Rapid Detection of Horseweed and Black Picker Sensitivity Levels to Saflufenacil

Abstract

Resistance to herbicides is one of the main factors responsible for weed control failures. Once uncontrolled and stressed, resistant weeds demand a new application of herbicides from different modes of action, which results in higher monetary costs and environmental impact. Knowledge of weed sensitivity levels to herbicides before making decisions for their management in the field is paramount to increasing the efficiency of integrated weed management. Thus, methods that allow the rapid determination of sensitivity levels can help to the correct recommendation before the application, and thus, favor the greater technical, economic and environmental efficiency of weed management. The objective of this work was to validate a rapid method to detect the levels of sensitivity of black picker (Bidens pilosa) and horseweed (Conyza sumatrensis) to saflufenacil. Dose-response experiments were performed in growth chamber, greenhouse and field. The control provided by different doses of the saflufenacil herbicide was evaluated in each environment, and the results correlated within each species. The results showed a significant positive correlation for the results obtained in growth chamber and greenhouse for black picker and horseweed. These results indicate that the method developed in the growth chamber can replace greenhouse tests for determination of the sensitivity of black picker and horseweed to saflufenacil.

Interaction between saflufenacil and imazapyr+imazapic in the management of barnyardgrass and weedy rice and selectivity for irrigated rice

“…Saflufenacil is an herbicide belonging to the chemical group of pyrimidinediones, acting in the inhibition of the Protoporphyrinogen IX oxidase (Protox). Among its characteristics are the absorption both by roots and leaves, translocation via xylem and phloem (LIEBLet al, 2008;SOLTANI et al, 2009;KNEZEVICet al, 2010), and efficiency in the control of wide range dicot weeds, such as Solanum nigrum, and Ipomoea purpurea (GROSSMANN et al, 2011), Amaranthus retroflexus, Abutilon theophrasti, and Polygonum persicaria (SOLTANI et al, 2009), Conyza canadensis (KUMAR et al, 2017), Conyza sumatrensis and Bidens pilosa (VARGAS et al, 2019). The registration of this herbicide is recent, and it has been indicated for pre and post-emergence applications in irrigated rice crops (MONTGOMERYet al, 2014).…”