bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of rates of application and sources of nitrogen on nitrate concentration in oat forage
Authors: JOSHI B. S. , PRASAD RAJENDRA 
Published: April 2006

AbstractA field experiment was conducted during the winter seasons of 1972–73 and 1973–74 to study the effects of rates of application (0, 100, 200 kg ha−1) and sources of nitrogen (ammonium sulphate, calcium ammonium nitrate, urea, sulphur‐coated urea and sulpha‐thiazole‐treated urea) on nitrate‐N concentration in oat (Avena sativa L.) forage. N application increased the nitrate‐N concentration, the effects being more marked when the rate was increased from 100 to 200 kg ha−1 than when it was raised from 0 to 100 kg ha−1. The highest nitrate‐N concentration in the dry matter (> 0·16%) was obtained when calcium ammonium nitrate was applied at 200 kg ha−1 N. Sulphur‐coated urea gave the lowest nitrate‐N concentration. In one year treatment of urea with sulphathiazole reduced nitrate‐N concentration in oats forage.
Temperature effects in determinations of leaf relative water content
Authors: SHEPHERD W. 
Published: April 2006

AbstractDifferences between field temperature and floating temperature during determination offect apparent leof relative water content (RWC). When floating temperature was lower or higher than field temperature, RWC appeared higher or lower, respectively, than when the temperatures were the same. Discrepancies averaged 0·24% RWC per TC temperature difference for wheat and perennial ryegrass, and 0·33% for the less xeromorphic white clover and potato. These averages might reasonably be used in future for correcting values obtained with these or similar species.
Dalapon resistance in Lolium perenne populations
Authors: CHARLES A. H. , JONES J. L. , RYAN P. J. 
Published: April 2006

AbstractThe resistance often early, ten medium late and ten late flowering ryegrass populations to two rates of dalapon (2.8 and 5.6 kg ha‐1 acid equivalent) was measured in a box experiment. There was no difference in the mean effect of dalapon on the maturity groups at the time of greatest yield reduction, but the recovery of the late flowering population was, on average, better than that of the medium late group. There was a range of reaction to herbicide within all three maturity groups and, in general, the high yielding populations without dalapon were the most resistant, but there were exceptions. Assessment at 2.8 kg ha‐1 acid equivalent gave a similar ranking order to that using twice the amount of dalapon. The results of the current box experiment with seedlings were consistent with those obtained in the field at another location (Faulkner, 1974) for the eleven cultivars common to both trials. The resistance of a permanent pasture population was much lower than that of some cuttivars.
Winter hardiness in Lolium multiflorum Lam. I. The effect of nitrogen fertilizer and autumn cutting managements in the field
Authors: HIDES D. H. 
Published: April 2006

AbstractFour Italian ryegrass varieties of different origins and winter hardiness were grown as spaced plants at a lowland and an upland site and subjected to ten managements comprising two nitrogen levels and five autumn cutting treatments. Tiller mortality after the winter of 1971–72 was measured in March and subsequent spring recovery from winter damage in April.Although the winter was not severe, there was considerable winter kill, particularly at the upland site where the most severe treatment combinations killed up to 90% of the plants of the more susceptible varieties. In general, winter kill was increased by raising the level of nitrogen fertilizer and by late or frequent autumn defoliations, and significant interactions between locations and the two treatment factors emphasized the importance of the siting of the experiment.The varieties difFered in their overall winter hardiness, with Bb 1430 and RvP suffering less tiller mortality than S22 and Grasslands Paroa in all the treatment combinations, but significant interactions of varieties with locations and cutting treatments revealed that the magnitude of the difference between varieties varied with location and cutting management. Regression analysis of these interactions, however, showed that the tiller mortality of all four varieties increased linearly with the increasing stresses applied by the location × management combinations. There was no differential variety recovery from winter kill, the spring yields being entirely related to the level of tiller mortality experienced.These results are discussed in relation to the breeding of winter hardy varieties, the choice of variety and autumn management practice.
The effects of nutrient supply on flowering and seed production in Poa annua
Authors: ONG L. CHIN K. , MARSHALL C. , SAGAR G. R. 
Published: April 2006

AbstractThe effect of nutrient concentration on the reproductive development and seed yield of Poa annua was examined in a sand culture experiment. The nutrient concentration during the initial vegetative stage did not affect the time taken for double ridge formation by the main shoot but did influence the subsequent development of the inflorescence as did the post‐initiation level of nutrients. At low nutrient levels flowering was inhibited in some individuals but at the higher concentrations inflorescence emergence was hastened, inflorescence size was increased and, in particular, the number of spikelets and hence the number of seeds per inflorescence was greatly increased. The mean weight of 100 seeds was unaffected by the nutrient concentration. The number of reproductive tillers per plant was increased by high nutrient supply but the proportion of dry weight allocated to root development was reduced.
The influence of vernalization on response to nitrogen of perennial ryegrass
Authors: BARTHOLOMEW P. W. , CHESTNUTT D. M. B. 
Published: April 2006

SummaryVernalized and unvernalized perennial ryegrass (Lolium perenne cv. Gremie) tillers planted in microplots in a glasshouse in April 1974 and 1975 were exposed to natural daylength thus inducing vernalized plants to produce reproductive, and unvernalized plants vegetative growth. Nitrogen was applied at 0–30 g m−2 (to 24 g m−2 in 1975) to both types of herbage. At the first defoliation in each year yields from vernalized grass were greater than those from unvernalized grass; subsequently differences were minimal or reversed. Vernalization had no significant effect (P > 0.05) on total yields over four defoliations in either year.Apart from the first cut in 1974 nitrogen application increased dry matter yields of both types of herbage. Tiller numbers were usually increased by the lowest level of nitrogen application but at higher levels the effect was variable.There was no evidence of an interaction effect of level of nitrogen application and vernalization on dry matter yields.
Nitrogen studies in Lolium perenne grown for seed. II. Timing of nitrogen application
Authors: HEBBLETHWAITE P. D. , IVINS J. D. 
Published: April 2006

AbstractThe effects of applying nitrogen at different growth stages to S24 and S23 perennial ryegrass grown for seed were investigated in a series of field experiments from 1971 to 1976. These varieties of ryegrass were found to be insensitive to timing of nitrogen application from apex initiation to the stage when ears first emerged. However, if nitrogen application was delayed until about 30% or more of the ears had emerged, yields were lower compared with earlier applications, this effect being significant when nitrogen was delayed until 70–80% ear emergence because of a decrease in both numbers of fertile tillers and number of seeds per unit area. No advantages were found for splitting nitrogen applications between apex initiation and ear emergence.
Winter hardiness in Lolium multiflorum Lam. II. The effect of defoliation and nitrogen application as assessed by low temperature response in a controlled environment
Authors: HIDES D. H. 
Published: April 2006

AbstractThe effect of defoliation and nitrogen application on the cold tolerance of four varieties of Italian ryegrass was assessed using controlled environment chambers. Both defoliation and nitrogen fertilizer markedly reduced overall cold tolerance and this closely matched changes in winter hardiness induced by similar treatments applied to the same varieties in a field experiment. However, the relative response of individual varieties differed from that found under field conditions. Thus, RvP showed high levels of tolerance to low temperatures in the controlled environments and was also winter‐hardy under field tests; by contrast Bb 1430, although previously shown to be winter hardy in the field, exhibited low tolerance of cold stress in growth chambers. Thus, results obtained in controlled environment tests cannot be entirely equated to winter hardiness in the field.Water‐soluble carbohydrate (WSC) levels were reduced by both defoliation and nitrogen application and there were significant overall differences between varieties. It was not possible, however, to detect any clear relationship between these differences in WSC levels and cold tolerance.The significance of these results in relation to the use of controlled environment chambers for selecting for improved winter hardiness is discussed.
The physiology of tiller death in grasses. 2. Causes of tiller death in a grass sward
Authors: ONG C. K. , MARSHALL C. , SAOAR G. R. 
Published: April 2006

AbstractThe causes of tiller death in a 2‐year‐old perennial ryegrass sward were examined between April and August 1977. Physiological causes accounted for most tiller deaths and grazing by slugs and rodents was more important than the damage caused by stem‐boring larvae. Tillers which died were mainly small and vegetative, although some flowering tillers died prematurely. Low nutrient status delayed but did not prevent tiller death.Using 14CO2 it was shown that small tillers fixed relatively less radiocarbon than did larger tillers and they did not receive much support for their carbon economy. Selective defoliation showed that in April defoliated tillers imported radiocarbon from undefoliated tillers but that in July at anthesis an undefoliated reproductive tiller retained most of the carbon it fixed, despite its vascular association with defoliated tillers. It appears that much of the tiller death during the period April‐August is due to the failure of the more favourably placed tillers to support other tillers which are heavily shaded.
Nitrogen and Italian ryegrass 5. Growth up to 14 weeks: residual effects
Authors: WILMAN D. 
Published: April 2006

AbstractIn a field experiment with Italian ryegrass residual effects of N applied in late April at four rates, 28, 84, 140 and 196 kg ha−1, and of different dates of first harvest ranging from 1 to 14 weeks after N application, were studied. The harvests after the first added about 10 kg dry matter yield and about 0.16 kg N yield for each extra kg N applied in April. Residual response was similar for each increment of applied N. A positive residual response to N was obtained in May of the year following N application despite high winter rainfall. N content of herbage during part of the summer was reduced by extra N applied in April although N yield was increased. The reduction in N content was accompanied by a reduction in P and K content, these latter elements having been applied only once and at a uniform rate on all plots. Loss of N, P and K from the crop, when a period of more than about 9 weeks regrowth was allowed prior to the first harvest, was not recouped at subsequent harvests. Residual marginal recovery of N in Aberystwyth was no higher than in comparable experiments in Cambridge although marginal recovery of N at the first harvest had been appreciably lower in Aberystwyth than in Cambridge.
Selection for resistance to ryegrass mosaic virus and crown rust (Puccinia coronata Corda) in Italian ryegrass populations
Authors: HIDES D. H. , WILKINS P. W. 
Published: April 2006

AbstractInoculation in the glasshouse revealed marked differences in resistance to both ryegrass mosaic virus (RMV) and crown rust (Puccinia coronata Corda) among eight unselected populations of Italian ryegrass (Lolium multiflorum Lam.). Two generations of selection for crown rust resistance led to a significant improvement in all eight populations, while one generation of selection for RMV gave a more variable response. Frequency distributions of individual genotype scores suggested that much of the resistance to crown rust was under the control of one or two genes with major effects, while resistance to RMV appeared to be controlled by a large number of genes each having a small effect.In the field, resistance to RMV meeisured after 20 months was strongly correlated with that obtained in the glasshouse. Natural infection by crown rust in the field was too low to reveal any differences between populations, although three populations from the Po Valley region of Northern Italy became heavily infected with Puccinia recondita.Selection for disease resistance significantly reduced the persistency of three populations, but that of four others was unaffected and one showed a significant improvement. Selection reduced water‐soluble carbohydrate (WSC) levels in spring slightly but significantly from 27.6 to 25.8% WSC overall. These results emphasize that agronomic performance must be monitored during selection for disease resistance.
Production of perennial ryegrass cultivars of different maturity types when grown as pure swards and in certain combinations
Authors: McBRATNEY JUNE M. 
Published: April 2006

AbstractA field investigation was carried out over 3 years to determine if there was a synergistic effect on total or seasonal yield when cultivars of perennial ryegrass were grown in combination.The three cultivars used were Stormont Zephyr, Hora and Perma, representing respectively early, medium late and late maturing groups. Each cultivar was grown as a pure stand and also as a 50:50 mixture with each of the other two cultivars. Each of these swards was maintained under two rates of nitrogen fertilization (300 and 600 kg per ha per annum) and under two harvesting treatments (4 and 8 harvests per annum).Mixture yield did not exceed significantly the pure sward yieid of the highest yielding component. Occasional yield improvements were detected for the mixtures averaged as a group over monocultures averaged as a group. There was a tendency, especially under frequent cutting, for the yield response to nitrogen to be greater from mixed than from pure swards.
Evaluation of a sward sampling technique for estimating herbage intake by grazing sheep
Authors: WALTERS R. J. K. , EVANS E. M. 
Published: April 2006

AbstractA sampling procedure for estimating herbage intake by the ‘Difference’ method over short grazing periods using an electrically powered sheep‐shearing head to cut long narrow sample strips, was compared with several indirect animal techniques on single‐variety grass swards. The method provided intake estimates in good general agreement with those obtained by animal methods but discrepancies arose when used on a semi‐prostrate variety due, probably, to incomplete recovery of sampled herbage cut from post‐grazing residues.It was concluded that the method might be usefully adopted for the preliminary assessment of the intake characteristics of herbage varieties in routine evaluation programmes, provided that care is taken to ensure the efficient collection of herbage sampled post‐grazing and that a reduction in the land requirement can be achieved without undue loss of accuracy or precision. Confirmation of results should be sought using animal methods when possible.
Silage and milk production: a comparison between soya, groundnut and single‐cell protein as silage supplements
Authors: CASTLE M. E. , WATSON J. N. 
Published: April 2006

AbstractGrass silage made in May from S24 perennial ryegrass was offered ad libitum to twelve Ayrshire cows in a 12‐week feeding experiment. The silage had a DM concentration of 217 g kg ‐1, contained 147 g crude protein per kg DM and had a D‐value of 64·6. In addition each cow consumed 1 kg hay per d plus concentrate supplements of dried sugar‐beet pulp with (A) soya bean meal, (B)‘Pruteen’, a single‐cell protein (C) groundnut cake. The three concentrate supplements each contained 250 g crude protein per kg DM and were offered at the rate of 2·9 kg per 10 kg milk. The daily intakes of silage DM were 8·38, 7·94 and 7·49 kg on treatments A, B and C, respectively, with the extreme values being significantly different. The mean daily yields of milk on treatments A and B were both 16·2 kg per cow, and were significantly higher than the yield of 15·2 kg per cow on treatment C. The fat and lactose contents of the milk on the three treatments were not significantly different, but the CP content on treatment C was significantly lower than that on the other treatments. It is concluded that soya bean meal and‘Pruteen’were superior to groundnut cake as a protein supplement in a silage‐based ration.
The effect of date of primary growth harvest and levels of nitrogen and potassium fertilizers on the dry matter production of timothy (Phleum pratense)
Authors: HUNT I. V. , FRAME J. , HARKESS R. D. 
Published: April 2006

AbstractScots timothy was harvested three times a year for 3 years under four harvesting patterns and at all combinations of three levels of application of nitrogen and four of potassium. Harvesting patterns, H1, H2, H3 and H4, comprised cutting primary growth on 27–29 May or 14, 28 or 42 d later followed by cutting a first regrowth 8 weeks afterwards and a second regrowth on 15–16 October. N treatments, N0, N1 and N2, involved annual totals of 0,108 and 216 kg ha‐1 N in three equal doses. K treatments, K0, K1, K2 and K4, involved annual totals of 0, 54, 108 and 216 kg ha‐1 K also in three equal doses.Mean herbage DM yields in successive years were 8·90, 9·54 and 9·61 t ha‐1 containing92·4%, 93·1% and 94·5% timothy, respectively. Systems H3 and H4 had 24% higher yields than H1 and H2. The superiority of the late systems derived from higher yields of primary growth. Mean response to 108 kg ha‐1 N at 36·7 kg DM per kg N was significantly higher than the response to an additional 108 kg ha‐1 N. Response in primary growth to successive increments of 36 kg ha‐1 N averaged 53·9 and 27·5 kg DM per kg N. The first regrowth gave linear responses up to 72 kg ha‐1 N. The possibility is discussed of more effective use of N by increasing the proportion applied to regrowth. Response to K was low except in the third year when there was a marked response at N2. It was calculated that to maintain soil potash it is necessary to apply 23·9, 47·7 and 86·6 kg ha‐1 fertilizer K for each harvest at N0, N1 and N2 respectively.
The effect of stage of growth on the rate of drying of cut grass at 20°C
Authors: JONES LEWIS 
Published: April 2006

AbstractThe drying of Italian ryegrass (RvP) tillers under controlled conditions at three stages of growth is described. The rate of water loss was dependent on tiller morphology as well as on water content. Leaf laminae dried faster than stems and also aided the loss of water from stems. Drying time was shortest for vegetative tillers despite their high water content, and longest for reproductive tillers shortly before ear emergence. The practical implications in relation to haymaking are discussed.
Amino acid composition of sainfoin forage
Authors: KALDY M. S. , HANNA M. R. , SMOLIAK S. 
Published: April 2006

AbstractThe crude protein concentration, amino acid composition and protein quality of sainfoin (Onobrychis viciifolia) forage was compared to that of lucerne (Medicago sativa). The amino acid analyses showed that sainfoin contained higher amounts of lysine, histidine, proline, cystine, glycine, alanine, valine, leucine, tyrosine, phenylalanine and tryptophan than lucerne, whereas lucerne contained more aspartic acid, methionine and isoleucine than sainfoin; the limiting amino acid in both legumes was methionine. The protein score, an estimation of protein quality for nonruminants, was 68 for sainfoin forage and 71 for lucerne forage compared to 100 for an ‘ideal protein’. The similarity of protein quality of sainfoin forage to that of lucerne indicates that, where conditions permit, sainfoin could be grown for the production of protein as an alternative to other crops.
Supplementary feeding of grazing beef cattle
Authors: VADIVELOO J. , HOLMES W. 
Published: April 2006

AbstractThe effects of cereal and protein supplements on feed intake and liveweight gain were studied. In 1975, steers were continuously stocked on autumn pasture and fed no supplement or 8 g dry matter (DM) per kg liveweight (LW) per d as rolled barley (crude protein (CP) concentration 120 g kg‐1), lucerne cobs (CP concentration 190 g kg‐1) or a mixed concentrate (CP concentration 300 g kg‐1). In 1976, steers were continuously stocked or rotationally grazed in summer and fed no supplement or 7 g DM per kg LW per d as either rolled barley (CP concentration 130 g kg‐1) or a mixture of rolled barley and groundnut meal (CP concentration 210 g kg‐1). Herbage organic matter (OM) intakes in 1975 and 1976 were depressed on average by 22 and 15% respectively with supplementation, but total OM intakes were increased by 9 and 15% respectively. Daily liveweight gain was not significantly increased by supplementation in 1975 when herbage allowance was ample but was significantly increased in 1976 when herbage allowance was limited and herbage digestibility was lower. Protein concentration of the concentrate did not significantly affect daily gain in either year nor was there any difference in gain between rotational grazing and continuous stocking.
A comparison between barley and groundnut as supplements for dairy cows at pasture
Authors: CASTLE M. E. , WATSON J. N. , LEAVER J. D. 
Published: April 2006

AbstractIn two 12‐week grazing experiments using twelve and eighteen spring‐calved cows in 1976 and 1977 respectively, the effects of feeding either a barley or a groundnut concentrate supplement were investigated. The mean yield of herbage DM on offer was 2330 and 2030 kg ha‐1, with crude protein concentrations of 192 and 193 g per kg DM in 1976 and 1977 respectively. Grazed herbage was the sole feed in the control treatment. In the other two treatments the herbage was supplemented with 3 kg per cow per d of a concentrate containing either 82·2% barley or groundnut with mean crude protein concentrations of 109 and 409 g per kg DM respectively. Similar results were obtained in both experiments with average daily milk yields of 18·3, 19·8 and 19·9 kg per cow on the control, barley and groundnut treatments respectively. The supplements had no significant effects on either milk composition or liveweight change. It is concluded, that with an ample supply of herbage of high crude protein concentration, a supplement of groundnut had no advantages over one of barley.
A comparison between supplements to silage of high digestibility offered to dairy cows
Authors: ADAMSON A. H. , NEWELL D. W. , CASTLE M. E. 
Published: April 2006

AbstractGrass silage containing 180 g crude protein and 660g digestible organic matter per kg DM was offered to forty‐two dairy cows for 20 weeks in a self‐feeding system. In addition, supplements of either mineralized barley (130 g crude protein per kg DM) or barley plus groundnut (180 g crude protein per kg DM) were offered. The mean daily milk yields were 18·5 and 19·4 kg per cow respectively.