Assessment of a decision support system for chemical control of annual ryegrass (Lolium rigidum) in winter cereals

Gonzalez‐Andujar JL, Fernandez‐Quintanilla C, Bastida F, Calvo R, Izquierdo J & Lezaun JA (2011). Assessment of a decision support system for chemical control of annual ryegrass (Lolium rigidum) in winter cereals. Weed Research51, 304–309. Summary Field studies were conducted at five locations in North and East Spain to evaluate the agronomic, economic and environmental implications of a decision support system (LOLIUM‐PC) for herbicide control of Lolium rigidum in winter cereals. The chemical control treatments evaluated were as follows: (i) LOLIUM‐PC‐based recommendations, (ii) full herbicide dose (standard farmer practice) and (iii) half herbicide dose. Results indicate that there were no statistically significant differences, within sites, between treatments with respect to weed density, crop yield and economic return. On average, LOLIUM‐PC resulted in less herbicide application compared with the full herbicide dose treatment. This also was true in three of five localities for the half‐dose treatment. The results of this research indicate that LOLIUM‐PC provides a flexible tool for recommending less herbicide than other herbicide decision systems, adequate weed control and similar crop yields to those obtained with the standard farmer practice (full dose) in Spain.