bluuebunny/crossref_metadata_2025_split huggingface dataset:
The evaluation under grazing of legumes associated with Andropogon gayanus in a tropical savannah environment on the central plateau of Brazil
Authors: Thomas D. , de Andrade R. P. 
Published: March 2009

SUMMARYThe persistence and productivity under grazing of seven accessions of Stylosanthes macrocephala, Zornia latifolia and Zornia brasiliensis in combination with Andropogon gayanus (cv. Planaltina) were investigated in small plots at two stocking rates on a low fertility, acid oxisol in the tropical savannah of the centre-west region of Brazil.Two new accessions of S. macrocephala CIAT 2039 (CPAC 1033) and CIAT 2053 (CPAC 1034) were more productive and persistent than the control cultivar Pioneiro. After 4 years there were no differences in dry-matter yield between the two accessions. No anthracnose (Colletotrichum gloeosporioides) problems were noted in these accessions. Animals refused to graze Z. brasiliensis accessions at any time during the trial. Stocking rate effects became pronounced over time and legume contents were highest in the treatment grazed at 3·0 animals/ha. The advantages of the small-plot grazing method used in the experiment are discussed.
Progress achieved by breeding open-pollinated cultivars as compared with landraces of sorghum
Authors: Blum A. , Golan G. , Mayer J. 
Published: March 2009

SUMMARYTo assess the progress made in modern breeding of open-pollinated sorghum cultivars, 24 contemporary and improved sorghum cultivars from ICRISAT (International Crops Research Institute for the Semi-Arid Tropics, India) were compared with 40 sorghum landraces collected in Ethiopia. The experiment was performed at Bet Dagan, Israel, in 1988 under near-potential (dripirrigated) and dryland (stored soil moisture) growing conditions. Data on phenology, biomass, harvest index, grain yield and its components were collected. ‘Drought susceptibility index’ (S) was calculated for each genotype as the reduction in yield from irrigated to dryland conditions relative to the mean reduction for all genotypes.On average, cultivars produced about three- to fourfold more grain than landraces. Cultivars had the same mean growth duration and biomass but were 40% (irrigated) to 27% (dryland) shorter in mean plant height than landraces. This yield advantage was fully accounted for by a proportionately greater mean kernel number per panicle and harvest index, irrespective of the water regime. ‘Drought susceptibility index’ was near average for all cultivars and much more variable among landraces. Dryland yield became progressively dependent on the yield potential as the yield potential was genetically improved in the cultivars.It was concluded that, irrespective of the water regime, the large yield improvement in modern open-pollinated cultivars of sorghum, as compared with landraces, has been achieved only through greater dry matter partitioning to the panicle accompanied by a reduction in plant height. The genetic improvement of yield in open-pollinated cultivars and hybrids of sorghum is discussed.
Effect of green manuring with dhaincha (Sesbania aculeata) on growth and yield of direct-sown and transplanted rice under intermediate deepwater conditions (0–50 cm)
Authors: Sharma A. R. , Das K. C. 
Published: March 2009

SUMMARYIn intermediate deepwater conditions (0–50 cm) at Cuttack, India during 1990 and 1991, rice and dhaincha (Sesbania aculeata) were either mixed-sown in different arrangements (parallel lines and mixed broadcasting) in dry soil by the end of May or rice seedlings were transplanted in plots grown with pure dhaincha after the accumulation of water in the field by mid-July. Incorporation of dhaincha in situ after 48 and 54 days of growth added 60·8–65·2 and 72·9–76·9 kg N/ha in the mixed stands compared with 81·3 and 85·1 kg N/ha in the pure stand in 1990 and 1991 respectively. Although the growth of rice when sown simultaneously with dhaincha was affected initially due to the more vigorous growth and shading by the latter, tillering of rice increased after the incorporation of green manure following an increase in inter-row spacings. The performance of the direct-sown and transplanted rice was similar in 1990, when the water level rose relatively slowly, but in 1991 the transplanted crop yielded significantly less due to the sudden accumulation of water to higher depths (48 cm), resulting in greater mortality of seedlings at planting. However, the grain yield of both directsown and transplanted crops increased with dhaincha green manuring compared with the control (no application of dhaincha) and was equal to the application of 40 kg N/ha applied as urea fertilizer. The highest yield was obtained when rice and dhaincha were grown at a 2:1 ratio in 20 cm wide rows and the clonal tillers uprooted from the adjoining rice rows were planted in lines vacated by dhaincha. The yield was, however, equal to that from treatments where rice and dhaincha were grown in alternate rows at 15 cm spacing or mixed broadcasting. Increase in yield under green manuring was due to greater panicle weight, which was probably due to a continued supply of N following decomposition of organic matter added through dhaincha. Therefore, green manuring of direct-sown rice with dhaincha was beneficial for higher crop productivity under excess water conditions.
Evaluation of fatty acids in oil as reaping indices for Caribbean-grown groundnut (Arachis hypogaea)
Authors: Hinds M. J. , Singh B. 
Published: March 2009

SUMMARYStudies were conducted to evaluate amounts of fatty acids in the oil as possible indicators of crop maturity in the groundnut, cultivar NC2, grown in St Vincent, Eastern Caribbean. Percentage fatty acids in oil of the composite samples of seeds collected between 99 and 141 days after planting for a period of 3 years (1985–87) was determined by gas-liquid chromatography. Results indicated variation in the amounts of individual fatty acids with crop maturity. There were definite trends, however, with respect to oleic and linoleic acids. As seeds matured, percentage oleic acid increased and percentage linoleic acid decreased, and consequently, the oleic:linoleic acid ratio in oil of the composite seeds increased significantly. The percentage oleic acid peaked significantly at a value of 55.8 ± 0.59 at optimum harvest dates. The results clearly suggested therefore that percentage oleic acid in oil could be used as a reliable reaping index for groundnut.
The effects of limestone, N, K and Mg fertilizers on Mg absorption by oats and barley
Authors: Alston A. M. 
Published: March 2009

Oats grown in a pot experiment on two sandy loams were sampled at four stages of growth. Neither KC1 nor MgSO4.7H2O had any effect on yield but % Mg and total Mg uptake were consistently decreased by applying K and increased by applying Mg.Ca(NO3)2 increased % Mg more than did (NH4)2SO4, but yield and total Mg uptake were higher where (NH4)2SO4 was applied. The effects of fertilizers were similar on both soils.The effects of applying (NH4)2SO4 and NaNO3 to the soil on % Mg in barley were compared in a field experiment on an acid loam to which several rates of limestone had been applied. Treatments had no effect on the % Mg in grain or straw at maturity. At four earlier stages of growth (NH4)2SO4 increased % Mg in the plants more than did NaNO3. Limestone slightly increased % Mg. Nitrification of NH4 in the soil was rapid.
The effects of grazing intensity on herbage consumption and animal production. I. Short-term effects in strip-grazed dairy cows
Authors: Greenhalgh J. F. D. , Reid G. W. , Aitken J. N. , Florence E. 
Published: March 2009

1. The object of the experiment was to determine the effects of varying the quantities of herbage available to cows on their diet and milk production.2. Four groups of five Ayrshire cows were strip grazed for three periods of 3-4 weeks on areas calculated from sample cuts to supply (A) 25, (B) 35, (C) 45 or (D) 55 lb. dry matter per cow per day. These periods were interspersed between four standard periods of 2-3 weeks, in which all the cows were strip grazed on 50-60 lb. dry matter per head per day.3. Measurements of milk production and of herbage consumption, by the chromic oxide-faecal nitrogen technique, were made for the last 12 or 16 days of experimental and last 8 days of standard periods. The observations made in the standard periods were used as covariates in the analyses of those made in the experimental periods.
Soyabeans in Tanzania. I. The exploitation of hybridization for the improvement of soyabeans
Authors: Auckland A. K. 
Published: March 2009

1. The main objectives of the breeding programme were to develop two types of soyabeans:(a) High yielding, non-shattering, resistant to lodging, determinate in habit, with pods formed 5-6 in. from ground level, for mechanical harvesting.(b) High yielding, non-shattering but with no qualifications as to habit, for hand harvesting by African farmers.An account of the breeding programme carried out on twelve crosses is given. The breeding method used was a combination of the bulk and pedigree methods.
Effects of leaf shear breaking load on the feeding value of perennial ryegrass (Lolium pevenne) for sheep. II. Effects on feed intake, particle breakdown, rumen digesta outflow and animal performance
Authors: Inoué T. , Brookes I. M. , John A. , Kolver E. S. , Barry T. N. 
Published: March 2009

SummaryA series of experiments was conducted at Palmerston North, New Zealand, during 1988–91 to compare the efficiency of chewing during eating and rumination, rumen fractional outflow rate (FOR), voluntary organic matter intake, liveweight gain and wool production in sheep fed either low (LS) or high (HS) leaf shear breaking load perennial ryegrass (PRG). The LS ryegrass had a 13% lower mean leaf shear breaking load and ingestion rates tended to be higher than for HS PRG, but no consistent significant treatment differences were observed in rate of particle breakdown, rumen FOR, voluntary intake or animal performance. It was concluded that selection for reduced leaf shear breaking loadper sedid not improve feeding value. The total shear load required to reduce a unit dry weight of PRG leaf to < 1 mm particles (index of masticatory load; IML) differed by only 3% between LS and HS PRG in this study, due to higher leaf length:dry weight ratios for LS PRG. It is therefore suggested that IML, which takes into account both leaf shear breaking load and associated changes in leaf morphology may be a better criterion for selection than leaf shear breaking load alone in breeding programmes to improve the feeding value of perennial ryegrass.
Effect of non-uniform distribution of particle-associated markers on the measurement of duodenal digesta flow by the double-marker technique
Authors: Faichney G. J. 
Published: March 2009

SUMMARYSimulating changes in the distribution of the particle marker between particle-phase and fluid-phase dry matter by ±40% resulted in calculated flows of dry matter to the duodenum that differed from the ideal of uniform distribution by 1 to 2%; true digesta flow values were virtually unaffected. These errors are small and can probably be ignored.
Hatchability of layers' eggs stored and incubated in different positions at 5500 altitude
Authors: Arif M. , Joshi K. L. , Shah P. , Kumar A. , Joshi M. C. 
Published: March 2009

SUMMARYThe hatchability of layers' eggs stored and incubated in different positions was examined at the Defence Agricultural Research Laboratory, Almora, India (5500' above sea level) in 1990. Hatchability was found to be highest in the eggs stored and incubated with their narrow end up and lowest in eggs stored and incubated horizontally.
Further studies of water use by irrigated and unirrigated Arabica coffee in Kenya
Authors: Blore T. W. D. 
Published: March 2009

1. Frequent soil sampling to 10 ft. depth was carried out on irrigated and unirrigated plots and, with the assistance of rainfall data, fairly accurate measurements of water uso were obtained unless the soil was at, or near to, field capacity. Evapotranspiration could then not bo distinguished from drainage beyond the root range.2. A previous method of relating the water uso of unirrigated coffee to the readings of a sunken evaporation pan was shown to be reliable. The relationships between the water use of unirrigated coffee and meteorological factors (Penman's Eo, sunken pan evaporation or solar radiation) were shown to be dependent on soil-moisturo deficit, and on this basis a more precise method of predicting water use from sunken pan evaporation is proposed. When this method was applied to meteorological data from earlier years, good agreement was obtained between measured and estimated quantities of water in a 10 ft. profile.
Grazed pasture parameters. II. Pasture dry-matter use in a stocking rate and grazing management experiment with dairy cows
Authors: Campbell A. G. 
Published: March 2009

1. Dry-matter intake, pasture utilization and grazing pressure were studied over 3 years on a small-scale replica of a dairy cow grazing management x stocking rate trial.2. The four treatments were:(i) Controlled rotational grazing, light stocking rate (0.95 cow/acre).(ii) Controlled rotational grazing, heavy stocking rate (1.19 cow/acre).(iii) Uncontrolled, set stocked grazing, light stocking rate (0.95 cow/acre).(iv) Uncontrolled, set stocked grazing, heavy stocking rate (1.19 cows/acre).3. Mean D.M. intakes were: (i) 29, (ii) 21, (iii) 28 and (iv) 21 lb./cow per day. D.M. intake was reduced on average by 7 ± 2.1 lb./cow per day at the higher level of stocking.
White clover investigations. III. Effect of irrigation on seed production
Authors: Zaleski A. 
Published: March 2009

During 1962-65 investigation was carried out at Cambridge on the effect of irrigation combined with cutting treatments on vegetative growth, inflorescence formation and yield of seed of S184 white clover sown on gravelly loam of poor waterholding capacity.Under the conditions described, irrigation was beneficial for seed production when it was applied between the period of shutting-up and the start of clover flowering. An excess of water either from natural precipitation or irrigation during the flowering period had, however, a harmful effect on seed production.Apart from the first year, the effect of differential cuttings up to the early bud stage was insignificant on the seed yield. The interaction cutting x irrigation was not significant.The author is grateful to Mr F. R. Home, Director of the National Institute of Agricultural Botany, for opportunities and facilities provided for this experiment.
Competitive ability of maize and common bean (Phaseolus vulgaris) cultivars intercropped in different environments
Authors: Rezende G. D. S. P. , Ramalho M. A. P. 
Published: March 2009

SummarySixteen common bean (Phaseolus vulgaris L.) cultivars with different life cycles and growth habits were intercropped with four maize cultivars, to evaluate the competitive ability of each yield component, following a methodology similar to that used for diallel crosses. The experiments were done in 1991 at two sites in Brazil. The intercropping combinations were evaluated using an 8 × 8 quadratic lattice design with three replications. Two other experiments were done on monocultures, using a randomized complete block design with three replications. The variable considered was ‘maize equivalent yield’, obtained by adjusting for the price difference between the species. The method used showed that the differences in performance of the many intercropped combinations can be explained by ‘general complementing ability’ (gĉa) of each cultivar, since there was no significant effect of ‘specific complementing ability’ (sĉa). The best maize cultivars to be intercropped with common bean (indicated by high gĉa values) were BR–201 and C–525, which produced high grain yields when intercropped without detrimental effects on legume yields. FT–84–292, Carioca 300V and ESAL506 were the common bean cultivars with the highest yields when intercropped, which was also reflected in their good performance in monoculture. Significant cultivar × location interactions occurred only in monocultures, supporting the belief that intercropping is a more stable cropping system.
Inhibition of iron precipitation by humic substances in field drains
Authors: Vaughan D. , Ord B. G. 
Published: March 2009

SummaryFerrous iron is oxidized and precipitated as iron ochre in field drains. In drainage waters taken from an ochre-producing site near Aberdeen, Scotland in 1987, iron deposition was inhibited by the addition of humic and fulvic acids, which form complexes with Fe(II). The inhibition was dependent on the concentrations of soluble humic materials and the proportion of Fe complexed. Iron deposition in the presence of humic substances is discussed in relation to the amount of the cation which is complexed and its oxidation state.
The effect of energy and protein intake on the excretion of purine derivatives
Authors: Susmel P. , Stefanon B. , Plazzotta E. , Spanghero M. , Mills C. R. 
Published: March 2009

SummaryIn three separate experiments, groups of four, three and six mature, rumen-cannulated Simmental cows were fed diets designed to supply different quantities of energy (E) and nitrogen (N) to the rumen microbes. Experiment 1 (straw plus concentrate plus urea) had balanced E and N supplies; Expt 2 (hay and four levels of soyabean meal) had different sub-optimum N levels at the same intake as Expt 1; and Expt 3 (hay plus maize plus two levels of urea) reproduced the N shortage in Expt 2 at a higher level of intake.The amount of total N excreted in the urine (TUN) was 574 mg/kg LW0·75in Expt 1 and 420 mg/kg LW0·75of this N was excreted as total purine nitrogen (TPN). In Expt 2, TUN increased significantly (P< 0·05) with increasing soyabean levels; TPN also increased, reaching the level observed in Expt 1 when soyabean meal supplementation was highest. In Expt 3, TUN and TPN increased with increasing dietary urea concentrations; TUN and TPN were always higher than in Expts 1 and 2.Estimated microbial nitrogen supply (EMNS, based on TPN) was always considerably lower than estimates based on fermentable non-protein OM and crude protein (EMNR-EN) or an assumed yield of microbial N per kg OM apparently digested in the rumen (EMNR-OM). Regression analyses of EMNS on EMNR-EN, EMNR-OM or OM intake had moderater2values (0·76, 0·65 and 0·62 respectively) but the constant terms were significantly different from zero. The regressions of EMNR-EN and EMNR-OM on TPN gave angular coefficients of 15·81 and 11·47 respectively.The correlation between rumen liquid parameters (total count, bacterial DM, ATP and nitrogen) and OM intake, EMNS or EMNR increased with sampling time (from 09.00 to 16.00 h). The EMNR-OM produced correlation coefficients similar to those obtained with OM intake; these correlations were numerically higher than those obtained with EMNS or EMNR-EN.
Influence of dietary supplementation and partial suckling on body weight and on lactation and reproductive performance of primiparous Boran (Bos indicus) cows in Ethiopia
Authors: Tegegne A. , Geleto A. , Osuji P.O. , Kassa T. , Franceschini R. 
Published: March 2009

SummaryThis study was conducted in the central highlands of Ethiopia during 1990–92 to examine the effects of diet and partial suckling on lactation and reproductive performance of Boran (Bos indicus) cows. Primiparous Boran cows were allocated to dietary supplementation or no supplementation with either milking or partial suckling based on body weight at calving. All cows received grass hay ad libitum and the supplemented groups were provided with additional concentrate feed which supplied 222 g/kg DM crude protein and 10 MJ/kg DM energy. Calves were weaned at 8 weeks of age. Mean (±S.E.) dam calving and calf birth weights were 314±11·4 and 25±0·6 kg. Body weights at first postpartum oestrus and at conception were not affected by suckling. Supplemented cows however, were heavier at first oestrus (P = 0·06) and at conception (P < 0·01) than non-supplemented cows. Lactation length was longer (P < 0·01) and mean daily milk yield higher (P < 0·001) in suckled than in milked cows. Diet, however, did not influence either lactation length or daily milk yield. In suckled cows, mean daily milk yield declined sharply after weaning (week 9) and was lower by 38 and 43% of week 8 production in the supplemented and non-supplemented groups, respectively. The overall mean lactation yield was 212·4±64·6 litres; with a significant (P < 0·05) diet × suckling interaction effect. Concentrations of milk fat, total protein and total solids were not affected by either diet or suckling treatment. The postpartum anoestrus interval was longer (P < 0·01) in non-supplemented than in supplemented cows, but did not differ between suckled and milked cows. The percentage of cows cycling by 150 days postpartum was higher (P < 0·05) in supplemented than in nonsupplemented and in milked than in suckled (P > 0·05) cows. By this interval, a higher (P < 0·05) percentage of supplemented-milked (90%) cows cycled than in the other three treatment groups (48·5%). Pregnancy from the first insemination ranged from 45·5 to 63·6% in the four treatment groups. It was concluded that although partial suckling extended the postpartum anoestrus interval, lactation length and milk yield were improved. The negative effects of partial suckling on postpartum reproduction could be overcome with the appropriate dietary supplementation. The economic tradeoff between dietary supplementation, milk yield and reproduction has to be determined in partially suckled cows.
The response to selection of different procedures for the analysis of early generation variety trials
Authors: Cullis B. R. , Gleeson A. C. , Thomson F. M. 
Published: March 2009

SUMMARYA simulation study was conducted to determine the relative response to selection of a one-dimensional spatial analysis of field experiments (SAFE) specifically adapted for early generation trials. The primary purpose of the analysis in these trials is to obtain accurate estimates of genotypic effects of the unreplicated test lines by adjusting for local variation, using either the yields of all neighbouring plots or the yields of neighbouring plots of (replicated) check varieties. The response to selection of the SAFE analysis, relative to the use of unadjusted yields of test line plots, was consistently greater than the relative response to selection of check-plot-only analyses. The relative response to selection of SAFE increased as the percentage of trend variance increased.