By Mark Sulc
This week I was asked about applying fungicides to alfalfa because of the wet weather pattern we are experiencing. There are indeed some foliar fungicides that are labelled for alfalfa. The benefit to their use depends greatly on the weather conditions, with positive yield responses occurring when conditions favor foliar diseases. I will share results in a later article. But for now, the important point is that although conditions this spring have favored foliar disease development, it really is too late to apply a foliar fungicide to alfalfa right now. The foliar fungicide should be applied at a younger stage of growth in order to protect the crop before diseases develop. Most fungicides are preventative not curative and foliar diseases are already at work under the canopy. Besides, the crop is quite tall now and coverage of the foliage with the fungicide would be less than ideal.
If the wet pattern appears to be persisting into the second growth cycle, fungicides may show a positive yield response on the second crop this year. I will prepare an article for this newsletter by the end of May in preparation for that option on the second growth cycle. In that article I will share what we and others have found when applying foliar fungicides to alfalfa.
Source:osu.edu