Richard Taylor, Extension Agronomist; rtaylor@udel.edu and Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu
While checking out a barley field for possible manganese (Mn) deficiency problems, we discovered that the field had recently been damaged by freezing temperatures. Photos 1, 2, and 3 below show the typical whitening or bleaching of the leaf when temperatures drop below the critical level for barley at its current development stage. Photo 2 and 3 show the typical leaf tip bleaching but also show how freezing temperatures affect leaves differently depending on the stage of emergence of the leaf involved. Some leaves were affected only at the leaf tip while others were damaged around mid leaf leaving a whitened area in the middle of the leaf and green leaf at the tip and base of the leaf blade.
The question we can’t answer at this point with 100% certainty is whether the low temperatures caused pollen sterility in the developing seed head. The plants appeared to be at the Feekes 5 growth stage when the first node is just visible above the soil surface. We think that at this early stage damage will be limited to the leaf bleaching symptoms we observed. We won’t be able to know for sure until after heading when the anthers extrude from the florets and we can detect whether pollen release occurs. If pollen viability is impacted, the heads will not set grain and the heads will appear blank.
In the areas where Mn deficiency was observed, the leaf damage from the freezing temperatures was much worse causing significant injury to the barley plants (Photo 4). These plants will likely recover but yield will be much reduced.
Photo 1. Generalized tip burn on barley subjected to freezing temperatures following renewed spring growth and nitrogen application.
Photo 2. Leaf tip burn and mid-leaf frost injury showing stage of leaf emergence at the time of freezing temperatures.
Photo 3. Close-up view of leaf injury caused by freezing temperatures on barley. The growing point is just above the soil surface at this stage of growth.
Photo 4. Close-up view of severity of frost damage on Mn deficient plants.