Influence of Early‐Season Nitrogen and Weed Management on Irrigated and Nonirrigated Glyphosate‐Resistant and Susceptible Soybean

Autor: Krishna N. Reddy, Stan R. Spurlock, Larry G. Heatherly
Rok vydání: 2003
Předmět:
Zdroj: Agronomy Journal. 95:446-453
ISSN: 1435-0645
0002-1962
Popis: Field studies were conducted on Sharkey day soil (very-fine, smectitic, thermic Chromic Epiaquert) at Stoneville, MS (33°26' N lat) The objectives were to determine the effect of application of 0 and 35 kg N ha -1 applied early in the growing season to glyphosate-resistant (GR) and non-GR soybean [Glycine max (L.) Merr.] cultivars using two weed management systems in irrigated and nonirrigated environments. Weed management Systems were (i) pre-emergent followed by postemergent weed management using nonglyphosate herbicides applied to both GR and non-GR cultivars (PRE + POST) and (ii) postemergent weed management using glyphosate on GR cultivars and nonglyphosate herbicides on non-GR cultivars (POST). Applied N had no effect on weed management in or yield from soybean and lowered average net returns by $28 to $50 ha -1 . Average seed yields from the highest-yielding GR cultivar in 1999 and 2000 were 135 and 270 kg ha -1 more than 1999 and 2000 yields from a non-GR cultivar in the nonirrigated environment (all net returns were negative and yields
Databáze: OpenAIRE
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