bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precision drilling combining peas (Pisum sativum L.) of contrasting leaf types at varying densities
Authors: Heath M. C. , Hebblethwaite P. D. 
Published: March 2009

SummaryField experiments were conducted in 1983–4 to investigate the effect of precision drilling and plant density on establishment, growth, radiation interception and yield of combining peas of varying leaf phenotype (Varieties ‘Birte’, leafed; ‘Filby’, leafless; and ‘BS3’, semi-leafless). Precision drilling established a more uniform plant distribution than øyjord drilling; visual differences observed soon after emergence were not observed at flowering. Precision drilling resulted in more radiation interception early in the season for semi-leafless but not leafed peas; dry-matter production and photosynthetic area index (PAI) were not increased. Yield data indicated that precision drilling produced similar yields to øyjord drilling at similar densities. Increasing plant density increased radiation interception, dry-matter production and PAI during vegetative growth; density treatment effects were less marked post-flowering. Pea leaf phenotypes differed in their yield response to increasing density. Radiation interception was related to dry-matter production and PAI to obtain an estimate of photosynthetic efficiency (ε) and the attenuation coefficient (k), respectively, ε and k were constant irrespective of spatial arrangement, leaf phenotype and plant density. The relative importance of spatial arrangement and plant density in increasing radiation interception and PAI and influence on yield is discussed; other potential agronomic advantages of precision drilling are described.
Control of berry production of potato plants
Authors: Wedgwood R. B. 
Published: March 2009

SummaryA trial to investigate possibilities of berry control by cultivation depth is described. Tubers planted at 10 cm produced significantly more potato plants in flower than those planted at 30 cm at the commencement of flowering. However, 3 weeks later the difference in numbers of flowers had disappeared. Emergence of overwintered tubers was about 53%, and of spring-planted tubers about 97%. Depth of planting did not affect emergence. A comparison of overwintered and spring-planted potato tubers showed earlier flowering and berry production by the overwintered tubers of about 1 week on average compared with the spring-planted tubers.Six chemical treatments were compared at different concentrations and growth stages of potatoes and peas to assess potential control of berry production in potato volunteers growing in a vining pea crop.Best control was found to be achieved with a combination of 4-(2-methyl-4-chlorophenoxy) butyric acid (MCPB) at 8300 mg a.i./l and Bentazone at 7300 mg a.i./l applied with the potato volunteers at full foliage to flowering stage, and before the pea crop reached the flowering bud stage, or by application of MCPB alone at 8300 mg a.i./l with the potato plants at full foliage to the pre-flowering stage. No chemical treatment either totally destroyed potato foliage, or completely suppressed potato flower and berry production, but it is argued that growers may reduce the effects considerably by careful observation and use of the appropriate chemical at the appropriate time.
Effect of contrasting tillage procedures on the emergence of onions in relation to measured physical properties of seed beds
Authors: North P. F. 
Published: March 2009

SummaryA new tillage procedure was examined for the improvement in physical environment it might provide during the establishment of a vegetable crop, particularly in a dry spring. This procedure, of cultivating the soil mainly in autumn, was compared with the conventional method of cultivating in the spring on a sandy loam soil. The physical condition of seed beds prepared by the two methods was assessed by in situ measurements of soil temperature, water retention characteristics, hydraulic conductivity and surface roughness. Plant responses were compared by monitoring the emergence of onion seeds. Dry spring conditions were simulated by sheltering some plots from rain.Final emergence, emergence time and rate of emergence were all superior following autumn cultivation for both dry and wet seed beds. The major factor affecting emergence was the coarseness of the seed bed which influenced the mechanical impedance to shoot growth. Differences in soil temperature between treatments were small, as were hydraulic conductivities under dry conditions. Preparing a seed bed in autumn rather than spring resulted in a good tilth with lower mechanical strength. This minimized the constraints on emergence when soil strength increased under dry conditions.
The effect of protein infusion on urinary excretion of purine derivatives in ruminants nourished by intragastric nutrition
Authors: Fujihara T. , Ørskov E. R. , Reeds P. J. , Kyle D. J. 
Published: March 2009

SummaryTwo experiments were carried out to determine endogenous excretion of purine derivatives in steers and lambs, and to investigate the relationship between microbial nucleic acid input and urinary excretion of purine nitrogen.The endogenous excretion of allantoin after conversion of hypoxanthine, xanthine and uric acid to allantoin, was calculated to be 72 and 26 mg/kg W0·75per day in steers and lambs, respectively, when the dietary protein contained no nucleic acid nitrogen.The excretion of purine derivatives increased linearly with increasing microbial nucleic acid input in lambs. The excretion of purine derivatives in excess of endogenous contribution was closely related to the theoretically expected values. The average recovery was calculated as 0·96 for one sheep and 1·0 for the other.
Genetic analysis of yield and yield components in field peas
Authors: Singh B. B. , Singh U. P. , Singh R. M. , Rai B. 
Published: March 2009

SummaryThe genetic parameters controlling the expression of seed yield and the yield components have been studied using both generation mean and triple test cross (TTC) analyses in two crosses of field pea. From generation mean analysis, it is obvious that in addition to significant estimates of additive and dominance components, epistatic components of mean [(i) and (I) types] were also important and duplicate type of epistasis was predominant for all the traits in both sets of crosses. In the TTC analysis, the major genetic component of variance was the additive component, though the dominance component was also found to be significant. There was evidence of epistasis for most of the characters studied. In fact, the overall epistasis (i type) was the major component of epistasis, but the parameter F was found in the non-significant range. The mean performance of the characters studied was higher in randomly-mated biparental progenies (BIPs) but there were more desirable transgressive segregants in the TTC population. Thus the genetic information obtained from both analyses seems to be complementary rather than alternative modes of inheritance in governing the expression of these useful economic traits.
Description and evaluation of a telemetry system for measuring body temperature in cattle
Authors: Hetzel D. J. S. , Bennett I. L. , Holmes C. R. , Encarnacao R. O. , MacKinnon M. J. 
Published: March 2009

SummaryA telemetry system based on calibrated radio transmitters implanted in the right sublumbar fossa of cattle is described. It was evaluated in different situations. Rectal temperature was used as a standard measure of body temperature. Implant temperatures were on average 0·2 °C higher than rectal temperatures. The magnitude of changes in the two temperatures in response to environmental stimuli were very similar but the implants changed faster in response to heat stress, feeding and exercise. When cattle were confined in unshaded yards the repeatability (within-animal correlation) of implant temperatures measured at different times of the day was 0·41 ± 0·05, compared with 0·30 ± 0·05 for rectal temperatures. It was concluded that there was less extraneous variation associated with telemetric measurement.The telemetry system proved effective for monitoring the body temperature of grazing cattle within a range of 300 m. The repeatabilities of individual daily maximum and minimum temperatures were 0·43 ± 0·12 and 0·43 ± 0·11 respectively. Observations confirmed that cattle in part regulate their body temperatures by behaviours such as shading, grazing and exposure to wind. Thus body temperature whilst grazing was alone not a good index of physiological heat tolerance.
Investigations into the use of indicator methods of estimating the digestibilities of feeds by ruminant animals
Authors: Sein T. , Todd J. R. 
Published: March 2009

SummaryThis paper describes a comparison of acid insoluble ash (AIA) and acid detergent lignin (ADL) ratio techniques for estimating digestibility with the conventional total collection method using sheep fed a range of feeds. In only two of 17 digestibility trials were the results obtained by AIA ratio techniques significantly different from those obtained by the total collection method. In the case of ADL no significant differences occurred between the results obtained by the ratio technique and total collection method.In a trial using sheep in metabolism cages the AIA and ADL contents of faeces excreted in consecutive 4 h periods covering 48 h did not show any significant variation either within or between the two 24 h periods.The results obtained from ‘grab’ samples of faeces (25–40 g) taken per rectum or from faeces bags attached to sheep fed communally can be expected to give acceptable agreement with total collection provided the marker concentration in the faeces represents a number of sheep sampled on several days, since variation between individual samples of faeces may be high.
Phosphorus and calcium metabolism in growing calves with special emphasis on phosphorus homoeostasis: 1. Studies of the effect of changes in the dietary phosphorus intake on phosphorus and calcium metabolism
Authors: Challa J. , Braithwaite G. D. 
Published: March 2009

SummaryCalves were fed continuously at 4 h intervals a low P basal diet with or without P supplementation to give three levels of dietary P intake: one was deficient in P (2·5 g/day), the second adequate (6·0 g/day) and the third contained an excess of P (10·0 g/ day) according to Agricultural Research Council (1980) recommendations. Once steadystate conditions were achieved (after 2–3 weeks on the diet)32P and46Ca kinetic studies were carried out, together with measurements of P flow rates at the reticulorumen and P and Ca balances. With increased dietary P intake, the amount of dietary P absorbed increased as initially did the efficiency of P absorption. Both the serum P concentration and the rate of P retention increased in direct relation to increased P intake and increased P absorption. Salivary secretion of P increased with increased P absorption and in direct relation to serum P concentration. Endogenous faecal losses of P were also directly related to P intake and P absorption and results suggest that increased loss with increased P intake is inevitable.Despite a constant and adequate Ca intake, the rate and efficiency of Ca absorption, which was low on the low-P diet, increased significantly on the adequate and high-P diets. Similarly, Ca retention increased substantially on the higher P diets, showing that Ca metabolism can be controlled according to P status.
The performance of Ongole heifers grazing native and introduced pasture species at Sumba, Indonesia
Authors: Rudolf I. G. W. , Blair G. , Orchard P. W. , Til A. R. , Hunt M. 
Published: March 2009

SummaryAn experiment was conducted to examine the effect of fertilizer (triple superphosphate) and stocking rate on animal and pasture productivity on Sumba Island, Eastern Indonesia. The Ongole heifers used in the 1-year experiment gained weight during the wet season and lost weight during the dry season at stocking rates of 0·5 and 1·0 head/ha when grazing nativeThemedapasture. The dryseason weight loss was arrested when a prepared seed-bed pasture, which contained 21 % Siratro at the start of the experiment was grazed at a stocking rate of 1·5 head/ha. Increasing the stocking rate to 2·5 head/ha on this pasture resulted in an increase, in the weed component of the pasture from 12 to 84% in 1 year.The mineral content of plucked samples of pasture indicated that levels of Ca and Mg were generally adequate for growing beef cattle and that Na supplementation would be beneficial. Plant N concentration was below 1·5% in theThemedaandImperatacomponent but above this in the legume at the prepared seed-bed site. The P concentration in theThemedaandImperatawas always below the 0·24 % level required by cattle, as it was in the legume at the end of the experiment.The introduction of herbaceous legumes into pastures under set stocking conditions can lead to pasture instability.
Effects of native vesicular–arbuscular mycorrhizal fungi and phosphate fertilizer on red clover growth in acid soils
Authors: Sainz Maria J. , Arines J. 
Published: March 2009

SummaryThe effect of P applications and native vesicular-arbuscular mycorrhiza (VAM) on the growth and P nutrition of red clover plants was studied in two acid hill soils with similar edaphic characteristics.Mycorrhizal and non-mycorrhizal plants were compared under sterilized soil conditions. Plant growth increased on P addition in both soils, but the effect of mycorrhiza in improving drymatter production and P uptake was significant only in one of the soils. Fourteen and twenty-five mg/kg Olsen-P were needed in this soil to obtain the same yields by mycorrhizal and non-mycorrhizal plants, respectively. Results are explained in terms of a different effectiveness of the two fungal populations, and the possible effect of the soil sterilization process on percentage VAM infection is discussed.
Yield stability of selected forage vetches (Vicia spp.) under rainfed conditions in west Asia
Authors: Moneim A. M. Abd El , Cocks P. S. , Swedan Y. 
Published: March 2009

SummaryWith the current high prices for livestock, forage legumes are increasingly attractive to farmers in west Asia. There has been very little genetic improvement of the main species, of which three vetches, Vicia saliva (common vetch), V. villosa subsp. dasycarpa (woollypod vetch), and V. narbonensis (Narbon vetch), show promise. As a first step in genetic improvement 23 genotypes of common vetch and one each of woollypod vetch and Narbon vetch were grown at four sites in Syria and one in Lebanon over three seasons. Since local climatic conditions were considered to be of considerable importance, each site in each year was treated as a separate environment, to give 15 environments in all. genotype × environment (G × E) interactions were analysed using linear regression.There was considerable variation in herbage and seed yields within both genotypes and environments, and G × E interactions were highly significant. In the case of herbage yield good environments could be defined as those receiving high rainfall and low incidence of frost. Several genotypes appeared to possess wide adaptation, in terms of both yield and stability. Climate, except for late spring rains, had little effect on seed yield, nor were any of the genotypes widely adapted. However, in the broad sense heritability was much higher for seed than for herbage yield.There is a need to define good and bad environments for seed yield. Based on observations during the study it is likely that good environments for Narbon vetch are those where broomrape (Orobanche crenata) is absent, while root-knot nematode (Meloidogyne artiella) may affect seed yield of common vetch. In view of its high seed yield the possible role of Narbon vetch as a grain legume is briefly discussed.
Distribution of14carbon-labelled assimilates in flowering plants of oilseed rape (Brassica napusL.)
Authors: Keiller D. R. , Morgan D. G. 
Published: March 2009

SummaryA study has been made of the distribution of14carbon-labelled assimilates in flowering oilseed rape plants. Up to 10 days after anthesis individual flowers were strong sinks for assimilates for 2 days after opening but thereafter became weak sinks for a period of 24 h. This period coincided with pollination and subsequent fertilization. After fertilization the young pods again became strong sinks. Between 13 and 16 days after anthesis other flower buds, flowers and young pods which had previously been strong sinks failed to attract assimilates and aborted. This fall in sink capacity occurred at about the same time on all branches and appeared to be co-ordinated on a whole-plant basis.
The effect of plant raising and cultural factors on the curd initiation and maturity characteristics of summer/autumn cauliflower crops
Authors: Wurr D. C. E. , Elphinstone E. D. , Fellows Jane R. 
Published: March 2009

SummaryExperiments were conducted in 1986 and 1987 to determine the influences of plant raising temperature, transplant age, N top-dressing and irrigation regime on the curd initiation and maturity characteristics of the cauliflower variety White Fox. The prime objective of this work was to determine whether changes in crop production practice had an influence on the period between curd initiation and maturity, in order to aid the development of techniques predicting when curds will reach a specific size.The duration of the period from curd initiation to curd maturity was not significantly affected by any treatment in either year and treatment effects on curd size at maturity were of no practical importance provided that the recommended level of N top-dressing was achieved. It is therefore concluded that changes in production practices within the normal commercial range are unlikely to have any significant practical effect on the use of techniques to predict the timing of crop maturity.There were large differences between the experiments in the mean number of leaves formed at curd initiation, which ranged from 22·0 to 36·7. In order to interpret these data a relative vernalization stimulus was calculated from 12 leaves onwards. It had a maximum rate of vernalization between 5 and 17 °C and a reduced rate at lower and higher temperatures and adequately accounted for the differences in the number of leaves at curd initiation.
An approach to the determination of rumen degradability of nitrogen in low-grade roughages and partition of nitrogen therein
Authors: Negi S. S. , Singh B. , Makkar H. P. S. 
Published: March 2009

SummaryRumen degradability of dry matter (D.M.) and N in wheat straw, rice straw and local grass hay, containing 5·16, 6·37 and 4·58 mg N/g D.M. respectively, was estimated by rumen fermentation measurements at 3, 6, 9, 12, 24 and 48 h using the nylon bag technique. The degradability of D.M. at an assumed rumen outflow rate of 0·025/h was 21·7, 34·9 and 22·4 for wheat straw, rice straw and grass hay, respectively. Theestimation of degradability of N was confounded by thedeposition of ruminal microbial nitrogen in the nylon bag. A correction was made by measuring the accumulation of N when N·free fibre and cellulose were incubated in the nylon bags. The effective degradability of N in the roughages at the assumed rumen outflow rate was 54·5, 36·9 and 42·8% respectively, showing that the roughages contain rumen-degradable N for microbial nutrition. The undegradable nitrogen (UDN) values in wheat straw, rice straw and grass hay were 2·35, 4·02 and 2·62 mg/g D.M., and after correction for unavailable acid detergent-linked N, the available UDN values were 0·58, 2·95 and 1·32 mg/g D.M., respectively.
Response of soya bean (Glycine max (L.) Merr.) to phosphorus, potassium and molybdenum applications
Authors: Pal U. R. , Olufajo O. O. , Nnadi L. A. , Singh L. 
Published: March 2009

SummaryField experiments during the wet seasons of 1981–1985 determined the response of soya bean to the application of P, K and Mo at four locations in the Nigerian savanna. Soya bean was grown at factorial combinations of four rates of P (0, 13·2, 26·4 and 396 kg P/ha) and two rates of K. (0 or 41·5 kg K/ha) in 1981, but in subsequent years two or three rates of Mo (0, 0·5 or 1·0 kg ammonium molybdate/ha) were included in a randomized complete block design with three replications at all locations.Significant yield increases due to the application of P were recorded in 10 out of 11 trials. Yield increases due to 13·2 or 26·4 kg P/ha were from 29 to 210% over the control. The effects of K and Mo application were not significant in 10 out of 11 trials and eight out of nine trials, respectively. Whereas P x Mo interaction effects were significant in three trials only, highest yields were recorded due to application of 26·4 or 39·6 kg P/ha in combination with 0·5 kg ammonium molybdate/ha.Application of P increased the percentage of P in soya-bean leaves significantly and a range of 0·275–0·330% P appears to be the critical nutrient range of P in soya-bean leaves at full bloom stage. Application of K had no effect on K concentration in leaves.
Effects of chlormequat application on stem characteristics, yield and panicle conformation of winter oats
Authors: Leitch M. H. , Hayes J. D. 
Published: March 2009

SUMMARYThe responses to treatment with chlormequat of winter oats at various rates of applied N were investigated in field experiments over two seasons. Chlormequat, applied at crop growth stage (GS) 32, significantly reduced stem length by an overall average of 25·3% in 1985/86 and 27·4% in 1986/87. The percentage reduction was not significantly influenced by variety or by the rate of N applied. All intcrnodes apart from the basal one were significantly shortened. The third internode from the base showed the largest percentage reduction and the uppermost internode the largest actual reduction in length, in all three varieties. Stem shortening was always associated with an increase in the weight per unit length of stem. In 1985/86 lodging in untreated control plots became more severe as N rate increased, but was completely controlled by the application of chlormequat at all but the highest rate (150 kg N/ha).Combine-harvested grain yields of the variety Pennal in 1985/86 and of Bulwark and Pcnnal in 1986/87 were reduced where chlormequat had been applied. Hand-harvested samples from these treatments did not show the same reductions in yield, but revealed a significant increase in the number of grains per panicle and a significant reduction in their mean individual weight. The grain characteristics of Peniarth were unaffected.The lengths of the main-stem panicles and primary branches in the panicle were shortened as a result of chlormequat application. In addition, the degree of branching and the number of spikelets were increased in the lower third of the panicle but reduced in the upper two thirds. In both Bulwark and Pennal the numbers of sterile grains were increased by the application of chlormequat and, in Bulwark only, the number of fertile grains was reduced. In Peniarth the numbers of fertile and sterile grains were unaffected.
Effect of thin layer drying rate and swath architecture on the rate of grass swath drying under controlled conditions
Authors: Lamond W. J. , Spencer H. B. , Graham R. , Moore A. B. 
Published: March 2009

SUMMARYA total of 51 grass swaths was dried in a wind tunnel under controlled conditions of temperature and humidity. The swath treatments covered a range of conditioning treatments, crop types, maturities and porosities. Drying rates of the swaths were related to crop and swath properties to establish which variables were important in influencing the overall drying rates of the swaths. Multiple regression analysis was used to assess the statistical dependence of drying rate on variables reflecting crop and swath properties: the dependence on swath structure was approximately four times greater than the dependence on crop conditioning. Improved swath drying rates could be achieved by lesssophisticated machinery than the current mower conditioners.