Agnieszka Hołodyńska-Kulas

Barley has consistently been ranked among the four most grown cereals in the world. Integrated agronomic approaches, combining a selection of optimal genotypes and growing conditions, may help to provide high yields of quality and safe barley grains. This study aimed to assess the yield, polyphenol and carotenoid content, and mycotoxin presence in grains of four winter barley varieties—Hobbit, Zoom, Galation, and Sandra—grown under different nitrogen (N) fertilization levels. High-performance liquid chromatography (HPLC) was used to analyze bioactive compounds, while liquid chromatography tandem mass spectrometry (LC-MS/MS) was applied to determine mycotoxin occurrence. Results showed that Hobbit and Zoom had higher yields, with Hobbit benefiting from higher N fertilization levels. While no significant differences in phenolic acids (sum) were observed among the barley varieties tested (av. 80.50 ± 6.78 mg/100 g), higher N levels raised flavonoid content (46.78 ± 4.35 vs. 38.82 ± 3.54 mg/100 g). Zoom was characterized by the highest total polyphenol levels (130.45 ± 12.50 mg/100 g). Among the 14 mycotoxins tested, only two were frequently found in the grain samples (DON and 15-Ac-DON), with Sandra being the least and Galation the most susceptible. The N fertilization doses did not significantly impact mycotoxin levels in grains. The insights gained from this study can inform the development and selection of barley varieties and growing conditions that offer optimized yields, enhanced nutritional value, and reduced susceptibility to mycotoxin contamination, tailored to the producers’ and consumers’ expectations and to sustainable farming goals.

In recent years, organic food, produced with the use of natural means and production methods, has been gaining more and more popularity among consumers. This is due, inter alia, to their belief that it is more abundant in health-promoting bioactive compounds and safer than conventional food. Consumers are increasingly aware of the harmfulness of plant protection products used in intensive agriculture, which are not allowed in organic production. At the same time, it is reported that a certain share of organic products on the EU market are contaminated with pesticide residues, which may raise consumer concerns and lead to a loss of trust in organic food. The aim of the present study was to investigate the problem of pesticide residues occurrence in random samples of organically produced fruits and vegetables (apples, potatoes, carrots, and beetroots) commonly used in the Polish households, and which are available directly from the organic producers in open markets in Poland. For simultaneous analysis of 375 pesticides, an LC-MS/MS system consisting of an Eksigent expert ultraLC 100-XL coupled to a triple quadrupole mass spectrometer QTRAP 6500 and GC Agilent 6890 N equipped with ECD/NPD system were used. Among the 96 vegetable and fruit samples studied, 89 samples (92.7%) were free from detectable pesticide residues, 7 samples (7.3%) of carrot (5) and potato (2) were contaminated, and in 1 of them (1.0%) the detected residues exceeded the maximum residue limit (MRL). None of the tested apple and beetroot samples were found to contain detectable residues. These findings are important for Polish consumers who look for high-quality organic food. However, the presence of detectable residues in a small proportion of the organic samples indicates a need to strengthen the monitoring of pesticides in organic crops, to educate farmers and to raise their awareness regarding the risks of unauthorized use of pesticides banned in organic farming, which can damage the reputation of the whole organic sector.

The main aim of this study was to optimize the QuEChERS methodology for the comprehensive determination of pesticide residues using a simple and inexpensive gas chromatography equipped with selective detectors working simultaneously (GC-ECD/NPD). The method was validated in accordance with the SANTE/11945/2015 guidelines. Representative fruit matrices were chosen from the commodities group with high water content (apples), and with high acidity and high water content (strawberry) for a 160 compounds in the range of 0.005−0.02 mg/kg. The accuracy of the method was as required (recovery: 70–120%, precision: below 20%) for 135 active substances in apples samples and 137 in strawberries samples. The main advantages of the methodology include: good detector response linearity (R2 above 0.995), low limits of detection (0.005 mg/kg for more than 20 compounds, 0.01 mg/kg for about 120 compounds), possibility of simultaneous determination of a wide range of compounds (including some “difficult” ones) without use of a single residue methods. The simultaneous use of two selective detectors allows to obtain more data during a single dose of the sample and confirmation of the result for most compounds, which allows to prevent false positives ones.

The study was conducted for the purpose of improving the application of fungicides against potato late blight (Phytophthora infestans (Mont.) de Bary) (PLB) in processing tomato. The usability of coarse spray quality with double flat fan air induction IDKT12003 nozzle and the impact of fixed and variable spray volume and adjuvants during alternate application of azoxystrobin and chlorothalonil were analysed on the basis of plant infestation and fungicide residues. The variable spray volume was calculated based on the number of leaves on a plant. The study was conducted during three vegetation seasons. Spraying of plants with significantly flattened canopies during the peak of the fructification season using an IDKT12003 nozzle was as effective as in the case of fine spraying performed with an XR11003 nozzle and facilitated the increase of fungicides residue. In the case of plants with high-spreading canopy at the beginning of fructification, XR11003 nozzle favoured the reduction of PLB infestation. Both spray volume adjustment systems enabled the same level of protection of tomato against PLB, which could result from alternate application of systemic and contact fungicides. Polyalkyleneoxide modified heptamethyltrisiloxane adjuvant, which causes siginificant increase in wetting and droplet spreading, facilitated the reduction of tomato PLB infestation during the application of fungicides using an IDKT12003 nozzle.

Effect of the spray volume adjustment model on the efficiency of fungicides and residues in processing tomato

In 2013, the Institute of Plant Protection – National Research Institute under the official control of pesticide residues in primary production analysed 1304 samples of agricultural products collected from production sites all over the country. The study included 38 products and 274 pesticides and their metabolites. Most of the samples tested were vegetables and fruits (88.9%), while the remaining percentage of the samples was comprised mainly of rape and cereal grains, and sugar beets. Overall, 98.0 % of the analysed samples were compliant with the legal limits, while 2.0% of the samples exceeded the European Union maximum residue levels (EU MRLs). The residues indicating the illegal use of plant protection products were detected in 6.5% of the samples. A total of 60 compounds were found in 32.4% of the samples. Fungicide residues were the most frequently occurring residue type (66.4%). Dithiocarbamates, carbendazim, boscalid were the most commonly detected. Pesticide residues were found in 46.5% of fruit samples, mostly in gooseberries (78.6%), strawberries (69.7%), apples (56.7%) and in 24.1% of vegetable samples, primarily in carrots (59.5%) and tomatoes (46.4%). Pesticide residues were also present in samples of rapeseed (27.3%) and sugar beet root (18.2%). W 2013 roku Instytut Ochrony Roślin – Państwowy Instytut Badawczy w ramach urzędowej kontroli pozostałości środków ochrony roślin na etapie produkcji pierwotnej przeanalizował 1304 próbki pobrane z gospodarstw produkcyjnych na terenie całego kraju. Badaniami objęto 38 produktów i 274 substancje czynne i ich metabolity. Większość badanych próbek stanowiły warzywa i owoce (88,9%), zaś pozostałą część przeważnie próbki ziarna zbóż i rzepaku oraz buraków cukrowych. Ogółem, 98,0% kontrolowanych próbek płodów rolnych spełniało wymagania dotyczące najwyższych dopuszczalnych pozostałości pestycydów, natomiast w 2,0% wykryto przekroczenia najwyższych dopuszczalnych poziomów pozostałości (NDP). Pozostałości wskazujące na stosowanie środków niedopuszczonych do ochrony stwierdzono w 6,5% próbek. Łącznie wykryto 60 związków w 32,4% badanych próbek. Pozostałości fungicydów były najpowszechniejsze (66,4%). Najczęściej wykrywano ditiokarbaminiany, karbendazym i boskalid. Pozostałości pestycydów zawierało 46,5% próbek owoców, głównie agrest (78,6%), truskawki (69,7%), jabłka (56,7%) i 24,1% próbek warzyw, zwłaszcza marchew (59,5%) i pomidory (46,4%). Ponadto były obecne w próbkach nasion rzepaku (27,3%) i korzeniach buraka cukrowego (18,2%).