Abstract Detail

Pteridological Section/AFS

Aguilar-Dorantes, Karla [1], Mata-Rosas, Martín [2], Vibrans, Heike [3], Esqueda-Esquivel, Valentín [4], Mehltreter, Klaus [1].

Herbicide impact on fern species of ruderal environments.

The use of herbicides has increased globally over the last 50 years. Their widespread use has not only contributed to increased harvests of crops, but also has caused resistance in more than 400 weedy plant species since 1975. Little attention has been paid to the accidental exposition of non-target plants to herbicide drift or residuals of herbicides in the soil, and especially their effect on tropical ferns. Ornamental ferns have been considered as very susceptible to chemicals such as fertilizers and pesticides. Consequently, we studied the effect of glyphosate - the most widely used herbicide - on seven fern species of ruderal environments close to agroecosystems where glyphosate is applied. Gametophytes and sporophytes of each species were exposed to commonly applied glyphosate concentrations (10.89 g/l) and a series of diluted solutions. After 7, 30 and 90 days, we observed the percentage of remaining green tissue of treated plants. At glyphosate concentrations ≥2.72 g/l, plants of all species died after 90 days. At even lower glyphosate concentrations of ≤0.65 g/l, fern species and generations suffered significantly different tissue discolorations. Young sporophytes were the most vulnerable life stage, even more susceptible to glyphosate than the supposedly delicate gametophytes. Macrothelypteris torresiana, a fern species introduced from Asia into Mexico, was the least susceptible species, perhaps because of its conspicuous wax cover, a characteristic that has been reported to limit herbicide absorption. Exposure to low herbicide concentrations may be common in the close neighborhood of agroecosystems with chemical weed control, because glyphosate can be dispersed by drift, lixiviation and surface water run-off and decomposes in the soil with a mean half-life of 47 days. The impact of herbicide treatments on non-target species might be even stronger than in this study, because glyphosate is often applied in combination with surfactants that promote herbicide uptake and increase their damaging effect.

1 - Instituto de Ecología, A.C., Red de Ecología Funcional, Carretera antigua a Coatepec No. 351, El Haya, Xalapa, Veracruz, 91070, México
2 - Instituto de Ecología, A.C., Red de Biotecnología Ambiental, Carretera antigua a Coatepec No. 351, El Haya, Xalapa, Veracruz, 91070, México
3 - Colegio de Postgraduados, Campus Montecillo, Postgrado en Botánica, km 36.5 carretera México-Texcoco, Montecillo, Texcoco, México, 56230, México
4 - INIFAP, Campo Experimental Cotaxtla, km 34.5 carretera Federal Veracruz-Córdoba, Medellín de Bravo, Veracruz, 94279, México

Keywords:
glyphosate
ferns
non-target plants
gametophytes
sporophytes
agroecosystems.

Presentation Type: Oral Paper:Papers for Sections
Session: 7
Location: Pines North/Boise Centre
Date: Monday, July 28th, 2014
Time: 8:45 AM
Number: 7002
Abstract ID:527
Candidate for Awards:None