GM Free Cymru

Confirmed:  Pre-harvest Roundup dessication damages wheat and soya seeds

Date Added to website 23rd May 2014

These two papers mentioned at the base of this post are important in that they demonstrate a rising concern about the death or deformity of seeds and seedlings in cereal and legume crops following pre-harvest dessication by Roundup and other herbicides.  Paraquat is clearly worse!  That's not much consolation -- since a proportion of the grain going into our food supply (and into the brewing of ale) is contaminated / dead / deformed.  Glyphosate and Roundup residues are another part of the scenario. 

See this:  Brändli D, Reinacher S
Herbicides found in Human Urine
Ithaka Journal 1/2012: 270–272 (2012)

We tend to agree with the authors.
In contrast, Monsanto is totally gung-ho about dessication "benefits to agronomy":

............... while admitting that Roundup-dessicated crops should not be used as seed because many of the seeds will not be viable.  So dead grain impregnated with glyphosate is OK in food, but not OK for planting.  EU regs connive in this, as pointed out in the article.

How best to tackle this?  We have highlighted the issue before, here: Dakota farmers encouraged to use glyphosate-sprayed crops for feed, not seed

See also:
Revealed: controversial herbicide found in bread and cereal bars


"Pre-harvest desiccation with glyphosate and quality of stored soybean seeds."

Toledo, M. Z., Ishizuka, M. S., Cavariani, C., de Barros França-Neto, J., & Picoli, L. B. (2014).

Semina: Ciências Agrárias, 35(2), 765-774.


Seeds from non-genetically modified soybean cultivars harvested after chemical desiccation of plants with glyphosate may produce abnormal seedlings; these may show phytotoxicity symptoms that could persist even after some time of storage due to accumulation of toxic residues. This study aimed to evaluate the quality of stored soybean seeds harvested after chemical desiccation of plants with glyphosate at R7 stage. Seeds from soybean cultivar ‘Conquista’ were produced with and without desiccation with glyphosate, at the dose 2.0 L ha-1, applied at physiological maturity stage. Seed quality was evaluated right after harvest and after eight months of storage by tests of moisture content, mass, germination and vigor. The experimental design was the completely randomized block with four replications. Data was submitted to variance analysis and means were compared by the Tukey test (p ? 0.05) as a 2 x 2 factorial. The results show deleterious effects of glyphosate used as desiccant for early harvest of soybean seeds from conventional cultivars. Accelerating plant senescence leads to production of seeds with lower germination and decreased seedling development, although the percentage of abnormal seedlings is reduced after 8 months of storage possibly due to degradation of toxic residues of glyphosate and/or derivates.


"Yield and quality of wheat seeds as a function of desiccation stages and herbicides"

Cristiano Bellé; Stela Maris Kulczynski; Claudir José Basso; Tiago Edu Kaspary; Fabiane Pinto LamegoI; Marlo Adriano Bison Pinto

J. Seed Sci. vol.36 no.1 Londrina 2014

(Study conducted in Brazil)


This study aimed to evaluate the yield and seed quality of wheat, cultivar ‘Quartzo’, harvested after desiccation with two desiccants (glyphosate and paraquat) at two reproductive stages (11.2 and 11.3). The study used a randomized block experimental design in a 3 x 2 factorial arrangement (two desiccants and a control) and two growth stages of wheat, with four replications. The following were assessed: seed yield, thousand seed weight and seed quality (germination, first germination count, root and shoot weight, seedling dry and fresh weight, accelerated aging, electrical conductivity, cold germination, potassium leaching). Based on the results, it can be concluded that the use of desiccants on wheat at the two stages of development have not affected yield, but they have negatively influenced physiological seed quality. Generally, the herbicide glyphosate showed the lowest phytotoxic effect on seeds, and desiccant application at stage 11.2 resulted in higher physiological seed quality compared with application at stage 11.3.