Unlike last week’s report that was based on emails and phone calls, this report is based on observations in plots at Rohwer, Keiser and Newport and fields along the way.
Stripe rust was serious only in areas where it overwintered on varieties with low levels of adult-plant resistance and either no fungicide was applied or a fungicide was applied too late. Stripe rust did overwinter in and around plots at Rohwer where varieties in the Variety Test ranged in maturity from flag leaf emerging to just past flowering. Varieties Arcadia, Progeny 117, Progeny 185, and USG 3993 averaged 50-75% leaf area with stripe rust; varieties Croplan Genetics 554W, Dyna-Gro Baldwin, Dyna-Gro Yorktown, and AGS 2060 averaged 30-50% leaf area with stripe rust; and other varieties in the Variety Test had little or no stripe rust. A field of Ricochet surrounding the plots at Rohwer had numerous hot spots earlier in the season, but no stripe rust was evident on upper leaves.
There was no evidence of overwintering in plots at Keiser or Newport where varieties ranged in maturity from late jointing to boot split. There was very little stripe rust at Keiser and low levels in plots of susceptible varieties at Newport. With the exception of two fields of an unknown susceptible variety near North Little Rock with numerous large hot spots, little stripe rust was found in commercial fields. Susceptible varieties should continue to be scouted and fungicides applied to protect the upper leaves if stripe rust is active.
Barley yellow dwarf was prevalent in plots at Rohwer and some aphids were present. The two fields near North Little Rock with severe stripe rust also had severe BYD. It was too early to see pronounced BYD symptoms at Keiser and Newport, but at least two species of aphids were abundant at Newport. This is looking like an above-average year for BYD.
Septoria and/or Stagonospora Leaf blotches were found at low levels on the lowest leaves all locations. Jason Kelley reported higher levels in some varieties at Marianna.
Powdery Mildew was found on lower leaves here and there but did not seem serious.
Leaf rust has not been seen or reported yet, but likely is here based on reports from LA and MS.