Farmers will be confronted with a lot of decisions this fall when it comes to harvest management. We all recognize the curveballs that mother nature threw this spring. The soil was dry in many areas. This, along with some management decisions around soil preparation and fertilizer applications, resulted in many producers planting into extremely dry conditions.
Initial germination of pulse crops and cereals was, in many cases, satisfactory but deteriorated as days ticked on. By the time many of the smaller seeded crops such as canola were planted, germination was often marginal. Then came the general rains near the middle of June when the rest of the crop germinated. This resulted in two crops in many fields, including the cereals that initially looked like a good initial germination.
When looking at the fields, farmers will have to decide the optimum time for swathing, desiccating or making other management decisions. Do you manage the field for the early germinated crop or wait for the second growth and risk having the early plants shell out?
Frankly, there probably isn’t a correct answer today. Two months from now we will be able to look back and say “yeah, should have done that,” but it is one of those things a person will have to live with.
I will try to raise a few points to consider when trying to make harvest decisions, especially with canola, as it seems to be the one crop most affected.
Does your hybrid have harvest-management traits?
I have to say that there is a significant range of pod-shatter resistance. The hybrids with the patented pod-shatter reduction technology are, I feel, superior to those that have been selected for pod shatter reduction. And those hybrids are not all equal, with some performing better than others.
There is a continuum of hybrids from those that are quite resistant to pod shatter to those that will shatter at the drop of a hat. You will have a pretty good idea from your experience and that of other growers, where your hybrid fits in. And this matters because the better your shatter resistance, the less risk of yield loss there is if you wait until the second growth matures.
What percentage of your crop germinated soon after planting? The odds are that the first growth canola will yield the highest. There is a lot of research that indicates that on average, the yield potential of any hybrid drops approximately 1.5 to 2 percent every day seeding is delayed.
A crop where a high percentage of plants that germinated early – say, 80 percent – will probably make sense to swath or desiccate when the early crop is ready as probably over 90 percent of the yield will come from the early plants.
The opposite is also true. If 80 percent of plants that germinated late, it will probably make sense to swath or desiccate when the late crop is ready. It’s the fields in between that will be hard to decide upon.
Are you swathing or straight cutting? There may be less risk in swathing an uneven crop, especially if you are on the lower end of the pod-shatter continuum. By swathing you will lock in your losses but will also lock in your harvestability.
The last couple of years have shown that straight cutting comes with its own set of challenges – even with fairly even maturing crops. Herbicides are not as effective when applied in mid-September than in August and it would appear that there will be a lot of canola that will not be mature until mid-September.
What herbicide system are you growing? This will determine what you can use for a harvest aid product. Just remember that glyphosate products are quite slow acting, especially when applied in mid-September and will not be effective on Roundup Ready canola. Other harvest aid products will be quicker acting with the quickest product being those containing diquat, such as Reglone.
All of these factors, along with many others – including equipment, manpower and the crop growth in a particular field – will all influence your decisions.
With respect to other crops, I will limit my comments to the use of glyphosate on wheat. To determine if your wheat is ready to spray, look at the base of the head where it attaches to the stem. If this is green, wait. If it is beige, spray. For more information, I would ask that you refer to the Western Producer article “80 percent mature heads ideal time for pre-harvest glyphosate,” published Aug. 22, 2014. And with all pre-harvest herbicides, please refer to the product label for rates, staging and pre-harvest intervals.
Thom Weir is a certified crop adviser and former professional agrologist working in the Yorkton, Sask., area. You can reach him at email@example.com.