Susceptibility of weed populations to glyphosate in banana plantations of the Department of Magdalena, Colombia

Abstract

The prevalence and deficient control with glyphosate in some weeds in banana (Musa × paradisiaca L.) plantations in the Department of Magdalena, Colombia, have been evidenced. The susceptibility to glyphosate of prevalent weeds in farms with more than 10 yr of application of this herbicide was evaluated. Seeds and propagules of adult plants of five weedy species were collected from farms where deficient glyphosate control was observed (populations with possible resistance) and in areas not cultivated or free of herbicide use (susceptible populations). Under controlled conditions, seedlings obtained from 17 populations were treated with a commercial dose of glyphosate (1440 g acid equivalent [ae] ha -1 ) or twice this dose (2880 g ae ha -1 ). At 21 d after application, populations with a relative fresh weight and survival greater than 20% and visual control lower than 80% were categorized as resistant populations. To determine the resistance factor (RF) in the resistant populations, bioassays were performed with increasing doses of the herbicide (0, 720, 1440, 2880, 5760, and 11 520 g ae ha -1 ). Populations of Echinochloa colona (L.) Link and Melothria pendula L. were sensitive to both doses, while the populations of Commelina erecta L. and Syngonium podophyllum Schott were not controlled, confirming glyphosate-tolerant. Populations of Erigeron bonariensis L., from uncultivated areas was susceptible, while those from farms were resistant. Glyphosate-resistance was confirmed in two populations of E. bonariensis, with respective RF of 3.5 and 8.6. The repetitive application of glyphosate for weed control in the Magdalena banana farms has contributed to the prevalence of tolerant species and the appearance of herbicide-resistant weeds.

Widespread Occurrence of Glyphosate-Resistant Hairy Fleabane (Erigeron bonariensis L.) in Colombia and Weed Control Alternatives

“…P 10 (from plantain crop) had the lower ED 50 values. Dry biomass ED 50 values are also comparable with the values reported previously; thus, for R populations, the ED 50 values may vary from 1129.9 to 14,261 g ae ha −1 [16][17][18][19][38][39][40][41][42][43][44].…”

“…In addition, four putative susceptible populations were classified as S and these included two rainforest accessions (P 7 , P 8 ), a shrubland (P 17 ), and one from a farm where glyphosate had not been sprayed for over ten years (P 2 ). Conversely, three R accessions (P 5 , P 6 , and P 16 ) were classified as glyphosate-resistant (R 2 ) in concordance to their respective previous reports [16,17]; the sub-categories for the reference populations are summarized in Table 5. Resistant Railway [17] (Spain)…”

“…The dose-response test allowed estimation of the susceptibility levels found in two S populations, which resulted in intermediate and similar values when comparing ED 50 with the values reported by other studies in the same species [16][17][18][19][38][39][40][41][42][43][44]. In summary, these studies report ED 50 values based on dry biomass in S biotypes from 34.8 to 335 g ae ha −1 .…”

“…The reference-susceptible population (P 3 ) collected from the understory in a rainforest was confirmed glyphosate-susceptible according to the characterization by Quintero-Pertuz et al [16]. In addition, four putative susceptible populations were classified as S and these included two rainforest accessions (P 7 , P 8 ), a shrubland (P 17 ), and one from a farm where glyphosate had not been sprayed for over ten years (P 2 ).…”

“…As a resistance reference, two previously confirmed glyphosate-resistant populations [17] collected on railway sides in Cordoba (Spain) were used; these accessions were kindly conveyed by Dr. Rafael de Prado. A third glyphosate-resistant and one glyphosate-susceptible population collected in banana plantations, previously characterized by Dr. Irma Quintero, were also used in the study [16]. Three putative glyphosate-susceptible populations were collected from the understory in rainforests, and a fourth from a farm where glyphosate had not been used for over ten years.…”