bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of plant type, plant population density and application of phosphate fertilizer on growth and yield of pigeon pea
Authors: Singh A. , Prasad R. , Saraf C. S. 
Published: March 2009

SUMMARYA field experiment was made with pigeon pea (Cajanus cajan (L.) Millsp.) at the Indian Agricultural Research Institute, New Delhi, during the rainy seasons of 1975 and 1976 to study the effects of plant type, plant population density and the application of phosphate fertilizer on growth and yield of pigeon pea. Cultivars BS-1 and UPAS-120 produced significantly more grain with 100 × 103 plants/ha, whereas the cultivar Prabhat produced most when 200 × 103 plants/ha were grown. Application of 13 kg P/ha increased most growth and yield attributes and increased the grain yield significantly over the control to which no P was given; however, no additional increase was obtained when 26 kg P/ha was given. The highest-yielding cultivar BS-1 benefited most from phosphate fertilizer.
A comparison of the organic matter, biomass, adenosine triphosphate and mineralizable nitrogen contents of ploughed and direct-drilled soils
Authors: Powlson D. S. , Jenkinson D. S. 
Published: March 2009

SUMMARYSoil samples were taken from four field experiments on the growth of cereals in direct-drilled and in mouldboard-ploughed soil. When sampled, one of the experiments had run for 5 years, one for 6, one for 8 and one for 10 years. Sampling was to just below plough depth and was done on an ‘equivalent depth’ basis, i.e. the more compact direct-drilled plots were sampled more shallowly than the ploughed plots in such a way that both samples represented the same weight of soil per unit area. No significant differences in total nitrogen or in total organic carbon were observed between cultivation treatments at any of the four sites.In three of the four sites, there was no significant difference in microbial biomass carbon, adenosine 5'-triphosphate (ATP), or mineralizable nitrogen between directdrilled and ploughed soils. In the fourth, which contained more clay than the others, there was slightly more biomass carbon and ATP in the direct-drilled soil. As microbial biomass carbon (or ATP, which is closely correlated with microbial biomass carbon) responds more rapidly to changes in management than do total carbon and nitrogen, a change in biomass carbon should provide early warning of changes in soil organic matter, long before changes in total carbon and nitrogen become measurable. That no such change was observed, with one partial exception, is evidence that a change from traditional methods of cultivation to direct drilling has little effect on soil organic matter other than altering its distribution in the soil profile.
Cotton growth and nutrient uptake following Temik aldicarb application
Authors: Ragab S. M. 
Published: March 2009

SUMMARYThe feasibility of enhancing cotton (Gossypium hirsutum L.) growth and nutrient uptake with Temik aldicarb was investigated using sand culture with a continuous flow of 1/5 strength of Hoagland solution. Aldicarb was incorporated in the nutrient solution at different rates, and was applied to the plants when they were 30 days old for a period of 1, 3, 5, or 7 days. The cation exchange capacity of the fresh roots of treated plants as well as the ionic permeability of the untreated plants as influenced by aldicarb application were also studied. Low rate of aldicarb provided a stimulus effect on the plant and enabled it to grow faster and to take up more N, P, K, Ca, Mg, and Na than the control. This suggested a direct effect of aldicarb on mineral metabolism especially those processes involving N and P. Maximum dry-matter yield and nutrient uptake occurred at the 5 mg aldicarb rate for all times of treatments. At a rate of 7middot;5 mg aldicarb, growth and nutrient uptake were inhibited, suggesting a toxicity of assimilatory processes within the plant which might have reduced its ability to take up and assimilate nutrients. Aldicarb facilitated the transfer of Na to the stem and leaves resulting in a more uniform distribution of Na throughout the treated plants compared with the control.
Studies on reproduction in prolific ewes
Authors: Robinson J. J. , McDonald I. , Fraser C. , Crofts R. M. J. 
Published: March 2009

SUMMARYSeventy-nine Finnish Landrace x Dorset Horn ewes in lamb to Suffolk rams were used in a comparative slaughter experiment to assess the effects of numbers of foetuses on the growth of the products of conception. The mean number of foetuses was 2·7, with a range from 1 to 5. The ewes were individually penned and given a standard diet with metabolizable energy concentration 7·7 MJ/kg and N concentration 21 g/kg, rationed at 2 kg/day during the first month and 1·25 kg/day during the second and third. Allowances beyond that time were on two scales and depended on the number of foetuses being carried as diagnosed by radiography. The ewes were slaughtered between 50 and 145 days of gestation. The gravid uterus was dissected into foetal, placental, foetal fluid and empty uterus components. Equations were fitted to the weights of each component to describe the effects of stage of gestation, litter size and ewe weight. For the mean weight per foetus (Y, kg) the preferred equation isIn (Y)= 2·419–17·574e-0.01976t–00079ft+0–0046w,where tis the time in days from conception, / is the number of foetuses and wis the weight (kg) of the ewe at mating. This is a version of the Gompertz equation, with additional terms to express the effects of / and w.The weights of the placenta and of the empty uterus were similarly fitted by versions of the Gompertz equation but the mean weight of fluids per foetus (Z, kg) or, rather, its natural logarithm was best described by a third degree polynomial, which isIn(Z) = –11·518 + 0–326t;–0·00316t2+0·0000102t3.None of the weights was significantly affected by the level of feeding in late pregnancy.Estimates of mean weights from the equations and of daily rates of gain in weight from the first differentials of the equations are tabulated against stage of gestation and litter size, and the forms of the weight, growth rate and specific growth-rate curves are illustrated graphically.The equation for foetal weight estimates that at the end of pregnancy the mean weight per foetus is reduced by a factor of 0–89 for each additional foetus being carried. The mathematical model implies that the differences originate in early pregnancy, when the factor is very close to unity, and that the mean weights gradually diverge. In the absence of direct evidence this would appear to be the simplest hypothesis, rather than the assumption in most of the earlier literature that the effect is entirely confined to the last 4 or 5 weeks of gestation.Just before parturition the total daily weight gain of quadruplet foetuses was about 250 g and was associated with a similar gain in weight of foetal fluids, the ratio of fluid weight to foetal weight appearing to increase with litter size. The ewes were clearly under considerable physical stress. It is suggested that this aspect must be closely considered when greater prolificacy is sought.
Studies on reproduction in prolific ewes
Authors: Wenham G. 
Published: March 2009

SUMMARYA radiographic study was made of the skeletons of 216 Suffolk x (Finnish Landrace x Polled Dorset Horn) sheep foetuses of known gestational age within the range 50–145 days. They comprised 10 singles, 42 twins, 105 triplets, 44 quadruplets and 15 quintuplets.The ages at which the primary and secondary centres of ossification first appeared are presented together with a description of the normal pattern of skeletal development. Attention is drawn to the variations which are found from one foetus to another. The main anatomical features of ovine foetal bone development are illustrated by line drawings and charts.By anatomical grouping the number of ossification centres was reduced to 80, including 40 primary and 40 secondary centres. Scores were obtained for each foetus by taking the numbers of primary and secondary centres that were present as percentages of the possible totals. The primary score was linearly related to foetal age up to about 100 days, and the secondary score was linearly related to foetal age beyond about 100 days. The relationships to foetal weight were similar but less close.
The effect of a wide range of fertilizer nitrogen application rates and defoliation intervals on the dry-matter production, seasonal response to nitrogen, persistence and aspects of chemical composition of perennial ryegrass (Lolium perennecv. S.24)
Authors: Bartholomew P. W. , Chestnutt D. M. B. 
Published: March 2009

SUMMARYA small-plot experiment was made to assess the influence on dry-matter output from grass of a wide range of fertilizer nitrogen and defoliation interval treatments. There were five defoliation treatments, 22, 28, 45, 75 and 112-day regrowth intervalsroughout the growing season each at six levels of nitrogen application, ranging by 300 kg increments from 0 to 1500 kg/ha/year.There was a marked interaction effect between treatments; a positive dry-matter response was maintained to a higher level of applied nitrogen with more frequent defoliation. In 2 years out of 3 maximum dry-matter yield was produced under a 75·day defoliation interval although the mean yield advantage over a 45-day defoliation system was only 11%. Mean yield of digestible dry matter appeared to reach a maximum under a 45·day defoliation interval at 600 kg N/ha but at the lower levels of N the maximum yield was reached at the longest growth interval.Seasonal response to nitrogen under the 22–day and 28–day defoliation systems measured as the increase in yield resulting from increased N at each cutting date reached its peak in July–August. Application for these short growth periods early and late in the growing season appeared to be a relatively inefficient use of nitrogen.The less frequently the sward was harvested and the higher the nitrogen application the greater was the reduction in ground cover as estimated by eye at the end of the growing season, this reached an estimated 25% reduction under 112·day defoliation at 300 kg N/ha/year.In relation to published figures nitrate content of herbage did not reach dangerous levels until nitrogen application reached levels beyond those at which maximum dry·matter yield was achieved.
Some effects of leaf posture on the yield and water economy of winter wheat
Authors: Innes P. , Blackwell R. D. 
Published: March 2009

SUMMARYSelections for erect-(E) and lax-leaf (L) posture in winter wheat were made from a cross between parents which contrasted in the character. By the F5 generation there were consistent, heritable differences between E and L lines. The lines were evaluated in three field experiments and a glasshouse experiment.In an experiment in which plots were automatically sheltered from rain and in which there were three irrigation treatments, there was no treatment-posture interaction, and over all treatments E lines outyielded L lines by 0·26 t/ha. When fully irrigated the water use of both E and L lines between 1 May and maturity was approximately 280 mm. Withholding water caused a reduction in water use and a corresponding reduction in grain yield for both E and L lines.When the four most erect- and the four most lax-leaved lines were considered over all three field experiments, E lines maintained a slight, though not significant, grain yield advantage of 0·17 t/ha over L lines. However, the E lines produced significantly more biomass, averaging 0·7 t/ha more than L lines, and this extra biomass was not produced at the expense of additional water requirement. However, results from the glasshouse experiment suggested that the E lines may be more susceptible to a substantial pre-anthesis drought.It is concluded that varieties of winter wheat with the erect-leaf habit may provide an opportunity of increasing biomass production. In an environment in which a preanthesis drought is unlikely to occur, such varieties may give the highest yields. However, on light soils prone to early drought or at sites which would not permit the maximum expression of leaf area index at anthesis, varieties with a lax-leaf posture may give greater yield.
The early weaning of pigs: III. The influence of protein supply during two stages of growth on the performance of pigs from 9 lb. to bacon weight
Authors: Smith H. , Lucas I. A. M. 
Published: March 2009

1. The main experiment described was a 4 × 2 factorial designed to test levels of 18, 21, 25 and 28% crude protein in diets fed from 25–50 lb. live weight and to compare an all-vegetable diet with one containing white fish meal for pigs of 50–100 lb. live weight.Forty-eight pigs were used in the experiment. They were weaned at an average weight of 9 lb. and were fed a standard 29% protein diet until they each weighed 25 lb. Between 100 lb. and slaughter at 200 lb. they were fed a standard all-vegetable diet containing 14% protein.Live weights and food-consumption figures for each pig were recorded throughout the experiment and carcass-quality measurements were taken.2. Forpigs of 25–50 lb. there was no advantage in raising the level of crude protein above 18% in a diet based on white fish meal, dried skim milk, rolled oat groats, ground barley and fine millers' offals. Level of protein fed during this stage of the experiment did not affect performance at any subsequent stage, nor did it affect carcass quality.3. For pigs of 50–100 lb. rates of live-weight increase and food-conversion efficiency were poorer by 13 and 14%, respectively, on an all-vegetable diet containing 17% crude protein than on a diet including 7·5% white fish meal and containing 15% crude protein. This difference was not affected by level of protein fed before 50 lb., and in its turn it did not affect either growth performance from 100–200 lb. or carcass quality measurements.4. The following notes relate to the overall performance of early weaned pigs during this experiment: After being weaned at an average of 9 lb. when 10 days old, the pigs reached 25 lb. at 36 days old and 50 lb. at 58 days old. They each ate an average of 29 lb. of the 29% protein diet 1A and 59 lb. of the diets 2 A–D fed from 25–50 lb. Between 50 and 200 lb. food-conversion efficiencies were lower than is usual for individually fed pigs at the Rowett Institute, but rates of live-weight increase were satisfactory when considered in relation to the plane of feeding followed, and the average age at 200 lb. was 185 days. Of the carcasses 85% graded A.5. In a pilot trial pigs were changed over from the 29% protein diet 1A to the 18% protein diet 2D at 13, 17, 21 or 25 lb. live weight.There was a linear trend towards slower rates of live-weight increase as the weight at change-over was reduced, and pigs changed at 13 lb. took 7 days longer than those changed at 25 lb. to reach 40 lb. live weight. Overall food-conversion efficiency was best when the change was made at 25 lb., but because of the high cost of diet 1 A in relation to diet 2 D there was a linear trend for the total cost of food per pig to be lower as the weight at change-over was reduced.6. The results of the pilot trial were discussed in relation to the effects on the lightest pigs in a group of changing to diet 2 D as the average weight per pig reached 25 lb.
Reproduction in farmed red deer. 2. Calf growth and mortality
Authors: Blaxter K. L. , Hamilton W. J. 
Published: March 2009

SUMMARYThe sex and number of calves born to a breeding herd of red deer kept under farm conditions are analysed together with information on mortality and on growth rate of the calves until weaning in September–October. The results showed some anomalous deviations of the sex ratio from a 50:50 expectation. Birth weight was related to the weight of the hind at the time of the rut, and so too was the subsequent daily rate of gain of the calf. Stag calves weighed more than hind calves and there was no effect of age of hind on birth weight once weight of hind had been discounted. Mortality was divided into two components; perinatal mortality included stillbirths, deaths at parturition and during the first 24 h of life and an unidentified mortality representing failure to find a calf although the hind had calved. Postnatal mortality was defined to include all deaths from after 24 h of life to weaning. Mortality was related to the weight of the calf at birth, being 100 % for calves weighing less than 4·0 kg and declining to 5 % for calves weighing 6·0–7·0 kg. The data are discussed and the effect of size of hind at the time of the rut on her fertility, the time at which she calves, the birth weight and growth rate of her calf and its survival rate are combined to estimate the annual number of viable weaned calves and the total weight of calves produced by herds of hinds of different weights. An increase in hind weight of 50 % (from 60 to 90 kg) results in a doubling of the number of calves born and surviving to September and an increase in the weight of the calf crop by 160%. Reasons are given to suggest that total calf mortality could be reduced to 7 %.
The influence of dietary antibiotics on the activity of the cellulose-splitting bacteria in the intestine of the bacon pig
Authors: Evans R. E. , Maguire M. F. 
Published: March 2009

The present investigation is concerned with the influence of procaine penicillin and aureomycin on digestion. In particular, the effect of antibiotics, in amounts generally included in feeding-stuffs, on the bacterial digestion of cellulose in the large intestine of the pig, was investigated.The digestibility of a basal diet composed of fine bran, maize meal, dried lucerne meal and whitefish meal was determined with and without the addition of antibiotic. No effect was noted on the digestibility of any food constituent.The diet fed in four digestion trials contained 500 g. of shredded fodder cellulose. The digestion coefficient for the crude fibre, in these diets rich in cellulose, was 76·2% when 18 mg. of procaine penicillin was added per lb. of meal and 76·8% when no antibiotic was added.The nitrogen-free extractives in the fodder cellulose are mainly if not entirely composed of xylan. If the nitrogen-free extractives and crude fibre are combined to give ‘cellulose’ as defined by Norman & Jenkins, the digestion coefficients for the cellulose were 85·7, 83·4, 85·7 and 87·2%, respectively, thus showing little difference between treatments.There is no warrant for assuming that the antibiotics had any bactericidal or bacteriostatic effect on the cellulose-splitting organisms.
Short day-length and egg production in the fowl
Authors: Sykes A. H. 
Published: March 2009

1. The effect of a short, unchanging day-length of 6 hr. on age at sexual maturity and egg production has been observed.2. The birds matured at the same age as the controls but at a lower body weight.3. Egg production over 58 weeks was considerably reduced.4. An increase in day-length between December and August always increased production.5. A decrease in day-length between February and August always decreased production; this decrease was greater the later in the year that the change occurred.6. It is concluded that age at sexual maturity is not affected by the absolute length of the day, and that egg production is affected both by the absolute length and by the change in length.
Field studies on 14C assimilate fixation and movement in oil-seed rape (B. napus)
Authors: Chapman J. F. , Daniels R. W. , Scarisbrick D. H. 
Published: March 2009

SummaryThe roles of leaves, stems and reproductive parts in 14CO2 fixation and its subsequent movement in winter oil-seed rape, cultivar Jet Neuf, were investigated in two field experiments carried out on the Wye College Farm. The relative importance of these organs changed with time. At early flowering the leaves were the most important photosynthetic organs (66·8% 14CO2 activity). Midway between flowering and maturity the stems became the major supplier of photosynthates, a role eventually taken over by the developing siliquae (pods).These data stress the importance of keeping all photosynthetically active surfaces free from disease if efficient resource utilization and higher yields are to be achieved.
Some effects of genetic variation in drought-induced abscisic acid accumulation on the yield and water use of spring wheat
Authors: Innes P. , Blackwell R. D. , Quarrie S. A. 
Published: March 2009

SummarySelection for high-(H) and low-(L) drought-induced abscisic acid (ABA) accumulation in spring wheat was made from a cross between parents which contrasted in the character. By the F5 generation H and L selections were homozygous for ABA accumulation, which differed between the classes by 80%. The selections were evaluated in field experiments in which the amount of available water was varied.In one experiment, in which plots were automatically sheltered from rain, H selections outyielded L selections by an average 0·36 t/ha both when fully irrigated and when water was withheld between anthesis and maturity. The extra grain yield of the H selections was not produced at the expense of additional water requirement in either treatment. When water was withheld during the 4 weeks preceding anthesis, the grain yields of H and L selections were similar, but H selections used less water between 1 May and maturity. Averaged over all treatments the ratio of grain yield to water use was greater for H selections than for L selections by 0·12 t/ha/100 mm. Withholding water caused a reduction in water use and a corresponding reduction in biomass production in both sets of selections.In two trials in which plots were either irrigated weekly or received natural rainfall only, the ratio of grain yield to water use was again greater for H than for L selections, by an average 0·10 t/ha/100 mm.It is concluded that in spring wheat, selection for high levels of ABA accumulation in response to water stress may provide an opportunity of increasing grain yield and water-use efficiency.
The relative importance of some different sources of plant-weight variation in drilled and transplanted leeks
Authors: Benjamin L. R. 
Published: March 2009

SummaryIn six experiments the effects of various factors on plant-weight variation (sum of squares of deviation from the mean shoot weight) at harvest were examined. These factors were seed size, sowing depth, time of seedling emergence, size at different stages of development, within-row spacing, density and row position within a bed.In a drilled experiment, up to 25% of the variation in mature leek size could be attributed to variation in time of seedling emergence. Similarly, in the experiments which used transplants, 15% of the variation in the mature crop could be associated with variation in size shortly after seedling emergence from peat blocks.Variation in row position within a 4-row bed never accounted for more than 11% of the weight variation at harvest, and variation in within-row spacing never accounted for more than 4% of weight variation. However, the coefficient of variation (c.v.) of leeks growing at 22 plants/m2 was 44% whereas the c.v. of those growing at 50 plants/m2 was 61%.Using large seeds or sowing deeply gave a quicker emergence and a higher percentage emergence than using small seeds or sowing shallowly. However, these factors each never accounted for more than 7% of the weight variation in mature leeks.Most of the plant-weight variation could not be attributed to any of the measured factors in any of the experiments. The c.v. of leeks which had emerged on a specific day and had been grown in a uniform environment, was between 50 and 66%, which was similar to the c.v.s observed in the transplant and drilled experiments. However, selecting for large transplants reduced the c.v. to 28% in one experiment; this effect was only partly attributable to the greater mean plant size resulting from this treatment.