Soil Fungicide Research Articles

Evaluation of the antagonistic effect of different plant species on white root disease causing fungus: <em>Rigidoporus microporus</em>

Antagonistic effect of some locally available plant spp. on Rigidoporus microporus (Fr.) Overeem, which causes white root disease was tested in vitro and in the field. As in vitro tests, Poisoned Food Technique (PFT) and Soil Fungicide Screening Test (SFST) were used. In the field study, the plant species were established in plots and were inoculated with Rigidoporus microporus. The innoculum potential of the soil of each plot was assessed after a certain period of time. Among the nine species used, several species showed antagonistic action over Rigidoporus microporus at in vitro tests, while Alpinia galanga L. (Galangale) showed the most significant inhibitory effect. In the field trial, the plot with Alpinia galanga showed a significantly low innoculum potential. Alpinia galanga has the potential to be developed as an antagonistic agent against the white root disease.

Effect of Several Fungicide Soil Treatments and Spraying to Wood Decay Development in Japanese Pear Trees Caused by Fomitiporia torreyae

Effect of Several Fungicide Soil Treatments and Spraying to Wood Decay Development in Japanese Pear Trees Caused by <i>Fomitiporia torreyae</i>

A fungal endophyte defensive symbiosis affects plant-nematode interactions in cotton

Most investigations of fungi as nematode antagonists have focused on their interactions with nematodes in the soil. This study tested a foliar-isolated endophytic Phialemonium inflatum for its effects against the root-knot nematode as an endophyte in cotton using a seed treatment inoculation. Cotton seeds were inoculated with P. inflatum spore suspensions prior to planting. Nematode infection and reproduction were quantified at Day 12 and 6 weeks after nematode egg inoculation, respectively. To establish whether the observed negative effects on nematodes were due to P. inflatum in the soil or as an endophyte in the plant, we also applied a soil fungicide treatment at the seedling stage to kill the fungi outside the plant. Persistent suppression of nematode penetration and galling, as well as subsequent reproduction, were observed in endophyte-treated plants independent of fungicide treatment, consistent with an endophytic mode of nematode suppression; and these negative effects did not depend on the concentration of fungal inoculum used to treat to the seed. Our study highlights a novel role for P. inflatum as part of a plant-fungal defensive symbiosis in cotton, as well as the need for a broader understanding of endophyte-plant-nematode ecological interactions.

Soil environmental quality in greenhouse vegetable production systems in eastern China: Current status and management strategies

Greenhouse vegetable production (GVP) has become an important source of public vegetable consumption and farmers' income in China. However, various pollutants can be accumulated in GVP soils due to the high cropping index, large agricultural input, and closed environment. Ecological toxicity caused by excessive pollutants' accumulation can then lead to serious health risks. This paper was aimed to systematically review the current status of soil environmental quality, analyze their impact factors, and consequently to propose integrated management strategies for GVP systems. Results indicated a decrease in soil pH, soil salinization, and nutrients imbalance in GVP soils. Fungicides, remaining nutrients, antibiotics, heavy metals, and phthalate esters were main pollutants accumulating in GVP soils comparing to surrounding open field soils. Degradation of soil ecological function, accumulation of major pollutants in vegetables, deterioration of neighboring water bodies, and potential human health risks has occurred due to the changes of soil properties and accumulation of pollutants such as heavy metals and fungicides in soils. Four dominant factors were identified leading to the above-mentioned issues including heavy application of agricultural inputs, outmoded planting styles with poor environmental protection awareness, old-fashion regulations, unreasonable standards, and ineffective supervisory management. To guarantee a sustainable GVP development, several strategies were suggested to protect and improve soil environmental quality. Implementation of various strategies not only requires the concerted efforts among different stakeholders, but also the whole lifecycle assessment throughout the GVP processes as well as effective enforcement of policies, laws, and regulations.

Формування та функціонування симбіотичних систем та мікробіоценозу ризосфери сої за використання різних фунгіцидів

The Relevance. At the recent years in soybean crops the quantity of plant pathogenic fungi has increased. The fungicides of systemic and contact action have been applicated intensively against of them. After introducing into the soil fungicides and/or their deg- radation products can to disrupt the activities of non-target objects - beneficial soil mi- croorganisms, inhibit nodulation process and the nitrogen-fixing activity of diazotrophs. The purpose of the work was to investigate the impact of combined application of fungi- cides with inoculation on the soybean symbiotic system and rhizosphere microorganisms. The Methods. The microbiological and statistical methods, gas chromatography method. The Results. Inoculation of seeds by the highly active Bradyrhizobiumjaponicum UCM B-6035, UCM B-6018 and UCM B-6023 strains the activity of nitrogen-fixing symbiotic systems increased by 1.4-3.4 times in comparison with the variant without of fungicides application and bacterization. Seed treatment by Vitavaks 200 FF fungicide caused a de- crease of'nitrogen-fixing activity of rhizobia industrial strains in symbiosis with soybean by 3-5 times. The seeds inoculation by B. japonicum UCM B-6035 strain promoted to reduce the negative impact of the Maxim Star 025 FS fungicide on the nitrogenase activity of nodulation apparatus. The positive effect of seeds bacterization was observed in the in- crease of the quantity of rhizosphere microorganisms of main ecological trophic groups. In the variant with seed treatment by Maxim Star 025 FS and Kinto duo fungicides was found a decrease in the number of microorganisms of studied groups in comparison with the control variant; the Vitavaks 200 FF fungicide application promoted to improve of these microorganisms development compared with the variant without the fungicides application and bacterization. At the inoculation of rhizobia industrial strains the negative effect of the Maxim Star 025 FS and Kinto duo fungicides to oligoazotrophic and prototrophic micro- organisms was not observed. The Conclusion. The symbiotic system of variant with the combined application of the Kinto duo fungicide with B. japonicum UCM B-6023 strain characterized by the highest nodulation and nitrogen-fixing activity.

Management of Major Diseases of Indian Mustard Through Balanced Fertilization, Cultural Practices and Fungicides in Calcareous Soils

Indian mustard, Brassica juncea (Linn.) Czernj and Cosson is ravaged by several diseases viz., Alternaria blight, Sclerotinia stem rot, white rust and nutrient deficiency causing substantial yield loss. A field experiment was conducted on the integrated management of major diseases in Indian mustard through different combinations of balanced fertilization, cultural practices and restricted use of fungicides (as seed treatment and foliar spray) to observe their role in augmenting the seed yield and its attributes in calcareous soil at the Indian Agricultural Research Institute, Regional Station, Pusa, Bihar (India) during 2012–2013 and 2013–2014. Seed treatment with propiconazole plus two foliar sprays of propiconazole at 70 and 80 days after sowing showed lowest per cent disease index of Alternaria leaf blight (2.40), pod blight (8.61), white rust (1.39), Sclerotinia twigs infection (1.90) and Sclerotinia stem rot (8.76) in comparison to other treatments and control during both the years. However, integrated treatments i.e. seed treatment with propiconazole (0.1 %) + balanced fertilization + removal of four lower leaves at 60 days after sowing + one foliar spray of propiconazole (0.1 %) at 70 days after sowing resulted in second lowest severity and incidence of major diseases. This treatment produced significantly highest yield (2339 kg/ha) and its attributes in comparison to control (1050 kg/ha) and remaining treatments. Thus, inclusion of micro and secondary nutrients, cultural practices and restricted fungicidal spray in combination had a beneficial effect on yield enhancement of rapeseed–mustard with substantial reduction in all the major diseases.

Time-dependent sorption of two novel fungicides in soils within a regulatory framework.

Convincing experimental evidence suggests increased sorption of pesticides on soil over time, which, so far, has not been considered in the regulatory assessment of leaching to groundwater. Recently, Beulke and van Beinum (2012) proposed a guidance on how to conduct, analyse and use time-dependent sorption studies in pesticide registration. The applicability of the recommended experimental set-up and fitting procedure was examined for two fungicides, penflufen and fluxapyroxad, in four soils during a 170 day incubation experiment. The apparent distribution coefficient increased by a factor of 2.5-4.5 for penflufen and by a factor of 2.5-2.8 for fluxapyroxad. The recommended two-site, one-rate sorption model adequately described measurements of total mass and liquid phase concentration in the calcium chloride suspension and the calculated apparent distribution coefficient, passing all prescribed quality criteria for model fit and parameter reliability. The guidance is technically mature regarding the experimental set-up and parameterisation of the sorption model for the two moderately mobile and relatively persistent fungicides under investigation. These parameters can be used for transport modelling in soil, thereby recognising the existence of the experimentally observed, but in the regulatory leaching assessment of pesticides not yet routinely considered phenomenon of time-dependent sorption. © 2016 Society of Chemical Industry.

Copper in soil fractions and runoff in a vineyard catchment: Insights from copper stable isotopes

Understanding the fate of copper (Cu) fungicides in vineyard soils and catchments is a prerequisite to limit the off-site impact of Cu. Using Cu stable isotopes, Cu retention in soils and runoff transport was investigated in relation to the use of Cu fungicides and the hydrological conditions in a vineyard catchment (Rouffach, Haut-Rhin, France; mean slope: 15%). The δ65Cu values of the bulk vineyard soil varied moderately through the depth of the soil profiles (−0.12 to 0.24‰±0.08‰). The values were in the range of those of the fungicides (−0.21 to 0.11‰) and included the geogenic δ65Cu value of the untreated soil (0.08‰). However, δ65Cu values significantly differed between particle-size soil fractions (−0.37±0.10‰ in fine clays and 0.23±0.07‰ in silt). Together with the soil mineralogy, the results suggested Cu isotope fractionation primarily associated with the clay and fine clay fractions that include both SOM and mineral phases. The vegetation did not affect the Cu isotope patterns in the vineyard soils. Cu export by runoff from the catchment accounted for 1% of the applied Cu mass from 11th May to 20th July 2011, covering most of the Cu use period. 84% of the exported Cu mass was Cu bound to suspended particulate matter (SPM). The runoff displayed δ65Cu values from 0.52 to 1.35‰ in the dissolved phase (<0.45μm) compared to −0.34 to −0.02‰ in the SPM phase, indicating that clay and fine clay fractions were the main vectors of SPM-bound Cu in runoff. Overall, this study shows that Cu stable isotopes may allow identifying the Cu distribution in the soil fractions and their contribution to Cu export in runoff from Cu-contaminated catchments.

Determination and analysis of the dissipation and residue of cyprodinil and fludioxonil in grape and soil using a modified QuEChERS method

A simple and accurate method coupled with a gas chromatography-nitrogen phosphorus detector was developed to detect cyprodinil and fludioxonil in grape and soil. The accuracy and precision of the method in detecting the two fungicides were evaluated by conducting intra- and inter-day recovery experiments. The limits of detection were 0.017 mg/kg for cyprodinil and 0.030 mg/kg for fludioxonil. The limits of quantitation were 0.05 mg/kg for cyprodinil and 0.10 mg/kg for fludioxonil in grape and soil. The recoveries of the fungicides in grape and soil were investigated at three spiked levels and were found to range from 85.81 to 102.94% for cyprodinil and from 92.00 to 106.86% for fludioxonil, with relative standard deviations below 7%. Field experiments were conducted in two experimental locations in China. The half-lives of cyprodinil were 9.6-20.8 days in grape and 5.8-15.6 day in soil, and the half-lives of fludioxonil were 6.2-7.2 days in grape and 6.0-12.1 days in soil. When the cyprodinil and fludioxonil 62% water-dispersible granule formulation was sprayed at a low dosage three times, terminal residues of cyprodinil and fludioxonil were below 1.0 mg/kg in grape 14 days after harvest. This work may serve as a reference to establish the maximum residue limits for cyprodinil and fludioxonil in grape and promote the proper and safe use of these two fungicides.

Modeling fungicides mobility in undisturbed vineyard soil cores unamended and amended with spent mushroom substrates

The performance of the pesticide fate model PRZM to predict the fate of two fungicides, penconazole and metalaxyl, and the major metabolite of metalaxyl (CGA-62826), in amended and unamended vineyard soils was tested from undisturbed soils columns experiments. Three different treatments were tested in two soils: control soil (unamended), and soil amended with fresh or composted spent mushroom substrates, which correspond to common agricultural practices in Spain. Leaching experiments were performed under non-saturated flow conditions. The model was parameterized with laboratory and literature data, and using pedotransfer functions. It was first calibrated for water flow against chloride breakthrough curves. The key parameter was the hydrodynamic dispersion coefficient (DISP). No leaching of penconazole, the most hydrophobic fungicide, was observed. It remained in the top 0–8cm of the column. In any case, simulations were highly correlated to the experimental results. On the contrary, metalaxyl and its metabolite were consistently found in the leachates. A calibration step of the Kd of metalaxyl and CGA-62826 and of DISP for CGA-62826 was necessary to obtain good prediction of the leaching of both compounds. PRZM generally simulated acceptable metalaxyl vertical distribution in the soil profiles although results were overestimated for its metabolite. Nevertheless, PRZM can be reasonably used to assess the leaching (through breakthrough curves) and vertical distribution of fungicides in amended soils, knowing their DISP values.

Development and validation of one-step ultrasound-assisted extraction for simultaneous determination of multiclass fungicides in soils.

A rapid, efficient, and simple one-step ultrasound-assisted extraction (UAE) method was developed for the analysis of seven fungicides (cymoxanil, metalaxyl, mandipropamid, folpet, chlorothalonil, kresoxim-methyl, and famoxadone) in horticultural soils. Analytes in the samples were determined by HPLC with variable wavelength detection. Key parameters that influence the UAE procedure were optimized, such as the nature and volume of extraction solvent, number of sonication steps, and sonication time. The highest extraction efficiencies in the range of 61.1-87.8% were obtained by using only 7.5 mL of ethyl acetate-hexane (1+1, v/v) and sonicating for 10 min. At 0.5 and 2.0 μg/g fortification levels, satisfactory recoveries (>60%) with RSD<13% were obtained for each analyte, except for folpet (>52%). The method was linear over the range of 0.005 to 10 μg/g and the correlation coefficients (r2) obtained ranged from 0.9955 to 0.9992. The LODs (S/N=3) varied from 0.0015 to 0.006 μg/g. The proposed UAE procedure was compared to classical extractions (shake-flask and Soxhlet extraction) and showed satisfactory extraction efficiencies using shorter time and smaller amounts of organic solvents, thereby minimizing the costs of the analysis and the disposal of waste solvent.

Soil genotoxicity induced by successive applications of chlorothalonil under greenhouse conditions

Greenhouse production of vegetables has been developed rapidly in China. High temperature and humidity inside the greenhouse make this environment more suitable for fast reproduction of fungal diseases. Fungicides are among the chemicals used extensively in the greenhouse to prevent crops from invasive infections by phytopathogens; however, little is known about the accumulation of fungicides in soil and their effect on soil quality under greenhouse conditions. In the present study, the accumulation of the fungicide chlorothalonil (CT) and its toxic metabolite hydroxy-chlorothalonil (HCT) in soil as well as their related soil genotoxicity under greenhouse conditions was investigated. The results indicated that both CT and HCT accumulated in soil with repeated applications of CT, and the accumulation level was strongly correlated to application dosage and its frequency. In addition, soil genotoxicity, which was measured by Vicia faba, also increased with the accumulation of CT and HCT, and the main contributor to this phenomenon was CT rather than HCT. The data demonstrated that successive applications of fungicides may result in their accumulation in soil and thus a decline in soil quality.

Simultaneous stereoselective detection of chiral fungicides in soil by LC-MS/MS with fast sample preparation

An enantioselective method was developed for the simultaneous detection of five chiral fungicides in soil, including fenbuconazole (1), tetraconazole (2), nuarimol (3), triticonazole (4), and simeconazole (5) by LC-MS/MS on a chiral stationary phase of cellulose tris-(3-chloro-4-methylphenylcarbamate) with a gradient elution. A new multifunctional filter was designed to simplify the QuEChERS (where QuEChERS is quick, easy, cheap, effective, rugged, and safe) method by simultaneous cleanup and filtration when the sample extracts were directly passed through it. Good linearities (R2 > 0.9980) were obtained in the range 0.005-2.5 mg/L, and the recovery rates were 77.4-103.6% with RSDs of 0.7-12.2% for intraday precision and 1.2-11.0% for interday precision. The LODs and LOQs for all enantiomers were in the range 0.1-0.2 and 0.25-0.5 μg/kg, respectively. The analysis of the incubated soil suggests that this method is reliable and practical for the stereoselective detection of chiral fungicides.

Development of a one-step microwave-assisted extraction procedure for highly efficient extraction of multiclass fungicides in soils

A one-step microwave-assisted extraction procedure for highly efficient multiresidue extraction of seven fungicides in soil was developed.

Oviposition Preference of the Japanese Beetle (Coleoptera: Scarabaeidae) in Golf Putting Greens under Different Soil Moisture and Fungicide Regimes

Oviposition Preference of the Japanese Beetle (Coleoptera: Scarabaeidae) in Golf Putting Greens under Different Soil Moisture and Fungicide Regimes

The Effects of Copper Hydroxide, Captan and Trifloxystrobin Fungicides on Soil Phosphomonoesterase and Urease Activity

There is increasing community awareness of the potential environmental risks posed by Cu-based fungicide use, which is placing increasing pressure on governments and industry to undertake risk minimisation action. However, if there is going to be a widespread move away from the use of Cu-based fungicides, logically there needs to be assurance that the alternatives pose a lower environmental risk. To that end, this study compared the effect of copper hydroxide, captan and trifloxystrobin on soil enzymatic (phosphomonoesterase and urease) activity. Compared to an untreated control, copper did not inhibit either enzyme activity, even at the highest dose used in the study (156 mg/kg). At their respective high doses, captan (96 mg/kg) and trifloxystrobin (144 mg/kg) did not cause inhibition of phosphomonoesterase activity but did inhibit urease activity. Consequently, the results from this study suggest that the copper hydroxide alternatives, captan and trifloxystrobin, do not pose a short-term risk to P cycling processes in soil, although the results do suggest that these two are more toxic than copper hydroxide to N cycling processes in soil. Moreover, captan and trifloxystrobin compounds are unlikely to pose a long-term risk to soil microbial function as they are unlikely to persist in soil at concentrations found to cause an adverse effect on urease activity. Nonetheless, the potential disruption to N cycling processes needs to be recognised and consideration given to limiting the annual applications of these fungicides, particularly around the timing of repeat fungicide applications, to prevent accumulation of the fungicides in surface soils.

Chemical control of coffee leaf rust in Coffea canephora cv. conilon

The two species of coffee commercially harvested in Brazil and the world are Coffea arabica (Arabica coffee) and C. canephora (Conilon coffee). Coffee leaf rust, caused by Hemileia vastatrix, is the most frequent disease that affects coffee crops. However, damage has not been estimated, and the chemical control has not been determined for the Conilon coffee in Brazil. This study evaluated a new strategy to control coffee leaf rust through the application of triazole fungicides in soil and then to estimate the damage caused by the disease after treatment. To this end, an experiment was conducted in a randomized block design with eight treatments and four replications from November 2008 to May 2011. Every 30 days, leaves were collected from experimental plots to assess the disease incidence and severity. The coffee production was also evaluated between April and May each year. The disease progress curves were plotted with these data, and the area under the disease progress curve for the disease incidence and severity was calculated. The data of the incidence of disease and production were also used to estimate the damage caused by rust. The treatments with the applications in the soil were effective in controlling the disease; however, through the joint analysis of the disease’s control and productivity, the best treatments were those that used ciproconazol or flutriafol in the soil, with or without foliar sprays treatments. There were no additional benefits with the foliar fungicides in Conilon coffee. The damage caused by rust in Conilon coffee can reach 47 % if measures are not implemented to the disease control.

Development of a one-step microwave-assisted extraction method for simultaneous determination of organophosphorus pesticides and fungicides in soils by gas chromatography–mass spectrometry

A one-step microwave-assisted extraction (MAE) procedure was developed for the simultaneous extraction of organophosphorus pesticide and fungicide residues in soil which have been greatly used in agriculture. Parameters that could influence the MAE efficiency such as irradiation power, temperature, time and solvent were investigated, and extraction efficiencies in the range of 92.6−103.7% were obtained using 400W (100% output) at 160°C for 10min with only 12mL of acetone–hexane (2:1, v/v). The analytes in extracts were analyzed directly by gas chromatography–mass spectrometry (GC–MS) without any further cleanup. At 5 and 50ngg−1 fortification levels for each analyte, the average recoveries obtained were ranged from 70.0% to 120.0% with relative standard deviation (RSD) between 0.2% and 14%. The method was linear over 1–250ngg−1 with a correlation coefficient (r2) between 0.9916 and 0.9966. The detection limits (S/N=3) were between 0.10 and 0.12ngg−1. The applicability of the method was demonstrated by analyzing field soil samples collected from six intensive horticultural sites in Ethiopia.

Ecotoxicology of Copper in Horticultural Soils: A Review

Nowadays, the world is facing the problem of environmental pollution because of the increase of man’s needs requires development in life activities, progress industrialization, transportation tools, enhancement of agriculture and exploitation of natural resources. Soil and water resources are extremely exposed to pollution from different aspects. Agrochemicals in particular, have created severe problems, since they release thousands of chemicals to the environment. Several studies on the effect of environmental pollutants on agroecosystem have been carried out. On the other hand, the importance of trace elements as environmental pollutants is well known and well documented in literature. Cu contamination to agricultural soils has been accelerated due to its wide and repeated use in agriculture and horticulture as fertilizers or fungicides to protect vines, citrus trees, and other fruit crops against fungus diseases. Applied Cu from different agrochemical sources to agroenvironment may be adsorbed and are transported to the groundwater table and pollute it besides polluting the soils. The use of Cu-based fungicides in vineyard soils is widely documented worldwide. It has been found that many countries contain concentrations in excess of 100 mg kg−1. Importance of study of transport of Cu arises due to the fact that Cu is absorbed in soils and also reaches the groundwater table, thus polluting both soil and ground water. It is often more important to be able to estimate the mobile fraction, the readily soluble fraction, the exchangeable fraction, or the plant available fraction of Cu content of a soil as a more direct indication of the likelihood of deleterious or toxic effects on soils and groundwater. Therefore, the aim of present work was to highlight the behavior and ecotoxicological effects of copper on horticultural soils.

Development of a multi-residue enantiomeric analysis method for 9 pesticides in soil and water by chiral liquid chromatography/tandem mass spectrometry

A novel and sensitive chiral liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) method was developed and validated for simultaneous measuring individual enantiomers of 9 pesticides including herbicides, insecticides, and fungicides in soil and water. The separation and determination were performed using reversed-phase chromatography on an amylose chiral stationary phase, a Chiralpak AD-RH column, under gradient elution using a mixture of ACN-2mM ammonium acetate in water as the mobile phase at 0.45mL/min flow rate. The effects of three cellulose-based columns and three amylose-based columns on the separation were also investigated. The QuEChERS (acronym for Quick, Easy, Cheap, Effective, Rugged and Safe) method and solid-phase extraction (SPE) were used for the extraction and clean-up of the soil and water samples, respectively. Parameters including the matrix effect, linearity, precision, accuracy and stability were undertaken. Under optimal conditions, the mean recoveries for all enantiomers from the soil and water samples were ranged from 77.8% to 106.2% with the relative standard deviations (RSD) less than 14.2%. Good linearity (at least R2≥0.9986) was obtained for all studied analytes in the soil and water matrix calibration curves over the range from 2.0 to 125μg/L. The limits of detection (LOD) for all enantiomers in the soil and water were less than 1.8μg/kg or μg/L, whereas the limit of quantification (LOQ) did not exceed 5.0μg/kg or μg/L. The results of the method validation confirm that this proposed method is convenient and reliable for the enantioselective determination of the enantiomers of 9 chiral pesticides in soil and water.