bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rumen degradation of the main forage species harvested from permanent mountain meadows in North-western Spain
Authors: Lopez S. , Carro M. D. , Gonzalez J. S. , Ovejero F. J. 
Published: March 2009

SUMMARYHerbage samples were collected in late June, and again in early September (1987) from permanent mountain meadows situated in North-western Spain (León). Botanical composition was determined by grouping the species into grasses, legumes and herbaceous ‘weeds’. Rumen degradability of the dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF) of the botanical groups in each harvest season was determined by the nylon-bag technique.Grasses and legumes differed in their degradation characteristics, and the comparisons between forage species were different for the two harvest seasons. There were no significant differences between September grasses, June legumes and September legumes in the potential degradabilities of the DM (86·9, 87·1 and 88·4%) and CP (94·2, 92·4 and 93·8%). The NDF of grasses harvested in September was degraded to a greater extent (80·6%) than that of legumes from both harvests (70·9 and 73·6% in June and September respectively). However, June grasses showed significantly lower potential degradabilities for the DM (77·0 %), CP (84·3%) and cell wall (65·9%). Legumes were degraded at a faster rate than grasses (mean DM degradation rates of 0·143 and 0·057 respectively), and lag times were longer for grasses (4·7 h) than for legumes (2·5 h). Rumen degradation characteristics of the herbaceous ‘weeds’ were estimated, but it should be remembered that many other factors may limit their utilization by ruminants.It was concluded that the major constraint to the nutritive value of these permanent swards would be the maturity of the grasses harvested in June, which markedly reduced the rumen degradability of the forages.
Effects of herbicide use, fungicide use and position in the field on the yield and yield components of spring barley
Authors: Boatman N. D. 
Published: March 2009

SUMMARYSix experiments were carried out over 2 years (1985 and 1986) in commercial spring barley crops on calcareous soils in Hampshire. Herbicides increased grain yield by 0·05–1·21 t/ha, and fungicides by 0·01–0·68 t/ha. Herbicide use affected each of the yield components ears/plant, grains/ear, 1000-grain weight and harvest index in one or more cases but the effects were not consistent between experiments or consistently related to yield increases. Fungicide use had little effect on yield components other than 1000-grain weight, which was significantly increased in all experiments. There were no significant herbicide × fungicide interactions. Large differences in yield were recorded between field edge (headland) and midfield plots, with headland plots outyielding the midfield in two of the three experiments where this effect was considered.The effects of fungicide use were accounted for by associated increases in the green lamina area of the flag leaf and second leaf at the late milk stage of grain development. This is consistent with previous work. Differences in yield response to herbicide between sites were linearly related both to weed numbers early in the season and to weed biomass at harvest. Weeds did not always directly replace crop biomass; in some experiments the combined dry matter production was greater when herbicide was not used. However, the results indicate that, where a diverse weed flora composed of species of moderate to low competitive ability is present, simple weed counts may provide a useful indication of potential yield loss.It is concluded that headland areas can often be as productive as the rest of the field, but a greater understanding of the factors involved is needed if this potential is to be realized.
The control of potato pale cyst-nematode (Globodera pallida) by chemical and cultural methods in different soils
Authors: Whitehead A. G. , Nichols A. J. F. , Senior J. C. 
Published: March 2009

SummaryIn 12 field experiments in England (1985, 1991 and 1992), on soils infested with potato pale cystnematode (Globodera pallida), oxamyl increased yields of susceptible and partially-resistant potatoes and lessened nematode multiplication at some sites but not others. Attempts to explain these site differences were unsuccessful. In a heavily infested peaty loam, large amounts of aldicarb or oxamyl, smaller amounts of both conjointly or 6·8 kg oxamyl/ha incorporated in the top 10 cm of the soil were needed to prevent G. pallida multiplication on susceptible Wilja potatoes. In three experiments, 1,3-dichloropropene at 250 or 225 1/ha increased tuber yields more than oxamyl did but had little or no effect on G. pallida multiplication. Ethoprophos at 11 kg/ha or fosthiezate at 4 kg/ha lessened G. pallida multiplication on Désirée potatoes in a silt loam soil but not in a peaty loam soil.The multiplication of G. pallida was reliably controlled in ten experiments by partially-resistant Morag or Santé potatoes. Soil population densities of G. pallida were greatly decreased by one or two crops of Cara potatoes uprooted when the first female nematodes were visible on the roots.It is concluded that granular nematicides and 1,3-dichloropropene are best employed to lessen injury to susceptible and partially-resistant potatoes and that G. pallida increase is best controlled by partially-resistant potatoes protected by a nematicide. Soil infestation levels can be decreased rapidly by soil fumigation or trap cropping with Cara potatoes.
Effect of variation in density and phosphate supply on seed production of Stylosanthes humilis
Authors: Shelton H. M. , Humphreys L. R. 
Published: March 2009

SUMMARYStylosanthes humilis was grown at Brisbane at densities of 10, 50, 250, 850 and 3800 plants/m2 in boxes of sand which received basal nutrients, applications of 0, 10 and 50 kg P/ha as calcium dihydrogen phosphate, and frequent irrigation.Maximum seed yield was 69 g/m2 at a density of 850 plants/m2. Seed yield was linearly related to the logarithm of density up to 250 plants/m2, and was comparatively stable over the upper density range, declining slightly at supra-optimal density. Inflorescence density exerted the primary control over seed yield, but seed set per floret and floret number per inflorescence were also influential.The application of 50 kg P/ha increased yield of plant tops by 54% and seed yield by 20%.
An evaluation of Merino wool quality:IV. The classification of fibres according to follicle type
Authors: Gallagher J. R. 
Published: March 2009

SUMMARYHistological sections of skin samples from two Merino flocks were studied to determine if coarse fibres were from primary (P) or secondary (S) follicles.The mean fibre diameters of P and S fibres were 23.7 and 19.7 µ respectively in flock 1 (significantly different P < 0.5) and 23.1 and 20.5 µ respectively in flock 2 (not significantly different).The percentages of fibres exceeding 30 µ in flock 1 were 10.1% P and 1.0% S. In flock 2, the percentages of fibres exceeding 30 µ were 10.3% P and 0.6% S fibres. If 30 µ is taken as an arbitrary level of fibre fineness, then the majority of coarse fibres wore from P follicles.The observed S/P ratios were 22.8/1 at 16 months on flock 1 and 21.7/1 at 15 months in flock 2.
The concentration of minerals in the blood of genetically diverse groups of sheep:V. Concentrations of copper, calcium, phosphorus, magnesium, potassium, and sodium in the blood of lambs and ewes
Authors: Wiener Gerald , Field A. C. 
Published: March 2009

SUMMARYConcentrations of Cu, Ca, P, Mg, K and Na were examined in the blood plasma (whole blood for P) of 149 adult ewes and their 244, 15-week-old lambs in a grassland flock of sheep. The ewes were 3 or 4 years old and of five crossbred types produced by mating Scottish Blackface females to Border Leicester, dun Forest, Dorset Horn, Finnish Landrace and Tasmanian Merino rams. The lambs in turn were the offspring of these crossbred ewes, and two rams of each of the Oxford Down, Southdown, Soay breeds and one Cheviot ram.Breed of sire (but not sire within breed) was a significant source of variation in the concentration of all the minerals, except Na, in the blood of both ewes and lambs. Other factors considered were age of ewe and sex, birth type, type of rearing, and date of birth of lamb. None of these appeared to be significant sources of variation except that twins and triplets, if reared as such, had higher concentrations of Ca in their blood than lambs born and reared as singles; however the ewes with singles were on different pasture from those rearing 2–3 lambs. For the mineral levels in the blood of the lambs there was no significant interaction of breed of ram with cross-breed of ewe. The lambs had substantially higher concentrations of Cu and P in their blood than their mothers and also significantly higher concentrations of Ca, Mg and possibly K. This may not be attributable to age alone because the lambs and their mothers also differed in genotype.Heritability estimates based on parent-offspring regression were 0·4 ±0·14 for Cu and less than 0·2 for the other minerals.
Effect of weaning on the capacity of pig intestinal villi to digest and absorb nutrients
Authors: Miller B. G. , James P. S. , Smith M. W. , Bourne F. J. 
Published: March 2009

SUMMARYA comprehensive study of how age and weaning affect intestinal structure and enterocyte ability to digest and absorb nutrients has been carried out in 4- and 6-week-old piglets.Villus length, which did not change significantly in unweaned piglets 4–6 weeks after birth, was halved 5 days after weaning. Crypt depth, which increased normally in unweaned piglets, is further increased by weaning in both 4- and 6-week-old animals.Lactase activity, which decreased normally with age, was inhibited more than a-glucosidase by weaning. Weaning of 6-week-old piglets also caused a significant increase in maltase II and III activities. Alkaline phosphatase activity was unaffected by age or weaning in 4- and 6-week-old piglet intestine.Na-dependent alanine transport was reduced in 6- compared with 4-week-old unweaned piglet intestine. Weaning inhibited Na-dependent alanine transport in 4- but not 6-week-old pigs. Na-independent alanine transport, which was considerably less than that found in the presence of Na, was not noticeably affected by age or weaning.Weaning-induced problems in intestinal function appear from the present results to be caused more by changes in intestinal structure and specific loss of digestive enzymes rather than by any gross change in absorptive function. The possible role of immune as well as nutritional factors in causing these weaning-dependent changes in intestinal function is discussed.
Nitrogen relationships and residual effects of intercropping sorghum with legumes
Authors: Bandyopadhyay S. K. , De R. 
Published: March 2009

SUMMARYIntercropped with legumes, sorghum removed more N from the growing medium than when grown alone. 16N data showed that out of the total N removed by sorghum in a sorghum + mung mixture 18·1% was derived from the fertilizer urea and 81·9% came from the soil pool; the latter included 21·9 % N derived from current fixation by the legumes. When grown alone sorghum plants derived 18·6 % N from urea and 81·4 % from the soil.The yield of wheat grown in sequence was 5·13 t/ha after a previous sole crop of mung and 3·47 t/ha after sorghum. The yield of wheat after sole crops of legume was greater than after their mixture with sorghum. The latter was, however, greater than its yield after sole sorghum.The economic optimum rate of N required after wheat, computed from an experiment with several rates of applied N on an adjacent plot, was 124 and 105 kg N/ha at expected yields of 5·2 and 4·5 t/ha of wheat respectively. By interpolation the relative yield advantage from sole legumes ranged between 28 and 68 kg N/ha in 1982–3 and was more than 90 kg N/ha in the next year. These advantages from legume + non-legume mixtures equalled 12–17 kg N/ha applied to wheat, in addition to 50 kg N/ha applied uniformly to the sequential crop of wheat.
A survey of ryegrass endophyte (Acremonium loliae) in the U.K. and its apparent ineffectually on a seedling pest
Authors: Lewis G. C. , Clements R. O. 
Published: March 2009

SUMMARYAcremonium loliaeis an endophytic fungus which infects plants of perennial ryegrass (Lolium perenne), an important pasture grass in New Zealand and much of Western Europe. In New Zealand the endophyte–ryegrass association was found recently to give rise to tremorgenic substances (lolitrem A and B), which are the cause of a serious disorder of grazing and domestic livestock there. The endophyte also confers resistance in ryegrass plants to certain insect pests in New Zealand and enhances plant growth even in the absence of pests. In the present work 61 swards at 52 widespread sites in the U.K. were checked for the presence of endophyte mycelium, and it was found in 14 swards, of which 12 were at least 15 years old. ELISA (enzyme-linked immunosorbent assay) tests confirmed that the fungus wasA. loliae.Also, lolitrem B was detected in plants from most of the sites where the mycelium was found; this appears to be the first time this tremorgen has been reported in the U.K. or perhaps in Europe. In a small-plot experiment at two sites with newly sown perennial ryegrass the endophyte appeared to have no effect on infestation by frit fly larvae, a major pest of seedling ryegrass plants. Also, in the present work, the endophyte had no measurable effect on the growth or overwinter mortality of larvae.
The effects of frequency of cutting and nitrogen application rates on the yields from perennial ryegrass plus white clover swards
Authors: Reid D. 
Published: March 2009

SUMMARYThe results are presented for a 4-year experiment in which three cutting frequency treatments and four nitrogen fertilizer rates were applied on plots sown with perennial ryegrass and one of three varieties of white clover. The cutting frequencies were three, five and tencuts each year, and the nitrogen rates were 0, 150, 300 and 450 kg/ha annually. Two medium-large leaf clover varieties Blanca and Sabeda were compared with the medium-small leaf Aberystwyth S. 100. Comparison of the present results with those from an earlier experiment (Reid, 1978) suggests that, on average over the clover varieties, the inclusion of white clover in the ryegrass sward results in smaller effects of nitrogen application rate and cutting frequency. Decreasing the number of cuts from ten to five gave a marked increase in the dry-matter yield of mixed herbage and of clover at all nitrogen rates, but the decrease from five to three cuts had little additional effect. These results suggest that white clover may be more suited to conservation systems than previously thought, but for optimum production the interval between cuts should not exceed about 5 weeks. The medium-large leaf varieties of white clover did not appear to be in any way superior to the medium-small leaf varieties for conservation systems.
Studies on the establishment of white-flowered faba bean (Vicia faba)
Authors: Kantar F. , Hebblethwaite P. D. , Pilbeam J. 
Published: March 2009

SUMMARYEarly reports on new, nutritionally superior, white-flowered (zero-tannin) faba bean cultivars indicated that they may show poor emergence under field conditions. The field emergence of 23 winter and spring type white and coloured-flowered lines and cultivars was investigated in relation to fungicidal seed dressing in 1989/1990 and 1990/1991 in the UK. These trials showed no definite emergence problems in white-flowered faba beans, probably because of favourable soil and weather conditions. Further experiments were therefore conducted in relation to emergence under controlled environmental conditions. The emergence of lines near-isogenic except for flower colour (the coloured line SCI v. the white line SWI) was investigated in relation to a range of soil moisture levels (soil water potential (SWP) ranging from −1·02 to 0·0 MPa (waterlogged)) and to three temperatures (22, 12 and 5°C) in a clay loam soil. Emergence was rapid and high at the SWP range from −0·52 to −0·24 MPa in both lines, depending on temperature. Any decrease or increase in SWP beyond this range resulted in a substantial reduction and delay in emergence in both lines. Emergence of SWI was more adversely affected than SCI when the temperature decreased from 22 to 5 °C. The emergence of six winter and six spring lines/cultivars was tested in relation to fungicidal seed dressing using wet soil (-0·06 MPa) at 5 °C under controlled environmental conditions. White-flowered winter lines (WWI, Polar and WD) and the spring line, SWI, had poor emergence (56–85%) compared to coloured types (86–98%). In some lines there was a slight improvement when using a fungicidal seed dressing.
Effect of rates and timing of nitrogen fertilizer on the grain protein content of wheat (Triticum aestivum), grown in two contrasting seasons in South East England
Authors: Sajo A. A. , Scarisbrick D. H. , Clewer A. G. 
Published: March 2009

SUMMARYA field experiment was carried out at the Wye College Farm during 1988 and 1989. The aim was to study the effects of three rates and timings of nitrogen fertilizer application on the grain protein content of spring wheat cv. Axona. Results demonstrated that timing of fertilizer application was more important than the rate of nitrogen used. Grain protein development and final grain protein contents are discussed in relation to the seasonal variations experienced during the 1988 and 1989 growing seasons in South East England. Due to the early February sowing in 1989, grain protein content was not affected by the summer drought. Thus, the advantage of early sowing of spring wheat to reduce the detrimental effect of early summer drought on the grain protein content is emphasised.
Glomus intraradixeffects on citrus rootstock seedling growth in various potting media
Authors: Nemec S. 
Published: March 2009

SUMMARYFive potting media components mixed in various combinations and in various percentages of one with another (0, 14·3, 29, 42, 57, 71 and 100% by volume of the second component with the first) were inoculated withGlomus intraradixin six experiments. Seedlings of citrus rootstocks were grown from seed in these mixes. Sour orange in inoculated peat plus vermiculite, Astatula fine sand plus vermiculite, and peat plus Perlite® in all percentage combinations grewc.two- to threefold taller than noninoculated control plants. Up to twofold growth increases of sour orange occurred in vermiculite amended with wood shavings. The best evidence for fungus-mediated plant growth occurred in Astatula fine sand amended with 29–71% Perlite, and the roots in that combination had the highest percentage of infection. In another experiment in which Astatula fine sand was amended with up to 16% of an acid peat, ratios of inoculated rough lemon plant growth to controls decreased as the peat content in the medium increased. Top and root weight ratios of inoculated:control seedlings in the six experiments did not fit four simple linear models.
Influence of production and storage conditions on subsequent growth and tuber yield of potato (Solanum spp.) in the hot tropics
Authors: Midmore D. J. , Roca J. 
Published: March 2009

SummaryA series of experiments to quantify the response of diverse potato genotypes to production and storage conditions in hot climates was carried out in 1984–87 at three sites in Peru, two of which were characterized by at least one hot season per year. Yield stability and field performance of seed tubers of six clones produced in situ, and stored in diffused light (DLS) or cold stored (CS), were compared with those of good quality seed tubers produced and stored in cool conditions. The yield potential of tubers produced in hot climates and grown as (i) a double crop per year with short DLS (1–4 months) (ii) a single crop per year with long DLS (c. 8 months) and (iii) a single crop per year with long CS (c. 8 months) was compared with that of seed tubers produced in cool conditions and introduced in successive crops.The first replanting of tubers produced in hot climates resulted in lower yield than that of coolproduced tubers. Yield reductions in clones ranged from 30 to 93% when replanted within 4 months, from 10 to 100% when replanted after 7–10·5 months of DLS and from 0 to 82% after similar periods of CS. Reduced yield was often due to poor plant vigour and crop growth leading to inefficient interception of solar radiation. There was, however, no evidence that the efficiency of utilization of intercepted radiation for tuber dry matter production was influenced by storage treatment. Poor sprout growth at planting reduced yield considerably for late clones in double cropping. Low dry matter content of tubers produced in hot climates did not influence emergence rate, but was related to poor plant vigour in the first replant under warmer conditions. Replanting and storage in hot climates did not enhance the initial reduction of tuber dry matter, which was evident after the first hot season. Tuber yields continued to decline, particularly under single cropping with long DLS.For the clones studied, CS would be a feasible storage method for potato production in hot climates if replanted tubers were used on an annual basis. For double cropping, short dormancy is essential; however, poor plant vigour results in additional yield reductions. Our data indicate that clonal selection for maximum production in hot climates should take into account the proposed or existing production and storage schemes.
Short-term undernutrition and prenatal mortality in young and mature Merino ewes
Authors: Mackenzie A. J. , Edey T. N. 
Published: March 2009

SUMMARYPrenatal mortality was examined in 74 primiparous Merino ewes which, after hand mating to fertile rams on the second oestrus following synchronization, were allocated to two groups. One group of 38 ewes was confined to yards and restricted to approximately 30% of their maintenance requirement for 14 days while the other group of 36 remained at pasture. The degree and timing of prenatal loss was assessed by corpora lutea counts, pregnancy diagnosis about day 40, returns to service and lambing records.The mean ovulation rate was 1·06 and the 19-day non-return rate was 87·8%. Pregnancy failed in a higher proportion of the underfed ewes (45·0%) than in the control ewes (30·8%) but this difference did not reach significance. Of the ewes returning to service, significantly more did so with cycles longer than 19 days in the underfed group (9/12) than in the control group (2/8), indicating that in the latter stages, the treatment may have been detrimental to embryo survival.In a second experiment, ovulation rate and prenatal mortality, assessed as in the first experiment, were studied in 85 mature Merino ewes subjected to the following nutritional treatments: HH, control; HL, 30% submaintenance feeding for 14 days following mating; LH, 15% submaintenance feeding for 7 days prior to mating; LL, both submaintenance treatments.Acute undernutrition prior to mating (LH) had no effect on ovulation rate or prenatal mortality. Ovulation rates were low over all groups (mean 1·09) and thus precluded any valid examination of ovulation rate and body weight relationships. The right ovary was significantly more active in producing ova than the left in all groups (P < 0·05). Although ova wastage was apparently higher in. the post-mating undernutrition groups (HL, 44%; LL, 48%; LH, 50%) than in the control group (HH, 35%), the differences were not significant. An increased incidence of extended (> 19 days) first-return cycle lengths in group LL provided some evidence of induced prenatal mortality.In so far as the experiments can be considered together, they indicate that if body weights are comparable, primiparous 1½-year-old ewes are not necessarily more susceptible than mature ewes to prenatal mortality induced by severe short-term undernutrition.