Yield Increases After Heading?

Source: How Pasture Plants Grow, Iowa State University

Cool season hay yields are likely to be mixed this year. We’ve now had back to back springs that were warm early with limited moisture. Fall Armyworm damage last year was followed by a dry fall/winter then a mid-March freeze. It’s combined to make life tough for cool season grasses.

If you’ve ever wondered if delaying harvest might ‘add on’ some yield, the answer is: probably not. As the graph above shows, most of our yield is accumulated by heading. Some yield from elongated stems + seedheads may add a little tonnage, but most of what we’re going to get is already out there.

If harvest is delayed too long, we may also see regrowth from the plant’s base, and while seemingly advantageous, this growth is what we need to allow for plant recovery. If we remove the initial growth plus this regrowth, we’ll be asking the plant to start over yet again – not an ideal situation for our stands, particularly those already under stress. Probably best to harvest as normal.