bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Choice of Fixed or Variable Stocking Rates in Grazing Experiments
Authors: Wheeler J. L. , Burns J. C. , Mochrie R. D. , Gross H. D. 
Published: October 2008

SUMMARYPasture experiments may be grazed using either variable (put-and-take) or fixed stocking rates. Considerations such as the risks of introducing bias, the reliability of the data, and the resources required for these methods of grazing are discussed, and criteria are described for choosing between the methods.
Effects of Fertilizers on Harvest Time and Yield of Cowpeas (Vigna unguiculata) in Sierra Leone
Authors: Godfrey-Sam-Aggrey W. 
Published: October 2008

SUMMARYEffects of fertilizers on harvest time and yield of cowpeas were studied on upland soils in Sierra Leone. In a 25 confounded factorial trial, on soil which had been cropped successively with 2 years of Smooth Cayenne pineapples and 14 months of cassava, the treatments did not affect harvest time significantly, but N, P and NP Mg produced very favourable effects on grain yields. In a randomized complete block experiment on soil previously cropped with two successive cassava crops, there was a significant difference in total yield of dry pods between the control and most treatments.
Effects of CCC and Moisture Stress on Sunflower
Authors: Lovett J. V. , Campbell Desnee A. 
Published: October 2008

SUMMARYGrowth of the sunflower cultivar Peredovic was examined when exposed to periodic severe moisture stress, with and without soil drench application of CCG at the two-leaf stage. The experiment was conducted in sand culture under partly controlled environment conditions. Morphological and physiological measurements were made throughout the growing period. Amongst the responses to CCC were increased stem and petiole width, and decreased length of internodes, head diameter and photosynthetic area. Moisture stress reduced photosynthetic area and the root/shoot ratio. Both CCC and moisture stress increased the number of stomata per unit area.
Effects of Date of Sowing on Photosensitive Nigerian Sorghums
Authors: Andrews D. J. 
Published: October 2008

SUMMARYTall Nigerian Farafara and a dwarf line selected from the cross Combine Kafir 60 × Farafara were compared at Samaru in eight weekly sowings in 1969, which was a wet year, and 1970 which was rather dry. Whereas the dwarf line always gave more grain yield, its advantage over Farafara, and the effect of early sowing on its yield, were greater in the wetter year. In both varieties the date of flowering seemed to be determined mainly by photoperiod, but there was also a small but clear effect of sowing date.
Improving Precision of Cocoa Progeny Trials Using Calibrator Trees
Authors: Lockwood G. 
Published: October 2008

SUMMARYIn nine breeding trials with cocoa in Ghana the experimental trees were interplanted with temporary trees of a standard variety as ‘calibrators’. The calibrators were removed after 2–2½ years before there was strong competition with the permanent trees. Trunk diameters of the calibrators were used as covariates in analyses of trunk size and yield of dry cocoa up to 7 years after planting, giving reductions in standard errors of differences between progenies of up to 25% in analyses of size and 15% in analyses of yield.
Uptake of N, P and K by Irrigated and Unirrigated Pearl Millet (Pennisetum Typhoides)
Authors: Gregory P. J. 
Published: October 2008

SUMMARYUptake of nitrogen, phosphorus and potassium was measured for irrigated and unirrigated crops of pearl millet grown at Hyderabad, India. Irrigation slightly increased the concentration of nutrients in the crop and this, together with a higher dry weight, resulted in the nutrient content at harvest (day 82) being approximately twice that of the dry crop. Nutrient uptake by the latter ceased at about day 40 whereas the irrigated crop continued to take up nutrients for a further 7–21 days. However, both crops showed the importance of redistribution of nutrients from leaves and stems during the grain filling. The mean rate of nutrient uptake per metre of root per day (inflow) fell throughout growth in contrast with the rate of nutrient uptake per plant, which reached a maximum at about days 26 to 33. These findings are discussed in relation to possible strategies for fertilizer placement.
Timing the Application of N to Maize in Sierra Leone
Authors: Haque I. 
Published: October 2008

SUMMARYTwo experiments were conducted on timing the application of N to maize on Njala upland soils in Sierra Leone. Application of all the N (urea) at planting or thinning gave lower leaf N values and relatively poor yields compared to split applications. Lower grain yields in the minor season might have been due to poor and inadequate rainfall. Basal application of SCU does not seem to release enough N for maximum grain yield of maize. Total N (urea) in the major and minor seasons may be phased in two splits, viz. ½ N 30 DAP + ½ N 50 DAP or ⅓ N at planting + ⅔ N 25 DAP, respectively.
Effects of Viruses (SPVD) on Growth and Yield of Sweet Potato
Authors: Hahn S. K. 
Published: October 2008

SUMMARYSweet potato (Ipomoea batatas L.) virus disease (SPVD) causes severe disease symptoms of various combinations of leaf strapping, vein-clearing, puckering and stunting. The disease is widespread, especially in Africa, and yield is adversely affected, though there are no figures to quantify this effect nor is it known how yield is affected. Loss of tuberous root yield due to SPVD was studied in sweet potato showing symptoms of the disease. Slips were obtained from plants with and without symptoms and two yield trials in 2 years were conducted by planting them alternately in rows. Yield of fresh tubers was reduced by 78% in plants showing SPVD symptoms but the reduced chlorophyll level of diseased leaves did not appear to affect yield.
Effects of Continuous Fertilizer Use on a Ferruginous Soil (Haplustalf) In Nigeria
Authors: Singh L. , Balasubramanian V. 
Published: October 2008

SUMMARYIn a long-term fertility study it was observed that judicious use of chemical fertilizers maintained the levels of soil pH, total N, organic C, CEC and exchangeable Ca. Highest accumulation of exchangeable Ca and Mg was found in the 40–60 cm layer. Absence of Mg and K from the fertilizer schedule resulted in a decrease in the amounts of those elements in the soil. Profile CEC and exchangeable Ca were not affected much by the application of K or trace elements. Compared with adjacent grass fallow or virgin bush land, only the values of C/N ratio, CEC and exchangeable Mg decreased on cultivation. All the crops responded well to fertility levels but not to K; trace element response was confined to cotton and groundnut.
Inoculation of Soyabeans (Glycine max) In Israel with Rhizobium Japonicum
Authors: Okon Y. , Volfovitch M. , Henis Y. , Pinthus M. J. 
Published: October 2008

SUMMARYNo natural population of Rhizobium japonicum specific for soyabeans (Glycine max L.) could be found in any soil type in Israel. A crop of 5450 kg seed/ha was obtained in a field of sandy soil, inoculated with commercial granular inoculant, by maintaining soil at a moisture level near to field capacity during the growing season. In another field, on heavy soil inoculated with different strains of R. japonicum, the highest yield was obtained with strain 31-SM, a mutant derived from strain 61A75. Nitrogen fixation, as measured by the acetylene reduction method, was highest with strain 31-SM. Under local conditions soyabean plants snowed 100% nodulation when inoculated by the slurry method, by granular inoculant or by spraying bacteria into the furrow.
Simplified Growth Analysis of Non-climbing Dry Beans at Three Spacings in the Tropics
Authors: Kueneman E. A. , Wallace D.H. 
Published: October 2008

SUMMARYGrowth characteristics of dry bean genotypes of determinate (Type I), indeterminate small vine (Type II), and indeterminate large vine (Type III) types were evaluated over three spacings and two growing seasons. Important observations include: (1) Type I did not give increased yields in response to planting rows closer together in Trial II because there was a large decrease in harvest index, which did not occur for Types II and III; (2) accumulation of reproductive nodes prior to anthesis is important for high yields, as are biological yield, harvest index and leaf area; and (3) within-habit spacing combinations, factors such as flowering duration, branch-, leaf- and raceme-numbers, and stem length could not be used to predict yield.
Planting Date, Insect Damage and Yield of Cowpea in Western Nigeria
Authors: Nangju D. , Nwanze K. F. , Singh S. R. 
Published: October 2008

SUMMARYWith the exception of leafy and daylength-sensitive cultivars, cowpea (Vigna unguiculata (L.) Walp), produced larger yields in the first season (April-July) than in the second season (September-November) at Ibadan, Western Nigeria, whether or not the crop was protected by insecticide. The populations of major cowpea pests were low at the start of the rainy season and reached their peaks in September or October. The implications of these results in insect control strategy are discussed.
Effects of Harvesting Policy and Nitrogen Application Rates on the Production of Tea in Central Africa. I. Yield and Crop Distribution
Authors: Cloughley J. B. , Grice W. J. , Ellis R. T. 
Published: October 2008

SUMMARYThree levels of N were imposed on mature Indian hybrid tea and green leaves were harvested according to different plucking standards at either 7 or 14-day intervals throughout the main production period. Larger rates of N and less selective plucking standards improved the fresh weight of shoots harvested but dry matter yields were less and the proportions of waste fibre in the finished product were increased. Thus, saleable black tea production was less responsive to N and plucking standard and the order of combined treatment effects was altered. Plucking interval did not affect yield but it changed the distribution of the crop in time. A 7-day interval gave the most uniform crop. These data are discussed in relation to the economics of tea production in Central Africa.
Green Revolution Methodology in Nigeria
Authors: Waterworth J. V. 
Published: October 2008

SUMMARYThe implementation of a ‘Green Revolution’ programme in Nigeria, known as the National Accelerated Food Production Project, was linked with earlier programmes in other countries derived from CIMMYT and IRRI and with a previous FAO Fertilizer Programme in Nigeria. The methodology was based on ‘minikit’ demonstration trials on farmers' fields. Details are given of the the forms used in the field and plot size, number and choice of treatments and subsequent package demonstrations, and production kits are discussed.
Photosynthesis inCoffea arabica. I. Effects of Light and Temperature
Authors: Kumar D. , Tieszen Larry L. 
Published: October 2008

SUMMARYPhotosynthetic rates of coffee plants grown under the full sun and shade were compared. The saturating irradiance of 300 μE−1m s−1of shade plants shifted to near 600 μE in sungrown plants, but shade plants possessed substantially higher photosynthetic rates. Photosynthetic rates decreased above 25°C, which was apparently due to a decline in the mesophyll conductance, as stomatal conductance remained more or less unchanged between 25° and 35°C. Most of these measurements were made on seedlings in plastic bags. It is concluded that coffee is more suited to high density plantings where mutual shading, resulting in low light intensities and lower leaf temperatures, are likely to produce a favourable environment for efficient photosynthesis and growth.
Photosynthesis in Coffea arabica. II. Effects of Water Stress
Authors: Kumar D. , Tieszen Larry L. 
Published: October 2008

SUMMARYExperiments were carried out to relate soil moisture to leaf water potential (Ψ1), and to determine the effects of varying Ψ1, on leaf conductances and photosynthesis in coffee. Stomatal conductance was maximum at 0900 h, but plants growing in drier soil showed marked mid-day stomatal closure. After 1500 h, stomata began closing although plant water status improved. Photosynthesis in relation to changing Ψ1 appeared to exhibit roughly three different rates. At the fixed experimental temperature (25°C) low Ψ1 reduced photosynthesis throughits influence on stomata, but under field conditions low Ψ1 and an accompanying rise in temperature could lower the rate by lowering both mesophyll and stomatal conductances.
Effects of NPK Fertilizers on young Coconut (Cocos nucifera) on a Sandy Soil in Sri Lanka
Authors: Loganathan P. , Balakrishnamurti T. S. 
Published: October 2008

SUMMARYIn a 4 × 4 × 4 NPK field experiment with coconut on a sandy soil, N increased girth, height and leaf production during the pre-bearing period, but phosphorus (up to 6½ years) and K (up to 3½ years) had no effect on any vegetative growth parameters. The rates of fertilizers for optimum copra and nut yield (13 to 16 years) were 0.35, 0.73 and 0.64 kg N, PO and KO/palm/ year respectively. The high P requirement was due to the low solubility of the saphos phosphate in these sandy soils. A positive N × P interaction was also observed.
Tree Development, Yield and Leaf Nutrient Levels of Old-clone Lemon Trees on Eight Rootstocks
Authors: Levy Yoseph , Shaked Abraham , Ashkenazi Sam 
Published: October 2008

SUMMARYThe effects of rootstock on tree development, leaf nutrient levels and yields of two old-clone lemon cultivars, Eureka and Villafranca, were studied. The largest canopy development and yields were obtained on Alemow and Volkameriana; red rough lemon failed due to foot rot; Rangpur lime trees were severely stunted; and Citremon induced high chloride and relatively low boron contents in the leaves.
Dry-season Legume Forages to Follow Paddy Rice in N. E. Thailand. II. Soil Fertility and Planting Methods
Authors: Shelton H. M. 
Published: October 2008

SUMMARYResults clearly demonstrate that Crotalaria juncea (sunnhemp) is well adapted to the dry season paddy environment; peak dry matter production was 3170 kg ha−1 in a field experiment with rows 30 cm apart and 100 kg−1 ha of seed. A pot experiment gave yield responses of 179 and 16% to P and S application respectively but there was no response to fertilizer in the field. Cultivation increased DM production in one experiment from 86 to 1590 kg−1 ha, attributed to a reduction in bulk density from 1·65 to 1·19 g cm−3. This effect was not fully substantiated in a second experiment on a coarser soil, where good DM production of sunnhemp was achieved even on broadcast uncultivated plots. The toxicological implications of using sunnhemp as a forage legume are briefly discussed.
Adjustment by Neighbouring Plots in Progeny Trials with Cocoa
Authors: Lockwood G. 
Published: October 2008

SUMMARYIn Ghanaian cocoa progeny trials plot values were adjusted by covariance on neighbouring plots. Standard errors of differences between progenies were usually reduced by 10% and often by over 20% when covariates were formed from the residuals of neighbouring plots and analyses were iterated using successive improved estimates of treatment effects to derive fresh residuals. The method gave larger reductions in error and was effective over a wider range of variates than adjusting on early growth data from interplanted temporary trees of a standard variety.
Evaluation of Yield Stability in Intercropping: Studies on Sorghum/Pigeonpea
Authors: Rao M. R. , Willey R. W. 
Published: October 2008

SUMMARYData from 94 experiments on sorghum/pigeonpea intercropping were examined for evidence that the stability of yield is greater with intercropping than sole cropping. Stability of the major component (sorghum) was examined by calculating the distribution of yields; stability of the overall intercropping system was examined by calculating coefficients of variation, by computing regressions of yield against an environmental index, and by estimating the probability of monetary returns falling below given ‘disaster’ levels. All these approaches have some merit; taking the last as an example, it was found that for a particular ‘disaster’ level quoted, sole pigeonpea would fail one year in five, sole sorghum one year in eight, but intercropping only one year in thirty-six. Intercropping gave yield advantages under a wide range of environmental conditions and there was no significant evidence that advantages were greater under stress. This is discussed in relation to possible mechanisms contributing to greater yield stability.
A Competitive Ratio for Quantifying Competition Between Intercrops
Authors: Willey R. W. , Rao M. R. 
Published: October 2008

SUMMARYA simple competitive ratio (CR) is proposed as a measure of intercrop competition, to indicate the number of times by which one component crop is more competitive than the other. Intercropping data show that this CR term could be useful in (i) comparing the competitive ability of different crops, (ii) measuring competitive changes within a given combination, (iii) identifying which plant characters are associated with competitive ability, and (iv) determining what competitive balance between components is most likely to give maximum yield advantages.
Effects of Pre-Sowing Flooding, Rainfall, Irrigation and Surface Drainage on Sesame in the Central Sudan Rainlands
Authors: Hack H. R. B. 
Published: October 2008

SUMMARYSesame was grown in four seasons in which differences in the distribution of the rains and treatments of pre-sowing flooding, irrigation during crop growth and surface drainage resulted in contrasts in soil water content and crop development. In wet years pre-sowing flooding, absence of surface drainage and premature irrigation gave 32–37% decreases in yield. In a season of low rainfall prevention of surface run-off and one later irrigation gave, in the absence of pre-sowing flooding, a 43% increase in yield over that from plots irrigated only at sowing and with surface drainage. Agronomic applications are discussed.
Estimating Leaf Areas of Cowpea and Soyabean Using Dry Weights of Terminal Leaflets
Authors: Nangju D. , Wanki S. B. C. 
Published: October 2008

SUMMARYLeaf area index is an important parameter in many agronomic and physiological studies, but its determination in cowpea (Vigna unguiculata) and soyabean (Glycine max) is difficult and time consuming. A simple and rapid method is described in which dry weights of the middle leaflets were used to predict leaf areas of cowpea and soyabean. This method was based on results which indicated that leaf dry weights were highly correlated to leaf areas and that the ratio between leaf area of the terminal leaflet and total area of a trifoliate leaf was constant, at least in some cultivars, giving ratios of 0.37 for cowpea and 0.33 for soyabean.
Effects of Seed Carriers on Seedling Establishment after Fluid Drilling
Authors: Darby R. J. 
Published: October 2008

SUMMARYSix products possessing suitable physical properties as fluid carriers for pre-germinated seed were assessed for their effects on seedling emergence. Both glasshouse and field experiments measured the carriers' performance on eight crop species at varying extrusion rates and under different environmental conditions. Synthetic clay or polyacrylate increased seedling emergence by 10% compared with the sodium alginate control. Seedling emergence was least affected by moisture stress when synthetic clay was used as the carrier.
Varietal Response of Cowpea to a Range of Densities in a Forest Zone
Authors: Remison S. U. 
Published: October 2008

SUMMARYCowpea cvs Ife Brown and New Era were sown at a wide range of densities in 1976 and 1977 (early season) at Ibadan in the rainforest zone of Nigeria. In 1977 (late season), the experiment was modified and Ife Brown and Vita 5 were used. All the cultivars were indeterminate. Grain yields were higher at lower densities, especially in 1977 (late season). Numbers of leaves, branches and pods were also inversely related to density, but there were differences between varieties in flowering, branching and leaf and pod production.
Dry-season Legume Forages to Follow Paddy Rice in NE Thailand. III. Influence of Time and Intensity of Cutting on Crotalaria juncea
Authors: Kessler C. D. J. , Shelton H. M. 
Published: October 2008

SUMMARYAn experiment at the University of Queensland studied the response of Crotalaria juncea to a single cut above node 4 or 10 at 6, 8 or 10 weeks after planting under long or short (inductive) daylengths. Initial deleterious effects of cutting on plant parts were in the sequence nodules > roots > shoots. Subsequent greater regrowth from plants cut earliest and at the higher node was associated with higher residual leaf area and negative growth rates were inferred below 90 cm2 pot−1. Redistribution of assimilate from stem to leaf production followed cutting; in inductive daylengths of 11.4 hours, flowering was delayed and the proportion of leaf increased from 21.0 to 32.4%. The high nitrogen content of leaf (3.5–5.3%) compared to stem (0.6–1.7%) indicated that early cutting was important in producing good quality hay.
The Concept of a ‘Land Equivalent Ratio’ and Advantages in Yields from Intercropping
Authors: Mead R. , Willey R. W. 
Published: October 2008

SUMMARYCriteria for evaluating different intercropping situations are suggested, and the Land Equivalent Ratio (LER) concept is considered for situations where intercropping must be compared with growing each crop sole. The need to use different standardizing sole crop yields in forming LERs is discussed, and a method of calculating an ‘effective LER’ is proposed to evaluate situations where the yield proportions achieved in intercropping are different from those that might be required by a farmer. The possible importance of effective LERs in indicating the proportions of crops likely to give biggest yield advantages is discussed.
Growth, Longevity and Nodulation of Roots in Relation to Seed Yield in Chickpeas (Cicer arietinum)
Authors: Minchin F. R. , Summerfield R. J. , Hadley P. , Roberts E. H. 
Published: October 2008

SUMMARYFactorial combinations of three daylengths (11, 12 and 15 h), warm and cool days (30° and 22° C) and warm and cool nights (18° and 10°C) were imposed on nodulated plants of three chickpea cultivars grown in pots in controlled environment growth cabinets. The treatments had large effects on growth, phenology and seed yield and no single environmental regime was optimal for all successive stages of development. Root growth and nodulation were extremely responsive to the environment experienced by the shoot. Conclusions are drawn on the potential contribution of these data to the development of empirical screening techniques suitable for large, segregating populations in field programmes devoted to the production of chickpea cultivars better adapted to their intended environments.
Relations Between Growth Parameters in Oil Palm Seedlings Grown in Polybags
Authors: Lucas E. O. 
Published: October 2008

SUMMARYThe relation between some growth parameters in polybag oil palm nursery seedlings were assessed. ‘Non-destructive’ parameters such as leaf number, seedling height and girth were highly and positively correlated with one another and with the dry weight of seedlings. Amongst the ‘destructive’ parameters only leaf area, height/weight ratio and fresh weight were positively correlated with dry weight. The Leaf Area Index was poorly correlated with other parameters examined. The relevance of these findings to the selection of oil palm seedlings for transplanting into the field is discussed.