Why poa is the 1st to fail in the heat

Mixed stands of poa and ryegrass are common in fairways and roughs. Also common, quite unfortunately, is that during the heat of the summer, poa frequently flashes out and dies, while the ryegrass can hold out for a bit longer.

So what does rye know that poa doesn't? What's the rye doing right?

At first glance, both turf types appear to share the same unfortunate summer survival traits. Both poa and rye are susceptible to a wide range of diseases…