Organizing Committee


Poster Presentations


Poster Presentations


Phakopsora pachyrhizi urediniospore escape from a soybean canopy

Presenter: Jeremy M. Zidek(1)

Other authors and affiliations: Scott A. Isard(2), Jim Marois(3), David Wright(3). (1)The Pennsylvania State University, IGDP Ecology, University Park, PA 16802, U.S.A.; (2)The Pennsylvania State University, Department of Plant Pathology, University Park, PA 16802, U.S.A.; (3)University of Florida, North Florida Research and Education Center, Quincy, FL 32351, U.S.A.

Predicting the potential arrival of soybean rust through the use of aerobiological modeling may help growers decide if a fungicide application is needed. Many of the variables that govern the aerobiological transport of P. pachyrhizi from one location to another are well understood. However, P. pachyrhizi spore escape from a soybean canopy is a poorly understood aspect of the modeling process. The objectives of this research were to estimate the proportion of released P. pachyrhizi spores that escape a soybean canopy and relate this value to atmospheric turbulence and canopy structure. Spores were collected for 15-min intervals near the center of a severely diseased field of soybeans at the University of Florida, North Florida Research and Education Center in Quincy, FL. Spores and paint chip particles were also sifted onto healthy canopies and were collected in the same manner. An experiment was also conducted at the Russell E. Larson Agricultural Research Farm at Rock Springs, PA, using only particles. Rotorod samplers were placed on four vertical towers at heights relative to canopy height, H, at the following levels: 0.5, 1.0, 1.5, and 2.5 H. The towers were situated in a 3.0 3.0-m square. Atmospheric turbulence was measured using a three-dimensional sonic anemometer (CSAT3). Three experiments and 37 trials were conducted during the summer of 2006. The measurements indicated that atmospheric turbulence, canopy structure, and atmospheric stability were important predictor variables for the proportion of released spores that escape a soybean canopy.

                                        Back to Poster Presentations