A contractor comparison of novel IPT tools and techniques for Brazilian peppertree (Schinus terebinthifolia) management

Abstract

Brazilian peppertree (Schinus terebinthifolia Raddi) is a multistemmed shrub or small tree from South America that is invasive in Florida, Texas, Hawaii, and Australia. It forms multi-stemmed trunks with spreading branches that create dense thickets. State agencies in Florida manage it at annual costs of over three million dollars and individual plant treatment techniques are widely used for control. Recent research testing novel hack and squirt approaches with aminopyralid and aminocyclopyrachlor and basal bark treatment with a new triclopyr formulation has shown they are highly effective. However, they have not been evaluated at larger scales, which would be useful to land managers. Therefore, our objective was to compare the reduced hack and squirt technique using aminopyralid and aminocyclopyrachlor herbicides to basal bark treatment with triclopyr on a field scale. We used two contractor crews to apply treatments to twenty-four, 0.2-ha plots. Treatments included aminocyclopyrachlor (120 g L-1) or aminopyralid (120 g L-1) applied with the reduced hack and squirt technique and triclopyr ester (108 g L-1) and triclopyr acid (34 g L-1) formulations applied with two basal bark treatment techniques. We confirmed reduced hack and squirt significantly reduced the amount of herbicide and carrier applied compared to the basal bark treatments. By 540 DAT, aminocyclopyrachlor more effectively controlled Brazilian peppertree than aminopyralid with reduced hack and squirt and was not different from either triclopyr basal bark treatment. These results verify reduced hack and squirt treatment with aminocyclopyrachlor and basal bark treatment with triclopyr acid as alternatives to basal bark treatment with triclopyr ester. Both resulted in significantly less herbicide use with comparable efficacy. This operational research approach has accelerated our understanding of novel individual plant treatment strategies and their implementation in the field.