bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence of herbage treatment effects in barley and consequences for subsequent crop experimentation
Authors: Fairey N. A. , Lefkovitch L. P. 
Published: March 2009

SUMMARYA study, conducted in the Peace region of Canada, determined the effects of the stand and management treatments of four herbage experiments (1986–88) on the yield and quality of subsequent crops of barley (Hordeum vulgare L.) harvested in 1989 and 1990. Quantitative relationships indicated that the crop management treatments most conducive to good yield and quality of herbage were also the most beneficial for subsequent high yield and quality of the barley grain. Unless designs orthogonal to those previously used can be found, covariance adjustment procedures are recommended to minimize the residual effects of previous experiments.
Heterogeneity of variance in field experiments: some causes and practical implications
Authors: Krajewski P. 
Published: March 2009

SUMMARYData from 62 field experiments on various crops in 1973–85 at Rothamsted Experimental Station were used to obtain knowledge about the heterogeneity of variance of yield. The results suggest that explaining heterogeneity of variance in terms of a mean–variance relationship is inadequate; better understanding of the patterns of changing variance can be gained by investigating the influence of the experimental factors on the variance. The effects of the factor ‘amount of nitrogen’ on mean yield and on the variance were positively correlated; factors which tend to affect variability but not the mean were identified. Suggestions are given for controlling variance but the need for further experimental evidence is emphasized.
New estimates of dry matter intake of lactating beef cows grazing three pasture systems
Authors: Barlow R. , Ellis K. J. , McLennan D. J. , Costigan P. , Hirst P. H. 
Published: March 2009

SUMMARYEstimates of dry matter intake reported by Barlow el al. in this journal in 1988 appeared low for grazing beef cows during early lactation. Further estimates for 144 crossbred and Hereford cows at Grafton, NSW, support the contention that the previous estimates for early lactation were biased downward. This appears to have been simply a scale effect as rankings of pastures and cow genotypes remained unchanged, although the magnitude of differences did alter.
Feeding value for finishing pigs of silage effluent with a high initial pH
Authors: Patterson D. C. 
Published: March 2009

SUMMARYSilage effluents with pH values of 4·1, 4·7 and 5·1 (normal (N), high (H) and very high (VH), respectively) were treated with hydrochloric acid to bring the pH of each effluent to 40. The effluents were offered to finishing pigs in a randomized block experiment (November 1983 to February 1984 at the Agricultural Research Institute of Northern Ireland) with dietary treatments which comprised a control diet in which meal was given to a standard scale of feeding, or effluent diets N, H and VH, in which the effluent was substituted on a dry matter basis for 150g/kg of the standard scale of feeding. In a negative control diet, meal was offered at 850 g/kg of the control diet. Water or effluent as appropriate was given on the meal, and water was also available ad libitum. A total of 60 pigs was used with mean initial and final live weights (LW) of 37·1 and 86·4 kg, respectively.Effluents H and VH had higher ammonia N: total N and lower amino acid N: total N and lactic acid contents than effluent N. The rates of LW gain, feed conversion ratios, backfat thicknesses and the proportions of lean and fat in the ham joint were similar for the control diet and effluent diets N and H, indicating a similar nutritive value for all three. Effluent diet VH gave a significantly (P < 0·01) reduced rate of LW gain and poorer feed conversion ratio than diets N and H. While diet VH was consumed reluctantly with widespread refusals (mean refusal 28 g DM/kg DM offered), the feed refusals together with the lower lysine and threonine contents of the effluent would not have produced the observed degree of deterioration in growth and feed conversion. Possible reasons for the lower nutritive value are undetectable wastage of feed or the presence of an antinutritional factor in effluent VHG, or a combination of both factors.
Effects of competition with weeds on the growth, development and yield of sorghum
Authors: Everaarts A. P. 
Published: March 2009

SUMMARYIn two field experiments in Suriname, competition between weeds and sorghum (Sorghum bicolor(L.) Moench) was studied in the rainy seasons of 1982 and 1983. The crop was kept either weed-free or without weed control for each of six different periods of time from planting. Observations made at the end of each period allowed an analysis to be made of the growth and development of a crop with and without weed control.Due to the crop canopy structure and fertilizer placement near the row, weed growth was concentrated in the rows. Starting atc.20–30 days after planting, competition with weeds reduced ground-cover and leaf area index of the crop. Competition reduced growth rates, leading to lower yields. Plant population density was not affected, but competition reduced the number of leaves present. Stem length initially increased with competition in one season, but was retarded in another. Competition for nutrients was strong and was found as early as 15 days after planting. Nitrogen was the element most competed for initially. Competition for water occurred, but competition for light seemed unlikely. About 20 weed-free days after planting were necessary to avoid yield losses and around 30 weed-free days to attain negligible weed growth at harvest. Yield reduction was mainly due to a decrease in number of grains per panicle. Competition during floret establishment (c.30–40 days after planting) should be avoided.
The influence of spring nitrogen on yield, yield components and glucosinolate content of autumn-sown oilseed rape (Brassica napus)
Authors: Bilsborrow P. E. , Evans E. J. , Zhao F. J. 
Published: March 2009

SUMMARYThe response of low glucosinolate, low erucic acid (double low) cultivars of oilseed rape to spring nitrogen application was examined at Cockle Park, Northumberland in three successive seasons (1987–90). Seed yield and protein content increased in response to increasing nitrogen application. In each season over 85% of the maximum recorded yield was obtained with an application of 150 kg N/ha. In the absence of spring nitrogen, seed yield varied considerably over the three seasons. The variation in seed yield and protein content between 1987/88 and 1988/89 can partly be explained by differences in the availability of soil nitrogen in the different seasons. Seed glucosinolate concentration was significantly increased withnitrogen applications between 0 and 150 kg/ha. Increasing nitrogen beyond 150 kg/ha hadlittle or no effect on seed glucosinolate concentration. The results are examined with reference to the varying effects of increasing nitrogen application rates on seed glucosinolate concentrations reported previously.
Comparison of seasonal patterns of growth, voluntary feed intake and plasma hormone concentrations in young sambar deer (Cervus unicolor) and red deer (Cervus elaphus)
Authors: Semiadil G. , Barry T. N. , Muir P. D. 
Published: March 2009

SUMMARYDuring 1991/93, young sambar (5 months old) and red deer (7 months old) were confined indoors in individual pens in New Zealand and fed a pelleted concentrate diet (12 MJ ME/kgDM; 2·9% N) ad libitum for 21 months. Seasonal patterns of voluntary feed intake (VF1), liveweight gain (LWG), scrotal circumference and plasma concentrations of prolactin (PRL), luteinizing hormone (LH), testosterone (T) and progesterone (P) were compared using five stags and three hinds of each species.Red deer showed a strong pattern of seasonality, with high VFI and LWG in summer and low VF1 and LWG in winter and with peak plasma T and scrotal circumference in stags in early autumn. Compared with red deer, sambar showed weaker seasonal patterns of VFI and LWG, with maximum values in autumn and minimumvalues in spring. Over a complete 12-month cycle, sambar deer gained similar amounts of liveweight to red deer but consumed substantially less feed, thus demonstrating a more efficient conversion of feed tobodyweight. Metabolizable energy (ME) requirements for both maintenance and gain were substantially lower for sambar than for red deer. Scrotal circumference and plasma T values in sambar stags attained their highest values during late autumn, winter and spring, but with a lower magnitude than peak values for red stags. Plasma PRL concentrations were seasonal in both species, with highest values in summer and lowest values in winter. Rapid increase of plasma P was first detected in red hinds in autumn and sambar hinds in spring when they weighed 96 and 90 kg respectively, and were aged 17 and 14 months. Rapid increase of plasma T was first detected in red stags in early autumn and sambar stags in mid-autumn whenthey weighed 117 and 101 kg, and were aged 16 and 15 months respectively.It was concluded that sambar deer had endogenous cycles of VFI, body growth and hormone secretion, which were of lesser amplitude and with different seasonality from those of red deer. Young sambar deer were more efficient feed converters than red deer, and attained sexual maturity at an earlier age and lower liveweight.
Pasture renovation: interactions of vegetation control with slug and insect infestations
Authors: Barker G. M. 
Published: March 2009

SUMMARYIn a field trial at Rukuhia, New Zealand, ryegrass (Lolium perenneL.) and white clover (Trifolium repensL.) seed was direct drilled into pasture (i) without herbicide suppression of the resident sward, (ii) with banded application of glyphosate or paraquat herbicide at drilling to remove 50% of the resident sward and (iii) after complete removal of the grass and weed components of the old sward with glyphosate or paraquat before drilling. These treatments were compared with the untreated old swards. Where the old sward was removed by herbicide before drilling, pests moved onto the drilled seedling rows, but, where herbicide was sprayed in bands over the drill rows, the pests remained in or moved into the residual bands of the old sward. Significant beneficial interactions between herbicide use and in-furrow applications of molluscicides and insecticides resulted in reductions in the numbers of pests on the seedling rows. The influence of vegetation control on the pest burden is discussed in the context of current pasture renovation practices.
Effects of cypermethrin + dimethoate and extracts of Piper guineense and Azadirachta indica on the pests and yield of cowpea, Vigna unguiculata
Authors: Ivbijaro M. F. , Bolaji O. O. 
Published: March 2009

SUMMARYField trials were conducted in 1988 at the University of Ibadan to determine the effects of cypermethrin + dimethoate (Sherpa Plus®), the oil extract from ripe seeds of Piper guineense Schum & Thonn and the aqueous extract of ripe seeds of Azadirachta indica A. Juss on the pests and yield of cowpea. Cypermethrin + dimethoate was consistently superior to all other treatments in substantially reducing the population densities of Megalurothrips sjostedti Trybom and of Maruca testulalis Geyer, which are serious pests on flowers and buds, and in reducing the densities of four pod-sucking bugs. Pest population densities were also reduced by foliar sprays with A. indica or P. guineense extracts.Seed yield after treatment with cypermethrin + dimethoate was 0·99 t/ha, more than double the yield from other treatments. A marginal increase in seed yield compared with the control was achieved by foliar spraying with A. indica extract.
Effects of late-autumn fertilizer dressing on accumulation of photosynthates in tea (Camellia sinensis) and its contribution to spring tea quality
Authors: Shen Y. , Yang X. , Xie X. 
Published: March 2009

SUMMARYTwo-year-old tea bushes were given NPK fertilizer on 12 November 1986 and 14CO2 on 22–23 December 1986 and 9–10 January 1987. Late-autumn fertilizer dressing stimulated photosynthate accumulation in the whole bush, especially in overwintering leaves and roots. Large amounts of photosynthates in overwintering leaves provide the nutrition required for early spring budding. Lateautumn dressing also accelerated the transport of photosynthates from leaves to roots in winter, where photosynthates, with absorbed nitrogen, synthesized more animo acids, especially theanine and phenylalanine. The re-use of photosynthates stored in the roots of the dressed bushes during shoot growth the following spring was also facilitated by late-autumn dressing. The contents of amino acids and caffeine in the shoots of dressed bushes were much higher than those in the control, whereas the content of polyphenol was lower than in the control. The results indicate that late-autumn dressing improves the quality of spring green tea.
Effects of plant population density and rectangularity on the growth and yield of poppies (Papaver somniferum)
Authors: Chung B. 
Published: March 2009

SUMMARYGrowth, yield and incidence of lodging of poppies were studied in Tasmania at 10–200 plants/m2 and at nominal rectangularities (within-row: between-row spacing) ranging from 1:1 to 10:1. In 1983/84 and 1988/89, there were asymptotic relationships between plant population density and both total dry-matter production and total head (capsule plus seed) yield at maturity. In 1983/84, a season with above-average wind, the incidence of lodging increased as density increased to > 50 plants/m2; morphine concentration decreased as density increased to > 100 plants/m2. This resulted in parabolic relationships between yield of erect (machine-harvestable) heads and yield of morphine from erect heads with plant density, the maximum morphine yield from erect heads being achieved at 70 plants/m2. In 1988/89, a season with below-average wind, the effects of lodging were less severe at high densities and the components of ‘erect’ yield were adequately fitted by an asymptotic function. Rectangularity of 1:1 gave higher total dry matter production, total head yield, yield of erect heads and morphine yield from erect heads than 4:1 and 10:1. Since calm conditions similar to those of 1988/89 occur only once in every 4 years, growers should be encouraged to establish c. 70 plants/m2. As most commercial crops in Tasmania are drilled in 150–175 mm rows, growing at 70 plants/m2 to maximize the effect of plant density would also approximate to the ideal rectangularity (2:1 in this case).
Rumen fill, forage palatability and alimentary behaviour in sheep
Authors: Baumont R. , Seguier N. , Dulphy J. P. 
Published: March 2009

SUMMARYFive sheep were fitted with rumen cannulas and fed once daily ad libitumat 09.00 h with a low-quality mixed-grass hay or a good-quality lucerne hay. The effects of a second amount of the same hay or of the second hay distributed at the end of the large meal following the morning distribution, when rumen fill reaches its daily maximum, were investigated for feed intake, alimentary behaviour and rumen fill. The second distribution induced a true meal (200–400 g dry matter intake), except in the case of mixed grass offered after lucerne. On the basis of initial eating rate and the amount ingested, the highest palatability was for lucerne offered after mixed grass, and the lowest for mixed grass offered after lucerne. Diet selection was more pronounced with lucerne than with mixed grass, as indicated by the larger decrease in the neutral detergent fibre content of the fraction ingested. The true meals following the second distribution were associated with an increase in rumen fill up to 10% of the daily maximum observed without the second distribution. However, rumen fill with lucerne remained 1 kg lower than with mixed-grass hay, even after a second meal. It is concluded that the sensory response induced by a distribution of a sufficiently palatable hay is able to override the satiety signals due to rumen fill, and that there is a permanent balance between the stimuli related to the characteristics of the food available and those related to reticulo-ruminal digesta.
Oviposition deterrence and ovicidal properties of some plant powders against Callosobruchus maculatus in stored cowpea (Vigna unguiculata) seeds
Authors: Ofuya T. I. 
Published: March 2009

SUMMARYPowders made from 15 plant species were tested in the laboratory against C. maculatus on stored cowpea seeds. Fewest eggs were laid on seeds mixed with Nicotiana tabacum powder. Few eggs were also laid on seeds mixed with powders obtained from Erythrophleum suaveolens and Ocimum gratissimum. N. tabacum powder, followed by E. suaveolens powder, was the most effective in reducing egg hatch.
Storage root quality in sugarbeet in relation to nitrogen uptake
Authors: Pocock T. O. , Milford G. F. J. , Armstrong M. J. 
Published: March 2009

SUMMARYThe relationships between the amounts of nitrogen fertilizer applied and taken up by sugarbeet crops and the concentrations of sugar and α-amino-N in the storage root were examined using data obtained from fertilizer-response trials on different soils in the UK and Belgium between 1974 and 1985. On unmanured mineral soils, crop uptakes of N without fertilizer ranged from 65 to 190 kg/ha and increased linearly with the amount of fertilizer N applied. On organic soils or mineral soils that had received large applications of organic manure, crop uptakes of N were very large (295–383 kg/ha) and were not increased by applications of fertilizer N.The amino-N contents of harvested beet increased with crop N uptake. The distributions of crop N to the storage root and of storage-root N to amino-N differed, especially in manured, diseased and drought-affected crops. Greater proportions of crop N were present in the storage roots of manured crops than in conventionally fertilized crops, and more of the storage-root N was present as amino-N in crops affected by virus yellows or drought than in healthy, unstressed crops.The fresh weight concentrations of sugar in the storage root also differed between sites and years but were not consistently reduced by applications of fertilizer N at individual sites. However, when compared across sites, concentrations were negatively correlated with crop N uptakes and the amounts of N in storage roots. This was because particular crops grown on mineral soils with large applications of manure or on organic soils had large N uptakes and exceptionally low concentrations of sugar.The physiological implications of these relationships between N uptake and amino-N and sugar accumulation are discussed.
Response of maize to copper and sulphur in tropical regions
Authors: Ojeniyil S. O. , Kayode G. O. 
Published: March 2009

SUMMARYField studies were conducted in order to determine the components of yield and response of maizeto soil applied copper and sulphur in the rainforest-savannah transition zone and Guinea savannah zone of Nigeria. Five CuO treatments, 0, 1, 3, 6 and 9 kg/ha, were applied to maize in 1988–90, and grain yield was consistently and significantly increased by the 1 kg/ha CuO treatment. Five S treatments, 0, 10, 20, 40 and 80 kg/ha, were applied to maize in 1989–90, and all treatments increased grain yield significantly in 1989, but only the 10 kg/ha S treatment increased grain yield significantly in 1990. Higher amounts of applied S increased leaf S significantly in the Guinea savannah zone.
Effects of modified circulating prolactin levels on seasonal wool growth in Romney ewes
Authors: McCloghry C. E. , Foldes A. , Rintoul A. J. , Maxwell C. A. , Hollis D. E. , Baker P. J. , Kennedy J. P. , Wynn P. C. 
Published: March 2009

SUMMARYThe study investigated the effects of chronic elevation or suppression of circulating prolactin levels on seasonal wool growth in Romney sheep. Ewes (n = 10/group) were housed indoors under natural lighting (latitude 34 °S) and received either 50 mg bromocriptine i.m./ewe/28 days (Group B), 1 mg spiperone s.c./ewe/day (Group S) or no treatment (Group C) commencing in summer. Wool growth and liveweight were measured every 4 weeks and venous blood samples were collected for prolactin determination. Plasma prolactin levels (mean±s.E.) in Group C exhibited a gradual seasonal decline from 121±29 ng/ml to 35±9 ng/ml. Bromocriptine suppressed prolactin levels rapidly from a pretreatment value of 118±2 ng/ml to below 12±7 ng/ml for the duration of the study. Prolactin levels in Group S were not significantly higher than Group C, with the exception of the first 14 days following the initial treatment. A seasonal reduction in wool growth of c. 25% was observed in all groups; however, no significant treatment effect was evident. Mean liveweight of all animals increased from 50·4±0·8 to 56·8±0·7 kg during the study. These results indicate that perturbation of the annual cyclic secretion of prolactin does not affect wool growth in the Romney ewe.
Effects of previous crop, sowing date, and winter and spring applications of nitrogen on the growth, nitrogen uptake and yield of winter wheat
Authors: Milford G. F. J. , Penny A. , Prew R. D. , Darby R. J. , Todd A. D. 
Published: March 2009

SUMMARYMultifactorial experiments at Rothamsted Experimental Station in two contrasting seasons, 1985/86 and 1986/87, tested the effects of treatment combinations that varied the supply of nitrogen at important stages of crop development in autumn and spring on the grain yield and nitrogen content of September- and October-sown winter wheat. Treatments that altered the nitrogen supply in autumn were an application of winter fertilizer N and sowing the wheat after rape or oats, which left different amounts of residual N. These were combined with treatments which tested the effects of 200 kg N/ha in spring applied as early or late dressings and as single or divided dressings. The effect of applying an additional 50 kg N/ha in summer was also tested in 1985/86.In both experiments, larger yields were obtained from sowing in September than in October. The September-sown wheat grew better over winter in 1986/87 than in 1985/86 but the early advantage in size and N uptake resulted in enhanced production of straw rather than grain. Residues of N from previous crops were smaller after oats than rape in both years. This difference in soil N did not affect the over-winter growth and N uptake of the October-sown wheats. Neither this difference in residual N nor an application of fertilizer N in winter affected the yield of the following September-sown wheat in 1985/86 because autumn growth and N uptake were restricted by adverse weather. In 1986/87, however, wheat that followed oats yielded 0·42 t/ha less grain than wheat that followed rape, and the deficit in yield was removed by an application of fertilizer N equivalent to the deficit in soil N.Yields were decreased when the spring N was applied as a delayed, single dressing in April especially if the wheat was sown in September after oats, or was not given winter N. Yields were not affected by any of the other combinations of single v. divided dressings or early v. late applications of spring N, despite these being given at very different stages of apical development.The percentage of N in the harvested grain was greatly increased by winter applications of fertilizer N, especially to wheat grown after oats, by applying the spring N as a late, single dressing and, in 1986, by applying N in summer.