bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple and rapid method of quantitatively measuring the glucosinolate concentration of rapeseed
Authors: Smith D. B. , Parsons D. G. , Starr Carol
Published: March 2009

A method is described in which glucosinolates are simultaneously extracted from crushed seeds and degraded by myrosinase. Glucose released by myrosinase is measured by an autoanalyser using a single reagent.

Using conditions optimized for samples of 200 mg, yields were slightly greater than those obtained from corresponding samples of defatted meal. Coefficients of variation of about 4% were obtained over a range of more than 100 μmol of glucosinolate/g seed. It is suggested that the method will be of value to plant breeders selecting from populations having low and intermediate concentrations of glucosinolate and to others wishing to obtain a rapid but precise measurement of these important compounds.
Vesicular-arbuscular mycorrhizae of winter and spring cereals
Authors: Buwalda J. G. , Stribley D. P. , Tinker P. B.
Published: March 2009

The importance of mycorrhizal infection for the growth of wheat and barley sown in winter and spring was assessed in two field experiments. Low temperatures during winter restricted the development of mycorrhizal infection, and calculations of ‘thermal time’ indicated that the percentage of root length infected did not increase when mean temperatures were less than 5 °C. Hence infection was less in the winter-sown crops than in the spring-sown crops at early stages of plant development. However, the effects of mycorrhizal infection on growth were greater in winter-sown than in spring-sown wheat.

At all levels of applied phosphorus up to 60 kg P/ha, artificial inoculation with mycorrhizal fungi increased the yields of both cereals at each sowing date by 17–25% after indigenous mycorrhizal fungi had been removed by fumigation, but the effects were smaller on non-fumigated plots. The results confirmed the potential importance of mycorrhizal infection for the growth of cereals.

Mycorrhizal infection increased the phosphorus concentration in the plant tissue at very early stages of growth, but the effect generally declined with time.
Fibrous root growth and water use of sugar beet
Authors: Brown Kay F. , Biscoe P. V.
Published: March 2009

Development of the fibrous root system of sugar beet was studied by washing soil samples taken from field experiments through the growing season. At the beginning of June the root system was still poorly developed but during June there was rapid proliferation. In the top 70 cm there was only little further increase in root density after the end of June. Below 70 cm root density increased up to the end of August. Throughout the season fibrous root density decreased with depth. Despite the origin of the lateral roots from two grooves on the storage root, fibrous root distributions at each depth around individual plants were essentially uniform from mid-June onwards. In the absence of nitrogen fertilizer, fibrous root development exceeded that of a crop given fertilizer, particularly at depths greater than 50 cm early in the season. The maximum value of root density was 2·8 cm/cm3 soil recorded in the top 10 cm in mid-September. Compared with published data for other crops, the sugar-beet root system was sparser than that of winter wheat or maize but denser than that of a soya bean or cassava.

Soil water content was measured with a neutron probe. Inflows to roots were calculated from soil water content changes in different soil layers. In the top 30 cm, inflows ranged up to 10·8 μl water/cm root.day and were up to five times higher than published inflows for winter wheat. At 30–100 cm sugar beet and winter wheat inflows were generally similar. The 0–30 and 30–120 cm layers contributed about 80 and 20% respectively of the total water use by sugar beet while no uptake was recorded below 110 cm. Previous studies have shown that sugar beet often takes up water from soil deeper than 110 cm, although it is not unknown for the depth of water removal to be restricted.
The effect of soil pH on the severity of Chocolate Spot infection on field bean varieties
Authors: Elliott Jennifer E. M. , Whittington W. J.
Published: March 2009

Field bean varieties were grown for 2 years on five plots varying in pH from 4·7 to 8·4. Non-aggressive Chocolate Spot infection was shown to be greater on plants grown in soil of pH 4·7 and 5·8 than on those grown in soil of pH 6·7, 7·7 and 8·4. Seed weight per plant was greater on soil pH 7·7 than on soil pH 4·7, suggesting that acid soil reduced plant vigour and consequently increased disease susceptibility. Varietal differences in infection were shown, although absolute resistance was not observed. Varieties differed in their susceptibility on soils of varying pH, and also showed different stability for susceptibility over the varying environmental conditions.
A drought experiment using mobile shelters: the effect of drought on barley yield, water use and nutrient uptake
Authors: Day W. , Legg B. J. , French B. K. , Johnston A. E. , Lawlor D. W. , Jeffers W. De C.
Published: March 2009

Automatic mobile shelters were used to keep rain off a barley crop in a drought experiment. The treatments ranged from no water during the growing season to regular weekly irrigation. This paper reports the effect of drought on the harvest yield and its components, on water use and nutrient uptake.

Drought caused large decreases in yield, and affected each component of the grain yield. The magnitude of each component varied by up to 25% between treatments, and much of the variation could be accounted for by linear regression against the mean soil water deficit in one of three periods. For the number of grains per ear, the relevant period included tillering and ear formation; for the number of ears per unit ground area, the period included stem extension and tiller death; for grain mass, the period included grain filling.

The harvest yields were linearly related to water use, with no indication of a critical period of drought sensitivity. The relation of grain yield to the maximum potential soil water deficit did show that a prolonged early drought had an exceptionally large effect on both yield and water use.

Two unsheltered irrigation experiments, also on barley, were made in the same year on a nearby site. The effects of drought on yield in these experiments were in good agreement with the effects observed on the mobile shelter site.

When fully irrigated, the small plots under the mobile shelters used water 11% faster than larger areas of crop, because of advection. The maximum depth from which water was extracted was unaffected by the drought treatment. When 50% of the available soil water had been used the uptake rate decreased, but the maximum depth of uptake continued to increase.

Measurements of crop nutrients at harvest showed that nitrogen uptake was large, because of site history, and that phosphate uptake was decreased by drought to such an extent that phosphate shortage may have limited yield.
Gross energy yields and the support energy requirements for the production of sugar from beet and cane; a study of four production areas
Authors: Austin R. B. , Kingston G. , Longden P. C. , Donovan P. A.
Published: March 2009

In t h e four production areas studied the gross energy contents of the biomass of the U.K. and Californian sugar beet crops were about 222 GJ/ha/year, while those for the Queensland and Transvaal sugar cane crops were about 682 GJ/ha/year. Recoverable sucrose constituted about 45% of the gross energy yield in the sugar beet crops but only about 29% in t he sugar cane crops, largely due to the bagasse (fibre) present in the cane. Since the sugar cane bagasse was used as fuel it provided nearly all the energy for the production of raw sugar from the sugar cane crops, but sugar beet by-products supplied no energy for t he production of sugar from sugar beet. This difference between the two species was the main reason why the support energy required for sugar production from beet, 28·8 GJ/t sugar, was greater than for production from sugar cane, 10·5 GJ/t sugar. The ratios, energy in refined sucrose:support energy required for its production, were 0·60 for sugar beet and 1·60 for sugar cane.

The efficiencies of conversion of the photosynthetically active solar radiation incident on the crops into energy in biomass (excluding fibrous roots) were 1·2% for sugar beet and 2·0% for sugar cane. This difference in efficiency did not appear to be due to a consistent species difference in the proportion of t he radiation intercepted by the crops, and may have been a consequence of the more efficient photosynthetic carbon fixation mechanism in sugar cane than in sugar beet. The efficiencies of conversion of incident photosynthetically active radiation into energy as sucrose recovered from the plants showed no consistent difference between species and averaged 0·56%.
Effects of some phenolic compounds and gibberellic acid on flowering and yield characters of cheena millet (Panicum miliaceum L.)
Authors: Datta K. S , Kumar Surinder , Nanda K. K.
Published: March 2009

Gibberellic acid (GA3); monophenols, salicylic acid (SA) and β-naphthol (β-N); diphenols, catechol (CT) and resorcinol (Res); and polyphenols, chlorogenic acid (CA) and tannic acid (TA) hastened the emergence of ears and increased the numbers of branches and ears, number of seeds, seed weight and the 1000-seed weight in cheena millet (Panicum miliaceum L.). The results show that the action of phenolic compounds is not related to their structural configuration as is considered by some workers.
Effects of sex and gonadectomy on the growth and development of Southdown × Romney cross lambs. Part II. Effects on Carcass grades, Measurements and chemical composition
Authors: Everitt G. C. , Jury K. E.
Published: March 2009

The influence of sex and gonadectomy on carcass grades, measurements and chemical composition is reported from a comparative slaughter experiment involving 100 Romney x Southdown cross lambs.

Grading results, although based on small numbers of carcasses, showed a tendency to down grade entire ram lamb carcasses.

Linear carcass measurements indicated some differences in conformation between the four ‘sexes’, although these were somewhat inconsistent over the two slaughter ages at which measurements were recorded. Relatively larger eye muscle areas were evident for gonadectomized than for entire lambs and for males than for females. Fat cover over the eye muscle was lower for entire rams than for the other ‘sexes’.
Factors affecting production records of lambs from a flock of East African Blackheaded sheep
Authors: Trail J. C. M. , Sacker G. D.
Published: March 2009

1. The effects of age of ewe, and year, sex and type of birth of lambs on lamb weights between birth and weaning were measured and appropriate correction factors estimated in a flock of East African Blackheaded sheep maintained over an 11-year period in Western Uganda. These correction factors were then used to examine the effects of a long dry season at different stages of lamb growth.

2. On birth weights the effects of sex ranged from 0-25 lb. to 0-40 lb.; twinning 1-0 lb.; gimmer's lamb 0-5 lb. On 2-month weights the corresponding adjustments were 0-2 lb.-l-4 lb.; 5-1 lb.; 1-7 lb. On weaning weights 0-3 lb.-2-9 lb.; 6-0 lb.; 2-6 lb.

3. A long dry season during late pregnancy did not appear to affect lamb birth-weights and a dry season between 2 months and 5 months of age did not affect lamb weaning weights. However a dry season during the main suckling period from birth to 2 months of age significantly lowered lamb weights at 2 months of age.
Studies on the cutting management of grass-clover swards. IV. The effects of close and lax cutting on the yield of herbage from swards cut at different frequencies
Authors: Reid D.
Published: March 2009

1. The effects of cutting herbage to either 1 in. or 2½ in. from ground level were studied at varying cutting frequencies in two experiments on a perennial rye-grass/white-clover sward. In one of the experiments the frequency of cutting was decided by the stage of growth of the herbage, and in the other it was decided on a time basis where cutting was carried out at intervals of 2, 4 or 6 weeks throughout the growing season.

2. Greater yields of herbage dry matter were obtained by cutting to 1 in. rather than to 2½ in. at all cutting frequencies in both experiments. This effect did not vary significantly with frequency of cutting where cutting dates were decided by the stage of growth of the herbage. However, where the cutting frequency was decided on a time basis, close cutting gave a relatively greater yield increase compared with lax cutting where the herbage was cut every 2 weeks instead of every 4 or 6 weeks.

3. The results suggest that the practice of cutting at an average stage of growth in previous experiments probably had little or no influence on the effects recorded for the contrasting closeness of cutting treatments.
Sodium appetite and sodium metabolism in ruminants assessed by preference tests
Authors: Bell F. R. , Sly Jennifer
Published: March 2009

Adult sheep, unweaned and mature weaned calves have been examined by metabolic studies for sodium balance. The ratio of sodium input/output was near unity with only a very small amount of the ingested sodium salt being retained. A positive sodium balance was always present, with excess sodium salt being excreted. The main channel of sodium excretion was the kidney, although when sodium intake was increased the sodium content of the faeces showed a proportional increase. Unweaned calves, a few days old, were quite able to excrete excess sodium salts in concentrated urine.

There was a clear difference in preference for sodium salts over water, between weaned calves allowed access to sodium salts while being fed milk, and weaned calves denied sodium salts at the milk feeding stage. Sodium-naive calves showed a marked preference for sodium salt solutions while the sodium-experienced calves showed at best an indifference and sometimes even an aversion. With continued access to sodium salts the volume ingested declined steadily in both groups but food intake remained constant.

In both calves and sheep the preference for sodium salts showed considerable variation between animals. The evidence from parallel metabolic studies suggests that this variation indicates that salt intake is controlled by some mechanism, possibly in the central nervous system, which is activated by dynamic sodium metabolism. Our experimental results confirm that ruminants have a well developed salt taste but predilection for sodium salts could be a biochemical manifestation rather than a hedonic propensity.
Compensation of oil-seed rape (Brassica napus L.) plants after damage to their buds and pods
Authors: Williams Ingrid H. , Free J. B.
Published: March 2009

The relationship has been investigated between the yield of oil-seed rape (Brassica napus L.) plants and (a) the proportion of podless stalks, (b) the proportion of pods infested by seed weevil larvae and (c) the effect of removing a proportion of buds and pods. Plants compensated for damage and, although late removal of buds or pods sometimes caused greater yield loss than early removal, only plants with more than 60% podless stalks or buds removed had diminished yields. The numbers of podless stalks per plant increased with plant size. Removal of 60 % of a plant's pods caused no yield loss; in the field a maximum infestation of only 25% of the plant's pods with seed weevil larvae occurred. The results are discussed in relation to damage by pollen beetles (Meligethes aeneus Fab.) and seed weevils (Ceutorhynch.ua ossimilis Payk.)
The effect of barley supplements on the voluntary intake and digestion of low quality roughages by sheep
Authors: Lamb C. S. , Eadie J.
Published: March 2009

Oat straw, timothy straw and two field-cured hays (43·8, 47·3, 52·0 and 56·0% organic matter digestibility (OMD) and 0·56, 0·75, 1·00 and 1·41% N respectively) were fed ad libitum together with 0, 235, 470 and 705 g D.M. of rolled barley to 5-year-old North Country Cheviot wethers in four 4x4 Latin square designs (Expt 1). In an attendant study (Expt 2) of conditions with in the rumen four rumen fistulated wethers were offered daily 0, 200, 400 and 600 g D.M. of rolled barley with ad libitum hay (54·3% OMD, 1·45% N), also following a Latin square design.

The voluntary intake of two of the hays (54·3 and 56·0% OMD) decreased progressively as the barley increased. Intakes of the other roughages were slightly increased when the lowest amount of barley was fed. For each roughage total organic-matter intake and the OMD of the ration increased progressively with increasing amount of barley consumed. No associative effects of barley on the OMD of the roughages were demonstrated. The acid-detergent fibre (ADF) digestibility of diets comprising the highest amount of barley with the oat straw and the field-cured hay of lowest N content were significantly lower than that of the respective all-roughage feeds. In Expt 2 the intake of increasing amounts of barley significantly reduced rumen pH, the molar proportion of acetic acid and the disappearance of hay and hay ADF from terylene bags within the rumen, while volatile fatty acid concentration and the molar proportion of butyric acid increased.

Multiple regressions were obtained relating the change in roughage intake to the amount of barley fed and the digestibility and chemical composition of the roughages. The equation with the least error, explaining 88% of the variation, was Y= 30·561 — 0·615C — 21·453N±3·69, where Y is the change in roughage intake as a percentage of the intake of roughage fed alone, Cis barley intake as g OM/W0·73 and N is the nitrogen content of the roughage.
Animal production studies in Jamaica. V. Live-weight production from pangola grass pastures used for rearing and fattening beef cattle and the economic implications of the yields
Authors: Nestel B. L. , Creek M. J.
Published: March 2009

Yields from improved (pangola) and unimproved pastures on a group of beef cattle farms have been recorded during the years 1958–62. On these farms it was shown that there was a highly significant relationship between the percentage of improved grassland and the live-weight output per acre of the whole farm. This relationship indicated that the output of unimproved land on these farms was of the order of 45 lb. per acre, and that of improved (pangola) pasture 260 lb. per acre.
The influence of abomasal supplements of zein and some amino acids on wool growth rate and plasma amino acids
Authors: Reis P. J. , Tunks D. A.
Published: March 2009

Merino sheep were given abomasal infusions of (i) zein (80 g/day), (ii) zein (80 g/day) supplemented with L-lysine (6 g/day), L-tryptophan (1 g/day) or lysine and tryptophan together, or (iii) L-leucine (20 g/day). Effects on wool growth (length growth rate, fibre diameter, fibre volume growth rate and mass of wool grown) and on plasma amino acids were measured.

Zein increased length growth rate and decreased fibre diameter; on average the volume growth rate and mass of wool grown were not significantly altered. The addition of tryptophan to the infusion of zein did not significantly alter wool growth, whereas the addition of lysine significantly increased all aspects of wool growth. The responses to these treatments were rapid and were adequately assessed during 12-day infusion periods. The infusion of leucine did not cause any appreciable changes in wool growth.

Leucine supplementation increased the concentration of leucine in blood plasma about six-fold. Zein decreased the concentration of lysine and ornithine in plasma and increased the concentration of several essential amino acids; leucine was increased about seven-fold. The addition of tryptophan to zein had no effects on plasma amino acids, whereas lysine decreased the concentration of several amino acids in plasma and markedly increased lysine.
Studies on forage cell walls
Authors: Choung C. C. , McManus W. R.
Published: March 2009

Results of a 13-week group feeding study (Expt 1) and a 16-day digestion and mineral, nitrogen and water balance study (Expt 2) in which alkali-treated rice hulls were fed to young Border-Leicester × Merino sheep of 24-kg body weight are reported.

Five pelletized diets comprising a 1:1 mixture of ground lucerne and alkali-treated ground rice hulls (Expt 1) or these five diets supplemented with biuret plus one diet of 100% lucerne pellet (Expt 2) were examined.

Sodium hydroxide at levels of 0, 2·5, 5, 10 and 15% (w/w) was applied to rice hulls for 12 h and neutralized with acid. Sheep fed the 5% NaOH treatment level or greater maintained or increased body weight: those fed the 0 and 2·5% level lost body weight. Daily food organic matter intakes were: 5% alkali, 1025 g, 0% alkali, 765 g; 100% lucerne, 1195 g.

Organic matter digestibility was highest (52%) for the diet containing rice hulls treated at the 15% alkali level and this digestion coefficient was significantly greater (P < 0·05) than for the control diet (nil alkali) (42%) but not significantly greater than for diets with 2·5, 5 and 10% levels of alkali.

It'is indicated that cell wall organic matter of rice hulls treated with 15% alkali was digested to an extent of 62% whereas cell wall organic matter in the control diet (0% alkali) was digested to an extent of 13%.

Cellulose digestion (52%) of the rice hull component of diets was not increased by alkali treatment suggesting the alkali to have freed hemicellulose components of the cell wall for digestive attack. Digestibility of lignin of the rice hull component of diets was not significantly increased by alkali treatment.

Animals tolerated the salt contents of diets containing rice hulls treated at high levels of alkali, were able to clear the excess salt from their bodies without significant alteration of their blood haematocrit ratios, and drank significantly more water. All sheep fed diets containing rice hulls had appreciable amounts of soluble silica in their blood plasma (> 100/μg/l) and urine (> 25 μg/l).

It is concluded that alkali beneficiation of rice hulls offers a means of enhancing their nutrient worth to ruminants and that the process requires further study.
Suitability ofSpodoptera littoralislarvae for development ofMicroplitis rufiventris
Authors: Hegazi E. M. , El-Minshawy A. M. , Hammad S. M.
Published: March 2009

A study of the solitary parasitoidMicroplitis rufiventrison larvae ofSpodoptera littoralisshowed that the age of the host at parasitization influenced the rate of development of the parasite, the percentage of parasitized hosts giving rise to mature parasite larvae, the number of moults subsequent to stinging, duration of larval instars, and the fecundity and longevity of the resulting adult parasites.
Effects of date of planting on growth and yield of contrasting potato varieties in Pembrokeshire
Authors: Allen E. J.
Published: March 2009

Four experiments over 2 years which examined the effects of date of planting (from mid-March to early May) on the growth and yield of early, second early and maincrop potato varieties are described. In two experiments the seed used was physiologically old (heavily sprouted) and in the other two experiments relatively young seed (limited sprout development) was used. In the early variety, Home Guard, tuber yield at maturity was unaffected by delay in planting when physiologically old seed was used but increased leaf area and higher tuber yields resulted from later planting of younger seed. With both types of seed the maincrop varieties, Desirée and Maria Piper, produced larger leaf areas from later planting in one year but smaller leaf areas in the other year. In both years with both types of seed, tuber yields at the end of August were higher from the earlier plantings of these varieties. The physiologically young seed of Red Craig's Royal behaved in a similar manner to the maincrop varieties and the physiologically old seed behaved in a similar way to Home Guard.

Any yield advantages of early varieties over maincrop varieties from any date of planting were small and short-lived and the physiological reasons for differences between varieties are discussed in the light of these results. It is suggested that the current classification of varieties is unjustified and that variety testing should take more account of the effects of physiological age.

Tuber yields from the maincrop varieties were very high (60·80 t/ha) and this is attributed to the synchrony of leaf growth and increasing light receipts which may be readily achieved in the mild springs of W. Wales.
The feeding value of normal and brown midrib-3 maize silage
Authors: Weller R. F. , Phipps R. H.
Published: March 2009

Normal and brown midrib-3 (bm3) maize silages were fed to sheep, lactating cows and dairy calves to determine the effect of the bm3 gene on in vivo digestibility, dry-matter intake and animal performance.

In two trials wether sheep were fed either normal or bm3 maize silage at maintenance level. In the first experiment the bm3 gene significantly increased the digestibility of the organic matter(OM), cell wall constituents (CWC), acid-detergent fibre (ADF), cellulose and hemicellulose from 76·9, 74·7, 67·3, 74·2 and 79·5% to 79·6, 79·2, 75·8, 80·8 and 81·5%. In the second experiment the gene increased the digestibility of the OM, CWC, ADF and cellulose from 65·9, 44·7, 28·5 and 38·7% to 701, 59·3, 560 and 66·1, 39·1,32·8, 40·4 and 45·5% to 68·1, 51·9, 53·7, 58·0 and 49·2%. The digestibility of the protein was similar for both diets.

In a feeding trial 6-month-old calves were fed either normal or bm3 silage ad libitum together with 1·6 kg D.M. of a protein supplement. The dry-matter intake of the two silages was similar; however, the daily live-weight gain of 0·92 kg for calves fed the bm3 diet was significantly higher than the 0·83 kg for calves fed the normal diet.
Some consequences of imposing different continuous grazing pressures in the spring on sward morphology, herbage quality and the performance of young beef cattle
Authors: Tallowin J. R. B. , Williams J. H. H. , Large R. V.
Published: March 2009

The effects of different severities of continuous grazing imposed during the spring followed by a uniform continuous grazing management from midsummer onwards were examined in relation to sward morphology, herbage quality and the performance of young beef cattle in the years 1980 and 1981. The three grazing severities were based upon maintaining a constant sward height, namely 35 mm (severe), 50 mm (moderate) and 75 mm (lenient). From 1 June onwards a uniform grazing severity with a sward height of 60 mm was imposed. The grazing pressure on each paddock was adjusted by either adding or removing of cattle to maintain the target sward heights. When the grazing pressure was changed in June, the digestibility of both the herbage components on offer and the total herbage selected by the cattle was higher in the swards that had been severely grazed than that in the leniently grazed treatments. This appeared to be due to the combination of a higher proportion of younger, more digestible leaf laminae, less dead and less maturing true stem being present in the swards that had previously been severely grazed. Over the season as a whole, there was no significant difference between the grazing treatments in terms of individual animal performance or overall animal live-weight production per hectare.
Response of winter-sown maize cultivars to sowing time and row direction in north-west India
Authors: Narwal S. S. , Poonia S. , Singh G. , Malik D. S.
Published: March 2009

In a 3-year study, maize (Zea maysL.) sown on 11 November or 1 December produced longer ears, higher grain yield per plant and greater grain yield per hectare than maize sown on 21 October. However, 100-kernel weight was greater when the crop was sown on 21 October and 11 November than on 1 December. There were no differences in yield characters or grain yield between cultivars or between row orientation. The sowing dates, maize cultivars and row direction had no influence on the number of ears per plant.
A reappraisal of the Pelshenke test as a screening technique in the breeding of bread-making wheats for the United Kingdom
Authors: Pushman Fiona M. , Bingham J.
Published: March 2009

Growing conditions and testing methods were varied to investigate the use of the Pelshenke test in breeding wheat varieties for good bread-making quality in the United Kingdom. Varieties of winter wheat representing a range of bread-making quality were consistently differentiated. Fresh compressed yeast gave greater varietal differences than did dried yeast but kneading time and grain moisture content were not critical. The values obtained were relatively insensitive to the early stages of germination, to the addition of α-amylase and to variation in grain protein content resulting from N fertilization and irrigation. Thus it appears that the Pelshenke test mainly reflects gluten quality, rather than the whole complex of characters which are integrated by baking tests, and the ranking of the varieties is sufficiently independent of environmental conditions to be of considerable value for selection of early generation breeding material.
An analysis of the problem of lodging with particular reference to wheat and barley
Authors: Neenan M. , Spencer-Smith J. L.
Published: March 2009

It has been shown that structural failure in small grain cereals occurs by buckling rather than by loss of anchorage. A theoretical study established the relationship between a lateral force applied to the head, and failure of the straw. Resistance to bending is determined by two factors, Young's modulus and outer diameter of the straw. These were determined in laboratory tests. The value of Young's modulus was affected by stage of maturity of the straw. Wind-tunnel experiments established a relationship between air velocity and deflexion of the head. An attempt was made to calculate the wind speed necessary to cause straw breakage in the field. The kinetic effect of raindrops was not a significant factor in lodging. Attention has been drawn to the possible importance of taper in the straw.
Influence of isolation distance on genetic contamination of field bean (Vicia faba L.) seed produced in small plots
Authors: Pope M. , Bond D. A.
Published: March 2009

Use of flower and seed colour genetic markers showed that in plots, each 4·5 m × 4·5 m in size, the genetic contamination decreased from 16·96% at 0·9 m to 1·25% at 92 m, and 0·59% at 184 m distance. Maximum contamination from other Viciafaba outside the experimental field and at least 1·1 km away was 0·44%. Implications for the multiplication of stocks in breeding programmes are discussed.
A comparison of cutaneous evaporation rates in cattle exposed to heat in a climate laboratory and in the field
Authors: Murray D. M.
Published: March 2009

1. The cutaneous evaporation rates of three animals of different genotype have been determined under artificial heating in a climate laboratory and during exposure to field conditions. Cutaneous evaporation rates were measured from the backthoracic region using a ventilated capsule technique.

2. In both climate-laboratory studies and field observations cutaneous evaporation showed little relationship with either rectal temperature, respiratory rate or skin temperature.

3. Basal cutaneous evaporation rates in the unheated chamber at 10 a.m. were found to be 40% lower in animals which were housed overnight than in those which entered the chamber following exposure to the early morning sunlight.
Studies in potato agronomy. II. The effects of variety and time of planting on growth, development and yield
Authors: Bremner P. M. , Radley R. W.
Published: March 2009

1. A factori al experiment involving four varieties (Ulster Chieftain, Arran Pilot, Craig's Royal and Ulster Torch) and three times of planting (28 March, 13 April and 2 May) was undertaken with a view to investigating the effects on growth development and yield of these factors. Only a limited amount of data was obtained in respect of Craig's Royal, because of its extreme variability in the first two times of planting. In addition, data in respect of King Edward and Majestic planted on the second date in an adjacent experiment are discussed.

2. In general, yields from Ulster Torch were about twice as great as those from Ulster Chieftain, with the other varieties occupying intermediate positions. The total yield of Ulster Chieftain increased with delay in planting, while in Arran Pilot, Craig's Royal and Ulster Torch, yield was greatest at the intermediate planting date, slightly lower than this at the first, and lowest at the third. Ware yield as a proportion of the total increased with delay in planting.
The indirect estimation of the digestibility of pasture herbage. IV. Regressions of digestibility on faecal nitrogen concentration: effects of different fractions of the herbage upon within- and between-period regressions
Authors: Greenhalgh J. F. D. , Reid G. W. , McDonald I.
Published: March 2009

1. In each of 6 digestibility trials, comprising a total of 21 measurement periods of 3-4 days, two steers were fed on herbage cut from the top of the sward, two on the remaining bottom growth and two on a mixture of equal parts of these fractions. Within each period the fractions were similar in digestibility although the top growth had a higher content of nitrogen.

2. The trials were divided into three groups, according to time of year, for the purpose of calculating regressions of digestibility on faecal nitrogen concentration. Regressions calculated in the usual manner on a between-period basis (i.e. within animals) had constant terms which differed significantly among animals but not from one fraction of the herbage to another.
The effect of dietary intake of calcium and phosphorus on their absorption and retention by mature Ca-replete sheep
Authors: Braithwaite G. D.
Published: March 2009

A combination of a mineral balance and a radioisotope technique has been used to study the effect of increased intakes of dietary calcium and phosphorus on the Ca and P metabolism of mature, Ca-replete wether sheep. Between Ca intakes of 40 and 100 mg/ day per kg body weight Ca absorption remained constant at a level just sufficient to supply maintenance requirements. Above 100 mg/day per kg body weight, however, absorption increased in direct relation to intake. It is suggested that the increased absorption occurred by diffusion and that at lower Ca intakes, increased diffusion was offset by a corresponding decrease, until it reached a negligible level, in the rate of active absorption.

In spite of the fact that the wethers were already Ca-replete, the increased Ca absorption resulted in increased Ca retention and not as might have been expected in increased excretion. Increased retention was brought about by a decrease in the rate of bone resorption and bone accretion remained constant. Maximum retention occurred when bone resorption ceased and it was equal to the rate of bone accretion. It was only when retention of Ca reached a maximum that further increases in absorption resulted in increased excretion of Ca into urine and intestine. P retention was also increased with increased Ca and P intakes and probably occurred as a result of the increased Ca retention.

The relevence of these findings to the control of parturient paresis (milk fever) in the dairy cow by dietary manipulation is discussed.
Milk-fed calves: 5. The effect of a change in milk intake upon the herbage intake and performance of grazing calves
Authors: Du Y. L. P. Le , Baker R. D.
Published: March 2009

The effect of the amount of milk consumed upon the herbage intake and performance of calves at pasture, following a standard rearing period, was investigated using 50 Hereford × Friesian calves purchased at 10–12 days ofage. All calves were offered 6 kg reconstituted milk substitute for a 58 day period indoors and for a subsequent 31 days at pasture. Ten calves were then allocated to each of five milk treatments (0, 2, 4, 6, 10 kg/day) and grazed for a further 63 days. The calves were offered a daily herbage allowance of 60 g dry matter/kg live weight.

Daily weight gain was increased by 59 g for each additional kilogramme of reconstituted milk consumed, and herbage intake per unit live weight decreased by 1–24 g/g milk organic matter consumed, equivalent to a reduction in metabolizable energy intake of 9 kJ. Clear effects of both age and diet upon the consumption of herbage were demonstrated. An explanation of the mechanisms governing intake of herbage in milk–fed calves is offered.
Protein and energy nutrition of the bacon pig. II. The effect of varying the protein and energy levels in diets of ‘finishing’ pigs
Authors: Robinson D. W. , Lewis D.
Published: March 2009

1. A feeding trial has been carried out with sixty-four individually fed Large White pigs offered eight different diets prepared at four energy levels and two levels of crude protein. A record was maintained of the rate of live-weight gain and food was given at a defined restricted level. Carcass quality was assessed by a procedure of complete dissection into visible fat, lean, etc.

2. Though differences in the rates of live-weight gain and food conversion efficiency were not statistically significant, the best performance was recorded when the diets contained 16 % crude protein and yielded the equivalent of 2950 kcal. digestible energy per kg. upon oxidation. The energy: lysine ratio (kcal. digestible energy per kg. per unit percentage lysine in the ration) was approximately 3500.
Studies of natural herbage of the sub-tropics. III. Concentrations of volatile fatty acids and ammonia in the rumen of sheep fed fresh herbage
Authors: Topps J. H. , Elliott R. C.
Published: March 2009

1. Concentrations of ammonia, volatile fatty acids, and molar proportions of acetic, propionic and butyric acids were determined in the rumen liquor of sheep fed fresh herbage harvested in the first month of growth.

2. Concentrations ofammoniacal nitrogen ranged from 4·06 to 13·65 mg./1OO ml. rumen liquor with a mean value of 8·21.

3. Concentrations of volatile fatty acids ranged from 7·50 to 12·20 m-moles/100 ml. rumen liquor with a mean value of 9·81. Mean molar proportions of acids were: acetic 65·8%, propionic 19·5%, n-butyric 9·0 % and higher acids 5·7 %. Differences in the proportions of acids found at different sampling times were not statistically significant.
Infrequent drinking, digestive efficiency and particle size of digesta in black Bedouin goats
Authors: Brosh A. , Choshniak I. , Tadmor A. , Shkolnik A.
Published: March 2009

When given access to water once every 4 days, black Bedouin goats that were fed dry lucerne hay required, on average, only half the water and 60% of the gross energy they consumed when water was offered to them once daily. Digestibility of the feed in these goats was increased by 4%. The outflow of fluid from the rumen slowed down during the water deprivation period. A flow rate of 1080 ml/kg0.75. day was recorded during the 1st day of the period and only 350 ml/kg0.75. day during the last day. While being offered water once daily the outflow from the rumen amounted to 1243 ml/kg0.75.day.

Following the subjection of black Bedouin goats to infrequent drinking the mean retention time of the digesta in the rumen was extended by 33 % and in the entire gastrointestinal tract by 43 %. It is suggested that the slowing down of the ruminal flow that followed the subjection of the goats to infrequent drinking enabled the particulate matter to stay longer in the digestive tract despite their smaller size.
Water content and turnover of identical twin Bos indicus and B. taurus in Kenya
Authors: Macfarlane W. V. , Howard B.
Published: March 2009

The water content and turnover of six pairs of identical twin cattle were measured in the Kenya highlands. Three pairs were stall fed, and one twin of each pair received water daily. Their water turnover averaged 14.21./24 hr. while the others watered each 4 days had an average turnover of 12.41./24 hr. These stall-fed animals used 74-132 ml./kg.0.82/ 24 hr., about one-third the water turned over by grazing cattle (261-364 ml./kg.0.82/24 hr.). There was little relationship between estimates of water intake measured from the trough and that derived from tritium dilution.

Members of each grazing pair differed in weight by an average of 4.2% and their total body water by 5.9%, whereas the water turnover differed by only 2.2% amongst the twin pairs.
The response to inoculation of the three chromosome races of Trifolium ambiguum sown with and without a companion grass. II. The effect of the method of inoculation on the clover and grass
Authors: Jones D. Gareth , Evans Alice M.
Published: March 2009

The inoculation of legumes is often carried out using skim-milk as the carrier for the nodule bacteria. Increased germination due to inoculation has often been reported but in this investigation the effects of the skim-milk and the bacteria have been separated. The results indicate that the early establishment of T. ambiguum was stimulated by the skim milk rather than the nodule bacteria. The mechanism of this effect is thought to be due to extra N present in the milk and possibly to an enhanced nitrogen-cycle in the inoculated soil and evidence is produced of increases in certain freeliving nitrogen fixing and nitrifying microorganisms.
The Saxmundham rotation experiments: rotation II, 1899–1952
Authors: Boyd D. A. , Trist P. J. O.
Published: March 2009

The rotation II experiment at Saxmundham, which ran from 1899-1952, was designed to show how limited quantities of FYM, N and P could best be allocated to the crops of a four-course rotation; there were also tests of additional quantities of N and P. Both FYM and P fertilizer gave large increases in the yield of all crops, but the profitability of the rotation as a whole proved to be little affected by which crops received FYM or P fertilizer. The rates of N tested were too small to provide any information relevant to current farm practices. The optimal dressing of P fertilizer at 1965 prices was 0.5-0.6 cwt. P2O6 per acre.
The assessment of herbage legume varieties. II. In vitro digestibility, water soluble carbohydrate, crude protein and mineral content of primary growth of clover and lucerne
Authors: Davies W. Ellis , ap Griffith G. , Ellington A.
Published: March 2009

The primary growth of eight varieties of three species–white clover (3), red clover (4) and lucerne (1)–was sampled at fortnightly intervals and the percentage dry matter, in vitro digestibility, crude protein, water soluble carbohydrates, P, Ca, K, Na and Mg were determined.

Differences between species were nearly always significant and the general order of merit was white clover, red clover and lucerne. The exceptions were for dry-matter percentage where this order was reversed, and red clover had the lowest Na and highest Mg content.
The metabolism of caesium-137 in dairy cows
Authors: Sansom B. F.
Published: March 2009

1. The metabolism of 137Cs in dairy cows has been studied after single oral and intravenous doses and during twice daily oral dosing for 28 days.

2. Gastrointestinal absorption of 137Cs was about 70-80% of the oral doses.

3. After 28 days continuous feeding the mean concentration of 137Cs in milk was 0.84% daily dose/1. and the body burden of the isotope varied between 5.7 and 8.2 times the daily intake.

4. When feeding of 137Cs stopped the concentration of the isotope in milk fell by a factor of five in 8 days, by a factor of ten in 16 days, by a factor of twenty in 32 days, and thereafter exponentially with a half-life of 30 days. The concentrations of the isotope in muscle decreased at first rather slowly but finally also exponentially with a half-life of approximately 30 days.
The pollination requirements of broad beans and field beans (Vicia faba)
Authors: Free J. B.
Published: March 2009

1. Broad bean plants caged with bees produced more seeds per pod, more seeds per plant, heavier seeds and a greater weight of seeds per plant than plants caged without bees. They also had more mature pods at the first harvest but the total number of pods picked was about the same for cages with and without bees. The flowering season of plants caged without bees was extended.

2. Field bean plants caged with bees had more seeds per pod and more seeds per plant than plants without bees.

3. For both crops, plants in the open had about double the number of pods, beans and weight of beans as plants in cages.
Changes occurring during a year in the soluble phosphorus and potassium in soil under crops in rotation experiments at Rothamsted, Woburn and Saxmundham
Authors: Garbouchev I. P.
Published: March 2009

From May 1963 to April 1964 seasonal changes in soluble nutrients were followed in soil samples taken monthly from plots having none, PK, and NPK fertilizers in experiments at Rothamsted and Woburn. Phosphorus, potassium and magnesium concentrations in equilibrium extracts of the soils made with 0.0lM-CaCl2 solution were determined. Exchangeable P was determined with an anion exchange resin. Samples were taken under five arable crops growing in rotation, and under permanent grass on the two soils.
Inheritance of resistance to bacterial blight of cotton. III. Herbaceum resistance transferred to tetraploid cotton
Authors: Innes N. L.
Published: March 2009

While the leaf resistance of many of Knight's B genes in a Sakel background is now much lower than that found in his original studies, that of B9K has remained unimpaired and this gene still segregates as a major gene. It is proposed to ascribe to the weak gene transferred by Knight from Wagad 8 (G. herbaceum) to Sakel the symbol B11, as gene homology tests between this gene and other B genes indicate that is non-homologous with them. The strong effect of environment on the expression of B11 was confirmed and it was noted that in Upland stocks B11 was much more effective than in Sakel, whereas the opposite was true of B9K.

While the leaf resistance of Bm Sakel is high its stem resistance is of a low level and it suggested that leaf, stem and boll resistance may be under the same control in some genetic systems but not in others.
Nitrogen fixation (C2H2reduction) as influenced by sulphate in paddy soils
Authors: Rao J. L. N. , Rao V. Bajaramamohan
Published: March 2009

The influence of addition of sulphate on acetylene reduction in three paddy soils differing in their properties under two water regimes was investigated in a laboratory experiment. Nitrogenase activity was high in a P-deficient alkaline soil and addition of sulphate further enhanced the activity under two water regimes, with a pronounced stimulation under non-flooded conditions. Sulphate application to submerged alluvial soil enhanced nitrogenase activity with no apparent effect under non-flooded conditions. In acid sulphate saline Pokkali soil sulphate addition had little effect on the nitrogenase activity. Sulphate addition did not result in significant changes in the soil pH and redox potential. No relationship seemed to exist between the sulphate disappearance and stimulation of nitrogenase in these soils. A differential stimulation of N2-fixing microorganisms was noticed as a result of sulphate application. Results suggest that sulphate-induced stimulation of nitrogenase activity occurs in non-flooded soils.