bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal adjustments of steers (Bos taurus) to abrupt changes in environmental temperature
Authors: McLean J. A. , Downie A. J. , Jones C. D. R. , Stombaugh D. P. , Glasbey C. A. 
Published: March 2009

SUMMARYBody heat storage changes of cattle were measured by means of simultaneous direct and indirect calorimetry and by thermometry in an environment that alternated in temperature between 12 and 25 °C. When the calorimeter temperature was increased deep body temperature (Tc) increased by approximately 0–5 °C, mean surface temperature (Ts) by 3 °C and mean body temperature (determined from calorimetry, Tb) by 1 °C, but these increases were not fully sustained during the next 24 h. Changes in the three temperatures were related by the equation: δTb = αδTc+(1-α) δTs where a was found to be 0·89±0·027 (S.E.).
Free proline accumulation during development of two wheat cultivars with water stress
Authors: Karamanos A. J. , Drossopoulos J. B. , Niavis C. A. 
Published: March 2009

SUMMARYThe course of free proline accumulation in leaves, stems, roots and ears was examined during the development of the wheat cultivars Yecora and Generoso grown in the field with or without irrigation. More negative values of leaf water potential were associated with higher amounts of free proline in the various organs. In most cases, proline accumulated more readily with increasing water stress before heading than after ear emergence in the leaves, stems and roots of both varieties. Differences between the two cultivars concerning the sensitivity of the mechanisms inducing proline accumulation to water stress existed mainly in the reproductive phase: Generoso accumulated proline more readily than Yecora. There is evidence that the increased amounts of free proline in Generoso can be associated with more effective dehydration and drought avoidance mechanisms.
Magnesium phosphate as a dietary supplement for lactating cows at spring pasture
Authors: Ritchie N. S. , Fishwick G. 
Published: March 2009

SUMMARYA total of 76 cows in seven, trials over a 3-year period were given a supplement of 53 g magnesiiun phosphate (supplying 11 g Mg and 10 g P/day) in 1 kg of concentrate for 21 days after starting to graze spring pasture. In contrast with 79 comparable cows given no supplement, there were significant improvements in the concentrations of magnesium and phosphorus in the blood of the cows, and significant reductions in the incidence of individual cows with low values.
Seedling vigour and grain yield of cereals grown from seeds of varying protein contents
Authors: Welch R. W. 
Published: March 2009

SUMMARYThe effect of seed protein content on grain yield has been studied in varieties of spring barley, oats and wheat grown under differing cultural conditions. Grain yield was affected by seed protein content in one experiment where very low yields were attained, but the effects were inconsistent. No effect was observed in two other experiments made in a glasshouse and the field. In a growth-room experiment, seed with high protein content produced more vigorous seedlings than low-protein seed; these differences were accentuated by increasing seedling age at very low nutrient levels, but decreased with seedling age at normal nutrient levels. It is concluded from the results that variations in seed protein content are unlikely to have a significant effect on yield under practical conditions.
Effects of manipulation of number of tillers and water supply on grain yield in barley
Authors: Jones H. G. , Kirby E. J. M. 
Published: March 2009

SummaeyThe effects of several detillering treatments on dry-matter production and grain yield in barley were investigated in a series of pot experiments using two water regimes. When ample water was provided, even quite severe reductions in the number of tillers only slightly reduced grain yield in spite of large effects on total shoot dry weight. When all the plants were grown with the same amount of water, however, the plants with few tillers tended to have greater grain yield, higher water use efficiency (in terms of grain yield) and higher harvest index than the plants permitted to tiller freely. This effect was probably related to the greater transpiration rates from the freely tillering plants which led to their suffering a greater degree of water stress than the plants with few tillers. This led to the freely tillering plants having a greater proportion of sterile ears and a lower harvest index. Water stress apparently had no effect on the grain yield of the main shoot or first tiller. It is concluded that genotypes which produce few large tillers having a high rate of survival should be able to achieve relatively high yields in drought conditions without sacrificing yield potential under optimal conditions.
A Comparison of Herbicide-Treated and Handweeded Sugar Beet
Authors: Wilcockson S. J. , Scott R. K. 
Published: March 2009

SUMMARYExperiments at Sutton Bonington in 1973 and 1974 compared the growth and yield of sugar beet which was handweeded at different stages with that where weed control was entirely by pre- and post-emergence herbicides, used alone and in various combinations. Data from the series of handweeding treatments enabled the crop's minimum weed control requirements to be specified. They indicated that an ideal herbicide would kill all the weeds present when applied at the six-leaf stage, persist in the soil to prevent weed infestation for 4 weeks, but not check the crop to the extent that recovery was incomplete. That the crop was capable of recovering from a degree of early check was clearly evident from the handweeded treatments; it proved possible for crops whose weights had been depressed by 25–30 % when first weeded to recover completely by harvest.The performance of all post-emergence treatments fell short of these requirements. When the crop was at the six-leaf stage, the earliest emerging weeds were too far advanced to be killed by the herbicide. By themselves, pre-emergence herbicides gave weed control equivalent to only 2 or 3 weeks of handweeding but they did pave the way for more effective use of post-emergence treatments by restricting the spectrum of weed sizes present and sensitizing those plants which did establish. The most effective herbicide regime used in the experiments was the sequence of chloridazon applied pre-emergence followed by two post-emergence applications of phenmedipham. However, phenmedipham clearly checked the crop. Two weeks after application crop dry weight was usually depressed by one-third. Provided weed control was adequate, recovery was usually complete by the end of the season.
Yield Potential of Heterozygous Seedling Lethal Mutants of Barley (Hordeum vulgare L.)
Authors: Rahman M. M. 
Published: March 2009

SUMMARYThe effects of homozygous and heterozygous loci of 20 seedling lethal mutants on yield and yield components of barley (Hordeum vulgare L.) were studied. Nine of the 20 populations studied exhibited one locus heterosis (positive or negative advantages of Aa genotype compared with AA genotype) for yield per plant or one or more components of yield. In five instances of significance all showed positive single locus (Aa) heterosis for number of seeds per spike. Seedling lethal mutants, Ac ac and Alb,, p alb,, p showed three yield-component-heterosis. These two mutants might be suitable for hybrid barley production.
Tillering of wheat as influenced by nitrogen and seed rate in the Sudan
Authors: Mahmoud Z. M. , Osman A. M. 
Published: March 2009

SUMMAYThe pattern, production and survival of tillers was studied in two spring wheat varieties in field and pot experiments for two seasons.The time-trend of tillering was such that tiller production reached a peak well before ear emergence, then death reduced the number of vegetative shoots to a level determined by seed rate (in the field) and nitrogen level (in field and pot experiments), and thereafter the number of live shoots remained more or less constant. In field experiments plants grown at high seed rates and low rates of N application attained their maximum numbers of shoots at an earlier date. Number of shoots perm2 increased with an increase in seed rate and N level. However, the number of fertile shoots per plant at harvest decreased with an increase in seed rate and were composed mostly of main shoots. The high mortality rate of shoots was attributed to the high temperatures prevailing in this country during the growth period. Mortality of shoots started earlier at high seed rates and low rates of N application.In pot experiments, giving the N fertilizer in doses throughout the growth period reduced the rate of mortality of tillers rather than increasing their rate of initiation. A lower dose of N, given in portions over a long period, resulted in a higher number of live tillers than a dose double this amount given once at sowing. Numbers of spikelets and grains increased to a greater extent as a result of split application of N than did grain weight per ear of main shoots and of primary + secondary tillers. Mexipak had fewer spikelets per ear than Giza 155 and yet its number of grains was greater, particularly in ears of primary and secondary tillers.
The effect of soil physical conditions and nitrogen fertilizer on the yield of Italian ryegrass
Authors: El-Karouri M. O. H. , Gooderham P. T. 
Published: March 2009

SUMMARYAn experiment is described in which plots of a silt loam soil and a clay soil were compacted by ploughing when the soil was ‘wet’ or ‘dry’. Further plots were thoroughly loosened by hand digging. These treatments resulted in a wider range of soil physical conditions than had been obtained in a previous experiment.A 2-year ley of Italian ryegrass was grown on the plots and was harvested twice in each year. Marked effects on crop yield were found at the first harvest but relative effects at subsequent harvests were much smaller. Yield responses to differences in soil physical conditions depended on stage of crop, levels of applied nitrogen fertilizer, inherent chemical fertility of the soil and distribution of rainfall during the growing season.
Effect of irrigation, pyrites and phosphobacteria on the efficiency of rock phosphate applied to lentils
Authors: Sharma S. N. , Ray S. B. , Pandey S. L. , Prasad R. 
Published: March 2009

SUMMARYA field experiment was made at the Indian Agricultural Research Institute, New Delhi, during the autumn-spring season of crop years 1979–80 and 1980–1 to study the effects of irrigation, pyrites and phosphobacteria on the efficiency of Mussoorie rock phosphate(north-western Himalayan deposits) for lentils (Lens culinaris Medic), and residual effects were studied in maize (Zea mays L.). Response to phosphate was observed only when the crop received irrigation. Mussoorie rock phosphate was only 40·5% as effective as ordinary superphosphate; its efficiency was increased to 50·4% when it was mixed with 25% (by weight) pyrites. When the lentil seeds were treated with the culture of Pseudomonas striata (phosphate solubilizing bacteria) the efficiency of rock phosphate was increased to 79·7%. Rock phosphate together with seed treatment with phosphobacteria also showed residual effects on the succeeding maize crop which were equal to those obtained with ordinary superphosphate. Our results thus show that use of phosphobacteria can considerably increase the efficiency of rock phosphate on neutral soils.
Take-all, Gaeumannomyces graminis var. tritici, and yield of wheat grown after ley and arable rotations in relation to the occurrence of Phialophora radicicola var. graminicola
Authors: Slope D. B. , Prew R. D. , Gutteridge R. J. , Etheridge Judith 
Published: March 2009

SUMMARYThe Rothamsted ley–arable experiments were on two fields with similar soils but with contrasting previous cropping: old grass on Highfield, old arable on Fosters field. Damage by take-all (Qaeumannomyces graminis var. tritici) occurred sooner in successive wheat crops grown after a lucerne ley and arable sequence (LU) than after a grass-clover ley and arable sequence (LC). On Highfield the difference was consistent and large, it occurred as soon as a second wheat crop was grown and resulted in wheat yielding 1 t/ha less after the LU than after the LC sequence. This difference did not persist in the next wheat crop where take-all was prevalent after both sequences. On Fosters field take-all developed more slowly and differences between sequences were mostly smaller.Wheat seedling bio-assay of soil cores from the LU and LC sequences showed that little take-all fungus persisted through the leys and that soils were much infested after a first wheat crop in the LU sequence on Highfield, but not in the LC sequence on Highfield or in either sequence on Fosters field. Microscopic examination of roots from assay seedlings and from field plants showed that Phialophora radicicola var. graminicola (PRG) was most common in soils where take-all developed slowly, but our results did not show if this was a causal relationship. The occurrence of much PRG in the LU sequence on Fosters conflicts with previous reports which associate large populations of this fungus only with grassland soils.
Studies on the digestibility of the cellulose fraction of grassland products. Part I. The relation between the digestibility of silage cellulose as determinedin vitroand silage crude fibre digestibility determined by feeding trial
Authors: Barnett A. John G. 
Published: March 2009

1. Anin vitromethod is described whereby it is possible to obtain the digestibility coefficient of silage cellulose. The apparatus and techniques used are described in detail and the reproducibility of the results obtainable is stressed.2. The results so obtained on twenty-seven samples of silage of diverse nature, with regard to composition and method of production, show a reasonable degree of correlation with the corresponding figures for the digestibility coefficients of crude fibre obtained by feeding trial.
The effect of level and pattern of feeding on the yield of milk constituents from cows of different yield potential
Authors: Johnson C. L. 
Published: March 2009

SUMMARYData from three dairy-cow nutrition experiments have been analysed in terms of the yields of milk, lactose, fat and protein. Yields of the three constituents varied linearly with milk yield. However, yields of fat from individual cows were much more variable at high milk yields than were the other two constituents. Patterns of feeding had relatively little effect on the pattern of protein yield in cows fed to their production potential but could be important in influencing yields of fat.Predicted responses of protein and fat yields to increments of feed were generally small in cows being fed according to their predicted yield potential and the conversion of metabolizable energy to milk constituents was of a low biological efficiency.
The effects of winter and spring defoliation on the subsequent yield of grain and straw of S.147 oats
Authors: Davies G. M. 
Published: March 2009

1. An investigation to compare winter and spring defoliation of S.147 oats, and incorporating an application of nitrogen, was carried out during the seasons 1950/1, 1951/2 and 1952/3.2. Forage available in the spring was considerably greater than that available in the winter, but it had a lower crude-protein content.3. Compared with the undefoliated oats, both spring and winter defoliation reduced the number of productive tillers by significant amounts, but nitrogen had no effect on tiller numbers under defoliated and undefoliated conditions.4. Spring and winter defoliation caused significant reductions in grain yields; with winter defoliation the decline in yields was substantial. On the undefoliated and spring-defoliated oats nitrogen increased yields by significant amounts.5. Spring and winter defoliation reduced straw yields, but nitrogen on both treatments and on the undefoliated oats gave significant yield increases.
Effects of nitrogen applied at different dates, and of other cultural treatments on eyespot, lodging and yield of winter wheat. Field experiment 1952
Authors: Salt G. A. 
Published: March 2009

Lodging and yield of winter wheat were studied in a factorial experiment on land infested with the fungus Cercosporella herpotrichoides Fron. causing Eyespot. Two varieties, Squareheads Master 13/4 with long, and Bersée with short, straw, were compared at two seed rates; sulphate of ammonia was applied at 0, 2, and 4 cwt./acre at four different dates; four of the 8 blocks of 10 plots were sprayed in March with sulphuric acid to control eyespot.Lowering the seed rate from 3 to 1½ bushels/acre decreased eyespot and the area lodged and increased the mean yield of the 2 varieties by 4·9 cwt. in unsprayed and 2·1 cwt./acre in sprayed plots. Spraying the variety Squareheads Master decreased the straws with severe lesions from 66 to 17%, decreased the area lodged from 95 to 36%, and increased grain from 22·4 to 32·4 cwt./acre; spraying Bersée decreased severe lesions from 56 to 15%, decreased lodging from 54 to 1% and increased yield from 32·6 to 43·5 cwt./acre.The mean percentage infection at harvest was little affected by nitrogen applied in March, April or May, but was decreased by nitrogen applied in October. In contrast, the time of applying nitrogen greatly affected the weight of straw and the extent of lodging, both of which were increased more by top dressings in March and April than by those in May. Plots that received nitrogen in March and October had similar weights of straw, but the latter, with less eyespot, lodged less. Where lodging was slight, grain yields were increased equally by nitrogen applied at each date; where lodging was extensive, yields were depressed by dressings in March and April, and increased by those in October and May. Sulphate of ammonia, applied at 0, 2 and 4 cwt./acre to sprayed (upright) plots of Bersée, yielded respectively 36·8, 42·9 and 47·3 cwt. of grain, whereas applied to unsprayed (completely lodged) plots of Squareheads Master yielded only 22·4, 22·0 and 22·9 cwt./acre respectively.
Studies of the skeleton of the sheep I. The effect of different levels of dietary calcium during pregnancy and lactation on individual bones
Authors: Benzie D. , Boyne A. W. , Dalgarno A. C. , Duckworth J. , Hill R. , Walker D. M. 
Published: March 2009

1. Three groups of mature ewes were fed during pregnancy and lactation on rations differing in their calcium content. The mean daily intakes of calcium were 1·4 g. (group A), 4·5 g. (group B), and 7·4 g. (group C). Blood samples were analysed monthly for calcium and inorganic phosphorus. The ewes were killed at approximately 100 days after parturition and the skeletons isolated. Individual bones, either whole or divided into definite fractions, were analysed.2. The level of calcium intake was without effect on the number of lambs born, birth weight, or growth while milk fed.3. Blood calcium was significantly lower in group A than in groups B and C, but blood inorganic phosphorus was unaltered.4. The resorption of bone substance was greater in group A than in groups B and C.5. The severity of resorption varied between bones, and in regions within certain bones. Resorption was most severe in the vertebrae and pelvis, and only slight in the metacarpal, the metatarsal and the shafts of other long bones. Resorption of intermediate magnitude was found for the remainder of the skeleton.6. Resorption was accompanied by reductions in the percentages of ash in bones, but this effect was proportionately less than the ash weight reduction.7. Radiological observations made on flesh-free bones at the end of the experiment gave a picture of resorption similar to that presented by the data for ash weights and percentages of ash, namely that resorption was much greater in group A than in groups B and C.
Relation between body size and muscle fibre diameter in the newborn lamb
Authors: Joubert D. M. 
Published: March 2009

1. An investigation is reported in which the relationship was examined between body size and muscle fibre size of nineteen newborn lambs and including twelve males and seven females. Body size was measured in terms of the dead body weight and that of the dressed carcass, while muscle fibre size was estimated on the basis of the mean crossdiameter of 150 fibres per lamb.2. It was shown that the dressing (or carcass) percentage tends to increase with an increase in body weight, from 42·26% at a body weight of 2000 g. to 49·04% at 7000 g.3. Of the 2850 cross-diameters recorded, the majority (33·8%) of the fibres measured between 8·0 and 9·6 μ, while individual fibres varied in size from 1·6 to 22·4 μ.4. Highly significant, positive correlations were shown to exist between both body (r = 0·996) and carcass (r = 0·946) weight, and mean muscle fibre diameter, indicating that differences in size between the lambs may be accounted for largely by corresponding variations in the size of individual muscle fibres.5. Of the three muscles sampled m. gastrocnemius had the largest mean fibre diameter (10·38μ), followed in decreasing order by m. rectus femoris (9·72 μ) and m. longissimus dorsi (9·09 μ). These inter-muscle differences were significant at the 1% level of probability.6. Ram lambs had significantly thicker muscle fibres (10·32 μ) than ewe lambs (8·72 μ), but also weighed the heavier and produced heavier dressed carcasses. Some evidence was produced, however, in support of the theory that at comparable weights males possess thinner individual, and therefore a greater number of fibres than females.
Grazing studies on the Guadalcanal Plains, Solomon Islands. 1. Climate, soils, and soil fertility assessment
Authors: Watson S. E. , Whiteman P. C. 
Published: March 2009

SummaryThe Guadalcanal Plains encompass approximately 460 km2 with both forest and grassland phases. Mean annual rainfall is 2160 mm, with a drier season from June to October, but soil moisture deficits seldom occur. Soils are freely to imperfectly drained brown loam to clays (Ustropepts). Soil analyses show available P concentrations of 15–17 μg/g, adequate K, Cu, Zn and Mn, and high Ca and Mg, but sulphate sulphur is low. A nutrient omission trial gave significant negative responses to the omission of P, K, S and Mo. However, responses to P applications were not obtained in the field with Centrosema pubescens, but significant responses to K and S were found under a cut and remove system. Yield response in the grasses Brachiaria decumbens and B. mutica to applied N was markedly limited in the absence of applied S, even though B. mutica was able to maintain S concentrations in herbage at 2–3 times those of B. decumbens. Without applied S, S contents and N:S ratios in B. decumbens were inadequate for beef cattle, but adequate in B. mutica except at high N inputs (300 kg/ha/year). Application of 40 kg S/ha to the legume C. pubescens increased yields by approximately 50%, reduced incidence of Cercospera leaf spot, and gave increased N concentrations. For establishment of sown mixed pastures on the Guadalcanal Plains we recommend the basal application of 20 kg P/ha, 50 kg K/ha, 30 kg S/ha and 0·15 kg Mo/ha, with 30 kg S/ha applied every 2 years.
The effect of age at which spring-born calves are introduced to pasture
Authors: Poole D. A. 
Published: March 2009

SummarySpring-born Friesian heifer calves were turned out to grass at either 3 or 4 months of age. In the summer of 1976 the experiment had 20 calves per treatment and in 1977 there were 22 calves per treatment. The calves remained outside for both day and night. They were the leaders in a leader–follower rotational grazing system based on nine paddocks. The followers were yearling heifers and sheep. Each calf was offered a daily grazing supplement of 1·8 kg concentrates. Housing was in mid-September.There were no management problems and summer growth rates were within the range 0·55–0·74 kg/day. Calves turned out at 3 months of age grew slightly better than calves turned out at 4 months. This difference was not statistically significant, but it does suggest there is no harm in turning calves out at an early age. From a practical viewpoint the result indicates that all spring-born calves could be turned out in one batch in early summer.