New Soybeans and Sunflower Rust
August 8, 2013
Good morning to all. I hope everyone has been having a very good week. Well what going on this week you may ask. Once again it’s been a very busy week, scouting fields, looking at trials, and attending field days. This past Tuesday I had the oppurtunity to attend a Roundup Ready Learning Xperience down in Clara City, MN. This field day was organized to make seed companies, applicators, and growers aware of the new soybean trait offering from Monsanto, Roundup Ready to Xtend soybeans. This new soybean will be a huge advancement in which the soybean will be tolerant to both glyphosate and dicamba, making it yet another tool in the toolbox to fight resistant weeds in the area. Many of you out there when I say dicamba you think of Banvel and how well it works…….and how much it drifts. This was one of my first concerns when I heard of this technology being developed. This field day was designed to show the participants the correct way to apply this product in their soybeans. First, they are developing a formulation of dicamba that is considered much less of a drift concern then previous formulations. Next, they have taken great steps in identifying steps that need to be taken to not only reduce off target spray issues but to also improve weed control. Here is a quick list:
- Nozzles – very course or ultra course
- Wind speed – 3 – 10 mph
- Boom height – 20″ above canopy
- GPA – at least 10 gallons
- Ground speed – less than 15 mph
With these steps listed above they will aslo recommend a spray buffer, the use of a drift retardent, and spaying weeds less then 4″ in height. The use of dicamba will help control glyphosate-resistant weeds such as marestail, palmer pigweed, kochia, and waterhemp. They will also be recommending the use of a pre-emerge herbicide, which should be used anyway in my opinion, to make this a complete systems approach. Also, this tecnology will add some flexiblity in post control with up to two applications of 0.5 lb ae/acre of dicamba though beginning of flowering in the soybeans. Look for this new soybean to be available for growers to plant in 2015.
One other issue that I would like to hit on really quick is the possiblitly of rust in sunflowers. Looking at the weather over the past couple weeks it has been very conducive for this pathogen to affect sunflowers. Look for the red/copper colored pustules on the top four leaves of the plant. In the past this disease has caused economic loss in sunflowers and it can spread very quickly. Concentrate your scouting on oil hybrids that you may know are more susceptible, and confection hybrids (naturally more susceptible then oils). If the amount of rust concentrated on the top four leaves is exceeding 1% of the total leaf on our before bloom an application of a fungicide is recommended. Headline, Quadris, and Folicur (and its generics) are all labelled for use on sunflowers, and all of them do a pretty good job. One important thing to remember when spraying for rust is that sooner is better, after sunflowers have reached full bloom much of the damage may have already been done. For more information on this topic feel free to email me at firstname.lastname@example.org.
Next week look for highlights from our Summer Kickoff Meeting. Until then I hope everyone has a very good day, and a great weekend.