Yield (bu./ac.)* TABLE 1. PRELIMINARY RESULTS
Moisture (%)* Dockage (%)*
Bushel weight (pounds)
Contribution margin ($/ac.)**
I would never seed without doing a burnoff herbicide first. But a significant body of data has shown a direct correlation between early seeding date and crop yield: In the long term, the earlier you seed the higher your yield will be. Producers wanting to get their crop in the ground early often skip the burnoff or to apply it afterward. Without check strips, the consequences of this management can be hard to evaluate.
An interesting thought that has surfaced from time to time is applying burnoff herbicide while seeding. This would have the novel benefit of not requiring a separate pass by a sprayer to apply the herbicide and would save considerable time and expense for direct seeders.
I don’t see any issues in terms of mounting the sprayer. I don’t think tank size and filling are issues either. And as more tractors are GPS equipped and autosteered, misses are virtually eliminated. Of course there are some considerations that need to be evaluated first.
Probably my biggest concern has to do with dust. We know that Roundup does have sensitivity to organic matter and that some soil disturbance and dust are produced even under zero till seeding situations, particularly with hoe openers. For this reason, spraying at the time of seeding when using hoe openers is generally not an option. Weeds get buried. But with disc openers, soil disturbance is very low and weeds are still exposed and virtually dust-free after the seeding operation.
Another Central Peace Conservation Society (CPCS) test plot is born! We wanted to see if disc openers might provide us with a special opportunity to mount our sprayer on the drill and achieve good weed control at the time of seeding without requiring a separate sprayer pass.
The purpose of this project was to evaluate different burnoff herbicide management strategies when using a zero-till drill with disc openers.
We ran a field scale replicated trial in 2006 at the farm of Jim Parks, five miles west of Rycroft, Alta., on a Gray Wooded silt loam, solodized solonetz soil. The previous crop was canola.
We compared four treatments:
1. Burnoff applied four days before seeding. (4DBS)
2. Burnoff applied seven days after seeding. (7DAS)
3. Burnoff applied immediately before the drill. (IBSD)
4. Burnoff applied immediately after the drill. (IASD)
The burnoff herbicide treatment consisted of 0.33 litres per acre of Roundup WeatherMax with
200 ml per acre of 2,4-D using a water volume of five gallons per acre. The major weeds noticed were dandelion and narrow-leaved hawk’s beard.
We seeded April 30 using a Haybuster 107 zero till disc drill. The crop was Metcalfe barley, seeded at 96 pounds per acre and 1.5 to two inches deep.
The fertilizer blend, providing 24-12-0-0, was seed placed.
For in-crop weed control, on June 14 we applied recommended rates of Assert and Refine Extra along with 114 ml of MCPA Ester applied in a water volume of five gallons per acre. The major weeds at this time were dandelion, narrow-leaved hawk’s beard, wild oat and stinkweed.
The centre strip of each plot was straight cut on August 21. Harvest volume for each strips was weighed with a weigh wagon and samples were retained to determine dockage, moisture and grade. Results are given in Table 1. Spraying costs are not calculated for the IBSD treatment, simulating the sprayer being mounted on the drill itself.
Spraying either several days before (4DBS) or after the seeding operation (7DAS) provided better results than spraying immediately after the drill (IASD). Spraying immediately before the drill (IBSD) did not differ from the other three treatments. There were no significant differences in moisture, dockage, bushel weight or protein for the four treatments. All treatments graded as No. 1 Feed barley.
This trial provided us with some preliminary results suggesting it may be possible to mount a sprayer on a disc drill to apply the burnoff herbicide at the time of seeding and still achieve results as good as applying the burnoff herbicide as a separate operation. The producer would not have to pay for a separate herbicide application which would give a moderate savings of $3 to $5 per acre.
More trials are needed before we can make solid recommendations.
Garry Ropchan is the research coordinator with the Central Peace Conservation Society in Grimshaw, Alta. Email him at [email protected]
*means within the column followed by different letters were significantly different at P=0.05
**using feed barley at $3 per bushel, spraying costs at $2.50 per acre.
Here are the yield and quality results for Metcalfe barley when the burnoff treatment is four days before seeding (4DBS), seven days after seeding (7DAS), immediately before seeding (IBSD) and immediately after seeding (IASD). The one-year trial was conducted at the farm of Jim Parks, Rycroft, Alta., in 2006.