Aims and Scope The Irish Journal of Agricultural and Food Research is a peer reviewed open access scientific journal published by Teagasc (Agriculture and Food Development Authority, Ireland). Manuscripts on any aspect of research of direct relevance to Irish agriculture and food production, including plant and animal sciences, food science, agri environmental science, soils, engineering, buildings, economics and sociology, will be considered for publication. The work must demonstrate novelty and relevance to the field of research. Papers published or offered for publication elsewhere will not be considered, but the publication of an abstract does not preclude the publication of the full paper in this journal. Current issues are also available on the publisher site https://www.degruyter.com/view/j/ijafr Back issues of the journal are available at the following links: Current title: Irish Journal of Agricultural and Food Research (1992-2014) http://www.jstor.org/journal/irisjagrifoodres Previous Titles Irish journal of agricultural research (1961-1991) http://www.jstor.org/journal/irisjagrirese Irish journal of agricultural economics and rural sociology (1977-1991) http://www.jstor.org/journal/irisjagrieconrur Irish journal of food science and technology (1967-1991) http://www.jstor.org/journal/irisjfoodscitech Contact ijafr@teagasc.ie

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  • The fatty acid profile and stable isotope ratios of C and N of muscle from cattle that grazed grass or grass/clover pastures before slaughter and their discriminatory potential

    Moloney, Aidan P; O'Riordan, Edward G.; Schmidt, Olaf; Monahan, Frank J (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-11-09)
    Consumption of grazed pasture compared to concentrates results in higher concentrations, in beef muscle, of fatty acids considered to be beneficial to human health. Little information is available on the influence of the type of grazed forage. Our objectives were to determine 1) the effect of inclusion of white clover in a grazing sward on the fatty acid profile of beef muscle and 2) the potential of the fatty acid profile and stable isotope ratios of C and N to discriminate between beef from cattle that grazed grass-only or grass/clover swards before slaughter. A total of 28 spring-born Charolais steers grazed from March until slaughter in October, either on a perennial ryegrass (Lolium perenne L.) sward that received approximately 220 kg N/ha or a perennial ryegrass–white clover (Trifolium repens L.) sward that received 50 kg N/ha. The longissimus muscle from cattle finished on grass/clover had a higher (P < 0.05) proportion of C18:2 and C18:3 but a lower (P < 0.05) proportion of conjugated linoleic acid and δ15N value than animals finished on the grass-only sward. Discriminant analysis using the fatty acid data showed that, after cross-validation, 80.7% of grass/clover and 86.1% of grass-only muscle samples were correctly classified. Discriminant analysis using the stable isotope data showed that, after cross-validation, 95.7% of grass/clover and 86.5% of grass-only muscle samples were correctly classified. Inclusion of white clover in pasture is likely to have little effect on healthiness of meat for consumers. However, changes in fatty acids and stable isotopes can be used to distinguish between grass/clover-fed and grass-only-fed beef.
  • Effects of mycorrhizal inoculation and digestate fertilisation on triticale biomass production using fungicide-coated seeds

    Caruso, C.; Maucieri, C.; Barco, A.; Barbera, A. C.; Borin, M.; PSR Regione Veneto; 2307827 (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-09-07)
    Crop fertilisation management using organic wastes and arbuscular mycorrhizal fungi (AMF) inoculation can play a crucial role in the sustainability of agroecosystems. However, in conventional agricultural systems, agrochemicals like fungicides could reduce the positive effect of AMF. The aim of this study was to evaluate the agronomic (biomass production) and environmental (soil CO2 emission) effects of AMF inoculation and digestate spreading on triticale cultivation using commercial seeds coated with fungicide. The field experiment was conducted in 2014–2015 at the University of Padua’s experimental farm (Italy), adopting a split-plot design, where the main plot factor was AMF inoculation (inoculated vs. uninoculated) and the subplot factor was fertilisation treatment (no fertilisation (NF), digestate liquid fraction (DL), digestate solid fraction (DS), mineral fertilisation (MF)). Low AMF root colonization was observed, likely due to the effect of fungicide; the only significant effect of AMF inoculation was a lower shoot density. Dry biomass production was significantly higher in the MF treatment (21.8 ± 1.04 Mg/ha) and lower in the NF treatment (14.5 ± 0.73 Mg/ha) compared to DS and DL treatments, which were not significantly different with an average yield of 17.2 ± 2.10 Mg/ha. During the cropping season, soil CO2 emissions were not significantly affected by either AMF inoculation or fertilisation treatment. The median value of soil CO2 emissions was 447.3 mg/m2 per hour.
  • Evaluating the effect of storage conditions on milk microbiological quality and composition

    Paludetti, L.F.; Jordan, Kieran; Kelly, Alan L.; Gleeson, David E (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-07-19)
    In this study, the effect of storage temperature (2 or 4°C) on the composition of milk and microbiological load was investigated over 96 h. Milk samples were collected from farm bulk milk tanks after one complete milking and stored at 2 or 4°C over 96 h. Total bacterial count (TBC), psychrotrophic bacterial count (PBC) and proteolytic bacterial count (PROT) were affected by storage time and temperature and varied significantly between farms (P < 0.05). The levels of TBC, PBC and PROT bacterial count increased from 4.37 to 6.15 log cfu/mL, 4.34 to 6.44 log cfu/mL and 3.72 to 4.81 log cfu/mL, respectively, when the milk was stored for 96 h at 2°C. The milk samples stored at 4°C had higher increases in these bacterial counts after 72 h in comparison to milk samples stored at 2°C. The casein fraction content was lower in milk samples stored at 4°C, which could be due to high levels of PROT bacteria or enzyme activity in these samples. Milk stored for 96 h at 2°C has less impact on composition or processability parameters compared to milk stored at 4°C.
  • Effect of biostimulants on cold resistance and productivity formation in winter rapeseed and winter wheat

    Gaveliiene, V.; Pakalniskyte, L.; Novickienė, L.; Balciauskas, L. (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-10)
    The aim of the study was to investigate the effects of biostimulants on the resistance to freezing under laboratory-controlled cold conditions and on the growth, development, overwintering and productivity of winter rapeseed and winter wheat in natural field experiments. The effect of free amino acids, macroelements and microelements that contain biostimulants Ruter AA, Terra Sorb and Razormin was tested on cultivars of rapeseed, ‘Hornet H’, and winter wheat, ‘Skagen’ and ‘Kovas’, applying morphometrical methods. We found that biostimulants applied to rapeseed at BBCH 13–14 stage and to wheat at BBCH 14–15 stage under controlled cold stress conditions increased the freezing tolerance of seedlings. Biostimulants more actively increased the freezing resistance of rapeseed seedlings at –5°C compared to that of wheat seedlings. The temperature of –7°C was mortal to rape seedlings, while the resistance of wheat seedlings increased under the influence of the tested biostimulants compared to that of the control seedlings. In natural field experiments, these biostimulants produced a significant effect on plant growth in autumn, acclimation to the cold, plant overwintering, vegetation renewal and, due to this, formation of productivity elements. The effects of Razormin (200 mL/ha), Terra Sorb (2 L/ha) and Ruter AA (1 L/ha) were significantly higher on growth parameters of winter wheat compared to the productivity of winter rapeseed.
  • Fortification of milk with phytosterol and its effect on sensory and physicochemical properties

    Nagarajappa, V.; Battula, S. N.; Arora, S.; Naik, L. N.; National Dairy Research Institute (NDRI), Karnal, India (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-08-31)
    Phytosterols are a group of lipophilic steroid alcohols found in plants, which have been shown to lower cholesterol when supplemented in the diet. A commercial phytosterol preparation was added to milk in the form of an oil-in-water emulsion. For the preparation of an emulsion, diacetyl tartaric acid ester of mono- and diglycerides was used as an emulsifier and butteroil was used as a source of fat. Three emulsion formulations, i.e. A (8% phytosterols), B (10% phytosterols) and C (12% phytosterols), were prepared in which the levels of emulsifier (6.5%) and butteroil (10%) were kept constant, and each emulsion was added to milk at a rate of 5% (w/w). Based on sensory evaluation, B-emulsion formulation was selected for fortification of milk. The phytosterol content of the fortified milk determined by reverse-phase high-performance liquid chromatography was 410.8 mg/100 g. No significant loss in the initial content of phytosterol was observed after 1 week of storage. Sensory and physicochemical analyses indicated that significant differences were not observed between control and fortified milk samples up to 7 days of refrigerated storage. The present study suggests that it is feasible to add phytosterol as a functional ingredient in milk in the form of water-soluble emulsion to enhance health benefits of consumers. Two servings of such fortified milk per day provide almost the entire recommended daily requirement of phytosterol.
  • A critical review of integrated grass weed management in Ireland

    Byrne, Ricky; Spink, John; Freckleton, R.; Neve, Paul; Barth, Susanne; Teagasc Walsh Fellowship Programme (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-04-10)
    Grass weeds affect arable crops throughout the world, inflicting yield penalties, reducing crop quality and taking available nutrients away from the growing crop. Recently in Ireland, the presence of herbicide resistance in grass weeds has been noted. In order to preserve the sustainability of crop production in Ireland, an integrated pest management approach must be implemented. How this applies to control grass weeds was the focus of this review. Here we examined the state of current research into grass weed biology and the nature of herbicide resistance, identifying gaps in research in the Irish context. We identified a number of cultural grass weed control techniques, as being relevant to the Irish mode of crop production. Crop rotation, cultivation techniques, manipulation of sowing dates and increased crop competition were recognised as useful strategies. Combining these strategies to provide effective grass weed control may be key to reduce dependence on herbicides.
  • A comparison of husked and naked oats under Irish conditions

    Hackett, Richard (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-02-22)
    During the harvesting of husked oats (Avena sativa L.), the kernel remains tightly enclosed by a lignified lemma and palea, collectively termed the husk or hull. In naked oats, which are the same species as husked oats, the lemma is much less lignified and the kernel threshes free during harvesting. The absence of the largely indigestible husk increases the nutritive value of naked oats compared to that of husked oats, particularly for non-ruminants and poultry. There is little information regarding the potential of naked oats as an arable crop in Ireland. The objective of this study was to determine the productivity of naked oats under Irish conditions. Field experiments were carried out in the south east of Ireland to compare the grain yield and grain quality of both autumn-sown and spring-sown naked and husked oat cultivars. Grain yield of naked oat cultivars was significantly lower than that of husked oat cultivars, irrespective of whether they were autumn sown or spring sown. However, when the kernel yield of husked oat cultivars was estimated, differences in yield between the two types were much smaller, and in some cases, kernel yield of naked oat cultivars exceeded that of husked oat cultivars. Grain quality, as indicated by hectolitre weight and grain N concentration, was generally greater for naked oat cultivars than for husked oat cultivars. It is concluded that under Irish conditions, naked oats have the potential to produce kernel yields equivalent to husked oats. The grain produced is of high quality and may be particularly suited for the nutrition of non-ruminants.
  • Ethical, moral and social dimensions in farm production practices: a segmentation study to assess Irish consumers’ perceptions of meat quality

    Regan, Áine; Henchion, Maeve; McIntyre, Bridin (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-03-09)
    Growing consumer concerns with modern farming and food production systems indicate a significant market opportunity for meat production practices that consider ethical, moral and social value traits. In the current study, we aimed to identify and characterise distinct segments of Irish consumers based on their perceptions of the quality of meat from different farm-level production practices (organic farming, high animal welfare standards, free range farming, and “natural”, treatment-free feeding regimes). An online survey was carried out with 251 Irish meat consumers. Using cluster analysis, we identified three distinct segments: “Target consumers”, “Purist consumers” and “Disinterested consumers”. Chi-square analyses revealed differences between the segments based on gender, age and meat-purchasing motivations. The results provide insight into the opportunities that exist for exploring new viable market segments as well as for engaging Irish consumers and empowering them with information around the ethical, social and moral aspects of farm-level practices related to meat production.
  • Insect assemblages and their preference for Lupinus albus and L. luteus

    Nikolova, Ivelina; Georgieva, N. (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-05-23)
    While lupin has undergone extensive research to ascertain its suitability for growth as forage or grain legume crop, the present trend is for research to be centered on its applicability in the seed protein and oil industry. Study of the literature showed that no intensive study of the lupin insect fauna had been carried out in Bulgaria. The purpose of this study was to identify the insect assemblages associated with Lupinus albus and L. luteus, as well as the insect preference for them. Thrips sampling was made by the tapping-method, aphids were directly counted on the plants and the composition and population density of other species were recorded by sweepings. Insect fauna was studied for the first time in Bulgaria. The fauna was represented on L. albus by 64 species, belonging to eight orders, 28 families and 57 genera, including 23 beetles, 25 hemipteras, five thrips, three butterflies, three bees, one leaf aphid, two grasshoppers, one leafminer and one green lacewing. L. luteus had similar species composition but was less preferred by insects. The use of lupin cultivars with shorter and intense reproductive periods, with a lower content of crude protein and phosphorus, would give an environmentally friendly protection against insect pests, which would be suitable for an organic production system.
  • Application of Dexter’s soil physical quality index: an Irish case study

    Fenton, Owen; Vero, Sara E.; Schulte, Rogier P.; O'Sullivan, Lilian; Bondi, G.; Creamer, Rachel E.; Department of Agriculture, Food and the Marine, Ireland; 6582 (Teagasc (Agriculture and Food Development Authority), Ireland, 26/08/2017)
    Historically, due to a lack of measured soil physical data, the quality of Irish soils was relatively unknown. Herein, we investigate the physical quality of the national representative profiles of Co. Waterford. To do this, the soil physical quality (SPQ) S-Index, as described by Dexter (2004a,b,c) using the S-theory (which seeks the inflection point of a soil water retention curve [SWRC]), is used. This can be determined using simple (S-Indirect) or complex (S-Direct) soil physical data streams. Both are achievable using existing data for the County Waterford profiles, but until now, the suitability of this S-Index for Irish soils has never been tested. Indirect-S provides a generic characterisation of SPQ for a particular soil horizon, using simplified and modelled information (e.g. texture and SWRC derived from pedo-transfer functions), whereas Direct-S provides more complex site-specific information (e.g. texture and SWRC measured in the laboratory), which relates to properties measured for that exact soil horizon. Results showed a significant correlation between S-Indirect (Si) and S-Direct (Sd). Therefore, the S-Index can be used in Irish soils and presents opportunities for the use of Si at the national scale. Outlier horizons contained >6% organic carbon (OC) and bulk density (Bd) values <1 g/cm3 and were not suitable for Si estimation. In addition, the S-Index did not perform well on excessively drained soils. Overall correlations of Si. with Bd and of Si. with OC% for the dataset were detected. Future work should extend this approach to the national scale dataset in the Irish Soil Information System.
  • The eating quality of beef from young dairy bulls derived from two breed types at three ages from two different production systems

    Nian, Yingqun; Kerry, Joseph P.; Prendiville, Robert; Allen, Paul; Teagasc Walsh Fellowship Programme (Teagasc (Agriculture and Food Development Authority), Ireland, 08/07/2017)
    Expansion of the Irish dairy herd has led to more dairy breed male calves being available for beef production. This study investigated the physico-chemical and sensory characteristics of beef from Holstein-Friesian (HF) and Jersey × HF (JEX) young bulls fed pasture grass only or pasture grass plus 2 kg concentrate during their first grazing season and slaughtered at 15, 19 or 22 mo of age. Longissimus thoracis (LT) muscles were collected from 67 carcasses. Postmortem pH, ultimate pH (pHu), meat colour, chemical composition, collagen content and solubility were evaluated. After ageing for 21 d, Warner-Bratzler shear force and cooking loss were determined, and assessments by a trained sensory panel were conducted. Meat from older animals was darker. The pHu, moisture and ash contents decreased, while residual roast beef flavour length increased with age. However, increasing age to slaughter did not negatively influence tenderness. JEX beef had lower cooking loss, was darker and redder, in addition to having higher sensory scores for initial tenderness and fattiness than HF beef. Warner-Bratzler variables were positively correlated with cooking loss and chewiness and were negatively correlated with intramuscular fat (IMF) content, soluble collagen and initial tenderness. In summary, most young dairy bull beef samples were acceptably tender after 21 d of ageing and half of them had acceptable IMF content. Slaughter age affected beef colour, pHu, chemical composition and flavour length. The eating quality of meat from the JEX breed type was considered to be superior to that of the HF breed type. Diet during the first season had no effect on meat quality traits.
  • Determination of Listeria monocytogenes numbers at less than 10 cfu/g

    Hunt, Karen; Vacelet, M.; Jordan, Kieran; Department of Agriculture, Food and the Marine, Ireland; Dairy Processing Technology Centre; 11/F/008; TC 2014 0016. (Teagasc (Agriculture and Food Development Authority), Ireland, 09/06/2017)
    Listeria monocytogenes is a foodborne pathogen that causes a relatively rare foodborne disease called listeriosis, with a high mortality rate of 20%-30% and an undefined dose response. Current European Union regulations permit up to 100 colony-forming units (cfu)/g in food at the end of its shelf life, where the food has been shown not to support the growth of this pathogenic bacterium. Therefore, enumeration of L. monocytogenes at low numbers in food is important. The objective of this study was to reduce the detection limit of L. monocytogenes in food by a factor of 10. The International Organisation for Standardisation (ISO) 11290-2 method for enumeration of L. monocytogenes in food recommends spreading 0.1 mL of a 1:10 dilution of the food on the surface of an agar plate (detection limit 100 cfu/g), or 1.0 mL spread in equal parts on the surface of three agar plates (detection limit: 10 cfu/g). The pour-plate method (using 1 or 10 mL of an appropriate dilution) was compared to the spread-plate method using the ISO-approved chromogenic medium Agar Listeria according to Ottaviani and Agosti (ALOA). Using the pour-plate method, the colony morphology and halo formation were similar to the spread-plate method from pure cultures and inoculated foods. Using the pour-plate method in a 140 mm Petri dish, 10 mL of a 1:10 dilution of food allowed determination of numbers as low as 1 cfu/g. Applying this method, L. monocytogenes in naturally contaminated food samples were enumerated at numbers as low as 1-9 cfu/g.
  • Scientific appraisal of the Irish grass-based milk production system as a sustainable source of premium quality milk and dairy products

    O'Brien, Bernadette; Hennessy, Deirdre (Teagasc (Agriculture and Food Development Authority), Ireland, 2017-12-29)
    The Irish dairy industry is critically important to the economy and general well-being of a large section of the Irish population. Its quality, sustainability and maintenance are the key for a vibrant rural society in the future. Two important elements for the future of this industry include (a) the quality, marketing and sale of dairy products on the export market and (b) sustainability from the perspectives of people, planet and profit. This paper provides a short review of current scientific evidence in relation to a number of topics, each of which is important in maintaining and developing dairy product quality and the sustainability of the Irish dairy industry. The topics addressed in the paper are as follows: the parameters of milk composition; milk processing; hygiene quality and safety; farm management practices and the regulations that govern such practices; animal health and welfare; environmental impacts; economic implications for farm families and rural communities; and the overall future sustainability of the family-based dairy farm structure.
  • Animal performance and economic implications of alternative production systems for dairy bulls slaughtered at 15 months of age

    Murphy, B.M.; Crosson, Paul; Kelly, Alan K; Prendiville, Robert; Department of Agriculture, Food and the Marine, Ireland; 11/SF/322 (Teagasc (Agriculture and Food Development Authority), Ireland, 2017-10-26)
    The objectives of this experiment were to investigate (i) the influence of varying levels of concentrate supplementation during the grazing season, (ii) alternative finishing strategies for dairy bulls slaughtered at 15 mo of age and (iii) economic implications of these management strategies. Bulls were assigned to a 2 (level of concentrate supplementation during the grazing season: 1 kg [LA] and 2 kg [HA] dry matter [DM]/head daily) × 2 (finishing strategies: concentrates ad libitum group [AL] or grass silage ad libitum plus 5 kg DM of concentrates/head daily group [SC]) factorial arrangement of treatments. Average daily gain (ADG) during the grazing season was greater (P < 0.01) for HA than for LA. Consequently, HA bulls were 16 kg heavier at housing: 214 and 230 kg, respectively (P < 0.05). During the finishing period, ADG tended (P = 0.09) to be greater for LA than for HA. Carcass weight tended (P = 0.08) to be greater for HA than for LA. Fat score was greater for HA. Live weight at slaughter (P < 0.001) and carcass weight (P < 0.001) were 41 and 23 kg greater for AL than for SC, respectively. Conformation (P < 0.05) and fat score (P < 0.05) were greater for AL than for SC. The Grange Dairy Beef Systems Model simulated whole-farm system effects of the production systems. Net margin/head was greater for LA than for HA and greater for SC than for AL. Sensitivity analysis of finishing concentrate price, calf purchase price and beef price showed no re-ranking of the systems on a net margin basis. Although greater animal performance was observed from the higher plane of nutrition, overall profitability was lower.
  • Sinapinic and protocatechuic acids found in rapeseed: isolation, characterisation and potential benefits for human health as functional food ingredients

    Quinn, Leah; Gray, Stephen G.; Meaney, Steven; Finn, Stephen; Kenny, Owen; Hayes, Maria (Teagasc (Agriculture and Food Development Authority), Ireland, 13/12/2017)
    Rapeseed is one of the world’s major oilseeds, and rapeseed oil is produced by pressing of the seeds. This process results in the production of a low-economic-value by-product, rapeseed meal, which is commonly used as animal feed. Rapeseed meal is rich in bioactive phenolic compounds, including sinapinic acid (SA) and protocatechuic acid (PCA). Isolation of these bioactive compounds from a by-product of rapeseed oil production is largely in agreement with the current concept of the circular economy and total utilisation of crop harvest using a biorefinery approach. In this review, current information concerning traditional and novel methods to isolate phenolic compounds – including SA and PCA – from rapeseed meal, along with in vitro and in vivo studies concerning the bioactivity of SA and PCA and their associated health effects, is collated. These health effects include anti-inflammatory, anti-cancer, anti-diabetes activities, along with histone deacetylase inhibition and protective cardiovascular, neurological and hepatic effects. The traditional extraction methods include use of solvents and/or enzymes. However, a need for simpler, more efficient methodologies has led to the development of novel extraction processes, including microwave-assisted, ultrasound-assisted, pulsed electric field and high-voltage electrical discharge extraction processes.
  • The effect of antimicrobials on verocytotoxin bacteriophage transduction under bovine rumen fluid and broth conditions

    Nyambe, Sepa; Burgess, Catherine; Whyte, Paul; Bolton, Declan J.; Department of Agriculture, Food and the Marine, Ireland; 11/F/051 (Teagasc (Agriculture and Food Development Authority), Ireland, 15/11/2017)
    The verocytotoxin genes in verocytotoxigenic Escherichia coli (VTEC) are carried by bacteriophages, incorporated into the bacterial genome (prophage). Antibiotics may promote phage replication and release to infect other cells (transduction), thus leading to the emergence of new VTEC strains. This study investigated transduction of a verocytotoxin2-encoding bacteriophage (3538(vtx2::cat)) under laboratory conditions, including the effect of antibiotic treatments. Luria-Bertani Miller broth and rumen fluid (raw and sterilised by irradiation) were inoculated with the donor (C600φ3538(Δvtx2::cat)) and recipient (E. coli C600::kanamycinR) strains (4 log10 cfu/mL) and incubated at 38°C. Antibiotic treatments (minimal inhibitory and sub-inhibitory concentrations of ampicillin, cefquinome, oxytetracycline and sodium sulfamethazine) were applied after 3 h. Samples were tested for donor, recipient, cell-free phage and transductants at times t = 0, 3, 4, 6, 27 (24 h post-antibiotic treatment) and 51 h. Free phage was detected in the untreated broth and rumen samples, as were the transductants confirmed by polymerase chain reaction. The antibiotic treatments did not significantly (P > 0.01) increase the concentrations of free phage or transductants detected. It was therefore concluded that, under laboratory conditions, the antibiotics tested did not induce bacteriophage lysis, release and infection of new bacterial cells beyond that constitutively found in the phage population.
  • Effects of water activity on the performance of potassium sorbate and natamycin as preservatives against cheese spoilage moulds

    Marin, P.; Gines, C.; Kochaki, C.; Jurado, M. (Teagasc (Agriculture and Food Development Authority), Ireland, 2017-10-26)
    This work investigated the effects of the food preservatives potassium sorbate and natamycin, combined with different levels of ionic (sodium chloride) and non-ioinic (glycerol) water activity (aw), on growth of fungi involved in cheese spoilage. In general, the combined effect of water stress and presence of preservatives enhanced fungal inhibition. However, some doses of potassium sorbate (0.02%) and natamycin (1, 5 and 10 ppm) were able to stimulate growth of Aspergillus varians, Mucor racemosus, Penicillium chrysogenum and P. roqueforti at aw values in the range of 0.93–0.97. P. solitum was the only species whose growth was consistently reduced by any doses of preservative. The results also showed that sodium chloride and glycerol differentially affected the efficacy of preservatives. This study indicates that aw of cheese is a critical parameter to be considered in the formulation of preservative coatings used against fungal spoilage.
  • The interactive effects of various nitrogen fertiliser formulations applied to urine patches on nitrous oxide emissions in grassland

    Krol, Dominika J.; Minet, E.; Forrestal, Patrick J.; Lanigan, Gary; Mathieu, O.; Richards, Karl G.; Department of Agriculture, Food and the Marine, Ireland; RSF10/RD/SC/716; 11S138 (Teagasc (Agriculture and Food Development Authority), Ireland, 19/09/2017)
    Pasture-based livestock agriculture is a major source of greenhouse gas (GHG) nitrous oxide (N2O). Although a body of research is available on the effect of urine patch N or fertiliser N on N2O emissions, limited data is available on the effect of fertiliser N applied to patches of urinary N, which can cover up to a fifth of the yearly grazed area. This study investigated whether the sum of N2O emissions from urine and a range of N fertilisers, calcium ammonium nitrate (CAN) or urea ± urease inhibitor ± nitrification inhibitor, applied alone (disaggregated and re-aggregated) approximated the N2O emission of urine and fertiliser N applied together (aggregated). Application of fertiliser to urine patches did not significantly increase either the cumulative yearly N2O emissions or the N2O emission factor in comparison to urine and fertiliser applied separately with the emissions re-aggregated. However, there was a consistent trend for approximately 20% underestimation of N2O loss generated from fertiliser and urine applied separately when compared to figures generated when urine and fertiliser were applied together. N2O emission factors from fertilisers were 0.02%, 0.06%, 0.17% and 0.25% from urea ± dicyandiamide (DCD), urea + N-(n-butyl) thiophosphoric triamide (NBPT) + DCD, urea + NBPT and urea, respectively, while the emission factor for urine alone was 0.33%. Calcium ammonium nitrate and urea did not interact differently with urine even when the urea included DCD. N2O losses could be reduced by switching from CAN to urea-based fertilisers.
  • Assessment of water-limited winter wheat yield potential at spatially contrasting sites in Ireland using a simple growth and development model

    Lynch, J.P.; Fealy, Reamonn; Doyle, D.; Black, L.; Spink, John; Department of Agriculture, Food and the Marine, Ireland (Teagasc (Agriculture and Food Development Authority), Ireland, 19/09/2017)
    Although Irish winter wheat yields are among the highest globally, increases in the profitability of this crop are required to maintain its economic viability. However, in order to determine if efforts to further increase Irish wheat yields are likely to be successful, an accurate estimation of the yield potential is required for different regions within Ireland. A winter wheat yield potential model (WWYPM) was developed, which estimates the maximum water-limited yield achievable, within the confines of current genetic resources and technologies, using parameters for winter wheat growth and development observed recently in Ireland and a minor amount of daily meteorological input (maximum and minimum daily temperature, total daily rainfall and total daily incident radiation). The WWYPM is composed of three processes: (i) an estimation of potential green area index, (ii) an estimation of light interception and biomass accumulation and (iii) an estimation of biomass partitioning to grain yield. Model validation indicated that WWYPM estimations of water-limited yield potential (YPw) were significantly related to maximum yields recorded in variety evaluation trials as well as regional average and maximum farm yields, reflecting the model’s sensitivity to alterations in the climatic environment with spatial and seasonal variations. Simulations of YPw for long-term average weather data at 12 sites located at spatially contrasting regions of Ireland indicated that the typical YPw varied between 15.6 and 17.9 t/ha, with a mean of 16.7 t/ha at 15% moisture content. These results indicate that the majority of sites in Ireland have the potential to grow high-yielding crops of winter wheat when the effects of very high rainfall and other stresses such as disease incidence and nutrient deficits are not considered.
  • A rapid and multi-element method for the analysis of major nutrients in grass (Lolium perenne) using energy-dispersive X-ray fluorescence spectroscopy

    Daly, Karen M.; Fenelon, A. (Teagasc (Agriculture and Food Development Authority), Ireland, 21/04/2017)
    Elemental analysis of grass (Lolium perenne) is essential in agriculture to ensure grass quality and animal health. Energy-dispersive X-ray fluorescence (EDXRF) spectroscopy is a rapid, multi-element alternative to current methods using acid digestion and inductively coupled plasma optical emission spectrometry (ICP-OES). Percentage phosphorus (P), potassium (K), magnesium (Mg) and calcium (Ca), determined from grass samples using EDXRF, were within 0.035, 0.319, 0.025 and 0.061, respectively, of ICP-OES values. Concordance correlation coefficients computed using agreement statistics ranged from 0.4379 to 0.9669 (values close to one indicate excellent agreement); however, the level of agreement for each element depended on the calibrations used in EDXRF. Empirical calibrations gave excellent agreement for percentage P, K and Ca, but moderate agreement for percentage Mg due to a weaker correlation between standards and intensities. Standardless calibration using the fundamental parameters (FP) approach exhibited bias, with consistently lower values reported for percentage P and Mg, when compared with ICP-OES methods. The relationship between the methods was plotted as scatter plots with the line of equality included, and although correlation coefficients indicated strong relationships, these statistics masked the effects of consistent bias in the data for percentage P and Mg. These results highlight the importance of distinguishing agreement from correlation when using statistical methods to compare methods of analysis. Agreement estimates improved when a matching library of grass samples was added to the FP method. EDXRF is a comparable alternative to conventional methods for grass analysis when samples of similar matrix type are used as empirical standards or as a matching library.

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