A Survey of Weed Scientists' Perceptions on the Significance of Crabgrasses (Digitaria spp.) in the United States1

A survey was conducted to document the significance of crabgrass species among cropping systems and geographical regions in the continental United States. Surveys were mailed to 117 weed scientists, at least one in each state, including, where possible, extension weed scientists with responsibilities in each of the major agronomic and horticultural crops plus turfgrass systems. A 62% response rate was achieved. Large, smooth, and southern crabgrasses were considered at least occasionally important, with India and blanket crabgrasses considered rarely or not important. Smooth crabgrass and large crabgrass were considered to be important species in most of the latitudinal range, whereas southern crabgrass was considered to be important only in the southern states. Crabgrasses were considered to be more problematic in turf than in other cropping systems. From a regional perspective in turf, large crabgrass was the most important species in the Southeast, followed by southern crabgrass and smooth crabgrass. In the Northeast, smooth crabgrass was perceived as the more important species, but large crabgrass was more important in the north-central states.Nomenclature: Blanket crabgrass, Digitaria serotina (Walt.) Michx. #3 DIGSO; crabgrass, Digitaria spp.; India crabgrass, Digitaria longiflora (Retz.) Pers. # DIGLO; large crabgrass, Digitaria sanguinalis (L.) Scop. # DIGSA; smooth crabgrass, Digitaria ischaemum (Schreb.) Muhl. # DIGIS; southern crabgrass, Digitaria ciliaris (Retz.) Koel. # DIGSP.Additional index words: Geographic distribution, turfgrass.