Phytotoxic Effects of Glyphosate on Pepper (Capsicum annuum)¹

Abstract

Glyphosate was applied to pepper as single or sequential applications to assess the consequences of drift or other accidental exposures. Foliar injury increased and plant vigor declined with increased rates of glyphosate and were exacerbated by a second application. Single applications at flowering (stage 1) were more damaging than single applications after fruit set (stage 2). Decline in marketable yield with increased glyphosate rate was greater with stage 1 applications, except in spring 1987 when marketable yields with single applications of glyphosate at stage 1 or stage 2 were statistically similar. Sequential applications resulted in the lowest marketable yields. Total yields declined with increased glyphosate rate and decline was more pronounced with sequential applications than with single applications. Total yield was affected to a greater extent when glyphosate was applied at stage 1 than at stage 2. Yield was more sensitive to two successive exposures than to single applications. Mean fruit weight was reduced by glyphosate in two of the four experiments.

Phelipanche aegyptiaca Management with Glyphosate in Potato

“…Phytotoxicity was mostly reflected in the tuber quality of potato yield grown for fresh market with a high incidence of deformed and small tubers. These results are similar to the observations by Gilreath et al [31] who observed that marketable yield of pepper declined with glyphosate dosages at 100 g·ai·ha −1 . Previous studies by Nadal et al [32] concluded that sequential application of glyphosate at 67 g·ai·ha −1 completely controlled Orobanche crenata infestation and increased seed production of narbon bean (Vicianar bonensis L), compared to the control.…”

Influência de doses reduzidas do glyphosate no tomateiro (Lycopersicon esculentum)

“…Isso se deve ao fato de as plantas em estádios iniciais de desenvolvimento apresentarem maior sensibilidade ao herbicida, quando comparadas às plantas mais desenvolvidas, como foi observado também por Gilreath et al (2000).…”

“…Nas avali açõ es sub seq üen tes foi constatada clorose, seguida de necrose e morte das plan ta s, conc orda ndo com o qu adro Esses dados são concordantes com os observados por Russo (1990), cujos sintomas visuais na cultura do tomateiro exposta às doses reduzidas de glyphosate foram clorose em folhas jovens e no ápice da haste principal. O glyphosate, por ser um herbicida não-seletivo, quando utilizado em doses reduzidas crescentes, promove aumento progressivo na injúria foliar, reduzindo o vigor de plantas e, conseqüentemente, também a produtividade na cultura do pimentão (Gilreath et al, 2000).…”

“…Nesse sentido, Gilreath et al (2000) observaram interação sign ificativa entre doses de glyphosate e estádios de desenvolvimento da cultura do pimentão. Os efeitos negativos de doses reduzidas do glyphosate também foram observ ados nas cul tur as de mil ho, sor go, algodão e eucalipto, em que a intoxicação das plantas resultou em redução de crescimento e produtividade (Alves et al, 2000;Magalhães et al, 2001a, b;Yamashi ta & Guim arãe s, 2005;Tuffi Santos et al, 2006;Yamashita & Guimarães, 2006).…”

Response of Transplanted Aman Rice Varieties to Herbicides in Strip-Tilled Non-Puddled Soil

“…This differential behaviour in leaf chlorophyll content of rice varieties to herbicide has not documented earlier and therefore the specific reason for the differential response in leaf chlorophyll content of rice varieties to herbicide is unknown. However, in another study Gilreath et al (2000) observed the phytotoxic effects of glyphosate on pepper (Capsicum annuum) and found that glyphosate injury was ranged from non-detectable to chlorosis of the terminal bud and extended to the foliage. In some cases, leaves of pepper became more pointed and darker green, however leaves turned to pale green with increasing rate of glyphosate application.…”