Emission Rates, Survival, and Modeled Dispersal of Viable Pollen of Creeping Bentgrass

Dispersal and deposition of pollen of creeping bentgrass ( Agrostis stolonifera L.) was estimated by using CALPUFF, a complex model originally developed to simulate dispersal of particulates and other air pollutants. In field experiments, peak pollen emission rates (8 × 10 6 pollen grains per min per m 2 of a creeping bentgrass stand) occurred between 1000 and 1200 h. Pollen survival under outdoor conditions decreased exponentially with time, and only 1% survived for 2 h. CALPUFF simulations showed deposition of 100,000 viable pollen grains per m 2 at distances of 2 to 3 km from the source field, and deposition of one pollen grain per 10 m 2 at distances of 4.6 to 6.7 km from the source field. Pattern of simulated deposition varied with weather conditions and, to a lesser extent, source field size. Simulation of dispersal by a small thermal vortex produced deposition of one grain per 10 m 2 at 15.3 km from the source field. Overall, the deposition modeling results suggest that pollen‐mediated gene flow is likely at distances of 2 to 3 km from a source field, and possible at distances up to 15 km.