Agrochemicals, Volume 2, Issue 3 (September 2023) – 6 articles

The short-term intake (ESTI) of pesticide residues in Hungarian consumers was assessed based on 2331 test results obtained during the 2017–2021 monitoring program on frequently analyzed apples, sour cherries, table grapes, peaches, nectarines, peppers, and strawberries (23.5% of all samples taken from 119 crops). The age-specific consumption data were obtained from national food consumption surveys (2009 and 2018–2020). The exposure was characterized by Hazard Quotient and Hazard Index considering the acute reference doses of pesticide residues detected in the samples. When ESTI was calculated with all detected “single” residues and a variability factor of 3.6, recommended for evaluation of monitoring results, the HI only exceeded 1 for children <3 years old eating grapes (1.50–1.81). HI was <1 when any of the six foods were eaten together within one day. Between forty and fifty percent of samples contained 2–23 residues. Though the individual residue concentrations were below the corresponding MRLs, multiple residues being present in one sample resulted in maximum HI values in apples (1.14); grapes (6.57); peaches and nectarines (2.57); strawberries (2.74); and peppers (10.44). Residues with low ARfD values contributed the most. Applying HI is simple, but provides only point estimates; therefore, it should only be used in first-tier risk assessment. Full article

Neonicotinoid (NN) insecticides derived from natural insecticide nicotine are EU chemical crop protection systemic active substances that are controversial regarding their toxicity and ecotoxicity, especially versus pollinators and birds. Clearly, the last European evaluation by the European Food Safety Authority exhibited a danger to wild and managed bees. Concomitantly, the decline in birds was partially attributed to this class of substances, which constitutes a family in itself, both in Europe and the USA. At the regulatory level, following the initial approval waves in 2011 and 2019, and mainly taking into account these ecotoxicological considerations, the commission banned the use of three NN insecticides in 2013 (imidacloprid, clothianidin, and thiamethoxam), and later, only one NN (acetamiprid) was renewed. Four NN approvals were removed by the end of approval or non-renewal in 2019 and 2020, and two are currently concerns for renewals in 2025, even if extensions of the approval durations of these NNs are to be expected due to the current slowness of the renewal procedure. Therefore, from the total number (17) of NN insecticide molecules known all over the world, up to seven NN were approved by the EU plant protection Regulation EC 1107/2009 between 2011 and now. All of these active substances are listed in Parts A and B of Regulation EU 540/2011 managing active substances. The regulatory evolution of these agrochemicals is analysed in this work, from the corresponding global modifications in terms of the number of active substances, employment, functions, uses covered, protected crops, and maximum residue limits. We also analysed their ability to persist as an agrochemical family and the potential of the inclusion of new NN members together with their current restrictions during their active substance life in Europe. Full article

Horseweed (C. canadensis) and fleabane (C. sumatrensis) are two annual or perennial herbaceous weeds present with high frequency and density in many parts of the world. Their response to water deficit was studied by means of seed germination tests and pot experiments. Seed germination was tested in solutions with different concentrations of polyethylene glycol (PEG). Two biotypes of each species were examined, one glyphosate resistant and the other susceptible. Growth responses were similar in the two species, both being more affected by lower (−1 MPa) than higher water potential (−0.2 MPa). The results revealed a significant effect of the biotype and the weed species on the drought stress response and adaptation. When high PEG concentrations were applied (−0.6 MPa), both C. sumatrensis biotypes had higher germination percentages (up to 88%) than the C. canadensis biotypes, while in most cases the seeds of the resistant biotypes germinated more (up to 72%) compared to the susceptible ones. These findings were confirmed by means of NDVI values, indicating that remote sensing can be used for a quick evaluation of the drought stress response of these weeds. The results obtained highlight the significant effect of species, biotypes and drought stress level on the germination, survival and growth of the weeds. Full article

As mandated by the EU and the national risk management duties, pesticide residues were determined by four specialized laboratories in 9924 samples taken from 119 crops of economic importance in Hungary and imported foodstuffs during 2017–2021. The screening method applied covered 622 pesticide residues as defined for enforcement purposes. The limit of detection ranged between 0.002 and 0.008 mg/kg. The 1.0% violation rate concerning all commodities was lower than in the European Union. No residue was detectable in 45.9% of the samples. For detailed analyses, six commodities (apple, cherry, grape, nectarine/peach, sweet peppers, and strawberry) were selected as they were analyzed in over 195 samples and most frequently contained residues. Besides testing their conformity with national MRLs, applying 0.3 MRL action limits for pre-export control, we found that 73% of the sampled lots would be compliant with ≥90% probability based on a second independent sampling. Multiple residues (2–23) in one sample were detected in 36–50% of the tested lots. Considering the provisions of integrated pest management, and the major pests and diseases of selected crops, normally three to four and exceptionally, seven to nine active ingredients with different modes of action should suffice for their effective and economic protection within four weeks before harvest. Full article

Use of glyphosate and glyphosate-based herbicides is ubiquitous in US agriculture and widespread around the world. Despite marketing efforts to the contrary, numerous studies demonstrate glyphosate toxicity to non-target organisms including animals, primarily focusing on mortality, carcinogenicity, renal toxicity, reproductive, and neurological toxicity, and the biochemical mechanisms underlying these physiological outcomes. Glyphosate toxicity also impacts animal behavior, both in model systems and in agricultural and environmentally relevant contexts. In this review, we examine the effects of glyphosate and glyphosate-based herbicides on animal behaviors, particularly activity, foraging and feeding, anti-predator behavior, reproductive behaviors, learning and memory, and social behaviors. Glyphosate can be detected both in food and in the environment, and avoided through activity and feeding strategies. However, exposure also reduces activity, depresses foraging and feeding, increases susceptibility to predation, interferes with courtship, mating, fertility and maternal behaviors, decreases learning and memory capabilities, and disrupts social behaviors. Changes in animal behavior as a result of glyphosate toxicity are important because of their sometimes severe effects on individual fitness, as well as ecosystem health. Implications for human behavior are also considered. Full article

The search for new classes of fungicides has long been important in plant protection due to the development of fungal resistance to currently used agrochemicals. Organic peroxides have long been regarded as exotic and unstable compounds. The discovery of the antimalarial activity of the peroxide natural product Artemisinin, an achievement that was recently recognized with the Nobel Prize, has brought organic peroxides into the medicinal and agrochemistry. In this paper, fungicidal activity of synthesized organic peroxides—geminal bishydroperoxide, bridged 1,2,4,5-tetraoxanes, and tricyclic monoperoxides—were tested in vitro against an important species of phytopathogenic fungi (F. culmorum, R. solani, A. solani, P. infestans, C. coccodes). We discovered that substituted bridged 1,2,4,5-tetraoxanes exhibit fungicidal activity comparable or superior to azoxystrobin and superior to geminal bishydroperoxide and tricyclic monoperoxides. The contact mode of action was demonstrated for the bridged 1,2,4,5-tetraoxane. Full article