According to some estimates, pine trees occupy more than 11 million acres in Georgia. Of those 11 million acres, seven million were planted and four million are natural stands. Consequently, pine trees surround most agricultural fields in Georgia. This diversity of flora in the Georgia landscape has enormous benefits but also brings some challenges.
One of the more interesting problems that I have encountered over the last few years has been the off-target movement of pine tree herbicides into peanut production fields. Because the response of peanut to most pine tree herbicides is unknown (at least by me), I have convinced a Columbia County, Ga., native to tackle this issue as part of his PhD graduate studies at the University of Georgia.
In 2020, we began investigating the effects of Garlon 3A (triclopyr) and Arsenal Powerline 2AS (imazapyr) on peanut growth, development and yield. These are two of the most common herbicide active ingredients applied for weed management in/around pine trees. In separate field studies, 1X, 1/10thX, and 1/100thX rates of these herbicides were applied to peanut at planting (PRE), 30 days after planting (DAP), or 60 DAP. Here are a few observations that we made from this inaugural year of research.