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QUIK STATS (last updated Nov 02, 2016 )
NOTES ABOUT THIS BIOTYPE
Ciência e Agrotecnologia 40(5):547-554, Sep/Oct. 2016 http://dx.doi.org/10.1590/1413-70542016405022316
Multiple resistance to atrazine and imazethapyr in hairy beggarticks (Bidens pilosa)
Resistência múltipla a atrazina e imazethapyr em picão-preto (Bidens pilosa)
Hudson Kagueyama Takano1*, Rubem Silvério de Oliveira Junior1, Jamil Constantin1, Guilherme Braga Pereira Braz1, Luiz Henrique Morais Franchini1, Nilda Roma Burgos2
1Universidade Estadual de Maringá/UEM, Maringá, PR, Brasil 2University of Arkansas - Fayetteville, Arkansas, USA *Corresponding author: email@example.com Received in May 30, 2016 and approved in July 29, 2016
ABSTRACT Resistance to herbicides is a serious threat to crop production worldwide, especially in agronomic crops and cereals. This research evaluated the possible occurrence of Bidens pilosa resistant to imazethapyr and atrazine in Brazil. The resistant biotype was collected from an area with a history of repeated application of photosystem II (PSII) and ALS inhibitor herbicides. The susceptible biotype was collected from an area with no history of herbicide application. Resistance verification experiments were carried out in the greenhouse. The treatments were arranged in a 3 x 8 factorial scheme, where the first factor was populations [susceptible (S), parent resistant (PR), and resistant F1 (RF1)]; and the second factor was herbicide dose (0, 375, 750, 1500, 3000, 6000, 12000 and 24000 g ha-1 for atrazine; or 0, 12.5, 25, 50, 100, 200, 400 and 800 g ha-1 for imazethapyr). The resistance factor to atrazine was 2.83 for PR and 5.55 for RF1. This population was more resistant to imazethapyr (>21-fold) than it was to atrazine. The recommended maximum dose of the herbicides did not control this B. pilosa population adequately. The data support the claim that B. pilosa population from this field in Quarto Centenário, Parana is resistant to two herbicide modes of action - PSII inhibitor (i.e. atrazine) and ALS inhibitor (i.e. imazethapyr). This is the first report of such case for this species, globally. Cross-resistance to other ALS inhibitors and other PS II inhibitors as well as the respective mechanisms of resistance to each herbicide are being investigated.
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