bluuebunny/crossref_metadata_2025 huggingface dataset:
Meat qualities in the sheep with special reference to Scottish breeds and crosses. II: Part III. Comparative development of selected individuals of different breeds and crosses as lambs and hoggets
Authors: Pálsson H.
Published: March 2009

It is not intended to present a detailed summary of the many points arising out of this investigation. The following represents merely a brief statement of the field covered and the major features emerging.

1. Complete anatomical dissection of eleven wether lambs at approximately 4·5 months old and 40 lb. carcass weight and five wether hoggets at approximately 13 months and 60 lb. carcass weight provided material for a comparative study of the anatomical composition and characters of different breeds and crosses of which the individuals concerned were selected as representative.

2. In both lambs and hoggets this study confirms the picture presented by the statistical comparison based on carcass measurements of the same breeds and crosses at constant weight described and discussed in Part II.

3. The breed differences in the relative development of the different regions of the body and the relative development of the major tissues, bone, muscle and fat in different joints and the total carcass have been studied in relation to carcass quality.

4. From the differential development of the different parts and tissues of the body in the various breeds and crosses, the concept of early and late development as a fundamental factor in meat production is demonstrated.

5. The proportional development of the various parts of the body and its major tissues in lambs and hoggets is compared. Regions of an intermediate rate of development are relatively best developed in the hoggets. In the total carcass, bone has increased least, muscle only slightly more and fat most, with an increase in age from 4·5 to 13 months and body weight from 40 to 60 lb. This is in line with the order of the development of the tissues.

6. The differential effect upon differentially developing tissues of the plane of nutrition is advanced as a major factor influencing the relative differences between lambs and hoggets.

7. Variations, affecting the value of the animal for meat production, in the number of vertebrae in the different anatomical regions have been described.

8. The bearing of the many factors discussed and principles elucidated upon practical problems of lamb and mutton production has been considered.
Observations on the mineral metabolism of pullets. IV
Authors: Common R. H.
Published: March 2009

1. Phytic acid in cereals and in certain rations based on cereals was incompletely hydrolysed during its passage through the intestinal tract of the pullet.

2. The percentage recovery in the droppings of phytic acid in a ration (24·2%) based on cereals plus extracted soya bean meal was considerable even when the ration included no calcium supplements. Both calcium carbonate and tricalcic phosphate greatly increased the percentage recovery. A supplement of calcium carbonate led to a somewhat higher recovery of phytic acid than a supplement of tricalcic phosphate containing the same amount of calcium.

3. The recovery of phytic acid tended to be somewhat higher in laying birds than in non-laying birds; this may have been associated with decreased amounts of calcium in the alimentary tract due to the demands for egg-shell formation.

4. The observations of Knowleset al. on the composition of the droppings of non-laying pullets on certain rations were confirmed; it was found, however, that their rule connecting the amounts of carbonate, calcium and phosphorus in such droppings did not extend (a) to the case of laying pullets, or (b) to certain other rations of wider Ca/P ratio.

5. The interpretation of the rule enunciated by Knowleset al. to mean that calcium and phosphorus are normally excreted by the pullet as dicalcium phosphate and calcium carbonate was shown to be untenable in view of the fact that the droppings may obey this rule and yet contain considerable amounts of phosphorus in organic combination.
The determination of the moisture equivalent by the silt-suction method and the shifting of the pF curve of stored soil samples
Authors: Da Costa J. V. Botelho , Alves J. Almeida
Published: March 2009

The relative unreliability of Bouyoucos's suction method for moisture equivalent determinations is a consequence: (1) of the variation of the suction force maintained with the nature of the soil, (2) of bad reproducibility of the results.

Constant and equal suction for all soils is secured by Schofield's silt-suction method, which may also be made to give fairly well reproducible results. The moisture content at pF 2·9 determined by this method should give a fairly close measure of the moisture equivalent.

While investigating this possibility it was found that the pF curves of stored soil samples may shift considerably with time. In the samples studied the pF at the moisture equivalent has dropped from 2·9 to about 2·4 in 7 years. In view of this shifting the reliability of the silt-suction method for moisture-equivalent determinations has not been definitely ascertained by the experiments reported.
Gas and vapour movements in the soil: II. The diffusion of carbon dioxide through porous solids
Authors: Penman H. L.
Published: March 2009

Apparatus for measuring the rate of diffusion of carbon dioxide through granular solids is described and the results obtained with it are shown to conform to the curve connecting D/D0 and S previously obtained for carbon disulphide and acetone. The equation D/D0 = 0·66S, which it is suggested should replace Buckingham's equation D/D0=S2, is applied to a discussion of soil aeration, and it is shown that at all porosities the rate of diffusion of carbon dioxide from the soil is sufficient to account for normal respiration without invoking the assistance of meteorological changes. A further application of the equation to water vapour movement in soils is briefly discussed.
Studies on character association in potatoes
Authors: Gaur P. C. , Kishore H. , Gupta P. K.
Published: March 2009

The phenotypic, genotypic and environmental correlation coefficients were calculated for 13 morphological and tuber quality characters, 17 of 78 possible combinations were found to be significant. Tuber yield was positively associated with average tuber weight and with total tuber dry matter per plant. Average tuber weight was negatively associated with number of tubers per plant and with most of the quality characters. The indices for selection for tuber yield were computed using the yield components and yield only. It was observed that the selections based on tuber yield itself are likely to be superior to those based on yield components. However, an index involving the yield components and the yield was found to be most efficient.

Among the tuber quality characters, percentage tuber dry matter showed significant positive association with the percentage alcohol-insoluble solids (AIS) and with the percentage of starch in fresh tubers, and a negative association with the percentage of protein in tuber dry matter. The associations between percentage of starch in fresh tubers and the percentage of starch in tuber dry matter, between percentage of starch in AIS and the percentage of starch in tuber dry matter and between percentage of protein in fresh tubers and the percentage of protein in tuber dry matter were also found to be significant and positive.

To increase tuber yield it is necessary to break the negative linkage between its two components. High total tuber dry matter per plant can be brought about by selecting for high tuber yield. For the improvement of tuber quality together with tuber yield, the selection for yield based on a large number of tubers is likely to be useful.
Dried potato products for egg production: statistical analysis of a laying experiment
Authors: Bolton W. , Hale R. W.
Published: March 2009

An experiment involving twelve pens of twenty-five pullets demonstrated that two types of dried potatoes compared favourably with cereals, as regards their effects on egg production, when up to 42½% of each product was included in the mash.

The records of the experiment, as regards (a) the number of eggs laid in 12 months, (b) the mean weight of eggs during the year, and (c) the change in live weight during the year, were studied by analysis of variance, using the approximate method of Yates (1933) for obtaining standard errors of pen means from the variance within pens. Similar analyses of the number of eggs laid in the month were carried out for each month separately. The latter analyses indicated the months in which increased production was obtained from the superior rations, and showed that duplicate pens had reacted similarly to the experimental feeding. The results of the statistical analyses are set out in some detail as an example of method.
A study in soil cultivation. The effects of varying soil consolidation on growth and development of rain-grown cotton
Authors: Heath O. V. S.
Published: March 2009

1. Experiments were carried out in four seasons at Barberton, South Africa, occupying approximately 2¼ acres of ground. Three soil treatments were used, viz. Normal (N), Compressed (C) and Grubbed (loosened) (G).

2. Measures of consolidation of the soil were made with a specially designed apparatus, and large differences established (pp. 516–520).

3. Estimations of water content and nitrate content were carried out. No great differences were found (pp. 520–524).

4. Fortnightly samples of the plants were taken, from which numerical data were collected designed to estimate morphological development (primary data, pp. 526–529).

5. Derived data on net assimilation rate, relative leaf-growth rate and efficiency index were calculated (pp. 529–533).

6. Growth in total dry weight was found to conform approximately with an exponential law up to the time of flowering. Up to this stage also net assimilation rate was found to remain constant.

7. Growth differences between treatments were related to variation in net assimilation rate only (p. 531).

8. The results were analysed statistically. Significant results alone are emphasized.

9. In all respects growth and development on the consolidated soil was more rapid than that on the grubbed soil, normal being generally intermediate.

10. The results are discussed with reference to the question of nitrogen supply, water supply and aeration of the soil.
Nitrogen metabolism in the ovine stomach: 2. Factors influencing ruminal ammonia levels in sheep maintained on different diets
Authors: Harrop C. J. F.
Published: March 2009

Factors which could be expected to influence levels of ammonia in the rumen were compared in sheep maintained on diets providing 11·4 or 20·7 g N/day.

The ruminal fluid volume in sheep given the lower-N ration was 78% of that in sheep maintained on the higher-N diet. The effect of this in diluting rumen ammonia from recycled urea is discussed.

Ruminal urease activity was higher in sheep given the lower-N diet, and was confined to the particulate fraction of rumen liquor in animals given either diet. At least 95% of the maximum activity occurred in the range of pH 5·4–7·05, and pH 6·0–7·25 in sheep maintained on the lower- and higher-N diets respectively. Small variations in activity were observed between the morning and evening meals.

In vitro rates of net ammonia production in samples of rumen liquor were similar in sheep given either diet; a positive correlation with the initial ammonia concentration was evident. Net utilization of ammonia was detected in some experiments in samples from sheep maintained on the lower-N diet. Starvation for 1 day was associated with increased rates of production and initial concentrations of ammonia.

Cellulose, as cotton thread, was digested at similar rates in vivo in sheep given the different diets. This is discussed in relation to the demand for ammonia by cellulolytic bacteria.
Four-year leys: the inclusion of red clover: first year management
Authors: Garner F. H. , Sanders H. G.
Published: March 2009

1. Two experiments have been carried out on the Cambridge University Farm to test the desirability of including late-flowering red clover in the seeds mixture in the case of a 4-year ley, and to compare grazing with cutting for hay in the first harvest year.

2. The majority of the red clover survived for the first 2 years, during which it increased the yield of dry matter very markedly; it did not lead to any reduction of yield in the last 2 years. By producing an early cover of the ground red clover checked the encroachment of weeds; although it reduced the proportion of wild white clover in the herbage in the later years, the reduction was not serious.

3. Where the young plants were well established at the time, and normal weather conditions were experienced, grazing was definitely preferable to cutting for hay during the first harvest year. Where the plants were slow in establishing themselves, and in a superlatively dry spring and summer, grazing checked the development of the sward too much, and cutting for hay gave much better results.
Ovulation and the descent of the ovum in the Fallopian tube of the mare after treatment with gonadotrophic hormones
Authors: Day F. T.
Published: March 2009

1. In mares which had a follicle of a sufficient size in the ovaries, in most cases the intravenous injection of 1000 mouse units or over of pregnancy urine extract caused ovulation at any time in the oestrous cycle.

2. In those mares which were in oestrus at the time of injection, ovulation occurred 22–30 hr. after injection, and the length of oestrus was reduced from 7 and 9 days to 3 days.

3. In those mares which were not in oestrus when injected ovulation occurred 30–60 hr. after injection without the appearance of any symptoms of oestrus.

4. Normal ovulation occurred after these injections, and in one case the ovum was recovered from the uterine end of the Fallopian tube about 95 hr. after ovulation, and 138 hr. after injection.
Variation in the protein intake of sheep in relation to wool growth
Authors: Fraser A. H. H. , Roberts J. A. Fraser
Published: March 2009

1. Two lots of twenty sheep each were fed indoors on rations known to produce satisfactory growth. The calorific value of the two diets was the same. One lot received 52 per cent, more digestible protein than the other. The diet of the low protein group was protein deficient according to the calculations of Wood.

2. The sheep were shorn at the beginning of the experiment and again at its conclusion. Fibre measurements were made on samples taken at the same two periods from the same body area. The fleece and fibres grown during the experimental period were compared in each case with the fleece and fibres grown during the pre-experimental period. The fibre measurements included fineness, length and fibre weight.
The fungicidal properties of certain spray-fluids, X. Glyceride oils. (With two text-figures.)
Authors: Martin H. , Salmon E. S.
Published: March 2009

1. The fungicidal action of vegetable oils on the conidial stage of the hop powdery mildew, Sphaerotheca Humuli (DC), Burr., is a property common to glyceride oils. When applied with 0·25 per cent. Agral I, the various samples of vegetable and animal oils examined, with the exception of castor oil, proved fungicidal at a concentration of 0·5–1·0 per cent.

2. The fungicidal action of glyceride oils is associated with the glyceride structure and, in the presence of Agral I, is unaffected by the presence of those impurities of the oil which are removed by refinement.

3. Glycerol, at 4 per cent., is not completely fungicidal and, under the conditions of the experiments, causes leaf injury; oleic acid, at 1 per cent. is phytocidal; triolein, prepared by synthesis from glycerol and oleic acid, is fungicidal at 0·5 per cent. and causes no injury to the leaves.

4. The fungicidal properties of glyceride oils are affected by the type of emulsification used and the stable emulsions produced by the twosolution oleic acid method are less effective than the unstable emulsions obtained by agitation with dilute Agral I solutions.
A simplified prediction equation for reactive solute transport in soils
Authors: Gupta S. K. , Pandey R. N.
Published: March 2009

A general equation for predicting the movement of interacting and non-interacting solutes is proposed. Equations to predict the leaching fractions and mean displacement depth of linearly adsorbed solutes have been derived from the solution of the general equation. A simple equation which considerably reduces the experimental and analytical work has also been derived to evaluate the adsorption coefficient. The predicted adsorption coefficient compares favourably with published data.
Effect of light and temperature on wool growth
Authors: Elsherbiny A. A. , Eloksh H. A. , Elsheikh A. S. , Khalil M. H.
Published: March 2009

Wool samples were collected from 39 rams representing five breed groups of sheep: Merino (M), Ossimi (0), and the crosses between them, viz. ¾ Ossimi–¾ Merino (¾ O), ½ Ossimi–½ Merino (½ O) and ½ Ossimi–¾ Merino (¼ O) maintained at Sakha Experiment Station, Kafrelsheikh, Egypt, with the objectives of detecting the effect of the seasonal changes in normal light rhythm and temperature on wool fibre length and diameter. Animals were divided into two light treatments groups, the first consisting of four animals from each breed kept under continuous dim light conditions throughout the year and the second of three animals from Ossimi and four from each breed group kept inside an open pen free to sunlight and shade zones under daylight rhythm throughout the year. It was found that fibre length as well as fibre diameter in normal light exceeded that in dim light except in winter time. Breed groups showed different responses to the absence of light especially the Ossimi and the ¾ O whose fibre lengths were most affected. The breed groups had larger fibre diameters in normal light than in dim light except Merino and ¼ O. Seasonal changes in temperature had a highly significant effect on fibre length but not on fibre diameter. Higher temperature coincided with lower increases in fibre length. Season to season variation in wool growth seemed to suggest that the number of light hours per day and atmospheric temperature counteracted each other resulting in a non-significant seasonal pattern.
Water relations of winter wheat: 1. Growth of the root system
Authors: Gregory P. J. , McGowan M. , Biscoe P. V. , Hunter B.
Published: March 2009

The production of root axes and the growth of the root system are reported for a commercially grown crop of Maris Huntsman winter wheat. Soil cores were extracted on 17 occasions during the growing season permitting a detailed study of root length and root dry weight with depth and time.

Production of seminal root axes was complete by the beginning of March when all plants possessed six (occasionally seven) axes which persisted throughout the life of the crop. Nodal axes were produced continuously from mid-February until late May and finally numbered approximately 20 stem nodal axes per main stem. Total root dry weight increased exponentially until the beginning of April and then almost linearly to reach a maximum of 105 g root/m2 field in mid-June (anthesis). After anthesis, total root dry weight decreased but root growth continued below 80 cm. From April onwards, approximately 65% of the total root dry weight was in the 0–30 cm layer.
Equations to predict leaching of soluble salts in saline soils
Authors: Pandey R. N. , Gupta S. K.
Published: March 2009

Simple mathematical models to predict leaching fractions and mean displacement depths of salts either uniformly distributed in the soil profile or surface applied have been derived from the solution of Peck's differential equation of salt balance. Predictions from these models are comparable with those obtained from Burns' equation and fit published data well.
Live-weight responses by young Friesian steers to supplements of oats, linseed meal and biuret
Authors: Morgan J. H. L. , Behrens W. C.
Published: March 2009

In the winter-rainfall areas of southern Australia cattle and sheep grazing dry pastures in late summer and early autumn commonly lose weight because of a decline in the availability and nutritive value of the dry herbage (McLaughlin, 1973). Early-weaned calves and young lambs are affected more severely than older animals probably because of their low feed intake and their high requirements for energy and protein (Preston & Willis, 1970).
Thermal time as a non-destructive method of estimating tuber initiation in potatoes
Authors: Jefferies R. A. , Mackerron D. K. L.
Published: March 2009

Water stress during the period when tubers are initiated may reduce the final number of tubers (MacKerron & Jefferies, 1986) and increase the incidence of common scab (Streptomyces scabies) in susceptible cultivars (Lapwood & Hering, 1970). It is important, therefore, for the maintenance of a large number of tubers and for the limitation of scab, to be able to estimate the time of tuber initiation. Tuber initiation has been defined differently by a number of workers (e.g. Sale, 1979; Sands, Hackett & Nix, 1979; O'Brien et al. 1983; MacKerron & Jefferies, 1986) based on either the number or proportion of stolon apices that have reached a certain size (usually twice the diameter of their stolons). These are definitions of tuber growth rather than development and require destructive sampling at frequent intervals for recognition of the event. Temperature has a major influence on the rates at which plant organs develop so that the time taken to reach a given developmental stage may be related to thermal time, defined as the time-integral of temperature (Jones, 1983). In potato the physiological age of tubers (Wurr, 1978; Allen et al. 1979; O'Brien et al. 1983), sprout development and extension (MacKerron, 1984), and the initiation of leaf primordia (Kirk, Davies & Marshall, 1985) have been related to thermal time. In a model of the development and bulking of potatoes Sands et al. (1979) used a single non-linear function to describe the effects of time and temperature on several development processes including tuber initiation. That function did not adequately describe the time taken to tuber initiation and Sands et al. (1979) did not then use tuber initiation as an important stage in their model.
Canopy apparent photosynthesis, respiration and yield in wheat
Authors: Shuting Dong
Published: March 2009

Field experiments explored the relationship between canopy apparent photosynthesis (CAP) and grain yield and examined the effect of plant population density on CAP. Two cultivars of wheat were grown at five plant population densities in 1986 and 1987 in Taian, China. Measurements of CAP were made at intervals during the growth period by placing a large plastic-covered chamber over a 0·7 m2 segment of the canopy and measuring CO2 depletion with infra-red gas analysers for 1–2 min at c. 25 °C around noon when solar radiation was > 1100 umol/m2/s. Canopy respiration (CR) rates were measured by covering the whole chamber with a black screen in the daytime. Calculations of CAP and CR were made using the chamber volume, air temperature and changes in CO2 concentration over time and expressed on a land area basis.

Maximum values of CAP and CR were 4–6 g and 2–3 g CO2/m2/h, respectively, at the anthesis stage, decreasing with age during grain filling. The decrease was more rapid at the high than at the low population density. The difference in CAP between plant densities before booting and after anthesis could be attributed to reductions in leaf area index (LAI) and photosynthetic rate.

Grain yield also differed between plant population densities, the range being from 5250 to 7500 kg/ha in both years. Grain yield and 1000-grain weight were positively correlated with CAP during grain filling (r = 0·78 and 0·99, P < 0·01, 8 D.F.). Effects of plant density on CR were highly significant, but CR was not related to yield (r = 0·50).
Digestion and rumen metabolism of red clover and perennial ryegrass/white clover forages by red deer
Authors: Freudenberger D. O. , Burns C. J. , Toyokawa K. , Barry T. N.
Published: March 2009

Red clover (RC) and perennial ryegrass (PRG)-based forages were cut fresh during late spring/early summer and fed at similar levels of dry matter (DM) intake to rumen fistulated castrated red deer kept indoors in metabolism pens. RC contained higher concentrations of total N and non-protein cell contents than PRG and lower concentrations of fibre. Rumen pool size and fractional outflow rates of liquid (13·3 ν. 15·1%/h) and of paniculate matter (2·5 ν. 3·9%/h) were lower for deer fed RC than PRG. Apparent digestibility of energy and fibre, rumen fibre fractional degradation rate and rumen fractional disappearance rate of non-protein cell contents were all higher for RC than for PRG deer. Nitrogen retention was similar for deer fed both forages. However, the concentration, pool size and outflow of ammonia from the rumen, together with urinary N excretion, were all much greater for deer fed RC than those fed PRG. The acetate: propionate ratio in rumen volatile fatty acids (VFA) was lower for the RC than the PRG group. It was concluded that the greater fibre digestion in deer fed RC was due to a faster rumen fractional degradation rate and a longer particulate mean retention time in the rumen, and that the very rapid outflow of water from the rumen relative to particulate matter in deer fed RC (5·5:1 ν. 3·8:1) may explain why deer are not susceptible to rumen frothy bloat when grazing RC. One reason for the greater voluntary feed intake (VFI) of deer grazing RC than those grazing PRG may be due to its greater concentration of protein and non-protein cell contents and their more rapid degradation and removal from the rumen.
Crop production and water-use. II. The development and validation of a water-use model for sugarbeet
Authors: Hamer P. J. C. , Carr M. K. V. , Wright E.
Published: March 2009

As a prerequisite for developing crop-yield/water-use functions for sugarbeet using the results of historical irrigation experiments, it was necessary to develop a water-use model which could operate with a limited data set. The general form of this model has been reported by Wright et al. (1994). In this paper the development and validation of the model for the sugarbeet crop is described.

The canopy was modelled in terms of the leaf area index and the relative interception of incoming solar radiation using functions based on thermal time and time. Four phases of growth were identified: emergence, slow-growth, fast-growth and full-canopy. An empirical drought factor was included to allow for the effects of water stress on canopy development during the slow- and fastgrowth expansion phases. Root development was described using a three phase model: initial (temperature dependent), linear and maximum depth (both time dependent).

Independent data previously reported from Broom's Barn Experimental Station were then used to validate the model in terms of its capacity to predict crop canopy development, with and without drought stress, soil water extraction at different depths and soil water deficits during the season. The study confirmed the validity of the model for predicting the water-use of sugarbeet.
The location and effects of genes modifying the response of wheat to the herbicide difenzoquat
Authors: Leckie D. , Snape J. W.
Published: March 2009

Single chromosome substitution lines of hexaploid wheat were developed using a variety resistant to difenzoquat, Chinese Spring, as donor and a susceptible variety, Sicco, as recipient, and were used to identify chromosomes carrying genes which modify the responses of these varieties. It was found that chromosomes 3B and 5D from Chinese Spring might act to reduce the amount of damage caused by the herbicide in the presence of the allele for susceptibility at the Dfql locus. The intermediate response to the herbicide, which is shown by some commerical varieties, was also investigated using a backcross reciprocal monosomic analysis. In these varieties, the allele at the Dfql locus determining the reaction to the herbicide was shown to be similar to that of the susceptible variety Sicco. It is, therefore, probable that the responses of intermediate varieties are due to the effects of modifier genes increasing resistance.
Response of pearl millet (Pennisetum americanum) to short-term flooding in a moderately sodic soil under field conditions
Authors: Sharma D. P. , Swarup A.
Published: March 2009

A field study in India in 1987 evaluated the effects of flooding at either tillering (25 days after sowing) or flowering (50 days after sowing) or at both on growth, yield and mineral composition of Pennisetum americanum L. Leeke in a moderately sodic soil (pH 8·5, exchangeable Na 18%).

Flooding for 1, 2, 4 or 6 days at tillering or flowering significantly reduced tillering, plant height, dry matter content, ear length and 1000-grain weight and resulted in a 6·3, 150, 21·6 or 26·6% reduction in grain yield, respectively. Flooding decreased oxygen diffusion rate, restricted root growth and decreased ion uptake, especially of N, P, K and Zn, and led to higher absorption of Na, Fe and Mn. The detrimental effects were greater when the crop was flooded at both stages.
Phenological development in bambara groundnut (Vigna subterranea) transferred from 14 to 11 h photoperiods
Authors: Linnemann A. R.
Published: March 2009

Aspects of the photoregulation of phenological development in bambara groundnut were studied in a glasshouse experiment in The Netherlands. The influence of a 14 h photoperiod (which retards podding) during a period of variable length prior to an 11 h photoperiod (which induces podding) on flowering, yield and on the position of pods on the plants was determined. The third generation of three plants of genotype ‘Ankpa 4’ from Nigeria was used as the split-plot factor in a split-plot design with three replicates. The main plots were four daylength treatments: a period of 21, 28, 41 or 54 days under the 14 h photoperiod before transference to the 11 h photoperiod. Plants transferred after 28 or more days started flowering sooner the earlier they were transferred. Plants transferred after 21 and 28 days began flowering at the same time (51 days after sowing), thus indicating juvenility. At harvest, 135 days after sowing, the total seed dry weight per plant was higher for plants transferred after 41 and 54 days than for plants transferred after 21 days. Plants transferred after 28 days gave an intermediate value. Most (79–91%) pods were produced on branches that developed on nodes 1–4 of the main axis. There were no differences in the fractional distribution of the pods along the main axis in plants transferred after 28 or more days. Pods of plants transferred after 21 and 28 days were more evenly distributed over the nodes of the first two primary branches than pods of plants transferred after 41 and 54 days. Plants of the latter treatments produced their pods more towards the tips of the branches and concentrated on two neighbouring nodes (nodes 5 and 6 for plants transferred after 41 days and nodes 6 and 7 for plants transferred after 54 days). Delaying the induction of podding in this experiment therefore resulted in higher seed yields per plant and a more synchronized development and hence maturity of pods.
Distribution, diversity and potential agronomic value of Medicago polymorpha in Sardinia
Authors: Loi A. , Porqueddu C. , Veronesi F. , Cocks P. S.
Published: March 2009

Thirty-five populations of Medicago polymorpha were collected from throughout Sardinia (Italy) in 1989 with a view to developing pasture species suitable for improving degraded grasslands in the northern Mediterranean basin. Herbage and seed production were compared with the Australian cultivar, Circle Valley, over 2 years at Bonassai, north Sardinia. Regeneration in the 2 years after sowing and seed size were also estimated. All variables were related to collection site parameters using multivariate analysis.

Herbage production varied between 2 and 8 t dry matter/ha, and up to 1·5 t/ha of seed was produced. K-means clustering of agronomic and morphological variables indicated that there were two groups present; one similar to variety polymorpha and one to variety vulgaris. There were two other single entry clusters, one of which contained cv. Circle Valley. Principal component analysis of the environmental variables indicated that cluster 1 (vulgaris) was more likely to come from mountainous areas where winter temperatures are low, and cluster 2 (polymorpha) from coastal areas where temperatures are mild. Regeneration of cluster 1 was better than that of cluster 2, which in turn was better than Circle Valley, indicating that populations in cluster 1 are better adapted to the management system imposed at Bonassai.

The results indicate that M. polymorpha has considerable potential to improve the grasslands of Sardinia. However, it is unlikely that imported cultivars will be successful, and it seems important that the selection of local populations should continue. Commercial seed production in Sardinia is likely to be a problem, and grazing management under the conditions of communal ownership may have to be reviewed. It is important that future research and development involves farmers and other industry groups.
Moisture and dry matter losses in field and wind tunnel trials of grass wilting with frequent mechanical disturbance
Authors: Spencer H. B. , Lamond W. J. , McGechan M. B. , Graham R. , Moore A. B.
Published: March 2009

In field and wind tunnel experiments in 1988 at the Scottish Centre of Agricultural Engineering, moisture loss in the 24 h after cutting increased when grass swaths were mixed, spread or turned and was positively related to the number of mixings. In the field trials, dry matter loss from conditioned swaths increased when the swaths were mechanically mixed or spreadafter cutting.
Effect of premating shearing on reproductive performance in ewe lambs after oestrus synchronization
Authors: O'Doherty J. V. , Crosby T. F.
Published: March 2009

One hundred and fifty-four, March-born, lowland ewe lambs, on the Lyons Estate farm, were allocated to a 2×2 factorial experiment. In September 1987, half were shorn and 1 month later the lambs were treated with intravaginal sponges, containing either 60 mg medroxyprogesterone acetate or 40 mg fluorogestone acetate, for 12 days. Following sponge removal, ewes were mated to fertile rams at a ram: ewe ratio of 1:6. There was no significant difference in reproductive performance between the two progestagen treatments (P > 0·05). Premating shearing increased (P < 0·01) conception rate and reduced the percentage of barren ewes (P < 0·01) but there was no effect on litter size. Time of gestation following shearing was increased (P < 0·01) by 1·24 days. Lamb growth rate up to weaning was not affected by the shearing treatment. The results of this trial indicate positive advantages of premating shearing of ewe lambs.
Developmental and tillering responses of winter wheat (Triticum aestivuni) crops to CO2and temperature
Authors: Batts G. R. , Wheeler T. R. , Morison J. I. L. , Ellis R. H. , Hadley P.
Published: March 2009

Winter wheat (Triticum aestivumL., cv. Hereward) was grown in the field within four double-walled polyethylene-covered tunnels along which near-linear temperature gradients were imposed at normal atmospheric or at an elevated CO2concentration (c.700 μmol mol−1CO2) in 1991/92 and in a further experiment in 1992/93. Development was more rapid the warmer the temperature. In 1991/92 an increase in mean seasonal temperature of 3·5 °C reduced the duration from sowing to harvest maturity (the stage when grain moisture content reduced naturally to 15–18%) byc.38 days, and reduced the duration from the double ridge stage to harvest maturity byc.34 days. A similar difference resulted from only 1·6 °C warming in 1992/93. Although the range of mean seasonal temperatures differed between years, the relation between temperature and rate of development from sowing to harvest maturity was common to both years (base temperature, −0.8 °C; thermal time 2410 °C d). Carbon dioxide concentration had no effect on this relation or on that between temperature and the rate of development from sowing to the double ridge stage and from the double ridge stage to harvest maturity. Carbon dioxide enrichment increased tillering substantially in 1991/92; there were 200 more shoots m−2at terminal spikelet formation in crops grown at elevated compared to normal CO2(additional shoots were principally coleoptile tillers and those developing after tiller 2) and this difference was reduced to 100 shoots m−2approaching harvest maturity (additional shoots remaining were those developing after tiller 2). In contrast, no effect of CO2enrichment on tillering was detected at any stage of development in 1992/93. The number of tillers per plant at terminal spikelet formation was a linear function of main stem dry weight at this developmental stage; this relationship was not affected by year or CO2. As CO2enrichment increased main stem dry weight in the first year only, when main stem dry weights at normal CO2were only one half of those values determined in the following year, it is concluded that any benefit of increase in CO2concentration to tillering in winter wheat may be greatest in those crop production environments where main stem dry weights at terminal spikelet are least andvice versa.
Proceedings of the Twenty-Eighth Meeting of the Agricultural Research Modellers' Group
Authors: France J.
Published: March 2009

This group, which is concerned with the applications of mathematics to agricultural science, is sponsored by the Biotechnology and Biological Sciences Research Council. It was formed in 1970, and has since met at approximately yearly intervals in London for one-day meetings. The twenty-eighth meeting of the group, chaired by Dr. D. A. Rose of the Department of Agricultural & Environmental Science, University of Newcastle, was held in the Wellcome Meeting Room at the Royal Society, 6 Carlton House Terrace, London on Friday, 29 March 1996, when the following papers were read.
The potential contribution of selected forage legume pastures to cereal production in crop-livestock farming systems
Authors: Tarawali S. A. , Peters M.
Published: March 2009

The potential of 3-year-old grazed pastures ofStylosanthes hamata, Chamaecrista rotundifoliaandCentrosema pascuorumto contribute to subsequent maize production was investigated in subhumid Nigeria in 1993. All three legume pastures had the ability to give better maize grain yields than native pasture but this was significant only forStylosanthes hamataandChamaecrista rotundifolia. For the legume species, maximum yield of maize per kg of N applied was attained at 60 kgN/ha. The subsequent yields of maize could be related to the legume species used, pasture management and the length of the fallow period.Centrosema pascuorumbehaved as an annual, and as such there was little legume present after 3 years; crop yield was therefore relatively low. Nevertheless, this species could be useful in 1-year fallow/pasture situations. Maize cropping was economically viable for legume plots only with 60 or 120 kgN/ha and not for native pasture. There were no significant differences in the time required to till or to weed legume pastures as compared with native pasture. Forage legume pastures could also have a positive effect on maize residue yields which represent a fodder resource in addition to the herbage understorey remaining after cropping, the quality of which could be enhanced by the presence of the forage legumes. The use of forage legumes for the promotion of both crop and livestock production in sustainable agricultural systems is discussed. The results of the study are used to highlight the importance of selecting the appropriate legume species, pasture management practices and duration of fallow period in relation to the prevailing farming system to maximize benefits from the legumes.
Assessment of ratoonability of short-duration pigeonpea genotypes
Authors: Chauhan Y. S. , Johansen C. , Gupta S. C.
Published: March 2009

The extent of variation in ratoonability was examined in a range of recently bred short-duration pigeonpea [Cajanus cajan (L.) Millsp.] genotypes in 1989/90, 1990/91 and 1991/92 at the ICRISAT Asia Center, Andhra Pradesh, India. Traits with which this variation could be associated were assessed. Differences in the total ratoon yield of two flushes were significant among the genotypes in each season. In a few genotypes, ratoon yield constituted 50% of the total yield, which could be as high as 5·6 t/ha. Total ratoon yield was positively correlated with leaf area index in the last 2 years of experimentation. The relationship of total ratoon yield to main crop yield was significantly positive in 1991/92 only. The results suggest that there is a large variation in ratoonability among short-duration genotypes and that high leaf area retention at main crop maturity appears to contribute substantially to this variation.
Substitution of reduced iron by zinc in total soil nitrogen estimation by modified Olsen's method
Authors: Praveen-Kumar  , Aggarwal R. K.
Published: March 2009

The conventional Kjeldahl method which is usually employed for determination of total N in soil does not effect quantitative recovery of NO2- or NO3- (Bremner, 1965). Therefore, various modifications have been suggested (Cope, 1916; Davisson & Parson, 1919). Bremner (1965) observed that the quantitative recovery of NO2- and NO3- by any method, other than the modified Olsen's method (Bremner & Shaw, 1958), is not certain.
Nitrogen use efficiency of unirrigated barley as affected by shortage of water
Authors: Adinarayana J. , Tiwari R. C.
Published: March 2009

The moisture use pattern and efficiency (MUE) of four barley cultivars (two hulled and two hull-less) were studied when the crops were grown in winter under unirrigated conditions at Varanasi, India, with different rates of application of nitrogen fertilizer. Increase in moisture use with age of the crop due to vegetative growth was recorded. Influence of varieties on consumptive use of water was found to be negligible except in the 1st year between 65 days after sowing and after harvest of the crop, when differences were due to differences in duration of the crop growth and rainfall which was received at the time of maturity. The moisture mining capacity of the barley crop from the profile (up to 120 cm) was increased with increase in the rate of nitrogen application. MUE of barley cultivars closely paralleled the grain yields, being more with hulled cultivars than hull-less ones. Higher MUE of barley was observed in the 2nd than in the 1st year of experimentation because of a better distribution of rainfall and moisture availability at the time of sowing, which boosted yields. Nitrogen application increased both yield and MUE of barley.
Effect of form, method and time of urea nitrogen application on growth, yield and nitrogen uptake of direct sown and transplanted rice under intermediate deep water (15–50 cm) conditions
Authors: Panda M. M. , Ghosh B. C. , Reddy M. D. , Reddy B. B.
Published: March 2009

Under intermediate deepwater (15–50 cm) conditions, sulphur-coated urea (SOU) drilled behind the plough at sowing was superior to other coated (neem, lac, coaltar) urea materials and broadcast incorporation of prilled urea in increasing the yield of direct-sown rice. In transplanted rice, the grain yield was highest with urea super granules (USG) placed 30 days after transplanting (DAT) followed by SOU broadcast incorporation at planting. N-use efficiency increased considerably with SCU drilled behind the plough or USG placed 20 days after sowing in shallow standing water in direct-sown rice and SCU broadcast incorporation or USG placed 30 DAT in transplanted rice.
Spot ν. furrow placement of phosphorus in potato at shillong
Authors: Sahota T. S. , Virk M. S. , Govindakrishnan P. M.
Published: March 2009

Water soluble P fertilizers have been reported to be best for potato (Mattingly, 1963; Sharma, Grewal & Sud, 1976). However, they are irretrievably fixed in the acid soils because of their high P fixation capacity. Placement of P fertilizers is, therefore, necessary for their efficient use. Furrow placement of P fertilizers reduces their contact with soil and enhances P availability to the plants. Placement of P in spots, rather than in furrows, will further reduce the contact between the soil and the fertilizers and may improve its efficiency over furrow placement. The present investigation was undertaken to study the relative efficiency of these two methods of P application for potato in the spring season.
Response of flooded rice to various sources of zinc
Authors: Sajwan K. S. , Lindsay W. L.
Published: March 2009

Zinc deficiency has been one of the major micronutrient disorders of flooded rice. Several researchers have reported that Zn deficiency could be corrected by the application of various Zn fertilizers to soil (Mikkelsen & Brandon, 1975), to seedling root (Yoshida et al. 1970; Katyal & Ponnamperuma, 1975) or to plants as foliar spray. Also there has been much speculation about the most suitable form of Zn fertilizer for correcting Zn deficiency of flooded rice. A glasshouse study was conducted to compare the effectiveness of various Zn fertilizers for rice grown under flooded conditions.
In vitrodegradation of amines by rumen micro-organisms
Authors: Van Os M. , Lassalas B. , Toillon S. , Jouany J. P.
Published: March 2009

Degradation of biogenic amines was studied in rumen contents obtained from wether sheep adapted to diets with different levels of biogenic amines: high (H), low (L) and without (W), containing 7·4, 2·4 and 0 g amines/kg dry matter (DM), respectively. To 200 g of the rumen contents (RC), 2 ml of a solution containing a mixture of the biogenic amines: cadaverine (73·5 mmol/1), histamine (45·0 mmol/1), putrescine (830 mmol/1) and tyramine (123·5 mmol/1) were added, followed by a 5 h incubationin vitro. The fermentation pattern in RC derived from H and L differed from that in RC derived from W. This difference was attributed to differences in fermentative properties of silage and hay-based diets in the rumen. The addition of amines increased ammonia production, which was highest in RC from sheep adapted to silage with the highest amine content (diet H). Amines had no influence on gas production. Amine degradation occurred in all types of RC, but the extent depended on adaptation of the rumen microflora, such that 709, 54·2 and 25·3% of the added quantity in RC from H, L and W, respectively, was degraded. Generally, the breakdown of the individual amines was highest for histamine, followed by tyramine, putrescine and cadaverine. Tyramine breakdown was particularly slow in RC from diet W. These results imply that in animals adapted to grass silage with high concentrations of biogenic amines, the accumulation of amines in the rumen will be prevented by an increase in the amine-degrading capacity of the rumen microbes.