Dr. Phil Brannen and Dr. Harald Scherm Give a Mummy Berry Update
Dr. Phil Brannen, University of Georgia Extension pathologist, writes:
Harald Scherm has generated current mummy berry information from a model he previously developed and tested. Based on his assessment, assuming that moisture is not limiting (could be limiting in our major blueberry region in south Georgia), we should be in the early stages of apothecium development and initial infections of exposed green tissue or early bloom tissue as these emerge. I am not that familiar with recent rainfall patterns throughout the blueberry belt, but if rain has recently occurred or will be occurring, mummy generation may coincide pretty well with the initial bud germination and push (again, minimally exposed leaf [green tip] or flower tissue can be infected). Please see Harald’s explanation of the information he generated. Also, there is a danger of mummy berry infection, especially if moisture is sufficient.
Dr. Harald Scherm, Unversity of Georgia pathologist, writes:
The figure below illustrates where we should stand relative to mummy germination based on weather data collected at the Alma (AL), Alapaha (AP), and Homerville (HO) weather stations. The model only considers the balance of chilling and degree-days and assumes moisture conditions are not limiting. The solid line indicates the combinations of chilling and heating that produce 25% apothecium germination. The symbols were the original lab and field data used to develop that line. Everything above the line has exceeded the requirement for 25% apothecium production. As you can see, this year’s data from the three locations already has satisfied this basic germination requirement. Thus, assuming moisture conditions were no limiting, there is a definite risk of apothecia being out there now based on the model.