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 × 106 pollen grains per min per m2 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 m2 at distances of 2 to 3 km from the source field, and deposition of one pollen grain per 10 m2 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 m2 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.