Southern rust observations from IPMPIPE.org

Our corn crop looks good and it looks like if the wind and tropical storms don’t take it down, we should have a good crop. It is warm (sunny) dry years that we grow our best irrigated corn crop here, and I would say March, April, and May definitely qualify as warm and dry. However that trend turned sharply lower with clouds and rainfall in late May and throughout June. In many cases following rainfall measuring not in inches, but instead in feet, farmers have made some late season nitrogen applications to finish out the crop. Generally speaking, it looks like our early corn is 10 days from physiological maturity, and our “average” corn is about 17 days from maturity.

Corn about 17 days from maturity with low disease pressure.

I feel like I have been playing catch-up to the boys in Georgia who identified Southern rust in corn on June 6th in Seminole County (See IPMPIPE.org HERE). We have experienced relatively disease free conditions, or at least I could not find any Southern rust, until recently. The corn I look at had fungicide applications at brown silk growth stage and those applications appear to be giving way to a little disease pressure now. In no case have I found disease signs on the ear leaf, and am mostly just seeing natural plant senescence (maturity). A general recommendation is that with the milkline halfway down there is no response to fungicides. We are in that ballpark of half milkline now with light disease pressure where we made our previous fungicide applications, and I haven’t recommended any follow-up applications. However, we should be looking closely at later planted or untreated fields with the recent wet weather, and presence of Southern rust in the region.

Southern rust identified this week on 6/19/17