End of Project reports from the departments comprising the Teagasc Crops, Environment and Land-Use Programme

Recent Submissions

  • Evaluation of the Effect of Tocopherols on the Stability of Biodiesel

    Frohlich, A. (Teagasc, 2005-04-01)
    A comprehensive study was carried out on the effects of naturally occurring tocopherols and carotenoids on the stability of biodiesel-grade methyl esters. Commercially available tocopherols and carotenoids, α-, γ- and δ-tocopherol, carotene and asthaxanthin, were added to destabilised methyl esters and the solutions were exposed to air at 65oC. The stabilising effect of the added tocopherols and carotenoids was determined from the number of days needed to reach the same increase of viscosity as destabilised methyl ester without tocopherols after 1 day. All three tocopherols stabilised methyl esters; γ- being the most effective and α- the least. The stabilising effect of tocopherols increased with concentration up to an optimum level. Concentrations above this level did not improve stability significantly. The stabilising effect of the tocopherols also depended on the composition of the methyl ester; they were most effective in tallow methyl ester, and had the least effect on sunflower methyl ester. Carotene and asthaxanthin had no effect on the stability of the methyl esters. However an unidentified carotenoid in rape methyl ester changed the oxidation pattern by reducing rates of peroxide and viscosity increase, without affecting overall stability.
  • Improving the Yield and Quality of Arable Crops in Organic Production Systems

    Crowley, J.G. (Teagasc, 2005-04-01)
    Ireland's ability to supply organic arable products to meet future market requirements depends on the provision of scientific quantitative information on the production of these crops. The conversion of an 8-ha site at Oak Park is described. The establishment of a single stockless 7-year rotation (wheat, potatoes, oats, legume, spring barley followed by two years’ grass/clover lea) with three replicates is described. The results of the first series of experiments are presented and the possible implications discussed.
  • Reduced Fungicide Inputs in Winter Wheat

    Dunne, B. (Teagasc, 1998-09-01)
    Nine trials were conducted over three years at three sites to evaluate the efficacy of reduced rates of various fungicide products for their biological efficacy in controlling stem, foliar and ear diseases of winter wheat as well as their effects on yield and grain quality, and to compare the relative profitability of full and reduced rates of fungicides. The results show that the use of half rates can give an economic benefit over that of full rates in many situations. In circumstances where variety or seasonal factors resulted in low to moderate foliar disease pressure the use of half rates gave similar yields to that of full rates. Where foliar disease pressure was high, half rates generally gave lower yields than full rates but the amount of the reduction varied with the fungicide product used. The use of spray additives improved the yield response of the half rate treatments in most cases. Disease levels (septoria) were higher in treatments where half rates were used, compared with the corresponding full rates, but the used of spray additives improved the disease control in the half rate treatments. The timing of spray applications is critical when half rates of fungicides are being used. Reduced rate treatments need to be applied more frequently. In these trials reduced rate treatments were applied as a three-spray programme rather than the conventional two-spray programme.
  • Reduced Herbicide Inputs in Cereals

    Mitchell, B.J. (Teagasc, 1998-09-01)
    The objective of this project was to examine if herbicides used in cereals at rates lower than recommended by the manufacturer (reduced rates) would give acceptable weed control resulting in lower crop production costs. Field trials with a number of herbicides at full and reduced rates were carried out in winter barley, winter wheat and spring barley in 1994-1996. Herbicides used at recommended rates gave the highest and most consistent levels of weed control. Herbicides used at 50% of the recommended rates gave slightly lower levels of weed control than the recommended rates but did not result in lower yields. While rates lower than 50% gave about 70% control of weeds, grain yield was reduced in some trials. Reduced rates gave higher weed control in barley than in wheat. The level of weed control was influenced by weed species and the growth stages of the weeds at the time of herbicide spraying. Thus selection of herbicides and their rates of application should be field specific. The findings show that it is possible to reduce the amount of herbicides used in cereals with considerable cost savings and reduced risk of herbicide residues in grain, soil and water.
  • Effect of seed treatment and harvest date on the yield and quality of ware potatoes.

    Burke, J.J.; O'Donovan, Timothy (Teagasc, 1998-09-01)
    The objective of this project was to investigate the effects of pre-planting seed handling procedures on the growth, yield and quality of the new Oak Park-bred potato variety Rooster. Statutory regulations and increased sophistication in packaging and presentation by retail outlets require that ware potatoes comply with narrower tuber size specifications. Appropriate pre-planting seed handling procedures provides the grower with an opportunity to influence emergence, crop establishment, yield at early harvest, tuber size distribution and quality.
  • Factors affecting the yield of winter lupins.

    Crowley, J.G. (Teagasc, 1998-09-01)
    The white lupin (Lupinus albus) is a temperate legume whose seed contains high levels of protein (36-44%), oil (10-16%) and high quality dietary fibre in the dry matter. Modern varieties contain extremely low levels of alkaloids (<0.01%) and no anti-nutritional factors. Thus their composition is more similar to soya bean than peas and beans, which contain much less protein (23-27%) and no oil. Nitrogen fixation by autumn-sown, determinate varieties is large (ca. 300 kg/ha) and harvest index for nitrogen is high (more than 85% of the crop N is recovered in the grain). Lupins also have the ability to release phosphorus and iron from mineral sources in the soil. These two characteristics make the winter lupin crop an ideal choice as a low input alternative crop, particularly in nitrogen-sensitive areas. Attempts to introduce spring-sown lupins have failed, mainly due to low yield potential, poor yield stability and late harvest. The release of the first winterhardy determinate varieties by French breeders in 1994 promised the first real chance of success. The successful introduction of lupins offers the possibility of reducing soya bean imports and replacing it with a high-quality, home-grown protein source, with the added advantage of traceability. Autumn-sown lupins are capable of producing satisfactory yields (3.7-4.5 t/ha). The crop does require careful management, i.e. early sowing (by mid-September), at the correct seed rate (100 kg/ha), into well-structured free-draining soil and with a pH below 7. Sown in early September, the crop will mature from late August to mid-September.
  • Improving yield and quality of forage maize.

    Crowley, J.G. (Teagasc, 1998-09-01)
    Maize silage is recognised world-wide as a high quality winter feed for livestock. Attempts to introduce the crop to Ireland in the early 1970’s failed because of the lack of suitable varieties. The release of maize varieties adapted to the colder North European and Irish climates has for the first time offered Irish beef and dairy farmers the opportunity to exploit the valuable assets of this crop. The transfer of the technology of growing maize under photodegradable polythene developed in France could further enhance the development of forage maize production in Ireland. The results presented show that the early type hybids released over the past five years are capable of producing high yields of high quality silage in selected sites across Ireland. To achieve satisfactory yields, site selection, early sowing and the use of adapted early maturing varieties is essential. Sowing maize through a photodegradable polythene film laid on the soil surface has proved successful. This technique can increase yields on average by 3.5 t/ha, increase dry matter content by 5% and starch content by ten percentage points. The system also advances maturity by approximately three weeks, guaranteeing that on most farms the maize crop will be mature and ready for harvest before the first heavy autumn frost.
  • 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.
  • Factors affecting the composition and use of camelina

    Crowley, J.G.; Frohlich, A. (Teagasc, 1998-09-01)
    Camelina (Camelina sativa), a member of the mustard family, is a summer annual oilseed plant. Winter hardy types also exist. False flax and Gold of Pleasure are the popular common names for the crop. The crop was widely grown in Eastern Europe and Russia up to the early 1940’s but was replaced with the introduction and widespread use of oilseed rape. The revival of interest in camelina oil is due to its high linolenic acid (38%) content. Linolenic acid is one of the OMEGA-3 fatty acids which are generally found in substantial quantities only in linseed and fish oils. Camelina offers an opportunity to supply the growing demand for high quality edible oils rich in OMEGA-3 fatty acids. A three year study established that camelina is a very suitable crop to grow in Ireland, producing 2.5 t/ha of high quality seed (42-47%) with no agrochemical inputs required. The oil contains 35 to 40% linolenic acid compared to 8% in rape and soya oils. The oil does not deteriorate during refining or storage and can be used in a number of oil based products such as spreads and salad dressings.
  • 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.
  • Epidemiology and control of pink rot in potatoes.

    O'Sullivan, Eugene; Dowley, L.J. (Teagasc, 1998-09-01)
    Rotting of tubers was reported in early potato crops in Co. Wexford in 1995. Geotrichum candidum, which causes a condition known as rubbery rot, was isolated from a sample of affected tubers. In further investigations in 1996 both G. candidum and Phytophthora erythroseptica, the cause of pink rot, were isolated from diseased tubers. In pathogenicity tests P. erythroseptica re-infected tubers while G. candidum did not. It was concluded that the disease was pink rot. In 1997 foliar applications of the systemic fungicide metalaxyl were evaluated for its control. The level of control obtained was insufficient to overcome the problem which pink rot can cause in early potatoes.
  • Enhancing and visualising data on soils, land use and the environment.

    Coulter, B.S.; McDonald, E.; Lee, J. (Teagasc, 1998-12-01)
    A computer based system was developed to produce new information, charts and map data on soils, environment and land use for environmental decision support. The process involved manipulation of data in tabular and electronic map form by combining features from digitised maps and tables to develop an information system of linked and harmonised data. This report reviews and illustrates the findings with outputs in the form of maps and tables. Maps presenting sheep census information for the years 1970- 1991 show greatly increased livestock densities, in the latter years. These changes mainly occurred in the (i) traditional drystock areas of the midlands (ii) south east arable areas and (iii) south east Connacht dry stock/sheep areas and reflect economic and structural changes arising out of Government policy and membership of the EU. Maps depicting the temporal changes in dairy livestock densities were not so dramatic; however the structural change is particularly reflected in the reduction of dairying in the Connacht/Midlands regions. The introduction of milk quotas in the 1980's accelerated the changes which had been taking place since the early 1970's. In comparison to dairy cows, the increased concentration of drystock seems to be more widely spread. High concentrations of drystock occurred in the east midlands in 1970. By 1980, the high concentration of dry cattle had spread to North and South Midlands. The density of cattle increased further in Leinster and Munster areas by 1991. In Connaught, where sheep numbers had increased markedly between 1970 and 1991, cattle numbers remained relatively static. The digitisation of detailed soil survey maps was undertaken in this project and a new soil survey map of the Lough Derg Catchment was produced using Great Soil Groups as the mapping unit. This map is included in the report.
  • Leaching of N compounds from swards used for dairying that are N based and irrigated with dirty water/slurry.

    Richards, Karl G.; Ryan, Michael; Coxon, Catherine E. (Teagasc, 1998-12-01)
    A study was carried out to investigate nitrate leaching on a dairy farm in Co. Cork. The farm had a history of high nitrate-N in borehole waters and the study aimed to elucidate the causative factors for this. Physical and chemical data regarding the soils, the hydrology, and the N input/output balances were determined and collated. Results showed that nitrate-N concentrations > the EU maximum allowable concentration (MAC) of 11.3 mg/l for drinking water occurred in soil drainage from the light textured soils studied due to a large imbalance between N inputs and outputs. High fertiliser N usage, animal manure and dirty water applications, atmospheric N depositions and soil organic N mineralisation in combination produced these results . While it is recognised that nitrate leaching will vary in amount from year to year the lessons from the study are clear - light textured soils that are used for intensive dairying and which receive high inputs of N are prone to release drainage water high in nitrate.
  • Effect of seed treatment and time of harvesting on the yield and quality of potatoes for processing

    Burke, J.J.; O'Donovan, Timothy (Teagasc, 1998-12-01)
    The effect of seed source, physiological age and desiccation date on sprout growth, crop development, yield and fry colour following storage was investigated over four seasons for the variety Maris Piper and in a parallel study for the variety Rooster. Seed tubers were obtained from two areas of production, Carlow and Donegal and received physiological ageing for either 0 or 200 day degrees >4oC. Sprout growth, crop development, yield and fry colour following storage was also compared over two seasons in the varieties Maris Piper, Rooster, Fianna and Navan which had received physiological ageing for 200 day degrees >4oC and grown at two sites. Seed source produced an inconsistent effect on dormancy break, sprout growth, emergence, tuber yield and reducing sugar concentration, but had no effect on tuber sucrose concentration or chip fry colour following storage. Physiological ageing advanced sprout growth, crop emergence, crop establishment, usually improved tuber yield and dry matter content but had no effect on chip fry colour following storage. Delaying the desiccation date significantly increased yield in the grade >45 mm in most experiments. Tuber sucrose concentration declined with delay in desiccation date whereas fry colour tended to deteriorate with delay in desiccation date. When the varieties Maris Piper, Rooster, Navan and Fianna were planted at Kildalton, Navan gave the highest yield of tubers >45 mm, while Rooster gave the lightest fry colour following storage.
  • Phosphorus loss from soil to water.

    Tunney, Hubert; Carton, Owen T.; O'Donnell, T.; Fanning, A. (Teagasc, 1998-12-01)
    The work described under this project covers field work on phosphorus(P) loss from soil to water under field conditions. In addition two International Workshops on P loss to water, held in Ireland in 1995 and 1998, are also covered under this project. The results indicate that P loss to water is a complex process and it is influenced by a number of factors, including hydrology of the soil, rates and timing of P application and soil P levels. Most work on this subject indicates that there is a positive relationship between soil test P levels and P loss to water. There is need for further work to establish the relative contribution of the different variables involved in P loss from soil to water for different soils and farming conditions. This should help provide answers to the most sustainable methods to minimise losses of P to water and ensure that agricultural production is compatible with good water quality.
  • The potential of new crop introductions

    Crowley, J.G. (Teagasc, 1998-12-01)
    As part of the ongoing Alternative Crops research programme at Oak Park five new crop species were evaluated. The three oilseeds, Turnip rape, Winter linseed and Sunflowers produced promising results with a potential for commercialisation. Commercial development depends, to a large extent, on the provisions of an oilseed crushing facility in Ireland. Phacelia performs well and is an option for set-aside management or as a means of reducing nitrate leaching. Meadowfoam development, in terms of breeding agriculturally acceptable varieties, has still some way to go before the crop could be considered as a commercially viable proposition. The objective of the present study was to evaluate the field performance of a number of crop species not previously grown in Ireland. Although the species evaluated, Turnip rape (Brassica rapa, var. annua) Winter linseed (Linum usitatissimum), Sunflowers (Helianthus annuus L.), Phacelia and Meadowfoam (Limanthes alba), are widely grown in other EU countries very little data is available on their agronomic performance in Ireland.
  • Low herbicide use in sugar beet

    Mitchell, B.J. (Teagasc, 1998-12-01)
    Trials with the new sulphonylurea herbicide, Debut, controlled a wide spectrum of weeds common to Irish sugar beet. These included problem weeds such as cleavers, charlock, mayweed and fools parsley. Best results were obtained when the new product was applied with half the normal recommended dose of the standard contact and residual sugar beet herbicides. Thus the overall active ingredient applied to crop and soil was reduced with no loss in weed control efficacy and crop safety. A three year study comparing two and three spray weed control programmes on triploid sugar beet varieties and the more erect growing diploid beet varieties was also undertaken. Results indicated no difference in weed control efficacy or yield response between the two variety types although similar work in the Netherlands indicated otherwise. A third investigation into the use of two spray weed control programmes for sugar beet indicated that when applied to sugar beet sown in April commercially acceptable weed control was feasible as long as weed pressure was not excessive and sprays were applied at the correct stage of weed growth.
  • The evaluation of phosphorus sources for nutrient budgeting on organic farms.

    MacNaeidhe, F. S.; O'Sullivan, A. N. (Teagasc, 1999-02-01)
    The use of synthetic P fertilisers such as superphosphate is not permitted by regulation on organic farms. The use of basic slag and rock phosphate is permitted by regulation but the effects of the application of these compounds on the soil and herbage concentrations of phosphorus (P) on organic farms has not been assessed. Experiments were carried out from 1994 to 1997 on the effect of basic slag and rock phosphate on the concentrations of P in four different soil types and on herbage in organic grassland. Superphosphate was included in some of the experiments as a comparison. The investigations showed that: Superphosphate applied at equivalent rates of elemental P gave the largest initial increase in soil and herbage concentrations of P but was no more effective at raising the soil and herbage concentrations of this element than basic slag or rock phosphate in the long term. The application of basic slag and rock phosphate gave increases in soil and herbage concentrations of P which were comparable to those obtained with superphosphate but were more slow acting Basic slag gave an increase in the concentration of P in an organic soil which was high in P (> 10 mg/kg) but gave only a slight increase of P in the herbage. Basic slag gave an increase in soil P concentration in a range of soils and was more persistent in these soils than superphosphate. Basic slag gave an increase in herbage yield which was equivalent to that given by superphosphate in a low P soil. Rock phosphate gave a larger herbage yield increase in a low P soil than superphosphate or basic slag. Rock phosphate is a more persistent source of P in low P soils than superphosphate or basic slag. In soils with a high pH rock phosphate may be less effective as a phosphatic fertilizer than superphosphate or basic slag.
  • Integrated environmental control in mushroom tunnels.

    Grant, Jim; Staunton, Liam (Teagasc, 1999-03-01)
    The main objective of this investigation was to achieve improved control of the micro-climate around the mushroom crop. The work was based on two approaches. One, which required the greater part of the work, was gaining an understanding of the characteristics/physics of the climate control system as a whole within mushroom tunnels and the other was the application of modern control strategies to manipulate more effectively the conditions at the cropping surface. The work showed that the influences of the operation of the air conditioning on the crop micro-climate was far greater than the expected adjustment of, say, temperature and that novel systems and improved measurement of the micro-climate were required in order to optimise the control of air conditions. The operation of the heating system caused a load dependent, i.e. seasonal, variation in the average drying power of the air at the crop. While heating (on/off control) was in operation, air flow effectively ceased at the cropping surface and the effect persisted for the duration of the heating and a recovery period afterwards. Various simple strategies could be implemented to minimise these effects but a novel design for air distribution provided a means of eliminating the effect. Because of the complex relationship between the delivery of conditioned air and the consequent flow at the cropping surface, improved feedback from the crop micro-climate was found to be essential for improved control. A new sensor was developed in conjunction with the Department of Electronic Engineering, NUI Galway that provided a low cost measurement of the very low air speeds used in mushroom growing. The Irish mushroom-growing system (bags and tunnels) offers more potential for accurate control than other, tiered, growing systems. The goal of the second aspect of this project was the provision of an accurate and robust control system for mushroom tunnels. Work focused on the control relationships between inputs and outputs of the system. A Teagasc Walsh Fellowship supported the early work which was carried out in conjunction with the Department of Electronic Engineering at NUI, Galway. Initial work prior to this project, with control specialists in DIT, Kevin Street College of Technology, was extended to provide a mathematical/control model of the main physical processes involved. A second Walsh Fellowship supported a link with the control systems group in the Department of Electronic Engineering, Dublin City University and allowed further control studies in mushroom tunnels.
  • Chemical and biological control of mushroom pests and diseases.

    Staunton, Liam; Dunne, R.; Cormican, T.; Donovan, M. (Teagasc, 1999-03-01)
    This study set out to determine the occurrence of diseases and pests in Irish mushroom units and their method of control using chemical, biological and other means of control. It also examined the role of a combination of these methods to enable control with minimal pesticide input. It was found that pesticides alone will never give effective disease and pest control and that they should only be considered an adjunct to the implementation of other methods. They include: (1) Exclusion (2) Containment of spread (3) Elimination. A major factor in good disease and pest control was found to be the implementation of a good programme of hygiene which must be followed from the time of filling a tunnel to the time of emptying after cropping. Biological systems offer good potential for control but at present are not as effective as the best chemical control methods.

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