Planting peanut in narrow rows for weed control has not been investigated in recently released Virginia market peanut cultivars. Research was conducted in North Carolina from 2007 to 2009 to determine the effect of cultivar, planting pattern, and level of weed management inputs on weed control, peanut yield, and estimated economic return. Experiments consisted of three levels of weed management (clethodim applied POST, cultivation and hand-removal of weeds, and clethodim and appropriate broadleaf herbicides applied POST), three levels of planting pattern (single rows spaced 91 cm apart, standard twin rows spaced 20 cm apart on 91-cm centers, and narrow twin rows consisting of twin rows spaced 20 cm apart on 46-cm centers), and two Virginia cultivars (‘NC 12C’ and ‘VA 98R’). Weed management affected common lambsquarters, common ragweed, eclipta, nodding spurge, pitted morningglory, Texas millet, and yellow nutsedge control, irrespective of cultivar or planting pattern. Cultivar and planting pattern had only minor effects on weed control and interactions of these treatment factors seldom occurred. Weed control achieved with cultivation plus hand-removal was similar to weed management observed with grass and broadleaf herbicide programs. Pod yield did not differ among treatments when broadleaf weeds were the dominant species but did differ when Texas millet was the most prevalent weed. The highest yield with conventional herbicide weed management was in standard twin and narrow twin row planting patterns, although no differences among planting patterns were noted when cultivation and hand-removal were the primary weed management tactics. Differences in estimated economic return were associated with weed species, and interactions of treatment factors varied by year for that parameter.
Nomenclature: Clethodim; common lambsquarters, Chenopodium album L. CHEAL; common ragweed, Ambrosia artemisiifolia L. AMBEL; eclipta, Eclipta prostrata (L.) L. ECLAL; nodding spurge, Euphorbia nutans Lag. EPHNU; pitted morningglory, Ipomoea lacunosa L. IPOLA; Texas millet, Urochloa texana (Buckl.) R. Webster. PANTE; yellow nutsedge, Cyperus esculentus L. CYPES; peanut, Arachis hypogaea L. ‘NC 12C’ and ‘VA 98R’.