bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of nitrogen fertilizer on growth and yield of semi-dwarf and tall varieties of winter wheat
Authors: Pearman I. , Thomas S. M. , Thorne G. N. 
Published: March 2009

SummaryEight amounts of nitrogen ranging from 0 to 210 kg N/ha were applied to two tall and one semi-dwarf variety of winter wheat in the spring of 1975 and 1976. The tall varieties were Cappelle-Desprez and Maris Huntsman; the semi-dwarf variety was Maris Fundin in 1975 and Hobbit in 1976. Interactions between varieties and nitrogen were few and small compared with the main effects. All varieties produced their maximum grain yields with 180 kg N/ha. The yield of the semi-dwarf varieties, but not the others, decreased slightly with more nitrogen.Cappelle-Desprez yielded less grain than the other varieties in both years. In 1975 the yields of Maris Fundin and Maris Huntsman were similar and in 1976 Hobbit yielded more than Maris Huntsman. The varieties had similar numbers of ears at maturity and similar patterns of tillering. The semi-dwarf varieties had most grains per spikelet, and hence grains per ear, and Cappelle-Desprez had least. The semi-dwarf varieties had the smallest grains. The semi-dwarf varieties had less straw than the other varieties and hence the largest ratios of grain to total above-ground dry weight. The decrease in dry weight of stem and leaves between anthesis and maturity was similar for all varieties. In 1975 the efficiency of the top two leaves plus top internode in producing grain was the same for all varieties, but in 1976 Hobbit was more efficient than the other two. There were some small differences between varieties in nutrient uptake that were not related to differences in growth. Maris Fundin tended to have a greater phosphorus and potassium content than the tall varieties. Hobbit contained slightly less nitrogen than the tall varieties at maturity, and had a smaller concentration of nitrogen in the grain.Applying 210 kg N/ha doubled grain yield in 1975. Applying nitrogen resulted in a largeincrease in number of ears and a small increase in number of grains per ear due to the development of more fertile spikelets per ear. Nitrogen decreased dry weight per grain, especially of the semi-dwarf varieties. With extra nitrogen, straw dry weight at maturity, shoot dry weight atanthesis and leaf area were all increased relatively more than grain yield, and stems lost moredry weight between anthesis and maturity than without nitrogen. The year 1976 was exceptionallydry and nitrogen had only small effects in that it affected neither straw dry weight nor numberof ears but slightly increased grain yield by increasing the number of spikelets and number of grains per spikelet. It also increased leaf area proportionately to grain yield. In 1975 nitrogen increased evaporation of water from the crop before anthesis but decreased it after anthesis, even though it continued to increase the extraction of water from below 90 cm.
Some effects of the inclusion of leys in a six-course rotation on light land
Authors: Hanley F. , Ridgman W. J. , Allen E. J. 
Published: March 2009

SummaryAn experiment comparing six-course rotations which included 1-, 2- and 3-year leys of pure grass, pure legume and grass/legume mixture is described, and the results from the fifth and sixth phases of the first cycle and first and second phases of the second cycle are discussed.Compared with all-arable cropping, the inclusion of leys increased the yield of barley grown as the second and third crops after the leys were ploughed up, although the difference was less when 58 kg N/ha had been applied. Neither length nor type of ley affected yield in the second crop after ploughing the leys, but in the third crop 2- and 3-year leys led to greater yield than 1-year leys.Only rotations containing 1-year leys were compared with all-arable cropping in the fourth and fifth crops after ley, but some effects of these were still apparent in that both Italian ryegrass and broad red clover leys led to an increased sugar percentage of sugar beet grown as the fourth crop when no nitrogen was applied, and broad red clover leys led to a greater response to nitrogen in barley grown as the fifth crop after ley.
American hybrid maize for silage in the south of England Part II. Composition, nutritive value and losses in the silo
Authors: Castle M. E. , Foot A. S. , Rowland S. J. 
Published: March 2009

The results are given of an investigation of the successful production, and of the chemical composition and feeding value, of maize silage made from early maturing varieties of hybrid maize grown for three consecutive years in the south of England. The maize was ensiled at a stage when the cob contributed approximately 50% of the total crop and the dry-matter content of the crop varied from 16·3 to 27·2%. The mean crude protein content of the dry matter of the silage was 9·5% (range 7·9–11·2%). Average weight losses in the silo were fresh matter 25%, dry matter 30%, crude protein 25%, and soluble carbohydrates 40%.In three controlled feeding trials with cows and heifers in milk, maize silage was found to be equal in nutritive value to a ration of mangolds and oat and tare silage when fed on an equal dry-matter basis. The silage was very palatable and a daily ration of 50 lb. was consumed.It is concluded that although maize silage compares favourably with an average crop of cereal -legume silage in feeding value, its adoption on a wide scale cannot be recommended in view of the relatively low yield of dry matter per acre, the high costs of production and the appreciable silo
Game domestication for animal production in Kenya: prediction of water intake from tritiated water turnover
Authors: King J. M. , Nyamora P. O. , Stanley-Price M. R. , Heath B. R. 
Published: March 2009

SummaryFive male animals of each of the following species, zebu, eland, small East African goat, fringe-eared oryx and Dorper sheep, were penned, and their water intake measured and metabolic water production estimated. The figures for water input were compared with simultaneous measurements of body-water turnover by liquid scintillation counting of tritiated water in plasma, following dioxane precipitation. It was found that the resultant regression was sufficiently linear with the intercept near zero to justify the use of a ratio to predict input from turnover. The tritiated water turnover overestimated the water input by an amount approximately equal to the overestimate of the body water pool by the tritiated water space. Although there was a considerable amount of variation in individual ratios which could not be explained, there was no significant difference in the mean ratios between species.
Resistance to bean common mosaic virus in dwarf beans (Phaseolus vulgaris L.)
Authors: Walkey D. G. A. , Innes N. L. 
Published: March 2009

SummaryNumerous dwarf bean accessions were screened for resistance to three strains of bean common mosaic virus (BCMV). Many lines were resistant to a strain of BCMV isolated at Wellesbourne (NVRS) and the Dutch NL4 strain, but only a few lines showed resistance or tolerance to the Dutch NL3 strain. The NVRS strain was found to belong to BCMV Group IVa.Hybridization experiments showed that resistance to the NVRS strain of BCMV in the dry bean cvs Seafarer and Aurora was controlled by a dominant gene and that in Seafarer this was probably the dominant I gene originally found in Corbett Refugee.
Yield improvement in spring oats
Authors: Lawes D. A. 
Published: March 2009

SummaryGrain yields of 14 spring oat varieties grown at two levels of nitrogen in three seasons at two locations were compared. A genotype × environment analysis demonstrated that the more recent varieties not only had higher yields but also were better adapted to high-yielding environments. Modern varieties demonstrated a yield improvement of 30% over the older varieties. Examination of components of yield by a series of simple correlations indicated that improvement in varieties by breeding has been associated with shortened straw and higher harvest indices. Within varieties, 1000-grain weight was the most stable character and harvest index the character which varied most consistently with variations in grain yield.
Defoliation studies in hybrid maize: II. Dry-matter accumulation, LAI, silking and yield components
Authors: Singh R. P. , Nair K. P. P. 
Published: March 2009

SUMMARYData are presented from an experiment made in two crop seasons, to examine the effects of plant density and degree of defoliation at different stages of growth in maize at Pantnagar, India, on the dry-matter accumulation in different plant parts, leaf area index (LAI), time of silking and grain yield components.Different patterns of dry-matter accumulation in various plant parts was observed. Silking was delayed by increasing plant density. Defoliation (even partial) at the 16th fully expanded leaf stage resulted in substantial reduction in LAI and such yield components as number of ears, ear length, ear diameter and 1000-grain weight. On the other hand, partial defoliation done at the 10th fully expanded leaf stage to simulate an ‘erectophile canopy’ led to yield increases even under high plant density (90000 plants/ha) in the Kharif (rainy season), mainly through an increase in number of ears, 1000-grain weight and grain to stover ratio coupled with a reduction in barrenness and percentage of lodging. It is suggested that an increase in the photosynthetic efficiency per unit area of leaf resulting from the ‘erectophile canopy’ is the reason for these effects.
The effect of weaning at 10, 25 or 40 days on the reproductive performance of sows from the first to the fifth parity
Authors: Walker N. , Watt D. , MacLeod A. S. , Johnson C. L. , Boaz T. G. , Calder A. F. C. 
Published: March 2009

SummaryA total of 146 nulliparous gilts at two centres were assigned to lactation lengths of 10, 25 or 40 days and maintained on the same weaning regime for up to five parities.The interval between weaning and conception tended to be shorter for the 40-day treatment with little difference between the 10- and 25-day treatments. The data from all parities were pooled on the basis of an assumed herd structure giving the number of litters produced per sow per year aa 2·63, 2·37 and 2·18 for the 10-, 25- and 40-day treatments respectively.The number of pigs born alive per litter remained more or less static with successive parities on the 10-day treatment but increased on the 40-day treatment with differences between treatment s reaching or approaching significance in parities 4 and 5. Although this trend was reflected in the number of pigs weane d per litter, the differences between lactation treatments were non-significant as a result of higher post-natal mortality in the larger litters of the longer lactating sows.Consequently sows on the 10-day treatment reared the highest number of pigs per year, 22·4 compared with 20·2 and 19·8 for 25- and 40-day lactations respectively.Data are also presented on changes in sow live weight.A high culling rate and an extended interval betwee n weaning and conception were experienced at one centre in parity 1. The possible reasons and effect on subsequent litter size are discussed.
The influence of particle size distribution on soil physical properties
Authors: Towner G. D. 
Published: March 2009

SummaryBatcombe series soils readily break down to good tilths, Beccles series soils form cloddy seed beds that are resistant to weathering, and Stackyard series soils form unstable tilths that readily break down. The soils differ in their particle-size distribution. The proposition that such differences contributed to the differences in field behaviour was examined by forming artificial soils, each of which was made up from particles of one of the soils, but redistributed with respect to size in the proportion in which they occurred in one of the other soils.As a measure of the relevant physical properties, breaking strengths and bulk densities of cylindrical ‘clods’ moulded from the artificial soils were determined. To aid interpretation of the observed soil properties, similar measurements were made on individual fractions, on various other mixtures and on the parent soils.The breaking strengths of the soils made up to a given particle-size distribution from particles from the different parent soils were reasonably close to each other, with those for the Beccles distribution being more variable. There was a significant difference between the two. The strength of the reconstituted Batcombe soil was markedly greater than that of its parent soil, whereas that for Beccles soil was markedly less. There was little difference for the Stackyard soil.The bulk densities of saturated soils reconstituted from all nine fractions could be estimated reasonably accurately from the properties of the separate components. The structure of each of these soils in the air-dry state was inferred from comparisons between measured and calculated bulk densities. The breaking strengths of air-dry reconstituted soils were estimated from the properties of the separate components, and agreed reasonably well with the measured values for soils in which the clay and fine silt fractions predominated.Whereas it was generally possible to predict various physical properties of the reconstituted soils from those of the separate fractions, it was not possible to extrapolate the results to explain field behaviour.
A comparison of supplementary sources of nitrogen and energy for increasing the voluntary intake and utilization of barley straw by sheep
Authors: Barry T. N. , Johnstone P. D. 
Published: March 2009

SUMMARYChopped barley straw was fed ad libitum to penned Romney wether sheep. Supplements of urea, ground wheat grain + urea, lucerne hay and autumn saved pasture (ASP) were given for five periods each of 3 weeks using a 5 × 5 Latin square design. The latter three supplements supplied similar amounts of nitrogen and approximately 20% of the energy required for maintenance.The concentration of ammonia in the rumen fluid of sheep fed the basal straw diet was low and was increased by all the supplements. The concentration of total volatile fatty acids (VFA) in rumen fluid was unaffected by supplementation with urea, but was increased by the three supplements of nitrogen and energy. Differences in VFA molar proportions between treatments were small.Sheep offered straw alone had a digestible energy (DE) intake of 69% of maintenance and showed a weight loss of 121 g/day. Supplementation with urea had no effect upon apparent energy digestibility (42%) or voluntary intake, but significantly reduced the rate of live-weight loss. The lucerne hay and ASP supplements also had no effect upon straw consumption, but increased total DE intake to 87% of maintenance due to the additional energy provided by the supplements, and reduced live-weight loss. Supplementation with wheat + urea increased the estimated amount of digestible organic matter derived from straw by 8·5%, increasing DE intake to 94% of maintenance and reducing live-weight loss to 18 g/day.Averaged over all five groups of animals, straw intake increased by 9% in the second period of feeding and then gradually decreased with time, reaching a value in period 5 which was similar to period 1.
Effects of site of seed production on seed yields and regrowth of progeny tubers in potatoes
Authors: O'Brien P. J. , Allen E. J. 
Published: March 2009

SUMMARYNine experiments are reported in which effects of site of seed production on dormancy, sprout and field growth of progeny tubers were recorded. The experiments used early varieties, Home Guard (four experiments), Red Craigs Royal (three experiments) and Arran Comet (two experiments) and in each, seed crops were grown with similar husbandry at sites differing in altitude and location in western England and Wales. There was no consistent effect of site of seed production on the timing of the end of dormancy, and the maximum effect in any year was 11 ± 1·2 (S.E.) days. The small effects of site on dormancy influenced initial sprout lengths, and this effect usually persisted up to planting in Home Guard and Red Craigs Royal, although the effects were small in magnitude. There was no effect of site of seed production on sprout lengths at planting or on field growth and yields in Arran Comet. In the other two varieties there was no effect of site of seed production on yield at early harvests, but at later harvests seed from cooler upland sites sometimes significantly outyielded lowland seed. There was, therefore, no evidence to support the view that locally produced seed was advantageous for early potato production. The results, together with those of the concurrent series with maincrop varieties reported by Wurr (1979), show that on half the occasions on which yields were measured covering the whole of the harvesting period, site of seed production had no effect on yields. In these experiments with early varieties effects of site occurred only at harvests later than the commercial harvesting of such old seed. It is therefore suggested that site of seed production is a much less important determinant of tuber yield than hitherto suggested, and of little practical significance.
Effect of phosphorus and aluminium in the response of spring barley to soil acidity
Authors: Bache B. W. , Ross J. A. M. 
Published: March 2009

SUMMARYSoil chemistry in relation to yield of spring barley (Hordeum vulgare, cv. Golden Promise) was investigated in three field experiments in north-east Scotland in 1982. Previous treatments had produced a range of soil pH values from 4·0 to 6·0 (measured in 10mM-CaCl2 solution). The experiments demonstrated the values for soil acidity components below which yields were reduced. Large additions of phosphate fertilizer allowed barley to withstand larger concentrations of soluble and exchangeable aluminium (the principal acid soil toxin), thus decreasing the critical soil pH from 5·2 to 4·8 (corresponding to about 5·9 and 5·5 if measured in a water suspension), and increasing the critical soluble Al concentration from 10 to 50 UM and the critical Al saturation of the cationexchange complex from 0·025 to 0·1.
Effect of sowing date and seed rate on the grain yield and protein content of winter barley
Authors: Conry M. J. , Hegarty A. 
Published: March 2009

SUMMARYAn experiment, carried out over a 5-year period (1984–88) on medium–heavy textured soil at Athy (Ireland), tested the effect of five sowing dates (early September–early December) and four seed rates (c. 100, 150, 200 and 250 kg/ha) on the grain yield and protein content of winter barley (cv. Panda).September-sown plots gave the greatest yields in all years. Plots sown in mid-October and later gave significantly reduced yields. Yield reductions over the 5-year period averaged 15, 24 and 34% for the mid-October, November and December sowing dates, respectively. Significant differences in yield between the smaller and larger seed rates were obtained, with the latter giving the greatest yields at all sowing dates from late September to December. Increasing the seed rate, however, did not compensate for the yield reduction due to delayed sowing. In the early September-sown plots, the higher seed rates gave reduced yields in four of the five years (1984–87) with the opposite result in 1988. In 1988 the early September-sown plots gave greater yields than the late September-sown plots.Regression analysis showed a strong relationship between yield and log(ears/m2) in four of the five years (1984–87) but the relationship was poor in 1988 primarily due to the inexplicably low ear population of the early-sown plots. The inclusion of 1000-grain weight in the model gave a better fit and accounted for a high proportion (62–80%) of the yield variation.The late September sowing date and the higher seed rates gave slightly lower protein levels in four of the five years. There was an inverse relationship between grain yield and protein for the same four years (1984–87).
Effect of age, abomasal cannulation and rumen catheterization on intake and site of digestion by early-weaned lambs
Authors: Cruickshank G. J. , Poppi D. P. , Sykes A. R. , Familton A. S. 
Published: March 2009

SUMMARYThe voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.
A new procedure for the continuous measurement of oxygen consumption in pigs
Authors: Giles L. R. , Annison E. F. , Black J. L. , Tucker R. G. , Gooden J. M. 
Published: March 2009

SUMMARYWhole-body oxygen (O2) consumption was measured continuously in pigs from the product of blood flow through the pulmonary artery and arterio-venous (AV) difference of blood O2 content across the lungs (pulmonary AV procedure). Blood flow in the pulmonary artery, a measure of cardiac output, was monitored continuously using a transit-time ultrasound flow probe surgically implanted around the artery. The O2 content of pulmonary artery blood, which represents mixed venous blood O2 aturation (SvO2) was recorded continuously by fibre-optic oximetry. The relative constancy of arterial blood oxygen saturation (SaO2), obtained by catheterization of the saphenous artery, obviated the need for continuous monitoring. Complete recovery from surgical procedures, as indicated by the absence of infection and a return to pre-surgery food intake, occurred in 3–5 days. The combination of transit-time ultrasound and fibre-optic oximetry allowed the pulmonary AV procedure to provide continuous data on the oxygen consumption of growing pigs at high temperatures.
The effects of alteration of grain moisture content by wetting or drying on the test weight of four winter wheats
Authors: Pushman Fiona M. 
Published: March 2009

SUMMARYThe rate of change in the test weight of four winter wheat varieties, with changing grain moisture content, was greater when the grain was wetted than when it was dried. The test weight of grain which had been dried and returned to its original moisture content was lower than that of the original sample.