bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of constant and varying heights of cut on the yield of Italian ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (Lolium perenne L.)
Authors: Ollerenshaw J. H. , Hodgson D. R. 
Published: March 2009

SummaryThree constant and four variable heights of cutting were applied to swards of Italian ryegrass (Lolium multiflorum Lam.) cv. Aberystwyth S. 22 and perennial ryegrass (Lolium perenne L.) cv. Aberystwyth S. 23 for a period of 2 years. The treatments were initially given in the seeding year of the Italian ryegrass swards and first harvest year of the perennial ryegrass. The same swards were used throughout the duration of the two experiments. The three heights of cutting 3, 6 and 9 cm were defined by the mean lengths of tiller remaining after defoliation with a flail harvester.The yield of dry matter (D.M.) was relatively low from Italian ryegrass cut repeatedly to 3 cm because many plants died. Higher yields were obtained by cutting repeatedly to 6 or 9 cm but only when the grass at the end of the season was cut to 3 cm. Italian ryegrass produced more herbage by variable than constant heights of cutting, especially when a lax cut occurred in mid-summer.Perennial ryegrass gave higher yields of D.M. by constant low than high cutting, but there were no differences in yield when the constant high cut swards were closely defoliated at the end of each season. More herbage was produced by variable than constant heights of cutting in the second year, especially when several lax cuts occurred in the variable height of cut treatments.As perennial ryegrass had a very prostrate growth habit in swards which received several close cuts tillers were not defoliated too severely. In contrast, Italian ryegrass remained erect in growth habit even in swards which were closely defoliated and thus tillers were cut more severely than those of perennial ryegrass. The need to measure accurately the actual lengths of tillers after defoliation is emphasized in height of cutting treatments.
The relationship between disease symptoms and parasite growth in bacterial blight of cotton
Authors: Brown S. J. 
Published: March 2009

SummaryLesion development and growth of Xanthomonas malvacearum (E. F. Smith) Dowson were followed in seedlings of different cultivars of cotton (Gossypium hirsutum L.) after inoculation of hypocotyls. There was a close relationship between numbers of the parasite and length of hypocotyl lesion. Disease development could be accurately determined by measurement of lesion length from 2 to 3 days after inoculation until growth of the parasite ceased. Growth patterns of the parasite in vivo took the form of a distinct period of exponential (phase 1) growth followed by relatively little, if any, further increase in numbers (phase 2 growth). The duration of phase 1 growth was related to host resistance and environmental factors.
Intercropping maize and sorghum with soya beans
Authors: Mohta N. K. , De R. 
Published: March 2009

SummaryField trials were made in the rainy seasons of 1970–4 at the Indian Agricultural Research Institute, New Delhi, to evaluate several systems of intercropping maize and sorghum with soya beans. Maize yields were not affected by intercropping with soya beans but sorghum yields were reduced. Though the yield of soya beans when intercropped was less than that of a sole crop, the combined grain yield of the two crops in an intercrop was more than the individual components. Land equivalent ratio (LER) increased to a maximum of about 48 and 31% by intercropping maize and sorghum with soya beans compared with the cereal sole crops. Maize rows planted 120 cm apart and intercropped with two rows of soya beans or sorghum planted 90 cm apart intercropped with one row of soya beans proved to be the best intercropping pattern.
The estimation of parameters by least squares from unbalanced experiments
Authors: Finney D. J. 
Published: March 2009

SummaryData from experimental and observational studies, in agriculture as in many other contexts, are often unbalanced in respect of important classifications. Treatments may be unequally replicated, some combinations of factors may be omitted, animals may die for reasons unconnected with an experiment. Unless means are adjusted in some manner that eliminates disturbance from unequal representation of different categories, comparisons between treatments may be thoroughly misleading. Optimal procedures for the simpler situations have been familiar to statisticians for a long time. They have been little used by other scientists analysing their own data, in part because of the computational labour and in part because their nature has not been properly understood.Modern computing power removes all excuse for the retention of methods that may be actively misleading because they bias summaries of data, or that are at best inefficient in their failure to estimate comparisons as precisely as is possible. The only remaining barrier is the mistaken belief that good methods are either so complicated that they can be comprehended only by professional statisticians or so devious that truth is destroyed rather than exhibited. This paper attempts to show good methods as inherently rational, to explain their main properties, and to illustrate them on examples small enough for the processes to be clear. The paper neither expounds statistical theory nor instructs in computing practice.
An evaluation of body size as related to weight of three West African breeds of cattle in Nigeria
Authors: Buvanendran V. , Umoh J. E. , Abubakar B. Y. 
Published: March 2009

SummaryBody measurements and weights of animals of varying ages were recorded in White Fulani (Bunaji), Sokoto Gudali and N'dama breeds of cattle. Chest girth accounted for 86–96% of the variation in body weight in the three breeds. The linear regression coefficient of weight on chest girth in the N'dama differed significantly from the other two breeds. Within each breed, the regression coefficient of young animals was lower than those of older groups. The variables that contributed most to improving the prediction of weights when added to chest girth were rump length and body length. Animals with low body condition scores had lower regression coefficients of weight on chest girth than those with high scores.
Effects of adding plant nutrients to the gel carrier used for fluid drilling early carrots
Authors: Finch-Savage W. E. , Cox C. J. 
Published: March 2009

SUMMARYPhosphates and nitrate were added to the gel used for fluid drilling without affecting its properties as a seed carrier. The addition of monosodium phosphate promoted early seedling growth but at concentrations higher than 30 g/1 it became phytotoxic. Nitrate added to the gel reduced plant growth and decreased the number of seedlings emerging. Ammonium phosphate was found to be an effective addition to the gel and could be used in the form of a proprietary liquid ammonium polyphosphate fertilizer. The earlier emergence of fluid-drilled germinating seeds and the enhanced growth brought about by phosphate addition to the gel increased plant size compared with that of the dryseeded controls. The results are discussed in relation to the early production of marketable-size carrots.
Comparisons between combine-drilling and broadcasting muriate of potash for spring barley
Authors: Widdowson F. V. , Penny A. , Williams R. J. B. , Cooke G. W. 
Published: March 2009

1. Twelve experiments were carried out in Bedfordshire and Hertfordshire in 1955–57 to compare combine-drilling and broadcasting muriate of potash for barley. Ordinary mineral soils were used and only one contained more than 25% of calcium carbonate.2. On average of all the experiments in each year 0·25 cwt. K2O/acre drilled with the seed gave higher yields than 0·5 cwt. K2O/acre broadcast and worked into the seedbed. The average extra yields of barley from combine-drilling, as compared with broadcasting, were 1·2 cwt./acre when 0·25 cwt. K2O/acre was applied and 2·0 cwt./acre of grain when twice as much K2O was given. In twenty-one of the total of twenty-four comparisons drilling gave higher yields than broadcasting and in onethird of these comparisons the effects were significant. Combine-drilling gave higher average yields of straw than broadcasting.3. The average level of response was not great, the low and high rates of combine-drilled muriate of potash increasing yields by 13 and 16%, respectively. Only a small proportion of the applied potassium was taken up by the crops; apparent recoveries by grain plus straw averaged 11% of the light-drilled dressing and 8% of the heavy dressing.4. The level of response to potassium varied from year to year, but was much greater on average in the 1955 experiments than in 1956 and 1957. There was no close relationship between the degree of response and values for dilute hydrochloric-acidsoluble potassium or exchangeable potassium in the soils used.
Field experiments on phosphate fertilizers. A joint investigation
Authors: Cooke G. W. , Widdowson F. V. 
Published: March 2009

The results of about ninety field experiments carried out over three years to test dicalcium phosphate, nitrophosphate, ammoniated fertilizer and Gafsa rock phosphate are summarized and discussed. Soils with pH values of 6·5 and below are listed as ‘acid’, those with higher pH values as ‘neutral’. All comparisons were made in terms of fertilizers supplying the same total amounts of phosphorus.Dicalcium phosphate dihydrate gave approximately the same yields as superphosphate for potatoes (both on acid and on neutral soils) and for grass, kale and barley. In one group of swede experiments mostly carried out in the north-east of the country dicalcium phosphate was inferior to superphosphate, but it was equal to superphosphate in another group of swede experiments, most of which were on acid soils in wetter areas.A nitrophosphate made in England on pilot-plant scale was consistently inferior to superphosphate for barley, potatoes and swedes.
The effects of oxalate in tropical grasses on calcium, phosphorus and magnesium availability to cattle
Authors: Blaney B. J. , Gartner R. J. W. , Head T. A. 
Published: March 2009

SUMMARYCattle were fed four hays in mineral balance experiments. Two of the hays (Cenchrus ciliaris and Setaria sphacelala var. sericea) contained 1·8 and 1·3% total oxalates and provided above- and below-maintenance intakes of calcium respectively. These grasses contain calcium oxalate crystals. The other two hays (Aristida spp –Bothriochloa spp. mixture and Triticum aestivum) contained 0·1% oxalates, and also provided above- and below-maintenance intakes of calcium. The absorptions of calcium from the hays providing above-maintenance intakes were 51% for the high and 57% for the low oxalate hay. At below-maintenance intakes, the cattle were in negative calcium balance and calcium absorptions were 52% for the high and 64% for the low oxalate hay. While in negative calcium balance the cattle were given single doses of calcium oxalate, followed by single doses of either limestone or rock phosphate. The cattle fed S. sphacelata hay absorbed sufficient calcium from calcium oxalate to achieve positive calcium balance, although the amount absorbed was only 52% of that absorbed from limestone. The cattle fed T. aestivum hay also absorbed calcium from calcium oxalate, but in insufficient amount to result in a positive calcium balance. The amount absorbed was 47% of that absorbed from rock phosphate. The results demonstrate that in tropical grasses containing calcium oxalate crystals, the availability of calcium is about 20% lower than it is in grasses containing little oxalate. Adaptation to oxalate may improve the ability of the rumen to utilize calcium oxalate. It is suggested that the availability of calcium to cattle grazing tropical grasses should be considered to be a maximum of 50%. Neither magnesium nor phosphorus absorptions from tropical grasses were affected by oxalate.
The conversion of pasture to milk: the effect of stocking rate and concentrate feeding
Authors: Hancock John 
Published: March 2009

1. An experiment is described in which the effect of the level of nutrition, as determined by stocking rate and the use of supplementary concentrates, on milk yield and efficiency of production was studied.2. Three levels of nutrition were used: Treatment (A)—one milking cow per acre plus 1 lb. of concentrate mixture for each 5 lb. of milk produced. Treatment (B)—one milking cow per acre—no concentrates. Treatment (C)—one milking cow per sixtenths of an acre—no concentrates.3. Fifteen sets of identical twins were used per year over an experimental period of 3 years. The groups were rotationally grazed with a daily shift to a fresh pasture on a 14-day rotation. Ninety complete lactations were available for analyses.4. The A cows produced 45% and the B cows 16% more f.c.m. than the C cows. Per unit area, however, the C treatment produced 30% more than the B.5. Significant differences in milk composition were established, but these were of much smaller magnitude than those in milk yield.
Losses in the conservation of grassland herbage as molassed and metabisulphite silage in lined trench silos
Authors: Brown W. O. , Smyth V. 
Published: March 2009

A conservation experiment is described in which a comparison of the nutrient losses and quality of sodium metabisulphite silage and molassed silage is made. The loss of dry matter in molassed silage is shown to be 3·5% higher than in metabisulphite silage.The lactic-acid content of metabisulphite silage is found to be some 40% less than that of molassed silage.The results obtained are discussed in relation to published work on conservation by metabisulphite and to the practical application of the method.
Nitrogen fertilizers for spring barley and wheat
Authors: Widdowson F. V. , Cooke G. W. 
Published: March 2009

1. Ten experiments on spring barley (mainly Proctor) and four on spring wheat (mainly Atle) in 1954–6 compared 0·25 and 0·5 cwt. N/acre (as ammonium sulphate) when drilled with the seed, with dressings broadcast before sowing. Tests were also made of ‘Nitro-Chalk’ dressings given in mid-May. In heavier split applications seedbed dressings were supplemented by top-dressings of 0·5 cwt. N/acre.2. Barley gave much larger average responses than wheat. For barley combine-drilling 0·25 or 0·5 cwt. N/acre gave consistently larger yields than broadcasting the same nitrogen dressing on the seedbed; for wheat combine-drilling gave slightly higher yields at the high rate of dressing only.3. For both crops 0·5 cwt./acre of N drilled with the seed was almost sufficient for maximum yields, but where only 0·25 cwt. N was applied at sowing a mid-May top-dressing of 0·5 cwt. N/acre gave higher yields.4. At most centres May top-dressings of ‘Nitro-Chalk’ gave lower yields than equivalent ammonium sulphate drilled with the seed. Yields were often reduced by lodging on plots which received seedbed dressings plus top-dressing or the heavier rates of top-dressing alone; these treatments also reduced the quality of the grain. Combine-drilled or broadcast seedbed dressings did not cause serious lodging or reduce grain quality.5. 0·25 or 0·5 cwt. N/acre broadcast on the seedbed or combine-drilled had little effect on the percentage of nitrogen in the grain; equivalent topdressings in mid-May consistently increased nitrogen content. Seedbed dressings plus top-dressings supplying heavier total quantities of nitrogen continued to increase nitrogen percentage in grain without giving any increase in yield.
Estimation of the body chemical composition of live cattle varying widely in fat content
Authors: Little D. A. , McLean R. W. 
Published: March 2009

SUMMARYFollowing the measurement of tritiated water (TOH) spaces, 31 cattle were slaughtered and chemically analysed in this study. They included several breeds, both females and castrate males, and were of varied nutritional history. Their body-fat content ranged from 4 to 21% of fasted live weight.Total body water (including the water in the gut contents) was reliably estimated from TOH space, measured after allowing an overnight 16 h waterless fast for TOH equilibration. Following this regime, residual D.M. in the gut contents amounted to 1·75% of fasted live weight. The relationships of body fat to body weight, and body fat to body water when both were expressed as percentages of body weight, were too variable to be used in any predictive fashion. Equations were derived, using fasted live weight, allowing the accurate estimation in vivo of the quantities of the chemical components in the whole body (i.e. total body minus D.M. in gut contents).It was demonstrated that the sum of total body water and total body fat constituted virtually 80% of total body tissues, and that total body protein closely approximated 80% of the fat-free dry matter, in cattle varying widely in body condition. These relationships constitute the physiological basis of the equations presented.Comparable principles appear to apply to sheep, and a range of other mammalian species.
Ripening in maize: interrelationships between time, water content and weight of dry material in ripening grain of a flint × dent hybrid (Inra 200)
Authors: Bunting E. S. 
Published: March 2009

SUMMARYResults are reported of ripening studies with maize (var. Inra 200) at Oxford, 1967–9. Sowings were made in late April or early in May, and crops grown at a standard density of 7–2 plants/m2. Areas were provided with cloche protection, for a 4- to 5-week period from time of sowing, to produce material for studies of the effects of flowering time on ripening patterns. From plants of known flowering date collections of 30–40 ears were taken at intervals from 30 until 100+ days after silking.Information is presented on water content, grain dry weight and number of grains/ear at the various times of harvest. Asymptotic, polynomial and inverse-polynomial regression models have been fitted to the data to elucidate the interrelationships between time (measured from date of silking), grain water content and grain dry weight.In plants flowering in mid-July grain continued to increase in dry weight until water content was reduced to 35 %, whereas in plants flowering early in August maximum dry weight was attained at a water content of around 40 %.Maximum dry weight of grain was approximately 10% higher in the earlier flowering plants; the corollary is that in the marginal areas of maize grain production in England maturity in such varieties as Inra 200 is often imposed by the environment with a consequent loss in potential yield.In the early flowering plants, the time taken from silking to reach the harvestable stage of 40 % grain water content was 69 d in 1967, 79 d in 1968 and 64 d in 1969. Rate of water loss from the grain during ripening was closely related to prevailing air temperatures. In the later flowering plants, differing by an average of 11 d in time of silking, 8 days longer was required for grain to be reduced to 40% water content, giving an average difference of 19 days in permissible dates of harvest.The results suggest that, in varieties of similar ripening pattern to Inra 200, an advance of about 7 days in flowering time is required to establish the maize grain crop beyond its present confines in south-east England.
The use of internal markers to estimate herbage digestibility and intake: 2. Indigestible acid detergent fibre
Authors: Penning P. D. , Johnson R. H. 
Published: March 2009

SUMMARYDigestibility trials were carried out using wether sheep, to determine the organicmatter digestibility of several forages. Acid detergent fibre (ADF) was isolated from samples of feed and faeces, incubated in buffered cellulase solution, and the ash-free residue remaining (IADF) was used as an internal marker to estimate the organicmatter digestibility (OMD) of the feeds. Estimates of the OMD value of the samples were also made using the standard in vitro digestibility technique.IADF had reached a constant value after incubation for 4–5·5 days and predicted OMD more precisely than the in vitro digestibility technique.It is concluded that IADF is a suitable internal marker and predicts OMD well. However, more work is required to test this technique over a wider range of herbage species and digestibilities.
Resistance of cow-pea pods to Callosobruchus maculatus Fabr
Authors: Fatunla T. , Badaru K. 
Published: March 2009

SUMMARYFour bruchid-resistant and four susceptible cow-pea cultivars and their F2 crosses were evaluated for oviposition, egg hatching and emergence scores of cow-pea weevils, Callosobruchus maculatus Fabr.Whereas oviposition and number of eggs hatched were normally distributed, percentage of eggs hatched was not. For percentage weevil emergence, the F2 progenies with susceptible parents as females had a different distribution from that of their reciprocals with resistant parents as females.Preferential oviposition was not observed among the parents and their F2 progenies. Resistance was observed at the egg hatching and weevil emergence stages. Percentage of eggs hatched was significantly and positively associated with percentage weevil emergence.
A study of the lactation and growth of hill sheep in their native environment and under lowland conditions
Authors: Owen J. B. 
Published: March 2009

1. A method is described suitable for the estimation of the milk yield of sheep under natural grazing conditions.2. The yields obtained from Welsh Mountain sheep in two environments are shown.3. A close but diminishing relationship is shown to exist between the milk yield of the ewe and the growth of the lamb. Evidence is given of the effect of milk yield at later stages.4. The estimation of the ewe's milk yield from the weight of the young lamb is discussed. These estimates are used in conjunction with actual milk records in the present study.5. The ewe's milk yield is shown to be significantly related to nutrition, body weight, udder size and the lamb's birth weight.6. The relation of milk yield to weight gain during lactation, fleece weight and fleece type were mainly non-significant.7. From the limited data available, it seems that milk yield has a fairly high repeatability and heritability.
Blood-urea concentration in relation to protein utilization in the ruminant
Authors: Lewis D. 
Published: March 2009

1. It has been shown that under a given feeding régime the concentration of blood urea in the sheep is constant.2. Changes in the diet lead to different levels of blood-urea concentration which can be correlated with different rumen-ammonia concentrations; the change in blood-urea concentration follows increases or decreases in rumen ammonia after a delay period of 4–8 hr.3. Fluctuations in blood-urea concentration in the sheep are not primarily due to changes in the overall nitrogen intake.4. It is suggested that these findings might form the basis of a supplementary test in assessing the value of the protein in a foodstuff for ruminants.
Pyrophosphate as a source of phosphorus for maize in some acid soils from southern Nigeria
Authors: Uzu F. O. , Udo E. J. , Juo A. S. R. 
Published: March 2009

SUMMARYHydrolysis and sorption reaction of pyrophosphate (PP) in soils and uptake of PP by maize were studied using some acid soils from southern Nigeria. Rate of hydrolysis varied with the soil type, and half-lives of hydrolysis ranged from 10 to over 40 days in unsterilized soils and more than 40 days in all cases when the soils were sterilized. An appreciable fraction (over 40%) of the added PP resisted hydrolysis, the effect being more pronounced in the sterilized soils.Sorption of both PP and orthophosphate (OP) by soils followed the Langmuir isotherm. The adsorption capacity and bonding energy index for all soils were greater for PP than for OP.A short-term glasshouse experiment showed that PP was as good as OP as a source of P to maize. When the soils were limed to pH 6, PP appeared to be superior to OP.