 I'm Michael Vunch on the plant pathologist at the Carrington Research Extension Center and we do a lot of sclerotinia head rot research on sunflowers, trying to improve the management of this really terrible disease. Our management research has been extensive and we've been conducting it for now, this is my eleventh year out here working on this. And what I'd like to discuss today is the effectiveness of using partially resistant hybrids, the effectiveness of using fungicides, and then a novel strategy of using bees to carry a biological control agent to the front of sunflower heads. And first off hybrids, what we have learned is that there are very good oil seed hybrids out there with really impressive levels of sclerotinia head rot resistance. No hybrid is completely resistant, but the difference between the susceptible commercial hybrids and the partially resistant ones is tremendous. We're talking the difference between 60 to 90 percent incidence of head rot in this season versus 10 to 25 percent. The difference between anywhere from four to 25 percent sclerotia, the resting bodies of the sclerotinia fungus by weight in the harvest of grain versus one to two percent or even lower in the exact same randomized study. And the difference between 400 to 800 pounds an acre yield and 1700 to 2500 pounds yield. So you're talking the difference between a money making crop under a conditions highly favorable for head rot, where you get 2000 pounds an acre and only 1 percent sclerotia by weight versus a total train wreck of 400 pounds an acre and 15 percent sclerotia by weight in the harvest of grain. There are very big differences. The challenge is finding the partially resistant hybrids. Disc flowers differ in their susceptibility head rot based on their growth stage. The further along they are in bloom, the percentage of the disc flowers in bloom, the more susceptible they are. And so if the susceptibility data originate from a variety trial run at any given location where during one point of the bloom period conditions became favorable for head rot, whichever hybrids happen to be predominantly in bloom during that period because of their maturity are going to come up with the most disease. And so the only way that you can rigorously and have any confidence at all in head rot susceptibility of hybrids is when the screening is done actually with supplemental overhead irrigation and hand inoculations where every sunflower head is inoculated at the exact same growth stage and every single sunflower head irrespective of maturity and when it entered bloom is subjected to the same overhead watering regime. We've run these tests here in Carrington and when we conduct the testing that way we get extremely replicable results. We've done it at other locations as well and you consistently get the same hybrids performing the best year after year location after location. But it has to be done that way. That collected from just a variety trial at any given location that happened to have conditions favorable for head rot during one period of the bloom period, those data are not going to be useful because again it's going to be those unlucky sunflowers who happen to have the level of maturity that caused them to be in bloom during that period that are going to come up as most susceptible just because they happen to be at peak susceptibility when the conditions were most favorable while other sunflowers were at other growth stages where they were less susceptible. So be very careful in choosing oil seed hybrids. Figure out where the data are coming from and remember also that the resistance is partial is you're never going to get complete resistance. With confection hybrids we found some differences in susceptibility but the differences are not as strong okay but some of the newer materials coming out of the companies are quite promising and can help with management of head rot quite significantly but it's again a less useful tool than in the oil seeds because the strength of that partial resistance is weaker. The next critical question is fungicides. Can you use a fungicide to manage head rot on sunflowers? The big problem is getting the deposition to the front of the head. We've done extensive trials looking at the application timing, the fungicide chemistry and the application method. We've tested dropper size. We've tested drop nozzles attached to high-boy sprayers and what we have learned through all of this testing and this is extensive testing with many years it's five to twelve acres of plots, very large plots, tractor applied, real world spraying conditions. What we have found is that fungicides do not offer satisfactory control of head rot under any conditions. The only conditions under which we get any efficacy from fungicides is when we apply the fungicide in such a manner we get very good deposition to the front of the head typically with drop nozzles attached to a high-boy sprayer that spray laterally into the heads between the rows. And then we inoculate within one day of spraying basically the only portion of the sunflower head that's protected by the fungicide is that ring of disc flowers that's in bloom or recently completed bloom when you spray the fungicide. Because incipient buds in the middle of the head they're really small and you cannot get good enough coverage to cover them all. And when those come into bloom they do not have sufficient fungicide on them and there's not a significant enough percentage of them with fungicide to get adequate control. So what we have learned is you get at best one day fungicide residual, maybe two out of a fungicide application. So in essence if you knew rain was coming in tomorrow you'd have to get out today with a high-boy sprayer and cover all your acreage and then you'd only get protection for that rainstorm tomorrow. It's not realistic and it's not economic and my recommendation is save the money. You're only going to be sinking more money in and not going to get any control out of it and it's not worth the money. The one strategy that we are testing that's shown promise thus far is a really novel idea and this is the use of bees, honeybees to carry a biological control agent to the sunflowers. And there's a company out of Ontario called Bee Vectoring Technologies that's developed a biological control agent that they dispense such that the bees when they exit their hive walk over it and have it on their tummies in their feet and then when they go out into the crop they carry the biological control agent to the crop as they pollinate. And what we have found is that we're getting often 50% control with this biological control agent. The big question that we have is how far away from the hive do you get adequate bee activity that you get satisfactory control? So behind me you'll see a half mile long strip of sunflowers. We have three of these located across the state this year and within this we are testing the lengths away from the hive that we are getting activity. And so we have beehives on the end right here and then another set of beehives two thirds the way down so that we have actually three gradients that we're testing because we want to know whether or not you're going to get adequate control if you just put beehives on the edge of your field and have these dispensers. And so this is a promising strategy that we're looking at and it has the added advantage that the bees on their own facilitate out crossing even when there isn't head rot and that out crossing gives you a yield bump. And so having bees in your sunflowers will increase your yield even if conditions don't develop favorable for head rot. And so there's a possibility to make money off of this regardless as long as the company doesn't price the product too high. With that I would recommend you go to the Institute of Carrington Research Extension website, click on plant pathology and scroll down to the section on sunflowers and you'll see our data on the use of hybrids and fungicides to manage claritinia head rot in sunflowers. Thank you for your time.