bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the sowing dates of cotton in the Sudan Gezira: I. The influence of date of sowing on plant growth and development
Authors: Jackson J. E. 
Published: March 2009

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.
Studies on the sowing date of cotton in the Sudan Gezira: II. The relationship between sowing date of cotton and the incidence of insect pests
Authors: Schultz L. Razoux , Jackson J. E. , Faulkner R. C. 
Published: March 2009

In factorial experiments covering a range of sowing dates and insecticide treatments the numbers of fleabeetle, jassid and whitefly on cotton in the Sudan Gezira were shown to be strongly influenced by the date of sowing and the age of the crop.Attack by fleabeetle was most severe on cotton seedlings from July and early August sowings. Few fleabeetle were found on either more mature plants from these sowing dates or on seedlings from later sown cotton.Whitefly numbers were highest on late July and early August sown cotton. Peak numbers were attained attained in late September and October and then fell to very low levels in November irrespective of date of sowing.Jassid numbers were related both to plant age and to time of year, more being found on cotton sown, in July and early August early in the season and on later sown cotton later in the season. The highest numbers were found in November and December at which time populations were higher on cotton sown in mid-August or later than on earlier sown cotton.
A comparison of the effects of white clover (Trifolium repens) and of perennial ryegrass (Lolium perenne) on fat composition and flavour of lamb
Authors: Cramer D. A. , Barton R. A. , Shorland F. B. , Czochanska Z. 
Published: March 2009

1. The carcass composition, the composition and characteristics of the subcutaneous and longissimus dorsi muscle fats, the volatile fatty acids of the rumen-reticulum fluid and the degree of flavour and odour of the cooked 12th rib chops of two groups each of fifteen Southdown–Romney cross ewe and wether lambs fed respectively white clover and perennial ryegrass have been determined. The lambs had been on treatment for 5 months and were slaughtered when about 9 months of age.2. The white clover-fed lambs had a mean live weight at slaughter of 94 lb ± 9 lb compared with 67 lb ± 7 lb for the perennial ryegrass-fed lambs. The carcasses of the white clover-fed lambs had greater (P < 0·01) amounts of fat.3. The iodine values of the subcutaneous fats of the white clover-fed lambs were highly significantly greater than those of the ryegrass-fed lambs and this result was consistent with the greater deposition of endogenous fat.4. The extra fatness of the white clover-fed lambs was consistent with their greater production of rumen-reticulum volatile fatty acids.5. The maj or differences in fatty acid composition of subcutaneous and intramuscular fats between pasture treatments were the highly significant increases in shorter-chain saturated and C15 branched-chain acids of the ryegrass-fed lambs. In addition, the subcutaneous fat of the ryegrass group contained highly significantly more octadecadienoic and octadecatrienoic acids while the 1. dorsi fat of the ryegrass group was highly significantly richer in stearic and oleic acids.
Experiments on the nutrition of the dairy heifer: VI. The effect on milk production of the level of feeding during the last six months of pregnancy and the first eight weeks of lactation
Authors: Broster W. H. , Tuck Valarie J. 
Published: March 2009

1. Forty-five Friesian first calf heifers were used in an experiment to study the effect on milk production of two levels of feeding in the last 6 months of pregnancy and two levels of feeding in the first 8 weeks of lactation.2. In each of two years herbage was rationed daily at different rates to two groups of pregnant heifers from late April until they calved in the autumn. The mean daily rations were 3·5 lb herbage dry matter and 2·4 lb herbage dry matter per 100 lb live weight for the two groups. The mean daily amounts consumed were 2·1 and 1·8 lb herbage dry matter per 100 lb live weight respectively.3. The rates of gross live-weight gain during the period April to August were 2·2 and 1·7 lb/day for the two groups respectively. Estimated as the net gain of the dam alone, the rates of live-weight increase during the experimental period were 0·89 and 0·49 lb/day respectively, amounting to a mean difference in live weight after calving of 57 lb between the groups.
Yields and tiller numbers of four perennial ryegrass varieties grown as monocultures and certain mixtures in micro plots
Authors: Thomson A. J. 
Published: March 2009

SummaryFour perennial ryegrass varieties, S.24, S.321, S.23 and Vertas Hardgrazing, were grown in micro plots containing 30 plants each at a spacing of 5 cm apart. Monocultures and four of the possible six binary mixtures between the varieties were grown in a randomized block design with four replicates. The data recorded comprised dry-matter yields and tiller numbers, and the components of the mixtures were harvested separately. The data were based on both whole plots, to give total production of mixtures and monocultures, and half plots, to give the contribution of mixture components to total mixture production. Four harvests were obtained during 1968, and the data from these were analysed separately and summed to provide the annual total data.Mixtures and monocultures did not differ significantly for annual total dry-matter yield or for dry-matter yield at the separate harvests. However, differences in drymatter
yields between monocultures and between mixtures were detected at some harvests. Within mixtures, significant differences between some of the respective components were found at certain harvests, but these were not obtained for the annual total data.The stability of monocultures and mixtures was investigated by a regression technique
and considered in the context of the environments used. This technique revealed that there was a specific mixture effect whereby the mixture (S.24 + S.23) differed significantly from all other treatments.Significant differences between monocultures for fertile and sterile tiller numbers were detected. Between mixtures there were differences for fertile tiller numbers, and within mixtures certain of the components differed for fertile, sterile and total tiller numbers.The relationship between dry-matter yield and tiller numbers was investigated by regression analyses over all treatments and for monocultures and mixtures separately. Significant differences between the slopes of the regression lines and zero and between the slopes of the regression lines themselves were obtained.Possible reasons for the differences recorded both between and within monocultures and mixtures are considered and related to the competitive relations existing in the trial.
Statistical research on the fate of dietary mineral elements in dry and lactating cows
Authors: Lomba F. , Paquay R. , Bienfet V. , Lousse A. 
Published: March 2009

SUMMARYStatistical analyses were carried out on the data obtained under strictly controlled conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows, and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.The authors have calculated and studied the correlations between faecal and urinary sodium losses, sodium excretion in the milk, digestible sodium and sodium balance and the 75 other nutritive factors which were analysedfor each of the 55 above mentioned experimental diets.The most important factor in the fate of sodium is the amount of dietary sodium. Sodium digestibility is neither total nor constant: faecal losses and digestible amounts are enhanced when sodium intake is increased and faecal losses are also positively correlated with dry matter and nitrogen intakes. An increase in digestible sodium benefits both urinary excretion and balance, the latter being reduced by an increase in dry matter and nitrogen intake.Sodium balance is always negative when sodium content of the diet is lower than 0.1% in the dry cows and 0.2% in the lactating cows. In our experimental conditions, the sodium requirements for milk production do not influence sodium digestibility, but are met above all to the detriment of urinary losses.
Plant growth in controlled environments as an adjunct to field studies experimental application and results
Authors: Hughes A. P. 
Published: March 2009

1. Field studies on Impatient parviflora DC. in shaded situations indicated the need for experimental investigation of the effects on growth of varying single factors of the aerial environment in otherwise constant conditions.2. The use of cabinets which allow accurate control of the aerial environment for studies in physiology, morphogenesis, pathology and plant selection is discussed.3. By comparison of the development and assimilatory ability of the leaves of I. parviflora, it is shown that plants may be grown in wholly artificial conditions which are substantially identical with those grown under comparable conditions out of doors.
Epidermal pigment distribution in buffaloes (Bos bubalis)
Authors: Chandra G. , Bharadwaj M. B. 
Published: March 2009

SUMMARYA quantitative evaluation of the pigment in Murrah buffaloes of both sexes ranging in age from 1½ to 7 years revealed that dorsal areas had most pigment, while the lateral body areas and the extremities were intermediate and the ventral and axillary regions revealed the least pigment. Maximum concentration of melanin granules occurred in stratum cylindricum, which gradually declined towards stratum corneum which was fully non-pigmented in axilla, groin, inter-digital and inter-dewclaw areas.Pigment granules blackened in silver preparations and were seen concentrated as protective ‘nuclear caps’ in the supranuclear zone of the cells of stratum germinativum. The infranuclear light-staining cytoplasm contained PAS reactive glycogen granules.
Liquid nitrogenous fertilizers
Authors: Jameson H. R. 
Published: March 2009

The results show that liquid fertilizers generally gave lower yields of dry matter than conventional solid fertilizers in four experiments on grassland. In seven trials, on autumn wheat, spring wheat, sugar beet and kale, the efficiencies of the two forms of fertilizer were similar.Liquid fertilizers containing ammonia must be injected into the soil and this needs special equipment, more complicated, particularly where anhydrous ammonia is to be used, than the distributors used for solid fertilizers. Running the injector over established grassland sometimes resulted in considerable damage to the sward. When used to top-dress winter wheat across the line of drilling some plants were killed.
Post-natal growth changes in the fibre cortex and medulla of the new zealand romney and N-type sheep
Authors: Tibbits Janet P. 
Published: March 2009

The relationship between cortical area and fibre area has been examined in the N/N, N/ +, + / +, + /nr and nr/nr genotypes of the New Zealand Romney, using skin biopsies taken at birth, 1, 3 and 16 months of age. The presence of the nr gene was shown to reduce significantly the relative cortical area. Within the genotypes there was an increase in relative cortical area with increasing age and in two-tooth ewes of N/N and N/ + there was an increase in relative cortical area in winter compared to summer.Fibre growth rates in length for primaries and for prenatal and post-natal secondaries were found for lambs between 1 and 3 months and for 16-monthold ewes. In N/N, N/+ and nr/nr primary fibre growth tended to be increased and post-natal secondary fibre growth tended to be decreased relative to + / + values.In both cortical area and fibre growth rate the greatest genotypic effect was shown by the primary fibres.Some estimates of cortical volume have been made by combining the information on cortical area and fibre growth rate and the relationship of these factors to follicle density and mean fibre area has been discussed. Finally, an indication has been given of how the associations of all these four factors might be usefully examined in some British breeds.
The cellulose-lignin complex in forages and its relationship to forage nutritive value
Authors: Allinson D. W. , Osbourn D. F. 
Published: March 2009

SUMMARYThe relationships between the cellulose-lignin complex, voluntary consumption and dry-matter digestibility were examined using forages of two varieties of Italian ryegrass and two legumes, lucerne and sainfoin. These forages had previously been shown to exhibit different intake-digestibility relationships. The cellulose, acid detergent lignin and acid detergent fibre contents of these forages as well as their digestibility coefficients were determined. Lignins were extracted from the fibre fractions and their ultraviolet difference spectra determined.Changes in maturity of a forage during a single growth phase, produced changes in dry-matter digestibility which were closely associated with changes in the digestibility of the cellulose and inversely related to the lignin content of the forage. Differences in digestibility between varieties of forage were less closely associated with lignin content. As the grasses matured a lignin fraction forming a difference peak at 350 mμ became evident and this was associated with decreased cellulose digestibility.Differences in voluntary food consumption resulting from changes in maturity of a single forage variety, in one growth phase, were also closely correlated with both dry matter and cellulose digestibility and inversely with lignin content. Differences between varieties and growth phases of the ryegrasses and between grasses and legumes were related less to the nature of the cellulose-lignin complex and more closely to the percentage of the total digesta deriving from cellulose.Sainfoin was characterized by the formation post-ruminally of an artifact that analysed quantitatively as lignin and qualitatively resembled a non-conjugated phenolic lignin fraction. The production of this artifact apparently disturbed fibre digestibility estimates and may have affected dry-matter digestibility estimates. Degradation of lignin apparently occurred both in the rumen and in the hind gut.
A comparison of ley and arable farming systems
Authors: Lewis A. H. , Procter John , Hood A. E. M. 
Published: March 2009

1. Alternate husbandry systems containing 1-, 2- and 3-year grazed leys were compared with continuous arable cropping at Jealott's Hill during the period 1945–56. Kale and wheat were used as successive test crops to measure the fertility accruing from the following crop sequences: (a) 3-year ley; (b) wheat, 2-year ley; (c) wheat, barley, 1-year ley; (d) wheat, barley, barley. A study was also made of the effect on crop yields of compost, dung and N fertilizer dressings applied to kale.2. The yields of kale and wheat were improved considerably by 1-, 2- and 3-year leys. Increments were: 5·2 tons fresh kale per acre and 8·7 cwt. wheat grain per acre from 1-year ley, 9·0 tons kale and 13·5 cwt. wheat per acre from 2-year ley and 9·2 tons kale and 15·0 cwt. wheat per acre from 3-year ley. Two- and 3-year leys were markedly superior to 1-year ley in their effects on kale and wheat. The slight benefit apparent in wheat yields from 3-year ley compared with 2-year ley was not significant and so the 2- and 3-year leys may be considered equal in their effect on the succeeding arable crops. In the third arable crop, wheat, the 2-year ley was still effective to the extent of 3·9 cwt. grain per acre but the residual effect of the 1-year ley had largely disappeared. Yields under the all-arable system were considered to have been reduced by the poor physical and nutrient status of the soil, by increased incidence of ‘take-all’ in wheat and by more weed growth.3. The response of kale to dung averaged only 1·1 tons per acre over all four rotations but this was largely obtained in the ley systems and little after all-arable cropping. Compost was generally ineffective on kale with some signs of detrimental effect, especially in the arable system. Wheat following kale benefited equally from dung and compost applied in the previous year; the average response to organics was 1·6 cwt. grain per acre and this was unaffected by rotation. The residual value of dung on subsequent crops amounted to an average of 2·0 cwt. grain per acre per annum but compost had no significant effect.4. The response to an additional 0·4 cwt. fertilizer N per acre to kale was greatest after continuous arable cropping and virtually nil after 3-year ley. Wheat grain yields were improved by 1·0 cwt. per acre on average by the addition of the extra 0·4 cwt. fertilizer N per acre to kale in the previous year.5. It was concluded that when mixed farming is practised the aim should be to have the land under grass for at least as long as it is under arable, e.g. 3 years of ley with 3 years of arable.
The effect of rising environmental temperatures (35°–95° F.) On thyroid 131I release rate of holstein, brown swiss and jersey heifers
Authors: Johnson H. D. , Ragsdale A. C. 
Published: March 2009

1. There were many distinct, consistent, individual differences in the thyroid activity of several of the animals used in this study. Graphic indications of breed differences were present at several high temperatures, and statistical analyses supported differences between the Jerseys raised at each temperature and the other two corresponding breeds. The Jerseys displayed higher rates. In no instances were there thyroid 131I release rate differences between Holsteins and Brown Swiss.2. There was a negative correlation between thyroid 131I release rate and temperature for each breed raised at each temperature. Correlations for the 50° F. animals were statistically significant below the 0·05 level of probability and for the 80° F. animals they were significant below the 0·01 level. As the environmental temperature increased from 35° to 80° F. there was a gradual decrease in thyroid 131I release rate. Above 80° F. there was a sharp decline in thyroid 131I activity.3. Within the range of environmental temperatures from 35° to 70° F. the animals raised at 80° F. displayed thyroid release rates higher than those of the animals raised at 50° F. At 80° and 90° F. the 50° F. Jerseys exhibited higher activity. The Jersey differences approached statistical significance. At the lower temperatures graphic differences between the Brown Swiss and the Holsteins raised at the two temperatures appeared to be present, but they were not generally supported by statistical analysis.4. At temperatures of 80° F. and above, when regulatory mechanisms could not control body temperature, both groups showed considerable rises in body temperature concomitant with decreases in thyroid 131I activity and TDN consumption. The 80° F. group showed a rise less sharp than that of the 50° F. group.
Fission products and the dairy cow 1. The fate of orally administered cerium-144
Authors: Garner R. J. , Jones H. G. , Ekman L. 
Published: March 2009

1. The excretion of 144Ce in the faeces, urine and milk has been followed in two dairy cows receiving twice daily doses of 120 μc. with the feed over a 10-day experimental period. During the terminal 3 days, recoveries from the faeces amounted to 93–119% of the daily dose. From the urine and milk, respectively, 0·23 and 0·17% and 0010 and 0·016% of the total amount fed was recovered from the two animals.2. The concentration of 144Ce in various parts of the gut was estimated after equilibrium conditions had been attained. The highest concentrations were found in the contents of the omasum and hind-gut.3. The possible use of 144Ce as a marker in digestibility and similar trials is discussed.
The effect of urea on the utilization of ground, pelleted roughage by penned sheep: II. Utilization of organic matter, nitrogen and minerals
Authors: Coombe J. B. , Christian K. R. 
Published: March 2009

SUMMARYAdult Merino wethers were fed for 16 weeks on diets of oat straw mixed with urea and pelleted (A); oat straw pellets, with access to a salt block (B); oat straw pellets, with access to a salt-urea block (C); Phalaris straw mixed with urea and pelleted (D); and Phalaris straw pellets (E). A commercial mineral supplement was given during the first 8 weeks, and a laboratory-prepared complete mineral supplement supplied during the second 8 weeks. During the fifth to eighth weeks (period I), and the thirteenth to sixteenth weeks (period II), digestibility and balance studies were conducted on sheep from each treatment.Digestibilities of organic matter (O.M.) and cellulose were generally increased by the addition of urea, but only in one comparison, between diets A and B, was the difference significant. Urea did not significantly affect water intake in relation to food intake.Urea increased nitrogen (N) intake, faecal and urinary N excretion, and N balance, these effects being more pronounced in period II. All sheep were in negative N status in period I; five of the 12 urea-fed sheep were in positive N status in period II. In diets B and C water intake and urine output were positively related to salt intake, but in no diet was there a significant relation between urinary N excretion and total output of urine.Sulphur balances (excluding wool) were generally positive and did not improve significantly in period II despite higher sulphur intakes. However, a corresponding increase in the intake of phosphorus, from 0·5 g/day to about 2·0 g/day, brought nearly all sheep from negative to positive phosphorus balance. With the urea diets there was a significant, negative relation between urinary N excretion and phosphorus balance.Intakes of sodium, potassium, calcium and magnesium appeared to be sufficient in both periods.It seems likely that the improved response to urea which occurred during the experiment was due to the change in mineral supplementation rather than to adaptation to urea.
Growth and yield of three varieties of wheat, with particular reference to the influence of unproductive tillers
Authors: Bremner P. M. 
Published: March 2009

SUMMARYAn experiment was done to see if three varieties of wheat (Jufy I, Yeoman and Cappelle) of widely different tillering propensities differed in their response to early spring application of nitrogen; and, concurrently and conjointly, to assess the effects of unproductive tillers on the growth of productive shoots.None of the varieties responded to the higher of two levels of nitrogen. The presence of a large number of unproductive tillers appeared to have only a transitory effect on the growth of productive shoots; the latter were able to grow rapidly after the death of tillers and caught up with productive shoots which had been subjected to much less inter-tiller competition.