Effect of seed treatment and harvest date on the yield and quality of ware potatoes.

End of Project ReportThe 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.European Union Structural Funds (EAGGF

Effect of seed treatment and time of harvesting on the yield and quality of potatoes for processing

End of Project ReportThe 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.European Union Structural Funds (EAGGF

Field Validation Of Four Decision Support Systems For The Control Of Late Blight In Potatoes

End of Project ReportField experiments were carried out between 2001 and 2003 to determine the efficacy of the NegFry, Simphyt, ProPhy and Plant Plus decision support systems (DSS) in controlling late blight of potatoes compared with routine fungicide treatments. The experiments were also used to determine the potential of the systems to reduce fungicide inputs. Over the three year period of the experiment the 7-day routine programme received an average of 13.7 fungicide applications while the DSS programmes varied between 5.7 and 12.3 applications. All decision support systems resulted in a reduction in the number of fungicide application (Fig. 2). Compared with the routine control, the NegFry and SimPhyt programmes resulted in a 58-44% reduction in application frequency. The ProPhy and Plant Plus programmes resulted in more modest savings of between 10 and 25% (Tables 1 & 2). All fungicide treatments significantly delayed the date of disease onset compared with the untreated control. Compared with the routine control treatment, the NegFry and Plant Plus significantly delayed disease onset in King Edward in 2001 as did NegFry and ProPhy in Rooster. In 2002 there were no differences between treatments in terms of delaying disease onset, while in 2003, disease developed significantly earlier the Plant Plus programme compared with the routine control. In general, the date of disease onset was not significantly different between routine programmes and DSS programmes irrespective of the cultivar. In each of the three years, all fungicide treatments significantly reduced the incidence of foliage blight at the end of the season compared with the untreated control. When compared with the routine control, no decision support system resulted in significantly more foliage blight at the end of the season, irrespective of the cultivar or year. Similar results were achieved when the treatments were compared using the area under the disease progress curve (AUDPC). These results would confirm that none of the DSS’s resulted in inferior disease control when compared with the 7-day routine application of fluazinam. All fungicide treatments resulted in significantly higher marketable yields compared with the untreated control in all years, irrespective of the variety. Within the fungicide treatments the DSS programmes generally out-yielded the routine fungicide treatment. However, these differences were only significant for Plant-Plus in King Edward in 2001. Within the DSS treatments there were no significant differences in marketable yield in any of the years or either of the varieties. Within the fungicide treatments there were no significant differences between treatments in terms of tuber blight control for the resistant variety Rooster. In the case of the more susceptible variety, King Edward, all the DSS programmes resulted in significantly lower levels of tuber blight than the routine Shirlan control in 2001 except for Simphyt. More importantly, the routine Shilan did not result in significantly better tuber blight control in any of the years when compared with any of the DSS programmes. This confirms that all DSS programmes give equivalent tuber blight control to the routine Shirlan application at 7-day intervals even with a very tuber blight susceptible variety

Decision Support Systems For Disease Control in Winter Wheat.

End of Project ReportA leaf diagnostic test and a computer-based decision support system were evaluated for the control of diseases of winter wheat caused by Septoria spp. Fungicide programmes, as dictated by both methods, were compared with a standard routine programme, a reduced-rate programme and an unsprayed control from 1998 to 2000. In some instances fungicide programmes, dictated by leaf diagnostic tests, resulted in lower disease and higher yields than routine programmes but these were not consistent. Fungicide programmes, based on the computer-based decision support system, offered no advantages over routine programmes in terms of lower levels of disease, reduced numbers of fungicide applications or increased yields. Reduced-rate programmes, based on more frequent applications of low rates of fungicides, resulted in substantial savings of fungicides and in 1999 and 2000 better disease control and higher yields than routine programmes

Evaluation of fermented whole crop wheat, urea-treated processed whole crop wheat and maize silage for dairy cows

End of Project ReportThere has been increased interest in and increased usage of forages other than grass silage for feeding dairy cows during the winter period. This has arisen because of the inconsistency in making good quality grass silage and the low intake characteristics of this feed. The main objective of this project was to evaluate the effects on dairy cow intake and performance of offering fermented whole crop wheat (WCW) silage, urea-treated processed WCW and maize silage in mixtures with grass silage compared with grass silage alone. The value of these feeds as supplements to grazed grass in the Autumn for late lactation spring calving cows and their effect on dietary nitrogen (N) utilisation for milk protein production were also investigated. The first two experiments evaluated the effects of including 67% of the forage mixture on a dry matter (DM) basis as fermented WCW, urea-treated processed WCW (also known as “Alkalage”) or maize silage in comparison to grass silage alone in the diet of autumn calving cows. The fermented WCW and urea-treated processed WCW were harvested at a stubble height of approximately 20 cm. Sixty and 95% of the grain was milled/cracked in the urea-treated processed WCW in experiments 1 and 2, respectively. Forages were supplemented with concentrates of varying crude protein (CP) concentrations so as to maintain a similar CP concentration in the total dietary dry matter across treatments. In both experiments all the feeds were well preserved. The DM (g/kg) and starch contents (g/kg DM) in the fermented WCW, urea-treated processed WCW and maize silage in experiments 1 were 406 and 282, 733 and 324, 221 and 140 and in experiment 2 were 370 and 323, 763 and 341 and 302 and 324, respectively. Results from both experiments were similar. The three forage mixtures resulted in greater DM intake and greater fat plus protein production than grass silage. The largest effect on intake was obtained with the urea-treated processed WCW which probably reflected the greater DM content of this forage mixture compared with the others. Milk protein content was generally similar across the three forage mixtures and greater than on grass silage as the sole forage. In the third experiment short-straw urea-treated processed WCW (harvested at a stubble height of 35 cm) was evaluated in comparison to the fermented WCW (harvested at a stubble height of 20 cm), maize silage and grass silage. The DM (g/kg) and starch (g/kg DM) contents in the fermented WCW, urea-treated processed WCW and maize silage were 389 and 316, 795 and 382 and 346 and 301, respectively. Fifty nine percent of the grain was cracked/processed in the urea-treated processed UP-WCW .Level of inclusion of forages in the diets was the same as in the first two experiments and total dietary CP was again maintained at a similar concentration across treatments by offering concentrates of varying CP concentrations. The higher harvesting height of the urea-treated processed WCW resulted in a greater starch concentration in this feed in comparison to the first two experiments. The results however were very similar to those obtained in the first two experiments with the forage mixtures again increasing DM intake and fat plus protein yield. Inclusion of the short-straw urea-treated processed WCW did not result in greater fat plus protein production compared with the inclusion of fermented WCW or maize silage. The greatest efficiency of conversion of dietary nitrogen (N) to milk N was achieved with the maize silage mixture and the least efficiency with the urea-treated process WCW mixture. In experiment 4 the nutritive value of fermented WCW, urea-treated processed WCW and maize silage were evaluated in comparison to a concentrate as supplements to grazed grass for spring calving cows in the autumn. A treatment with a high grass allowance of 24 kgDM (> 4 cm)/cow per day was also included while the grass allowance on the supplemented treatments was restricted to 17 kgDM (> 4 cm)/cow per day. All the supplemented treatments and the high grass allowance treatment gave greater milk yields than the unsupplemented restricted grass treatment. The concentrate supplement resulted in the greatest solids corrected milk yield and this was greater than any of the forage supplemented treatments which were not significantly different from one another. In the final experiment the output of N in milk, urine and faeces was measured when grass silage, fermented WCW, urea-treated processed WCW and maize silage were fed as the sole forages plus 6 kg of a concentrate containing 338 g crude protein/kg DM. The proportion of consumed N excreted in urine and faeces was greatest on grass silage and urea-treated processed WCW with fermented WCW and maize silage resulting in the greatest proportion of consumed N being excreted in milk. Overall, the project demonstrated that including either type of WCW or maize silage with grass silage increased fat plus protein production and protein concentration to a similar extent compared to grass silage as the sole forage. All three forages increased DM intake with the greatest increase observed with urea-treated processed WCW. Because of this greater intake resulting in similar fat plus protein production conversion of dietary DM to milk solids was less efficient on urea-treated processed WCW based diets than on fermented WCW or maize silage based diets. Grass silage and urea-treated processed WCW based diets were least N efficient with less dietary N being incorporated into milk N than on fermented WCW or maize silage based diets. Comparing the responses on the forage mixtures relative to one another and to grass silage across experiments 1 to 3 indicates that neither degree of grain processing or harvesting height (within the ranges studied here) are of substantial importance in determining the nutritive value of urea-treated processed WCW. All of the three alternative forages gave similar solids corrected milk yield responses when used as buffer feeds for spring calved cows at pasture in the autumn but these responses were less than 50% of the response to a concentrate supplement

Guided Modes in Negative Refractive Index Waveguides

We study linear guided waves propagating in a slab waveguide made of a negative-refraction- index material, the so-called left-handed waveguide. We reveal that the guided waves in left-handed waveguides possess a number of peculiar properties, such as the absence of the fundamental modes, mode double degeneracy, and sign-varying energy ux. In particular, we predict the existence of novel types of guided waves with a dipole-vortex structure of the Pointing vector.Comment: 4 pages, 4 figure

Winnowing Wheat from Chaff: The Chunking GA

In this work, we investigate the ability of a Chunking GA (ChGA) to reduce the size of variable length chromosomes and control bloat. The ChGA consists of a standard genetic algorithm augmented by a communal building block memory system and associated memory chromosomes and operators. A new mxn MaxSum fitness function used for this work is also described. Results show that a ChGA equipped with memory capacity equal to or greater than the minimal size of an optimal solution naturally eliminates unexpressed genes. © Springer-Verlag Berlin Heidelberg 2004

Near-field optical power transmission of dipole nano-antennas

Nano-antennas in functional plasmonic applications require high near-field optical power transmission. In this study, a model is developed to compute the near-field optical power transmission in the vicinity of a nano-antenna. To increase the near-field optical power transmission from a nano-antenna, a tightly focused beam of light is utilized to illuminate a metallic nano-antenna. The modeling and simulation of these structures is performed using 3-D finite element method based full-wave solutions of Maxwell’s equations. Using the optical power transmission model, the interaction of a focused beam of light with plasmonic nanoantennas is investigated. In addition, the tightly focused beam of light is passed through a band-pass filter to identify the effect of various regions of the angular spectrum to the near-field radiation of a dipole nano-antenna. An extensive parametric study is performed to quantify the effects of various parameters on the transmission efficiency of dipole nano-antennas, including length, thickness, width, and the composition of the antenna, as well as the wavelength and half-beam angle of incident light. An optimal dipole nanoantenna geometry is identified based on the parameter studies in this work. In addition, the results of this study show the interaction of the optimized dipole nano-antenna with a magnetic recording medium when it is illuminated with a focused beam of light