Herbicide treatments (4:1 ratio of 2,4-D amine:picloram) at 0.7 and 1.4 kg ae/ha at early postemergence (10- to 15-cm horsenettle height), midpostemergence (early flower), and late postemergence (fruit initiation) applied both early and late in the growing season provided >80% horsenettle control. Horsenettle density at season's end in all treated plots was less than 0.25 stems/m2, whereas untreated plots contained about 5 stems/m2. Horsenettle control the next spring was between 47 and 66% for all rates and application timings, and horsenettle density in treated plots was less than 3 stems/m2 as opposed to about 6 stems/m2 in the untreated plots. Clover drilled into the treated area the year after herbicide application was injured, indicating clover establishment the season after application of this package mixture would be difficult.
Nomenclature: 2,4-D; picloram; clover sp., Trifolium sp.; horsenettle, Solanum carolinense L. #3 SOLCA.
Additional index words: Crop tolerance.
Abbreviations: EPOST, early postemergence; LPOST, late postemergence; MPOST, midpostemergence.