By Travis Faske, Extension Plant Pathologist
Southern rust has been confirmed in sixteen counties since it was first detected on June 22 in Chicot Co. Since then, southern rust has progressed northward along the MS River Delta (Fig. 1), which is very common for this disease. Of these reports, disease severity has ranged from <1% to 10% of the most severe plant in a hot spots with corn ranging in growth stages from dough to dent. In most cases the southern rust is remaining lower in the canopy, which is likely due to favorable, humid conditions provided by furrow irrigation. Given the wide distribution of rust reports it likely present in other counties; however, the majority of the corn is beyond a stage where a fungicide would protect yield potential. See earlier reports on this blog website for fungicide recommendation.