (95+%) comes from the main head (50%+) and the first 2 tillers (20-25% each). Knowing this we can see that anything beyond 2 tillers is a waste of energy for the plant. This means the crop is taking more time, more moisture and more nutrients to finish off that 3^rd or 4^th tiller delaying maturity by up to a week, and taking away potential moisture or nutrients for next year without gaining any real yield advantage. Not efficient for your farms bottom line, to say the least.

Weeds constantly are robbing your crop of yield. A thicker and more even plant stand is better able to compete against this weeds and secure the use of moisture and nutrients for your crop which is going to add to yield. A thin plant stand is susceptible to increased competitions of weeds and choking your crop out, which hurts your yield that year and adds to your fields weed seed bank for the next year.

Insects and disease are constantly thinning your stand out. Wireworms and seedling disease are on your crop like white on rice from the second you put seed in the ground. Having a solid target stand is going to combat against these issues. If you target 30plt/ft sq (which is higher than a lot of growers I have talked too) then even if 2 plants are taken out by a wireworm and 2 are taken out by disease you are still securing yourself 26 plants per foot, a number that sets you up for a good yield come August.

I know this usually isnt an issue, but there is a lot of moisture in a lot of area as I write this, meaning there is potential for some big crops. Don’t be afraid to seed heavy this year because there is moisture and potential for big crops. A thicker plant stand is also better able to combat excessive moisture, so keep that in mind.

The last step to take is “insuring” your seed by putting a registered seed treatment on before seeding. Studies show consistent yield increases and enhancements in the “pop up effect” from these treatments and battle negative seedling diseases. These can be a fungicide, insecticide or a combination of the two. There are other options out there such as nutrient seed dressings and biological organisms to enhance your seeds ability to get out of the ground. The proper seed placed fertility program, seed depth and seeding speed can also help you hit that proper target plant stand, but those are for another time.