Interference of Horsenettle (Solanum carolinense) with Peanuts (Arachis hypogaea)

Duration and density experiments were conducted in the field to measure horsenettle (Solanum carolinense L. #3 SOLCA) interference with Spanish and runner-type peanuts (Arachis bypogaea L. 'Pronto' and 'Florunner'). Spanish peanut yield generally was higher with 6 to 8 weeks of weed-free maintenance. Horsenettle interference for 6 to 8 weeks did not decrease the yield of Spanish peanuts, and interference for 6 weeks did not decrease yields of runner peanuts. Weed-free maintenance for 2 or more weeks allowed increased runner peanut yield when compared to weedy plots. Linear regression predicted a 69 kg/ha Spanish peanut yield increase for each week of weed-free maintenance. Linear regression predicted a Spanish peanut yield reduction of 40 kg/ha for each week of weed interference in 1983, the only year in which the slopes of the regressions were statistically significant. Curvilinear equations with the runnertype cultivar predicted an 81 kg/ha yield increase or 96 kg/ha decrease for each week of weed-free maintenance or weed interference, respectively. In 1 of 2 yr, Spanish peanut yield was reduced by horsenettle at a density of 32 plants/10 m of row. Additional index words. Competition, peanut yield, weed fruit production, weed dry weight, SOLCA.