Control of Fungal Diseases in Mushroom Crops while Dealing with Fungicide Resistance: A Review.

Mycoparasites cause heavy losses in commercial mushroom farms worldwide. The negative impact of fungal diseases such as dry bubble (Lecanicillium fungicola), cobweb (Cladobotryum spp.), wet bubble (Mycogone perniciosa), and green mold (Trichoderma spp.) constrains yield and harvest quality while reducing the cropping surface or damaging basidiomes. Currently, in order to fight fungal diseases, preventive measurements consist of applying intensive cleaning during cropping and by the end of the crop cycle, together with the application of selective active substances with proved fungicidal action. Notwithstanding the foregoing, the redundant application of the same fungicides has been conducted to the occurrence of resistant strains, hence, reviewing reported evidence of resistance occurrence and introducing unconventional treatments is worthy to pave the way towards the design of integrated disease management (IDM) programs. This work reviews aspects concerning chemical control, reduced sensitivity to fungicides, and additional control methods, including genomic resources for data mining, to cope with mycoparasites in the mushroom industry.

Cultivation of Agaricus bitorquis mushroom as an strategy for the Integrated Pest Management of the myceliophagous mite Microdispus lambi.

BACKGROUND: The phorid fly Megaselia halterata Winnertz (Diptera: Phoridae) is the principal vector of Microdispus lambi (Acari: Pygmephoroidea) in Spanish Agaricus bisporus Lange (Imbach) mushroom farms. This myceliophagous mite does not appear to be a pest in Agaricus bitorquis (Quél.) Sacc mushroom crops. This study explores the role of phorid flies as vectors of Microdispus lambi in Agaricus bitorquis mushroom crops. RESULTS: The incidence of M. lambi in A. bitorquis growing substrates did not reach appreciable levels at any point during the growing cycle. The presence of phorid flies in A. bitorquis farms was normally higher than that in the case of Agaricus bisporus Lange (Imbach) species. The percentage of phorid vectors did not statistically differ between both Agaricus crops during infection periods. However, by the end of the crop, this percentage had increased only in A. bisporus crops, coinciding with a high incidence of mites in the substrate of this mushroom species; Megaselia halterata emerging from the mushroom substrate of A. bitorquis summer crops did not carry mites as they were absent from compost and casing. CONCLUSION: M. halterata is a pest in Spanish A. bitorquis mushroom crops, meanwhile M. lambi, its phorectic mite, has shown not to be a pest of this species mushroom farms during the spring-summer growing season. A. bitorquis crops could potentially be used as an IPM measure to decrease the incidence and prevent the propagation of the myceliophagous mite M. lambi in A. bisporus mushroom growing farms. © 2020 Society of Chemical Industry.

Evaluation of the Leaching Potential of Anthranilamide Insecticides Through the Soil.

The mobility of two relatively new antranilic diamide insecticides, cyanantraniliprole (CY) and cholantraniliprole (CH) in soil was examined, by means of disturbed columns loaded with a typical semiarid Mediterranean soil (Calcaric fluvisol) under laboratory conditions. Both insecticides appeared in leachates, with 52% of CY and 41% of CH of the initial mass added (1 µg g-1) present. For CY, 21% and 19% were recovered from the upper and bottom layers of the soil, respectively, while for CH, 33% and 22% were recovered from the upper and bottom layers respectively. Based on the calculated half-lives (29 and 27 days for CY and CH, respectively) and their log K OC (about 2.5 for both), the calculated Groundwater Ubiquity Score (GUS) index was higher than 5 for both, indicating they have the potential to leach. Two transformation products, C13H9Cl2N2O (IN-ECD73) and C19H12BrClN6O (IN-J9Z38) corresponding to the degradation of CH and CY, respectively were also identified and detected in leachates and soil.

Evaluation of residue risk and toxicity of different treatments with diazinon insecticide applied to mushroom crops.

This work describes the phytotoxic effect of different doses of diazinon and different application times on Agaricus bisporus mycelium, and determines the residue levels in mushrooms from the first three flushes. Mushroom cultivation is a widespread commercial activity throughout the world. The application of insecticide diazinon to the compost or casing layer is a common practice to control two mushroom pests, the phorid Megaselia halterata and the sciarid Lycoriella auripila. Application to the compost does not result in any appreciable fall in yield or quality, and does not delay the harvest time. In contrast, application to the casing led to a slight fall (6.2%) in production and a smaller number of mushrooms although they are larger in size. Residue levels of more than 0.01 ppm are detected in many of the samples analyzed, and raising the question whether the product should continue to be used in mushroom cultivation in the conditions in which it is currently applied.

Characters of compost teas from different sources and their suppressive effect on fungal phytopathogens.

Compost teas (CT) are fermented watery extracts of composted materials that are used to control plant diseases and on crop fertilization. In this work, aerated (ACT) and non-aerated compost teas (NCT) were obtained from four different composts: spent mushroom substrate compost, grape marc compost, greenhouse horticultural crop residues compost, and vermicompost. Physico-chemical and microbiological analysis were carried out to determine their properties. In vitro assays were performed to assess their suppressive effect on the mycelial growth of eight fungal phytopathogens. In vivo trials aimed to assess their effect on gummy stem blight (Didymella bryonae) and powdery mildew (Podosphaera fusca) in melon plants. Results showed that ACT and NCT filtrates inhibited the in vitro growth of all tested pathogens while autoclaved CT did not completely lose their inhibitory effect, and CT sterilized by microfiltration had no effect on the pathogen growth. The severity of powdery mildew was highly reduced by ACT and NCT from all sources, though in gummy stem blight assay only a delay in disease development was observed. In general, all compost teas showed a high level of microbial populations and nutrients. Results suggest that the efficacy of ACT and NCT firstly depend on the microbiota present in them. We consider compost teas from the four tested sources as a viable way to manage plant diseases and crop fertilization, throughout its integration in pest management programs and fertirrigation systems under different dilution rates.

Effect of spent mushroom compost tea on mycelial growth and yield of button mushroom (Agaricus bisporus).

Preliminary studies suggested that the use of compost tea made from spent mushroom substrate (SMS) may be regarded as a potential method for biologically controlling dry bubble disease in button mushroom. The aim of this study was to assess the effect of SMS compost tea on the host, the button mushroom, to ascertain whether the addition of these water extracts has a toxic effect on Agaricus bisporus mycelium growth and on mushroom yield. In vitro experiments showed that the addition of SMS compost tea to the culture medium inoculated with a mushroom spawn grain did not have an inhibitory effect on A. bisporus mycelial growth. The effect of compost teas on the quantitative production parameters of A. bisporus (yield, unitary weight, biological efficiency and earliness) was tested in a cropping trial, applying the compost teas to the casing in three different drench applications. Quantitative production parameters were not significantly affected by the compost tea treatments although there was a slight delay of 0.8-1.4 days in the harvest time of the first flush. These results suggest that compost teas have no fungitoxic effect on A. bisporus so that they can be considered a suitable biocontrol substance for the control of dry bubble disease.

The effects of Mozart's music on the performance of glaucoma patients on automated perimetry.

PURPOSE: The purpose of this study was to examine the impact of the Mozart effect on the reliability of the Humphrey visual field (HVF; Carl Zeiss Meditec, Dublin, CA) test in subjects with glaucoma. A previous study showed improved reliability in normal subjects undergoing HVF testing. METHODS: One hundred sixty subjects with glaucoma were randomized to three groups: control, headphones, or music for 10 minutes before HVF testing. The headphone group was provided noise-cancellation headphones but no music. The music group listened to Mozart's Sonata for Two Pianos in D Major. After treatment, subjects took an HVF test in both eyes. The reliability of the test was then compared between the groups and also to prior HVF results with regard to fixation losses, false positives, and false negatives. RESULTS: The rate of fixation losses did not differ significantly between the three groups (P = 0.30 right eye, P = 0.24 left eye). There were also no significant differences in the rate of false positives (P = 0.82 right eye, P = 0.18 left eye) or false negatives (P = 0.91 right eye, P = 0.97 left eye). The reliability of the subject's HVF result was also compared with past field results. No improvements were seen in fixation losses (P = 0.94 right eye, P = 0.17 left eye), false positives (P = 0.85 right eye, P = 0.38 left eye), and false negatives (P = 0.13 right eye, P = 0.50 left eye). CONCLUSIONS: The rate of fixation losses, false positives, and false negatives did not improve in subjects with glaucoma after they listened to Mozart's music. The Mozart effect did not enhance the reliability of the visual field test to a statistically significant degree (ClinicalTrials.gov number, NCT01027039).

[Mortality and prognostic factors in patients admitted with community-acquired bacteremia]. / Mortalidad y factores pronósticos en pacientes hospitalizados por bacteriemia adquirida en la comunidad.

BACKGROUND: Community-acquired bacteremia is a frequently clinical problem and is associated with a high mortality. The Pitt bacteremia score that is calculated using body temperature, mental status, and some respiratory and circulatory features is an useful tool in order to know the prognosis of patients with bacteremia. Objectives were to know microbial etiology of bacteremia in our community, percentage of patients that received an inadequate empiric antibiotic treatment and independent prognostic factors associated with mortality, including Pitt bacteremia score. METHOD: Observational study of a cohort of patients over 18 years admitted at a tertiary hospital due to an infection with a community-acquired bacteremia. Twenty-eight cases were rejected because possible blood culture contamination. RESULTS: Seventy-five patients were included, the mean age was 68.6 +/- 18.2 years, 38 women (51%). Mortality rate was 23% [IC95% 13.8-33.8]. More frequent bacteria isolated were Escherichia coli, Staphylococcus aureus, coagulase negative staphylococci, Pseudomonas aeruginosa, Streptococcus viridans, enterococci and Klebsiella spp. Mortality in patients treated with an inadequate antibiotic therapy (18%, 3 patients) was not lower than in adequately treated patients (24%, 14 patients, p = 0.42). Independent prognostic factors related to mortality were serum albumin concentration, OR = 5.17 (IC 95% 1.45-16.7) for every downing step of 1 g/dl, the Pitt bacteremia score OR = 1.50 (IC 95% 1.01-2.24) for every unit increase, and a high score at McCabe and Jackson classification OR = 5.08 ( IC 95% 1.43-16.7). CONCLUSIONS: An inadequate empiric antibiotic therapy was not associated with a worse vital prognosis. Independent prognostic factors related to mortality were serum albumin concentration, the Pitt bacteremia score, and the McCabe and Jackson classification.

Reduced sensitivity of the mushroom pathogen Verticillium fungicola to prochloraz-manganese in vitro.

105 isolates of Verticillium fungicola from Spanish mushroom crops collected between 1992 and 1999 were tested in vitro for their sensitivities to prochloraz-manganese. Dose response relationships for inhibition of mycelial growth by the fungicide were assessed in radial growth experiments on fungicide-amended malt extract agar. The ED50 values recorded for all 105 isolates studied ranged between 0.8 ppm in 1992 and 8.8 in 1998, with an average of 2.9. 86% of the isolates tested were more sensitive to prochloraz-manganese and had ED50 values below 5 ppm, while the other 14% were slightly tolerant with ED50 values equal or above 5 ppm. Of those tested from 1999, 60% (21 isolates) grew with 50 ppm and 40% (14) also at 100 ppm, although mycelial growth was inhibited at least by 82 and 87%, respectively. The resistance factor calculated ranged from low fungicide resistance (RF=3.0) in 1992 to moderate resistance (RF=12.6) in 1998. These data confirm that the sensitivity of V. fungicola to the prochloraz-manganese gradually diminishes.