Sclerotinia Blight Control

Data in the region indicate that Miravis plus Elatus has very good activity against Sclerotinia blight. There is debate about which component of this mixture is contributing the most to control, but the mixture may be the best approach. Syngenta is likely recommending two applications of Miravis plus Elatus which can cover 6 to 8 weeks of leaf spot, stem rot and Sclerotinia blight control during that window. Other MOAs would be applied on each end of that program (chlorothalonil is needed on both ends.) My recommendation (primarily to minimize development of resistance to Miravis in leaf spot) is to make one spray in the number 2 or possibly three spot and follow that spray with at least two sprays that include at least two MOAs (again, primarily from a resistance management standpoint.) With either my recommendation or the Syngenta recommendation for leaf spot and stem rot we are likely getting a major contribution toward Sclerotinia blight. Elatus has suppression of this disease on the label. I don't know this morning about Miravis.

So, when you get to the point in the season where peanuts are about to lap and the Sclerotinia blight advisory indicates for conditions are favorable for this pathogen, scout low areas in fields where you typically have issues with this disease first. If disease has not developed, don’t rush to apply Omega 500. There is a reasonable and possibly a good chance Miravis plus Elatus is going to give adequate Sclerotinia blight control for the season.  With that said, we still feel like Miravis plus Elatus is primarily a spray for leaf spot and stem rot control but it is a big plus if it gets Sclerotinia blight. We encourage people making a spray with this mixture late in the season to make sure this spray is followed by at least two MOAs focused on leaf spot control.

Our recent work shows that control by Miravis plus Elatus may be less effective when the interval after application and prior to a follow up spray is 4 weeks compared with a 3-week follow up. This changes the pricing dynamic (one spray of Miravis plus Elatus versus two sprays of other fungicides in a 4-week interval.) One way to make the 3 week interval more cost effective is to decrease the Elatus rate as you are shooting for 3 weeks of stem rot control rather than 4 weeks.