• Assessing populations of the major cereal pathogens for reduced sensitivity to MBC, DMI and Strobilurin fungicides

      O'Sullivan, Eugene (Teagasc, 01/08/2009)
      Studies of eyespot populations in winter wheat crops in the period 2001 to 2003 showed that the R type (Tapesia acuformis) is the dominant strain comprising 77% of isolates. Over 90% of isolates were resistant to MBC fungicides, 53% showed reduced sensitivity to prochloraz and 22% reduced sensitivity to cyprodinil. A study of winter wheat crops in February and March 2003 showed that resistance to strobilurin fungicides was widespread in Mycosphaerella graminicola (Septoria tritici) populations. Resistance was found in all but one of 21 crops sampled, at levels ranging from 9% to 84% with an average of 48%. Subsequent studies of 27 crops over the summer of 2003 showed that strobilunin resistance increased from an average of 31% before the application of the second (T2) spray to an average of 73%, three to four weeks after the application of the final (T3) spray. Strobilurin resistance in M. graminicola remained high in 2004, ranging from 50% to 100% with an average of 83% in populations in winter wheat crops sampled in March. The effect of different fungicide programmes on resistance was studied during summer 2003 at two experimental sites. Levels of strobilurin resistance in M. graminicola populations increased during the summer, in unsprayed plots and plots treated with triazole fungicides as well as in those treated with strobiurin fungicides at both sites. M. graminicola populations in winter wheat crops sampled in 2003 and 2004 were predominantly resistant to MBC-generating fungicides and sensitive to the triazole-based fungicides. Studies of the barley leaf blotch pathogen Rhynchosporium secalis showed that resistance to MBC fungicides occurred in 20% of isolates collected from crops from 2001 to 2003, but all isolates were sensitive to triazole and strobilurin fungicides.
    • Assessing the Economical and Environmental Impact of Cultivating Genetically Modified (GM) crops in Ireland

      Mullins, Ewen; Flannery, M.L.; Meade, Connor; Thorne, Fiona (Teagasc, 2004-01-01)
      At present, there is no GM crop cultivation in Ireland. This could change in the near future however, following the inclusion of several GM maize varieties on the EU Common Seed Catalogue in 2004. Before an Irish GM tillage sector develops, information must be provided to farmers/regulators in regard to the potential economic impact of the technology and the environmental issues associated with GM crops. This project (RMIS 5211) has examined: 1. The economic cost-benefit of cultivating several GM crops (Phytophthora resistant potato, Septoria resistant wheat, Rhynchosporium resistant barley, Fusarium resistant wheat and herbicide tolerant sugar beet) 2. The environmental issue of gene flow by modelling the propensity of seven crop species (wheat, barley, sugar beet, oilseed rape, maize, potato and ryegrass) to spread their genetic material (be it GM/non-GM) through pollen/seed-mediated gene flow. The cost-benefit analysis specifically examined the impact of reduced chemical input and indicated that each GM crop tested would be more cost efficient than their conventional equivalent. Inputting the regimes and subsequent costs for the 2002 and 2003 growing season into the analysis, farmers would have returned a greater cost savings in 2002 for each of the GM crops, with the exception of potato. While a significant increase in gross margin was recorded for all GM crops, the greatest savings (€ha-1) occurred in the case of herbicide tolerant sugar beet in the absence (9.8% saving) or presence (23.2% saving) of a yield effect. Modelling a crop’s propensity to spread its genetic material (‘gene flow’) was achieved through the creation of a composite gene flow index (GFI) model. Taking into account both pollen and seed mediated data, presence/absence of interfertile wild relatives and current farming practises, a GFI value was returned for each crop. Unless the GM event altered the seed/pollen production of the crop, it can be anticipated that the same GFI value will apply to a GM/non-GM variety of the particular crop. Crops that returned the highest GFI values were ryegrass, oilseed rape and sugar beet. Importantly, a high GFI score does not imply the prohibition of GM varieties of that crop. Rather, it highlights those crops that possess a higher propensity for gene flow and thus require greater management precautions in light of coexistence regulations. To facilitate the provision of this and other relevant research information, a website (www.gmoinfo.ie) has been provided to further public understanding of the issues. Structured in a non-scientific format, this resource will be updated on a regular basis in response to public requests for further information and with research findings from the risk assessment programme at Oak park.
    • Assessment and Control of Foodborne Pathogens in Ireland

      Ross, R Paul; Hill, Colin; Murphy, P.; Jordan, Kieran; Arendt, Elke; van Sinderen, Douwe; Morgan, S.M.; Hickey, Rita M.; Maher, M.J.; Kelly, J.; et al. (Teagasc, 2001-05-01)
      Consumers are increasingly demanding food that is free from pathogens, but with less preservatives and additives. As a response to these conflicting demands, current trends in the food industry include minimal processing, and the investigation of alternative inhibitors for use in foods. Additionally, the manufacture of an increasing range of novel foods, and the inclusion of non-dairy ingredients into dairy products, and vice versa, poses additional dangers with respect to safety. Furthermore, the dramatic increase in incidence of food-borne illness internationally, as a result of contamination with food-borne pathogens such as Listeria monocytogenes, is a cause of considerable consumer concern. Bacteriocins are inhibitory peptides produced by a number of Lactic Acid Bacteria which are capable of killing other bacteria. These natural inhibitors have widespread applications in the preservation of foods, since they can kill a number of pathogenic and spoilage bacteria. The broad spectrum bacteriocin Lacticin 3147 (discovered in a previous project and patented - see DPRC No. 3) is produced by Lactococcus lactis subsp. lactis DPC3147, a food-grade strain, similar to strains used for commercial cheese manufacture. Lacticin 3147 is effective in the inhibition of all Gram positive bacteria tested including the food pathogens Listeria monocytogenes and Staphylococcus aureus and food spoilage bacteria such as Clostridia and Bacillus species. As part of this project the bacteriocin Lacticin 3147 was assessed as a food preservative for improving food safety via inhibition of pathogenic organisms. Thus the project plan followed a "twin-track" approach to assessing and controlling the food safety aspects of Irish food. The first of these was designed to investigate the current safety status of Irish dairy products. The second approach involved an attempt to exploit natural antimicrobial substances, including Lacticin 3147, to protect foods from pathogenic bacteria.
    • Assessment of field sattelite-based positioning systems for reduced, more precise use of crop inputs.

      Rice, B.; Colfer, S. (Teagasc, 2000-11-01)
      The mapping of within-field crop yield variations offers a basis for the adjustment of input application rates to match yield potential. The aim of this project was to examine available yield mapping components and systems, and to assess the benefits that could accrue from yield mapping. The work also included site investigations of possible causes of yield reduction, and an evaluation of the potential increase in profitability from variable-rate N application. Yield mapping requires the continuous measurement of harvester position and grain yield. Accurate positioning was achieved with systems which received a remote correction signal via communications satellite. A grain flow meter in the clean grain elevator gave low errors in conditions where the deflector plate could be kept clean. The production of useful yield maps was sometimes limited by rainy weather leading to wet crops, lodging, and big variations in harvest conditions within the field. Difficulties are also presented by small, irregularly-shaped fields. The level of within-field variation in cereal yields (25% of the field area at least 21% below the mean) suggests that there is scope for identifying low-yielding areas and either taking corrective action or applying reduced inputs. An analysis of the results of N fertiliser trials suggests a potential gain from about £20/ha in sugar beet to less than £10/ha in spring barley if N application rate could be varied to apply the optimum amount to each area within a field. All the costs of application map development and variable-rate application would need to fall below these gains to justify the use of the technology. To allow further use to be made of yield maps, it is desirable that the factors responsible for yield reduction be identified, in particular those which recur each year. In the present study, soil chemical analysis and compaction affected yield in only a small proportion of cases. Differences between maps from successive years have been small. It is concluded that the immediate financial benefits from the use of this technology will be small. However, in a future where the recording, justification and minimisation of inputs such as pesticides and fertiliser will grow in significance, and where the cost of the equipment and software will continue to fall, yield mapping and variable-rate input application will find a useful role.
    • Assessment of Food Ingredient Functionality using Laser Microscopy

      Keogh, M.K.; Auty, Mark (Teagasc, 1998-09-01)
      The objectives of this project were, to establish a confocal microscopy facility at Moorepark, to develop suitable methodology for the examination of food products and ingredients, to apply confocal microscopy techniques to food research projects and to use the above technological expertise for commercial applications in the Irish Food Industry. The confocal laser scanning microscopy (CLSM) facility is now established and is fully integrated into the Teagasc research program at Moorepark. The new Confocal Microscopy Service has attracted significant commercial interest and client work is expanding. Results show that confocal laser scanning microscopy is a valuable technique for assessing the functionality of food ingredients in a wide range of food products, as well as being a powerful problem-solving tool. Work is ongoing to develop further specific ingredient localisation techniques, and to promote commercial awareness of the service. Confocal laser scanning microscopy offers a unique contribution to product research and development in the Irish food industry.
    • An Assessment of the Irish Speciality Food Enterprises’ use of the Internet as a Marketing Tool

      Canavan, Orla; Henchion, Maeve; O'Reilly, Seamus; Teagasc Walsh Fellowship Programme (Teagasc, 01/04/2005)
      This study set out to explore the role of the Internet as a marketing tool for Irish speciality food producers and to research on-line speciality food sales as a business opportunity. The project achieved this through a combination of consumer focus groups, a producer web audit, producer depth interviews and an e-mailed on-line producer survey. Irish consumers acknowledged potential for on-line sales of Irish speciality food products to export and gift markets; however they could not see significant advantages for on-line sales in the domestic market. Experience with the product (and consequent importance of the purchase experience), the high delivery cost of an already premium priced product and difficulties associated with receipt of deliveries were identified as the main reasons for not purchasing on-line.
    • An assessment of the long-term effects of three phosphorus fertiliser regimes on soil phosphorus and sward condition.

      Culleton, Noel; Murphy, W.E.; Carton, Owen T.; Cuddihy, A. (Teagasc, 1999-04-01)
      A grazing trial using beef animals (mean weight 260 kg) was used to determine optimum soil phosphorus levels for dry stock farming. · The trial commenced in 1968. There were three fertiliser P treatments, 0, 15 and 30 kg P/ha applied annually. There were two stocking rates, 3300 and 2400 kg liveweight at turn out, respectively. Animals were rotationally grazed around six paddocks per treatment and stocking rates were reduced in June and September to match feed supply. The trial continued until 1998. ¸ Nitrogen was applied at a rate of 220 kg/ha per year to all treatments. ¹ Liveweight gains/ha/year were monitored annually. Soil P levels were monitored by sampling to 10 cm depth. º The distribution of phosphorus in the soil was recorded by analysing P levels at various depths from 0-2 mm to 100 cm. Botanical composition was recorded at the commencement of the trial and again in 1997. Phosphorus levels in herbage were also recorded. » An analysis of the liveweight gain data showed that for optimum output a Soil Index of 3 (Morgans P between 6.1 and 10.0 mg/l) is the target Soil P Index. ¼ Phosphorus recovery (as expressed by percentage of P fertiliser recovered in product) in the P30 treatments was low and was better in the P15 treatments. ½ The vast bulk of P accumulated near the surface of the soil, but there was some evidence of movement down the profile in the P30 treatment over a 30 year period. The soil P status influenced both the botanical composition of the sward and the P content in the herbage. The perennial ryegrass content declined on the zero P treatment, while there were no significant differences between the P15 and P30 treatments. The P concentration in the herbage in the zero P treatments were not sufficient for healthy growth of plants or animals.
    • Automated detection and characterisation of foodborne pathogens

      Duffy, Geraldine; O'Hanlon, Karen; Catarame, Terese; Smyth, Davida S.; McCann, Máiréad (Teagasc, 2007-06)
      This study focused on the development of molecular tools for the rapid detection and characterisation of food-borne pathogens including Verocytotoxigenic Escherichia coli (VTEC) (serotypes O157, O26 and O111) and Salmonella spp. The study involved the development of enrichment systems and the identification of unique genetic targets in these pathogens which could be amplified and detected by Real Time Polymerase Chain Reaction (PCR).
    • Baled Silage - Development Of Reliable Baled Silage Systems

      O'Kiely, Padraig; Forristal, Dermot; Lenehan, J.J. (Teagasc, 1999-05-01)
      Baled silage is now made on two-thirds of all farms in Ireland, and accounts for one third of all silage made. It is particularly prevalent as the primary silage-making system on both beef farms and smaller-sized farms. However, it is also widespread as a second silage-making system on many other farms. The series of experiments contained in this report were conducted as part of a collaborative EU Structural Funds supported research project jointly carried out between the Teagasc research centres at Grange and Oak Park. Some of the research was also conducted in collaboration with the Botany Dept. at University College Dublin.
    • Barriers to Change: a Sociological study of Rural Development in Ireland

      Macken-Walsh, Aine; ICERTS Marine Beaufort Marine Award (Teagasc, 01/06/2009)
      Teagasc’s Rural Economy Research Centre (RERC) and Rural Development Advisory Unit initiated a research project in 2006 to investigate the ‘Barriers to Change’ experienced by farmers and fishers in adapting to challenges arising from a changed rural development mandate. Economic models developed by the organisation predicted farmers’ exodus over time from nonviable farming enterprises and in response to shifts towards postproductivist policies. A significant proportion of farmers, however, are continuing with what are officially categorised as nonviable farms and are slow to become involved in economic activities in line with the contemporary rural development agenda. In this light, the ‘Barriers to Change’ project was designed to explore the sociocultural inhibitors to farmers’ engagement. The project also incorporated a casestudy analysis of a fishing community whose members are experiencing similar ‘barriers’.
    • Beef Cross Breeding of Dairy And Beef Cows

      Keane, Michael G. (Teagasc, 2011-03)
      The rationale for crossing dairy cows with beef bulls is to increase the beef productivity and value of the progeny. The proportion of dairy cows available for beef crossing is determined by the dairy herd replacement rate. The performance of cross-bred cattle is generally superior to the mean of the parent breeds because of heterosis. This is most pronounced for reproduction, maternal and calf survival traits. Crossing dairy cows with early maturing beef breeds (e.g. Angus, Hereford) has little effect on growth but improves carcass conformation and reduces feed intake. Crossing with most late maturing beef breeds also improves carcass conformation and reduces feed intake, but in addition, growth rate, kill-out proportion and carcass muscle proportion are increased. Cross breeding can have small negative effects on dam milk production, and subsequent reproduction can be impaired following a long gestation or difficult calving. There is little advantage in crossing with double muscled sire breeds (e.g. Belgian Blue, Piedmontese) compared with the larger conventional late maturing breeds (e.g. Charolais, Blonde d'Aquitaine). There are few effects of sire breed on meat quality.
    • Beef production from feedstuffs conserved using new technologies to reduce negative environmental impacts

      O'Kiely, Padraig; Crosson, Paul; Hamilton, William J.; Little, Enda; Stacey, Pamela; Walsh, Karl; Black, Alistair D; Crowley, James C.; Drennan, Michael J; Forristal, Dermot; et al. (Teagasc, 2007-12-01)
      The three separate components with parallel objectives to this programme were to: 1. Develop technologies for conserving and optimally feeding alternative/complimentary feedstuffs to grass silage. 2. Quantify the use and re-use of plastic sheeting or film used to seal ensiled feedstuffs or mulch maize, and evaluate some new options. 3. Develop computer programs that will facilitate investigating prototype models of forage-based beef production systems.
    • Better management and economy of the N resource in Ireland.

      Ryan, Michael (Teagasc, 1998-09-01)
      The project, which was carried out at Johnstown Castle, was concerned with measuring denitrification at depth in grazed grass plots receiving 362 kg fertiliser N per ha. Reports in the scientific literature had indicated that such was likely, given the conditions necessary for the denitrifying microbial reactions to take place. In one experiment, denitrification was detected in measurable amounts to 90cm soil depth in spring-summer, using the acetylene block technique. A second more extensive experiment carried out under similar conditions within one year from March to August and from October to March looked at denitrification in greater detail to 50 cm deep. Results showed the importance of soil water and soil ammonium (NH4) to rate of denitrification. The rate was much greater in the 0-10 cm layer than in the lower layers in both time periods. Of the total denitrification occurring in the 0-50 cm layers in the year, which was 16.6 kg N per ha, 80% occurred at 0-10 cm with 62% occurring in the second time period, October to March.
    • Bi-cropping of winter wheat and white clover.

      Burke, James I.; Thomas, T.M.; Finnan, John (Teagasc, 1998-09-01)
      Growing cereals in a leguminous living mulch (bi-cropping) could potentially reduce the need for synthetic inputs to cereal production while preventing losses of nutrients and increasing soil biological activity. The objective of this project was to investigate how bi-cropping (a low input production system for cereals) would compare with conventional winter wheat production systems in terms of total biomass, grain yield and biological diversity. This study has resulted in valuable information on bi-cropping being generated as well as identifying the potential benefits that can be expected under Irish conditions. While the results indicate that winter wheat can be successfully established in an understorey of white clover if sown early in good conditions, competition from grass weed species represents a serious impediment to successful bi-cropping in the longer term. Consequently further research is needed before such a system can be presented to the agricultural community.
    • Biochemical and Functional Relationships in Cheese.

      Guinee, Timothy P.; Fox, P.F.; Fenney, E.P; Mullins, C.; Corcoran, M.O.; Mulholland, E.; Auty, Mark (Teagasc, 2001-01-01)
      Cheese is used extensively in cooking applications, mainly because of its flavour and heat-induced functionality, which is a composite of different attributes such as softening, flow and stretch. The functional attributes of cooked cheese generally have a major impact on the quality of foods in which cheese is included as an ingredient, e.g. pizza pie. Owing to its importance in cookery applications, numerous studies have been undertaken on the effects of different factors on the age-related changes in the functionality of cooked cheese, especially Mozzarella, and to a lesser extent, Cheddar and processed cheese. These studies have shown that the functionality of natural cheese is dynamic, with the different functional attributes undergoing marked changes during ripening, and, for a given cheese variety, the desired functional attributes are optimum within a specific time frame during maturation. The time at which the cheese becomes functional and the width of the window - and hence the functional shelf-life, are affected by the extent of chemical changes, including the increase in proteolysis and the ratio of bound to free moisture. The main aims of this project were to investigate the effects of the following on the age-related changes in heat-related functional attributes (e.g. stretchability, fluidity) of cheese: * fat reduction, * the degree of fat emulsification, * the pH and calcium content and their interaction, * the correlation between proteolysis and functional attributes, especially attributes other than flowability, e.g. rheological properties of raw cheese, stretchability of heated cheese, and * the age-related changes in the functionality of cheeses other than Mozzarella, e.g. analogue pizza cheese and Emmental. At the outset of this project, comparatively little information was available on the effects of the above parameters on the age-related changes in heatinduced functional attributes (e.g. stretchability, fluidity) of cheese, especially for varieties other than Mozzarella.
    • Biochemical and physical indicators of beef quality

      Troy, Declan J. (Teagasc, 1999-03)
      Beef of a consistent quality is required by the meat industry in order to maintain and expand markets. Measurement of beef quality is difficult at factory level. Measurements to indicate the final eating quality are not well developed yet. This project examined novel approaches to this problem using biochemical and physical methods. The Biochemical indicators of beef quality examined included: pH , Protease activity as a potential indicator of meat tenderness, Cathepsin B and cathepsin B&L activities in relation to beef ageing, Relationship between cathepsin B and cathepsin B&L activity and WBSF values, Protein fragments as an indication of beef tenderness and Myofibrillar proteins. The Physical indicators of beef quality examined included: Post-mortem changes in muscle electrical properties and their relationship to meat quality attributes, Near infrared reflectance spectra as indicators of beef quality, Shear force as an indicator of tenderness.
    • Biodegradable Microparticles as Non-Live Viral Vectors for Respiratory Tract Vaccination.

      Earley, Bernadette; Kavanagh, Owen; Adair, Brian (Teagasc, 2001-03-01)
      The potential of a microparticulate vaccine delivery system in eliciting a specific humoral response in the upper respiratory tract of calves was evaluated. Microparticles composed of poly(lactideco- glycolide) containing ovalbumin, a model immunogen, were prepared by a solvent evaporation technique. The microparticles were under 10μm in diameter as determined by fluorescence activated cell sorter (FACS) analysis. Following immunisation, the microparticles induced production of specific secretory IgA (sIgA) in nasal samples.The sIgA was detected after only one week and persisted throughout the length of the study. Additionally, the effects of microencapsulated synthetic peptides (F peptide (0.5mg) and G peptide (0.5mg), representing known protective epitopes against bovine respiratory syncytial virus (BRSV), on the cellular and humoral immune responses of calves were investigated. ∗ No significant change in the cellular immune response was detected. * The secretory IgA response was significantly more prolonged following administration of the SF (F111-148) peptide when compared with the SG (G174-187) peptide. * It is concluded that microparticles incorporating antigens show potential in the quest for generating complete protection in the young bovine against respiratory tract pathogens. * Vaccination of calves with the SF (F111-148) and SG (G174-187) peptide resulted in a significant reduction in the requirement to treat with antibiotics for respiratory disease in the post-vaccination period.
    • Biodiesel production from camelina oil, waste cooking and tallow.

      waste cooking oil; Rice, B.; Frohlich, A.; Leonard, A. (Teagasc, 1998-09-01)
      The high cost and lack of availability of raw materials is limiting the expansion of bio-diesel production. The aim of this project was to examine the potential of alternative vegetable oils, oil wastes or animal fats as bio-diesel feedstocks, and the performance of road vehicles using bio-diesel blends made from these materials. Three feedstock materials were considered: waste cooking oil from the catering industry, Camelina oil, and beef tallow. Thirty-four 300-litre pilot-scale batches of these materials were esterified, and yields and bio-diesel properties were measured. Five growers produced about 6 ha of camelina sativa on their set-aside land. Vehicle performance trials were carried out with five fuel blends involving bio-diesel and mineral fuel. A plant to produce approx 3000 tonnes per annum of bio-diesel was specified and costed. The work has concluded that waste cooking oil is the most promising raw material for the immediate start-up of bio-diesel production. A proportion of camelina oil could also be used. Further work is required to overcome technical problems with tallow. The cost of bio-diesel production in a 3000 t/yr plant from these raw materials was estimated at from 27 to 32 pence per litre of fuel. Reduction of excise on biodiesel to the level applied to heating and agricultural fuels would make its final price competitive with mineral diesel for road use. The excise remission could be justified by a reduction of global warming and harmful vehicle exhaust emissions, and the provision of a safe disposal system for otherwise waste materials.
    • Biotechnology in Cattle Reproduction.

      Morris, Dermot G.; Diskin, Michael G.; Sreenan, J.M. (Teagasc, 2001-12-01)
      Over the next decade the Irish agri-food industry will have to compete in a rapidly changing world environment arising from increased competitiveness, decreased world market prices and increased consumer demands for higher quality, healthier and safer food. To become competitive in this environment the scale and efficiency of production at both farm and factory level will have to increase significantly and this must be achieved with due regard for the protection of the environment and the welfare of animals. New technologies will be needed to achieve this. Biotechnology will be central to the development of these new technologies. This project has been concerned with the identification and evaluation of biotechnology developments that have the potential to increase reproductive efficiency in cattle. This includes a range of technologies relating to the in vitro production, manipulation, cryopreservation and transfer of cattle embryos. The potential of other emerging technologies such as embryo and sperm sexing, cloning and biopharming or the production of commercially desirable proteins in cows milk are also addressed in this report.
    • Blockage reduction to increase the efficiency of slurry application.

      Ryan, Declan; Brett, P. (Teagasc, 1999-12-01)
      Discussions with farmers using band and injection slurry spreaders suggested that the rate of breakdown due to blockages, in these machines, was approximately one per day. This report shows how the use of an intake filter and a modified distributor on a band spreader can reduce this problem. A set of obstacles was assembled on the basis of information from farmers and from literature. Ten classes of obstacles were selected, at random, and between size limits. Two prototype filters, a commercial filter and an open pipe were tested while drawing slurry from an open tank to a tanker. During each test, obstacles were thrown into the slurry stream. Obstacles retained by the filter were counted afterwards. A second filter trial was organised to test the tendency of filters to clog. Obstacle tests with 3 prototype distributors and a control were conducted in a similar manner to the first filter trial but, in this case, preliminary tests were conducted in water and final tests in slurry. The initial tests identified the best prototype. This was then compared to the control distributor using slurry. The open pipe allowed 80% of obstacles to pass while the filters allowed only 4 – 19% through. The new filters offered no improvement over the commercial unit. Filters required 16 hours agitation but the open pipe required 4 hours or less. The best prototype had the same diameter as the control but had an obstacle trap attached at the side. In a test using obstacles and slurry, the control was obstructed by 56% of the obstacles while the prototype allowed only 21% to cause a blockage. Flow through the prototype was initially too large. Slowing down the rotor in the distributor and restricting the outlet from the obstacle trap with a single long pipe, connected to two nozzles, controlled the flow. The results of the filter and distributor trials were combined. Of the seventy obstacles dropped above the filter, six passed through. Four of these caused blockages in the control distributor, but only one became stuck in the prototype. The blockage rate in the distributor and nozzles was significantly reduced compared to the original unit.