Current situation of Echinochloa spp. and other rice weeds in Valencian Community

Abstract

Weeds constitute one of the most important problems in rice cultivation in Valencian growing areas, Spain. The main management and control problems are restricted to a few species and the most problematic are the barnyard grass complex (Echinochloa crus-galli, E. hispidula, E. oryzoides, E. oryzicola), known locally by the common name 'cerreig'. The inherent characteristics of these plants and various factors related to the climate, cultivation, and their management in the area, make weed problems, and especially barnyard grass management and control, complicated. So, in recent years they have become more and more fields with high degrees of barnyard grass infestation. For this, we must add that biotypes resistant to the main herbicides used for its control have also been detected in the area. The purpose of the work has been to quantify the current state of the problem of barnyard grass and other problematic weeds in the area by carrying out systematic sampling of the entire rice-growing area in 2023 in order to locate, characterize and map the paddy fields with serious weed infestation problems, especially Echinochloa. The results obtained can help to making decisions about best measures to contain the problem. At mid-season, out of the total 15,346 hectares of rice cultivation, 2,307 hectares had poor weed control, with 1,870 hectares having deficient control of Echinochloa.