Herbicide-resistant weeds in the Philippines: Status and resistance mechanisms

Issue Date

6-2017

Abstract

Two major weeds in rice in the Philippines, Sphenochlea zeylanica Gaertn. and Echinochloa crus-galli (L.) Beauv., are controlled with chemical and cultural methods. In the 1980s, after >10 years of continuous use of 2,4-D, S. zeylanica evolved resistance to the chemical in those rice fields that had been treated with 2,4-D once or twice every cropping season. In the 1990s, E. crus-galli evolved resistance to butachlor and propanil in rice monocrop areas where both herbicides were used continuously for 7–9 years. Rice farmers continue to use 2,4-D, butachlor and propanil extensively and are often unaware of herbicide resistance or the potential for cross-resistance, its causes or its implications. In order to control herbicide-resistant E. crus-galli, farmers are shifting to locally available herbicides with different modes of action, such as bispyribac, an acetolactate synthase inhibitor, and cyhalofop, an acetyl coenzyme A carboxylase inhibitor. Follow-up manual weeding or rotary weeding after herbicide spraying, a common farmers’ practice, removes the susceptible and resistant biotypes and could help to delay or prevent the evolution of resistance. Although the resistance mechanisms of both weeds are not determined yet, they could be related to enhanced degradation that is similar to the mechanisms that are shown by the resistant biotypes in other countries.

Source or Periodical Title

Weed Biology and Management

ISSN

1444-6162

Volume

17

Issue

2

Page

57-67

Document Type

Article

College

College of Arts and Sciences (CAS)

Language

English

Subject

Butachlor; Echinochloa crus-galli; Herbicide resistance; Propanil, Sphenochlea zeylanica

Identifier

https://doi.org/10.1111/wbm.12120

Digital Copy

yes

En – AGROVOC descriptors

Butachlor; Echinochloa crus-galli; Herbicide resistance; Propanil, Sphenochlea zeylanica

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