Influence of Sulfometuron Methyl on American Chestnut Seedling Growth and Leaf Function

Abstract

The expected production, dissemination, and planting of blight-resistant hybrid chestnut seedlings calls for anticipatory studies to establish optimal management practices. To test phytotoxic potential of a site preparation herbicide, seedling growth and physiological function were measured for potted American chestnut (Castanea dentata [Marsh.] Borkh.). Six concentrations (0.0, 0.026, 0.053, 0.105, 0.158, and 0.210 kg active ingredient [ai] ha−1) of sulfometuron methyl (Oust) were applied to pots in April 2008, which were planted with 1 + 0 seedlings in May, and grown until November 2008. Changes in height, rootcollar diameter, and root volume and length were measured. A portable photosynthesis system was used to measure net photosynthesis, stomatal conductance, and transpiration. Seedlings treated with label-recommended doses (0.105‐0.210 kg [ai] ha−1) showed growth and leaf function suppression, including 55, 71, and 82% reductions in height growth, root volume, and net photosynthesis, respectively. These results indicate that a strong need exists for field trials, with various dose regimes, to be conducted to refine an application rate that minimizes phytotoxic damage while still providing suitable control of competition vegetation.

A conceptual framework for restoration of threatened plants: the effective model of American chestnut (Castanea dentata) reintroduction

“…Despite the competitiveness of juvenile C. dentata , aggressive silvicultural management will probably be necessary to ensure vigorous establishment of high‐value blight‐resistant seedlings (Griffin, ; Rhoades et al ., ). Specific recommendations for underplanting (Wang et al ., ), thinning and burning (McCament & McCarthy, ), and herbicide application (Selig et al ., ; Robertson & Davis, ) have been proposed to promote establishment in natural stands and field plantations. The co‐occurring species, yellow‐poplar, is a particularly serious potential competitor that may necessitate use of prescribed fire to promote establishment of C. dentata , particularly for reforestation in large openings on mesic sites (Griscom & Griscom, ), along with consistent silvicultural management through the stem exclusion stage of stand development (Morrissey et al ., ).…”