Root Production of Seedling Grasses in Soil Containing Picloram

Abstract

Root production of switchgrass (Panicum virgatum L.) seedlings was decreased when 1 or 2 ppm picloram were placed on the soil surface or at a depth of 3 inches. Root: shoot ratios by weight of switchgrass were decreased when picloram was placed on the surface or in the third inch of soil but were not affected by placement at 6 inches. Root production of sideaots grama (Bouteloua curtipendula (Michx.) Torr.) was decreased by picloram placed in the surface inch of soil. However, sideoats grama root production was increased in soil with 1 ppm picloram in the sixth inch. Root:shoot ratios of sideoats grama in treated soil were usually no different than those of seedlings grown in untreated soil but rooting pattern was affected.