Water volumes and speed of application

Last week we had both Allan Anderson with Bayer and Tylor Hunt with Syngenta out talking about disease management.  During their presentations they both touched on the importance of coverage when applying herbicides and especially fungicides.  Water volume and speed are the two main things that will make or break the results you will see after application. 
There is no fungicide that is registered for control and this is because of a few reasons, not least of which is coverage.  Tylor's summer student had done an experiment by wrapping litmus paper around some flags that he had situated like wheat heads. He took a typical high clearance sprayer and passed over the "wheat heads" at different speeds and different water volumes.  The results where not surprising based on every spray study that has been done, but interesting just the same.  The higher the water volume and the lower the speed, the better the coverage on the litmus paper.  The opposite was also true.  Best results where at about 8 miles/hour at at least 10 gallons of water.  The higher the speed or the lower the water volume, the more of the "wheat head" was missed be it the back or the front of the head. 
The problem is, how many people actually spray at a minimum of 10 gallons and at  8 miles/hour when they have 2500 acres to cover and still make it to the lake in the middle of July?  Here is the thing, the registered water volume and suggested speed of application are not there to make your life miserable, but instead they are there because of all the tests done. Those numbers are the lowest number possible to still get optimal results. 
Allan with Bayer has done some work with this too, and has actually found that in many cases, 1 pass of Libery with low travel speeds and high water volume has better control than two passes with low water volume and high travel speeds.  Contact chemicals must hit the plants with more than one drop to have an effect on the target, be it a disease or a weed, or and insect.

If you are going to spend the money and time on spraying then bite the bullet and use the recommended W/V and slow down so the spray actually has a chance of hitting your target zone.

2013 Things to watch for

According to the Alberta AG insect forecasting maps along with a lot of chatter in the industry about it, Berth Army worm numbers are expected to be high again for 2013.  The population trend is a three year cycles for Bertha's typically.  First year being slightly higher than normal, second year quite high and the third year is the peak.  Typically by the fourth year the parasite population is high enough to effectively control the Bertha's.  So with this forecast you will want to make sure to get out and plan to scout your fields. Here are a few added tips to make your life easier come late July and early August:
 *  It is practically impossible to scout the entire field without a tram line across it.  Cut across your canola fields make an "X" or some type of pattern with your quad ect that you can travel the entire season to make sure you can see more than just the front corner of the crop.
*  Pay attention to Bertha moth numbers in the traps in late May- June, this is a big indicator of overall population and a good timing tool of when to expect the larva to hatch.  ( we have the link to the maps and the trap counts at the bottom of our web site home page.)
*  The threshold might be different this year based on over all population and its relation to the low parasite population expected this year.
*  All of this  will depend slightly on the weather and the wind patterns so don't panic but just be aware to not take off for the entire summer only to return to empty canola fields.

As another precaution the Alberta Ag web site is also calling for an increase in Midge numbers for 2013. 2012 was predicted to be a high year for midge as well but with the low growing degree days and heat units until later on in the season we got away pretty easy.  Midge is very weather dependant as they will not emerge from the ground until enough growing degree days have accumulated.  These maps and forecast are also on the Alberta Ag web site at www.agri.gov.ab.ca.  The maps show that we may not get off so easy this year.

Moral of this story is to keep an eye out and to plan to be scouting your fields proactively this year so you don't miss the boat!