Full-season interference ofIpomoea hederaceawithGossypium hirsutum

Abstract

Four field experiments were conducted to measure the effects of sevenIpomoea hederacea(L.) Jacq. densities onGossypium hirsutumL. lint yield, stripper-harvest efficiency, and fiber properties. The seven densities were 0, 2, 4, 6, 8, 10, and 12 weeds 10 m−1of row. Data were used to develop prediction models to compare with those previously constructed that used fewer experiments and fewer weed densities in this range.Gossypium hirsutumlint yield in kilograms per hectare and as a percentage of the weed-free control best fit a linear regression model.Gossypium hirsutumlint yield reductions for each increase of one weed 10 m−1of row ranged from 30.7 to 36.2 kg ha−1at Chickasha and from 35.4 to 36.4 kg ha−1at Perkins. Lint yield reductions for each weed 10 m−1of row ranged from 3.8 to 6.9% at Chickasha and from 3.9 to 6.0% at Perkins. All plots could be mechanically stripper harvested, except for the 12-weed density at Chickasha in 1994 and the 10- and 12-weed densities at Perkins in 1996. Harvest efficiencies were not significantly different in any experiment. The only fiber properties to display significant differences were micronaire and strength at Chickasha in 1994. Prediction models calculated herein were highly similar to those previously constructed.