Ecotoxicological effects of commercial herbicides on the reproductive system of aquatic arthropod Limnocoris submontandoni (Hemiptera: Naucoridae)

Worldwide, conventional agriculture makes extensive use of pesticides. Although the effects of herbicides are relatively well known in terms of environmental impacts on non-target organisms, there is very little scientific evidence regarding the impacts of herbicide residues on aquatic arthropods from tropical conservation areas. This study evaluates for the first time the toxicity of the herbicides ametryn, atrazine, and clomazone on the aquatic insect Limnocoris submontandoni (Hemiptera: Naucoridae). The lethal concentration (LC50) of herbicides was evaluated for these insects, as well as the effect of the herbicides on the insects’ tissues and testicles. The estimated LC50 was 1012.41, 192.42, and 46.09 mg/L for clomazone, atrazine, and ametryn, respectively. Spermatocyte and spermatid changes were observed under the effect of atrazine, and effects on spermatogenesis were observed for some concentrations of clomazone, with apparent recovery after a short time. Our results provide useful information on the effects of herbicide residues in aquatic systems. This information can help minimize the risk of long-term reproductive effects in non-target species that have been previously overlooked in ecotoxicology studies.

The Impact of Cultivation Management and Weed Control Systems of Very Early Potato on Weed Infestation, Biodiversity, and Health Safety of Tubers

The aim of the research was to determine the impact of potato cultivation management and weeding systems on weed infestation and to evaluate the possibility of using biomarkers to assess consumer exposure to herbicide residues in potato tubers. The experiment was carried out in 2016–2018 in Central-Eastern Poland. The subject of research was the very early variety Lord. The experiment was established using the randomized block method in a split-plot design. The first order factor was cultivation management: (A) traditional and (B) under polyethylene sheeting (PE-sheeting) put “on flat”. The second-order factors were weed control systems: (a) mechanical (b) to (d)-chemical. The study determined the degree of damage to crops and weeds, fresh and dry weight of weeds, their number and floristic composition, and herbicide residues in tubers and in the soil. The fresh and dry mass of weeds was most effectively limited by mechanical and chemical treatment with the use of a preparation containing linuron. Managing potato cultivation with PE-sheeting and soil herbicides has proven to be safe for very early potato production. Used for pre-emergence care, the preparation containing linuron did not leave even trace amounts of this active substance in the tubers. The determined amount of the active substance fluorochloridon and clomazone was lower than the Maximum Residue Level (MRL) norm in the EU (European Union). As a result, the adopted, innovative management and weeding control systems in the cultivation of early potato varieties can be considered safe for the consumer.

Glyphosate residues in grain after desiccation of crops in the Ob Region

The residual amounts of glyphosate in wheat grain after desiccation of crops were determined. Glyphosate is the most widely used herbicide in the world. The level of its ecotoxicity is widely discussed in the scientific literature after the compound was classified as “a likely carcinogenic” pesticide. It is assumed that glyphosate residues can be highest when the crops are desiccated before harvesting. The studies were carried out in 2018 (central forest-steppe of the Novosibirsk Ob region (54°53'13.5"N, 82°59'36.7"E). In the experiment, desiccation of wheat was carried out with the herbicide Zero Super (the content of isopropylamine salt of glyphosate was 750 g/kg) at the recommended dose of 1.5- 2.0 kg/ha. Glyphosate residues in plant biomass were determined using the test system, based on the principle of enzyme immunoassay. Pre-preparation of the samples for the analysis was carried out according to the recommendation of Stylab laboratory, which validated the method for the determination of glyphosate in grain. Glyphosate residues were found in all of the 37 samples tested. Regardless of the sampling period after desiccation, herbicide residues in the grain did not exceed 4.4 mg/kg. In 14 days after desiccation, the minimum pesticide level was lower (0.5 mg/kg) compared to the data obtained in 7 days (2.6 mg/kg). The content of the herbicide residues in wheat straw was higher than in grain. The highest values of glyphosate residues were found in the dry biomass of weed vegetation (up to 9 mg/kg). In the grain stored for 1 year, the content of GR has not decreased. The data obtained were compared with the MRL for the residual amount of glyphosate in wheat grain accepted in the world.

Correction to: Infuence of herbicides under biofertilizer application on fennel (Foeniculum vulgare) yield and quality with special reference to herbicide residues

An amendment to this paper has been published and can be accessed via the original article.

Dynamics of herbicides degradation in carrot (Daucus carota L.) roots and leaves

This research had two main aims. First, to analyse the degradation dynamics of herbicides commonly used in carrot (aclonifen, clomazone, flufenacet, linuron, metribuzin, pendimethalin, S-metolachlor). Second, to compare the amount of herbicide residues with the maximum residue level and with requirements of non-residual production. The field experiments were conducted in 2012–2016. All tested herbicides resulted in relatively low concentrations of residues in carrot roots (up to 10 µg/kg) when the recommended withdrawal period was followed between application and harvest. The concentration of S-metolachlor in carrot roots exceeded the maximal residual limit (MRL) if the application was carried out four days before harvest. The measured values of other tested herbicide residues in carrot roots did not exceed the MRL in any of the tested samples. Pre-emergent use of clomazone, linuron and flufenacet could be recommended for non-residue carrot production. Post-emergent use of metribuzin can be used for non-residue carrot production if the interval between application and harvest is at least 80 days. Concentrations of herbicide residues in carrot leaves were many times higher than in roots. All tested herbicides can be applied for safe carrot production if applicators adhere to the requirements for use.