bluuebunny/crossref_metadata_2025_split huggingface dataset:
High biomass genotypes in spring barley
Authors: Hanson P. R. , Riggs T. J. , Klose S. J. , Austin R. B. 
Published: March 2009

SUMMARYThree experiments were carried out to measure grain and biomass yields of spring barley breeding lines and varieties. Leaf diseases were controlled by applying proprietary fungicides and in some treatments plants were supported by nets to prevent lodging. The trials, grown in 1982 and 1983, compared the grain and biomass yields of 14 breeding lines and two varieties with and without support. In a third experiment, comparing three lines and the varieties Triumph and Egmont, all the plots were supported and in addition each experimental plot was flanked by guard plots of the same genotype to minimize inter-plot competition.In the supported plots of all three experiments, three breeding lines, SB 543–3, SB 71–2 and HSB 258–93 produced significantly greater biomass yields than the mean of the varieties Triumph and Egmont. All three breeding lines were taller and had lower ratios of grain to grain + straw than the controls. Measurements were made of the accumulation of dry matter, chlorophyll content at anthesis and date of ear emergence but no single factor could be identified which was associated with increased biomass in these lines.The grain yield of the semi-dwarf, lodging-resistant variety Triumph was reduced by an average of 0·24 t/ha by the support treatment compared with the non-supported control. The results from the third experiment suggested that the yield of Triumph was reduced by inter-plot competition by about 10% in relation to the other entries in the trial.It is suggested that the high biomass lines identified here could be used as parents in a breeding programme to produce varieties with high yield if this high biomass could be combined with a high ratio of grain to above-ground dry-matter yield.
Effect of preceding season cultural practices on mustard (Brassica juncea Czern) under semi-arid rainfed conditions of north-west India
Authors: Giri G. , Saran G. 
Published: March 2009

SUMMARYA field trial was made for 3 years at the Indian Agricultural Research Institute, New Delhi under semi-arid rainfed conditions to study the effect of the preceding season cultural practices on mustard and to assess the possibility of double cropping, and the results are discussed. Preceding season cultural practices, i. e. ploughing in fallow or growing cow pea for fodder or mung for grain (both short-duration crops) increased the yield of the mustard crop compared with no tillage or growing pearl millet in preceding season. Yield of mustard following tillage, fodder cow pea or mung with mulch was similar; hence it is concluded that double cropping is possible under such conditions instead of conventional tillage-mustard, monoeropping practice. It is also concluded that frequent ploughings could be greatly reduced to give few but more effective cultivations, but more research into reducing cultivation during the preceding season should be carried out.
The climatic potential for field hay drying in north-west Europe
Authors: Thompson N. , Barrie I. A. , Harvey L. D. J. 
Published: March 2009

SUMMARYA model of a drying swath has been developed and used with 20-year long meteorological data sets from 32 sites in north-west Europe to provide an objective assessment of the influence of weather on field hay drying. The model considered the swath in terms of its bulk properties but incorporated the effects on swath drying of soil evaporation and stubble transpiration: delays in swath drying caused by interception of rain or dew were calculated explicitly.A cutting season from May to September was assumed, and results given in terms of the number of daily cuts reaching various moisture contents in less than 10 days, and especially those reaching 25% (dry-weight basis) within 5 days so that dry-matter losses were relatively small, and immediate long-term storage was possible. Rainfall amounts on the faster-drying swaths were usually less than 1 mm. A large inter-annual variability in hay-drying prospects was demonstrated, even at sites with fairly good climates for drying on average. The most favourable conditions for field drying were shown to occur substantially earlier in the cutting season at maritime sites than at those with a more continental climate. Conditioning of the swath allowed more cuts to dry to a prescribed moisture content, but with the penalty of larger average rainfall on the swath, and consequent loss of quality.
Estimation of amounts of microbial and dietary nitrogen compounds entering the duodenum of cattle
Authors: Smith R. H. , McAllan A. B. , Hewitt D. , Lewis Patricia E. 
Published: March 2009

SummaryYoung steers with rumen and simple duodenal cannulas were given diets of approximately equal amounts of flaked maize and hay (A) or of flaked maize and straw supplemented with decorticated groundnut meal (DCGM) (B), fishmeal (C), heated soya-bean meal (D) or raw soya-bean meal (E) or of dried grass (F). A cow with rumen and re-entrant duodenal cannulas was given diets of hay and dairy cubes.Some steers received doses of32P-labelled inorganic phosphate twice daily with their concentrate feed. This led to small diurnal variations in inorganic P–32P specific activity but at similar daily sampling times the32P specific activity in rumen bacterial nucleic acids reached a steady state after dosing for about 4 days. Contributions of microbial-N to non-ammonia-N (NA-N) entering the duodenum were then estimated by comparing nucleic acid32P/NA-N ratios in related samples of rumen bacteria and duodenal contents. Similar estimates were made in these and other animals using α-, ε-diaminopimelic acid (DAP) and ribonucleic acid (RNA) as bacterial markers.Estimates for steers given diets A, B, C and F based upon ‘32P-labelled RNA nucleotides’ were, on average, 85% of those based upon total RNA. The differences were attributed mainly to the latter being elevated by the presence of small amounts of dietary RNA. When RNA-based estimates of the proportion of microbial-N in NA-N in duodenal contents for these and other steers which were nearly free of protozoa were multiplied by 0·85 (‘adjusted RNA’) the values were, on average, similar to those based upon DAP. Similar estimates for the cow based upon ‘adjusted RNA’ measurements were, however, about twice those based upon DAP, probably because the cow contained a high protozoal population and the DAP based, method did not account for protozoal N.For some steers total flows at the duodenum of organic matter (OM), microbial-N (mean based upon ‘adjusted RNA’ and DAP) and residual food N were estimated by reference to chromic oxide. Average values for g microbial-N synthesized/kg OM truly digested in the rumen for the different diets ranged from 15 to 22 (mean 20). Mean degradabilities of food N (residual food N at duodenum/N intake) were 0·57, 0·71, 0·71, 0·70 and 0·84 for diets A, B, C, D and E respectively. No differences between diets were significant atP< 0·05.
The growth of maize
Authors: Iremiren G. O. , Milbourn G. M. 
Published: March 2009

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.
Game domestication for animal production in Kenya: shade behaviour and factors affecting the herding of eland, oryx, buffalo and zebu cattle
Authors: Lewis J. G. 
Published: March 2009

SummaryStudies on night-enclosed eland, oryx, buffalo and cattle in south eastern Kenya showed that the animals spent only a short time each day in the shade; the mean duration was not more than 2 h/day for any species.All four species actively sought shade in the middle of the day. The time spent in the shade by the three indigenous species was significantly related to activity times and environmental heat load; that of cattle was not.In general the time spent in the shade by the four species could be related to characteristics of their coat.The captive animals at Galana spend less time in the shade than their free-living counterparts. This is thought to be partly due to the need of wild animals to reduce their total body water turnover rate and for captive animals to spend more time feeding during the day.The inter-individual distances (IID) maintained by eland, oryx and cattle and the synchronization of the activity of these three species and buffalo were also studied.Eland maintained the largest mean IID (13·7 m) while those for oryx (6·5 m) and cattle (4·0 m) were considerably less. Calculations showed that herds of 250 eland might occupy an area of approximately 5 ha, oryx 1 ha and cattle would occupy 0·5 ha. The IID of all three species were significantly related to activity and the IIDs of eland and oryx were significantly related to meteorological factors. The differences in the IIDs of the three species were thought to be due to differences in feeding strategies and the length of time for which cattle have been domesticated.For all species feeding was well synchronized, but walking, idling and shade behaviour were not. Although only one activity was well synchronized it was the most time consuming one. The lack of synchrony in other activities did not pose a great problem in the management of the relatively small herds being studied. Lack of synchrony, however, might cause a problem if the size of the herds were substantially increased.
Effects of crop husbandry and growing conditions on storage losses of Pentland Crown potatoes
Authors: Wilcockson S. J. , Allen E. J. , Scott R. K. , Wurr D. C. E. 
Published: March 2009

SUMMARYOver five growing seasons (1976–80) experiments were carried out using at least three contrasting sites per season to study the relationship between growing conditions and storage losses in Pentland Crown potatoes. Crops were harvested by hand and storage was carried out in a single environment over a period of 6–7 months without sprout suppressants. The range in growing conditions was great and reflected in the pattern of leaf growth and range in yields of the stored crops (30–90 t/ha). Crops from Tenby (S. W. Wales) produced the most consistent and frequently the highest yields and usually lost the least weight during storage. Although the range in total weight loss over all experiments was large from 5·4 to 16·3%, treatment effects were much smaller than in field growth and yield. Delaying the date of harvest usually increased weight loss and tubers harvested in early August stored at least as well as late-harvested tubers. Tubers harvested without prior defoliation stored as well as tubers harvested on the same day from crops defoliated at least 2 weeks previously. Lengthening the interval from defoliation to harvest usually increased weight loss in storage. Although the tubers were hand harvested effects on saleability were found at the end of storage and there was no evidence that earlier harvesting, which may involve some loss of field yield, would result in any loss of saleable yield out of store.The results provided no evidence to support the widely-held view that the suitability of a tuber for harvesting improves during maturation associated with natural or imposed crop senescence. It is therefore suggested that the use of the term maturity be avoided as it is wholly unhelpful in studies of the relationship between field growth and storage losses in potatoes.
The effect of organic phosphates on the drying rate of grass leaves and dry-matter losses during drying
Authors: Harris C. E. 
Published: March 2009

SummaryTri-w-butyl phosphate has previously been shown to increase the drying rate of cut grass leaves. It also markedly inhibited respiration and thus reduced loss of dry matter during drying. In the work reported here, some other commercially available phosphate esters were tested for the same effects, except for the inhibition of respiration. Four mixtures of ethoxylated phosphate esters increased the drying rate of excised S. 24 perennial ryegrass leaves, and three of these also reduced the loss of dry matter during drying.The results suggest the possibility of devising single chemical treatments for both increasing the drying rate and reducing the respiration rate of forage crops conserved by drying in the field. The potential advantages of such treatments, together with the difficulties of realizing these advantages in practice, are briefly discussed.
Leaching of potassium in illitic soil profiles as influenced by long-term application of inorganic fertilizers
Authors: Singh Bijay , Sekhon G. S. 
Published: March 2009

SummaryThe correlation between sorption and mobility of potassium in illitic soils has been used to compare K leaching in profiles under different fertilizer treatments in longterm experiments. Estimates of potassium saturation of the cation exchange capacity in 15 cm soil layers to a depth of 225 cm indicated maximum leaching of K in unfertilized soils. Application of N, P and K increased K uptake by plants, reduced K saturation and thus its leaching.
The relationship between phosphate response and base saturation in acid soils
Authors: Birch H. F. 
Published: March 2009

In three groups of field experiments totalling fiftysix observations phosphate responses were found to be very significantly and inversely related both to the percentage saturation of the b.e.c. and exchangeable calcium as a percentage of exchangeable calcium plus hydrogen. The availability of the native soil phosphate was significantly and directly related to these values. The relationships between phosphate response or availability and the amounts of acid-soluble, adsorbed and water-soluble phosphate in the soils were much less conclusive.In acid soils considerable amounts of phosphate can be retained in a plant-available form associated with exchangeable bases, mainly calcium. Since practically all the soils from the field experiments lay within the range pH 4·7–6·3, it is believed that this form of phosphate is operative in these soils. The presence of such phosphate in the soil is, however, a function of the degree of base saturation in so far as this governs (probably through its influence on soil pH) the equilibrium distribution of the native soil phosphate between the available base-linked (saloid-bound) form and the less available colloid-bound form. With decreasing pH and base saturation increasing amounts of colloid-bound phosphate are formed at the expense of the saloid-bound phosphate. The degree of base saturation is therefore directly related to phosphate availability and, consequently, inversely related to phosphate response.In view of the significant regressions obtained, and the association of the exchangeable bases with a specific form of available phosphate, it is suggested that until methods are worked out for determining the amount of saloid-bound phosphate exchangeable base data may be used for assessing phosphato availability and response in acid soils. This method is contrasted with the more conventional methods of determining acid-soluble and adsorbed phosphates which are not always specific regarding tho form of phosphate extracted and the values for which, since they may represent the sum of a number of forms of different availabilities, aro difficult to interpret.
Effects of dietary deficiencies of energy, protein and calcium on the pregnant ewe
Authors: Sykes A. R. , Field A. C. 
Published: March 2009

SummaryScottish Blackface ewes were used to investigate the effect of protein deficiency during pregnancy on serum albumin, globulin, transferrin and plasma urea concentrations. Twenty-eight sheep were offered one of two iso-caloric diets in amounts which maintained energy intake at levels comparable to those found in hill sheep during winter. For half of the sheep (HP group) the crude-protein concentration was 11·8% and for the remainder (LP group) 6·0% in the dry matter. A further six sheep (group CL) were offered a diet containing 16·0% crude protein in amounts which prevented undernutrition. Concurrent changes in plasma volume and in certain serum proteins during pregnancy were determined in a second experiment.Serum globulins were not affected by protein intake and fell from 44·5 to 30·7 mg/ml during pregnancy. This was attributed mainly to a 30% increase in plasma volume which occurred during pregnancy.Serum albumin concentrations at the end of pregnancy were 29·3, 22·0 and 17'7 mg/ml and serum transferrin concentrations 400, 307 and 300 mg/100 ml in the CL, HP and LP groups respectively. Initial mean albumin and transferrin concentrations were 28·0 mg/ml and 383 mg/100 ml respectively. The usefulness of the parameters as indices of the protein status of pregnant ewes was discussed.Plasma urea N concentrations were related to the current protein intake of the animal. Mean values during late pregnancy were 26·0, 7'4 and 4·0 mg urea N/100 ml in the CL, HP, and LP) groups respectively. Limitations as to its usefulness were discussed.
The interaction of wheat genotypes with a specific factor of the environment
Authors: Easton H. S. , Clements R. J. 
Published: March 2009

SummarySeveral alternative statistical approaches to the analysis of genotype-environment interactions are summarized, and their inter-relationships are presented mathematically and graphically. An experiment was designed to test the ability of these analyses to satisfactorily describe genotype-environment interactions and to locate genotypes causing or contributing significantly to such interactions in a situation where environments differed in only one factor, i.e. soil nitrogen status.Twenty-five lines of wheat were grown at each of 5 levels of applied nitrogen (0–270 kg N/ha) in a sandy, nitrogen-deficient soil, and their grain yields and yield components (ears per unit area, grains per ear, weight per grain) were determined. Designating the nitrogen levels as ‘environments’, linear yield responses, and deviations from linear responses, of individual wheat entries to environment mean yield were calculated according to the various statistical procedures previously outlined. The results suggested that the linear response to environment mean yield was similar for all wheat entries. However, further inspection of the data revealed that the responses of eight entries to environment mean yield departed significantly from linearity. Although several analyses satisfactorily identified these aberrant entries, classifying them as ‘unstable’, it was concluded that the degree of departure from linearity of response was not an adequate measure of instability. Furthermore, as previously suggested by Knight (1970), it was confirmed that the relative ranking of an entry for yield stability according to such a concept varied according to the average response of the group of entries with which it was being compared.The general effects of applied nitrogen on yield components were to increase the number of ears and the number of grains per ear, and to decrease grain weight. However, only the first of these effects occurred consistently for all entries. The number and weight of individual grains per ear varied with the nitrogen treatment, often unpredictably, in a complex pattern which differed significantly between entries.
A radiographic study of skeletal growth and development in the pig. Temporal pattern of growth
Authors: Wenham G. , Fowler V. R. , McDonald I. 
Published: March 2009

SummaryThe skeletons of 34 pigs killed at a number of weights from birth to 120 kg were examined radiographically. Data were also used from radiographs of 83 foetuses of different ages.Estimates were made of the age of appearance of various ossification centres and measurements taken of the diaphyseal length and breadth. A chart is given showing the age of appearance of ossification centres. Exponential equations in which the independent variate was time were fitted to both pre- and post-natal linear measurements. These equations were used to calculate the age at which each of the measurements attained a given proportion of the post-natal asymptote. The development of the pig's skeleton is discussed in relation to that of other species. Attention is drawn to the possibility that the uncritical use of accepted terminology such as early and late maturing may tend to obscure an understanding of the manner in which certain components of the skeleton develop.