Biological activity of pyribenzoxim in winter wheat and associated weeds

Abstract

Pot and field tests were conducted to evaluate the efficacy of pyribenzoxim for winter weeds in wheat. In the pot tests, pyribenzoxim, at 50 g ha -1 , controlled certain biotypes of blackgrass, including a fenoxaprop-P-ethyl-resistant biotype (the "Notts" biotype). A chlorotoluronresistant blackgrass (the "Peldon" biotype) was not controlled. Cleaver, at the three-to-four-leaf stage, was completely controlled by pyribenzoxim at 30 g ha -1 . In the field, the application in December gave good control of common chickweed, but did not control other weeds. No damage to wheat was observed with this rate of pyribenzoxim in December.The application in March gave complete control of blackgrass, hairy chess, and soft brome at 70 g ha -1 , and cleaver at 140 g ha -1 . The partial control of corn poppy and field violet was achieved. The March application scorched the wheat at 50-70 g ha -1 , with prolonged stunting at 100-140 g ha -1 . In conclusion, it was shown that pyribenzoxim had potential as a wheat herbicide, but needed further fine-tuning to find an optimum dosage.

Phenological development of natural populations of European field pansy (Viola arvensis) in a semi‐arid Mediterranean environment

“…, ; Becker et al . ; Koo & Caseley ; Richardson & Zandstra ); thus, perhaps further research was not justified. Information on the phenological development of this weed in response to common abiotic parameters could be useful to explain its occurrence in common production systems under usual farming practices.…”

“…The available information on the biology of this species, with particular reference to phenological and demographic behavior in relation to environmental parameters, remains insufficient, probably because the species is considered to be a minor threat in agroecosystems (Degenhardt et al 2005c). In addition, the European field pansy is considered a rather easy weed species to tackle, particularly with the use of herbicides (Huggenberger & Gueguen 1987;Degenhardt et al 2005aDegenhardt et al , 2005bBecker et al 2008;Koo & Caseley 2008;Richardson & Zandstra 2009); thus, perhaps further research was not justified. Information on the phenological development of this weed in response to common abiotic parameters could be useful to explain its occurrence in common production systems under usual farming practices.…”