bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Duty Experiments with Sugarcane on Two Soils in Natal
Authors: Thompson G. D. , Robillard P. J. M. De
Published: October 2008

The irrigation water treatments in three experiments were based on a ‘water duty’ principle. One cosec of water was assumed to be available to irrigate 96, 211, 326 or 442 acres, representing minimum irrigation cycle times of 5, 11, 17 and 23 days respectively. Each experiment included a rainfed control treatment. The plots were watered as indicated by a soil moisture profit and loss account, but never more frequently than the minimum cycle time would allow. The results showed that maximum productivity could be achieved on a sand when I cosec of water was used to irrigate approximately 200 acres, but on clay maximum productivity was obtained with the largest water duty (442 ac/cusec). Net photosynthetic efficiency reached 3·9 per cent in the most heavily irrigated crops, and rainfall efficiency fell from about 85 per cent for rainfed conditions to about 50 per cent when the maximum amount of irrigation water was applied.
Investigation of Nitrogen Fertilization of Cotton by Tissue Analysis
Authors: Burhan H. O. , Babikir I. A.
Published: October 2008

The concentration of nitrate-nitrogen in cotton petioles was directly related to the rate of nitrogen applied and was greatest at the earliest sampling date, decreasing as the season progressed. There was an increase in the degree of association between the level of nitrogen applied and petiole nitrate-nitrogen, and between petiole nitrate-nitrogen and final yield, up to the time of early flowering, when peak correlation coefficients were reached, after which there was a decline. The level of petiole nitrate-nitrogen showed high positive correlations with the rate of nitrogen application as well as with yield. The final yield showed a significant, positive and linear regression on the level of petiole nitrate at the time of early flowering. A close relationship was also shown to exist between a critical concentration, represented by a narrow range of nitrogen levels in the neighbourhood of 2000 parts per million, and final cotton yield. Yield reductions were related to the number of days petiole nitrogen remained below the critical concentration. The use of petiole analysis as a guide in the nitrogen nutrition of cotton, in the evaluation of various experimental treatments and as an aid in interpreting research results, was demonstrated.
Effects of Growth Regulators on Fruiting and Yield of Black Gram (Phaseolus Mungo, Roxb.) in India
Authors: Mehrotra O. N. , Saxena H. K. , Roy A. N. , Nath Shiva
Published: October 2008

An experiment was conducted in 1964 and 1965 to study the effects of hormone sprays on pod setting, pod filling and grain yield of black gram. Sprays of 2-naphthoxyacetic acid and p-chlorophenoxyacetic acid, alone and in 'mixture, and gibberellic acid and 1-naphthaleneacetic acid increased pod setting, but grain filling in pods and grain size were only slightly improved. 2-naphthoxyacetic acid gave the highest yield, followed by p-chlorophenoxyacetic acid, 1-naphthaleneacetic acid and a mixture of the first two, which increased yield by 56, 39, 36 and 35 per cent respectively over the control and gave economic returns.
Effects of N, P and K on Yields of Cotton in the Sudan Gezira
Authors: Burhan H. O. , Mansi M. G.
Published: October 2008

Effects of N, P and K on yields of cotton were investigated using data obtained over an 18-year period from a factorial experiment comparing various combinations of the three nutrients. The results clearly indicated a significant and fairly consistent response of cotton to the application of fertilizer nitrogen, but the rate of increase in yield with increased N gradually diminished. The response to P was erratic and to K was negligible. The response to N did not vary with levels of P or K. Whether lack of response to P on the alkaline soils of the Gezira was due to sufficient already available in the soil, or because the added fertilizer was fixed and rendered unavailable to the plant needs further investigation. Lack of response to added K was attributed to the high content of available K already in the Gezira soil.
Root Penetration of Smeared Soil Surfaces
Authors: Prebble R. E.
Published: October 2008

Winter wheat seeds were grown on compressed soil (a) with and without smearing, (b) with surface horizontal or at 45°, and (c) with and without a sand cover. Germination was not affected. At a soil suction of 0·1 bar, root penetration of the horizontal surface was decreased by smearing and by absence of an overburden; on a surface of 45° smearing had very little effect. As a general summary of the limited information, root penetration is decreased by 50 per cent for a ten-fold increase in suction above 0·1 bar; the effect of smearing is equivalent to a five-fold increase; and the effect of slope is equivalent to a four-fold decrease.
Foliar Analysis as a Guide to NPK Nutrition of Pineapples in the Forest Zone of Ghana
Authors: Godfrey-Sam-Aggrey W.
Published: October 2008

In a 20 plot experiment with central composite second-order rotatable design, basal non-chlorophyllous sections of “D” leaves of Sugarloaf pineapples were sampled at harvest and analysed for N, P, K. Maximum yield of 17·8 tons per acre of good quality Sugarloaf pineapples and maximum fruit length of 27·4 cm. were associated with the nutrient combination of 36–42–32 lb/acre N P K applied at 4, 6, 11 and 12 months. The nutrient levels in the basal sections of “D” leaves corresponding to maximum fruit yield were 0·35–0·40% N; 0·04% P; 0·44% K; K/P 11·2–11·5: 1. K/P ratio for maximum fruit length was 10·4–11·5: 1. N/K ratio was associated with lodging.
The Foliar Composition of Oil Palm in West Malaysia III. Differences in Leaf Composition Between Fruit Types
Authors: Chin Poon Yew , Varley J. A. , Ward J. B.
Published: October 2008

In an oil palm uniformity trial in West Malaysia leaf samples were analysed and fruit type was recorded. Significant differences were found in foliar composition according to fruit type and it is suggested that this factor should be taken into account, together with other genotypic differences, in using leaf analysis as a guide to the fertilizer requirements of palms.
Viability of Cacao Beans
Authors: Ashiru G. A.
Published: October 2008

The rapid loss of viability in extracted cacao beans prevents long storage or long periods of shipment of selected seeds. Beans partially dried in a stream of carbon dioxide or nitrogen and stored at 25 to 28°C remained viable up to 60 days whereas those dried in air lost viability within 45 days. Storage of artificially dried beans in the absence of air was detrimental to their viability. A moisture content of about 50 per cent gave a high percentage germination within 30 days and reduced deterioration of beans.
Parallel Streak of Sisal (Agave Sisalana) in Kenya
Authors: Pinkerton A. , Bock K. R.
Published: October 2008

Sisal showing symptoms of parallel streak developed more slowly than symptomless plants, both leaf length and number of leaves unfurled being reduced. In streaked areas of the leaf, ground tissues surrounding the peripheral and internal fibre bundles collapsed; decortication of streaked leaves was difficult and fibre quality was adversely affected by reduction in length and discoloration. Parallel streak was seen only in vegetatively propagated Agave sisalana, in leaves lacking marginal spines. The condition was observed only where the mean minimum temperature fell below 16°C; symptoms appeared five months after the onset of a period of low temperature. Apparently every A. sisalana plant in Kenya is affected, but the condition is masked in coastal regions due to high mean minimum temperature. The disease seems not to be due to bacterial or fungal pathogens, or to nutritional factors, but may be caused by a virus, or a genetic ‘disease’ similar to June Yellows of strawberries.
Irrigation and Fertilizer Experiments on Cotton at Mubuku, Uganda
Authors: Rijks D. A. , Harrop J. F.
Published: October 2008

Results from five years trials showed that irrigation was frequently needed to ensure early and adequate germination of cotton, that the use of a water balance to determine time and amount of irrigation was practical and economic, that there was no appreciable effect of fertilizer on yield of seed cotton on these soils, and that there was no significant change in the fertility of the soil after four crops of cotton.
Use of Companion Crops in Grassland Establishment in Nigeria
Authors: Haggar R. J.
Published: October 2008

An experiment is described on the establishment of the grass Andropogon gayanus in the presence of different companion crops. Maize and soyabean proved the most suitable companion crops; mucuna and the annual grass Pennisetum pedicellatum were too competitive. The companion crops significantly reduced weed invasion. The establishment of A. gayanus was improved by early harvesting of companion crops. Dry matter yields were highest where grass had been sown in rows. Inclusion of a companion crop is a promising method of increasing herbage production without harming the establishment of the under-sown seeds.
Multivariate Techniques of Use in Biological Research
Authors: Pearce S. C.
Published: October 2008

Multivariate statistical methods are used increasingly in biological research to investigate the responses of organisms considered as a whole, whereas established statistical methods are usually concerned with measured characteristics considered one at a time. Multivariate techniques are mostly explained in terms of matrix algebra, which is a way of dealing with groups of numbers rather than individual ones. A brief description is given of some elementary results of matrix algebra and a method is presented whereby hypotheses can be generated about interrelations within an organism. Two techniques, principal component analysis and canonical analysis, are described in greater detail. It is emphasized that hypotheses need to be tested even though they have been generated by objective statistical means.
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

Pasture 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

Effects 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

Growth 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

Tall 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

In 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

Uptake 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

Two 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

Sweet 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

In 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

No 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

Growth 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

With 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

Three 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

The 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

Photosynthetic 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

Experiments 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

In 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

The 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

Results 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

In 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

Data 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

A 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

Sesame 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

Leaf 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

Six 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

Cowpea 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

An 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

Criteria 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

Factorial 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

The 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.
Effects of Lime, Drainage, Manganese Dioxide and Seedling Condition on Rice in Acid Sulphur Soil in Brunei
Authors: Williams C. N.
Published: October 2008

Yield of swamp rice on acid sulphur soil was increased by liming and could be related to soil pH but was unaffected by drainage and differences in H2S in the soil. The seedling stage was most sensitive to acid and yield could be dramatically improved by planting mature vigorous seedlings. Survival of seedlings, tillering and panicle formation were the most important yield components affected by liming and acidity. Liming also increased spikelet number and grain size to a lesser degree. The optimal economic lime level for 3-week seedlings was around 4 t/ha but could be lower with 5-week seedlings.
Rainfall Statistics: An Interactive Approach to Analysing Rainfall Records for Agricultural Purposes
Authors: Hills R. C. , Morgan J. H. T.
Published: October 2008

A continuous daily rainfall record provides much information for agriculturalists but initial questions are imprecise and are modified in the light of experience. In order to match this uncertainty the program ‘Rainfall Statistics’ is designed as a simple interactive procedure for studying quantity probabilities, dry spell frequencies and a simple soil-moisture budget. The program has various functions depending upon user requirements. Use of the program is illustrated with rainfall records from northern Thailand.
Block Size and Orientation, and Allowance for Positional Effects, in Field Experiments
Authors: Warren J. A. , Mendez I.
Published: October 2008

A random sample of 13 uniformity trials was examined in terms of sensitivity to choice of block size and orientation. Five trials were classified as insensitive and eight as sensitive. Trials insensitive to blocking choices showed little variation in experimental error for various sizes, shapes and orientations of blocks, but those sensitive to blocking choices showed considerable, sometimes drastic, effects of such choices. There was often an objectionable degree of inflation of experimental error due to large or improperly oriented blocks. It is proposed that the routine analysis of field experiments based on block designs be modified to reveal cases in which ineffective blocks have been used on sensitive sites.
Effects of Planting Date and Mulching on Cowpea in Sierra Leone
Authors: Kamara C. S.
Published: October 2008

The effects of date of planting and soil mulching on cowpea growth and yield were investigated for three years during the middle part of the minor season in Sierra Leone. Mulching at 8 tons/ha conserved more soil moisture than other mulch rates, with greatest difference in the top 15 cm of soil, especially during drier periods. Plant height, pod number and seed yield of cowpea planted in September were significantly greater than from other planting dates whether mulch was applied or not. The beneficial effects of mulching at 8 tons/ha on cowpea growth and yield were more dramatic when the crop received an average weekly rainfall of 100 mm before 50% flowering.
An Improved Small Scale Unit for Extracting Leaf Juice
Authors: Butler J. B. , Pirie N. W.
Published: October 2008

The unit for separating juice from which 5 to 10 kg of leaf protein could be made in a day has been modified so as to make it more efficient and more convenient to use.
Effects of Gypsum and Zinc on Rice Nutrition on Sodic Soil
Authors: Takkar P. N. , Nayyar V. K.
Published: October 2008

A field experiment was conducted on a Zn-deficient highly-deteriorated sodic soil of the Ghabdan series to determine the effect of three rates of gypsum (G0, G25, G50% of the gypsum requirement of soil) and three rates of Zn (Zn0, Zn11, Zn22 kg Zn/ha) on rice variety PR 106. Gypsum application significantly increased yield and Zn uptake in rice because of a significant decrease in soil pH and increase in Ca and Zn supply. Zinc application alone significantly increased soil and plant Zn but yields were poorer than with gypsum application alone because of Ca deficiency/Na toxicity. The same rates of Zn applied together with gypsum markedly increased yield and Zn uptake, revealing a deficiency of both Ca and Zn. The best grain yield was recorded either at G50Zn11 or G25Zn22, indicating an economy in gypsum at higher rates of Zn or of Zn at higher rates of gypsum application.
Effects of Winter Legumes on the Nitrogen Economy and Productivity of Succeeding Cereals
Authors: Ahlawat I. P. S. , Singh A. , Saraf C. S.
Published: October 2008

Results are described of an experiment conducted for 2 years in North-West India where grain legumes increased the N and P status of the soil compared with cereal or fallow. Maize following legumes recorded increases in growth, yield attributes, yield and N uptake. Various winter grain legumes such as chickpea, lentil, pea and Lathyrus sativus reduced the need for fertilizer N in maize to the extent of 18–68 kg/ha compared with cereal (wheat) or fallow. Application of nitrogen to the maize promoted plant growth and increased both yield and N uptake.
A Systematic Design to Examine Effects of Plant Population and Spatial Arrangement in Intercropping, Illustrated by an Experiment on Chickpea/Safflower
Authors: Willey R. W. , Rao M. R.
Published: October 2008

An intercropping experiment is described, using a parallel-row systematic design, to examine four plant populations of chickpea in all combinations with 15 systematically arranged populations of safflower in 1:1 and 2:1 row arrangements; four populations of the sole crops were included. Safflower was usually dominant and increasing the total population (i.e. both crops combined) made it more so. Safflower yield was little affected by changes in its own population and was independent of changes in the chickpea population. Chickpea yield increased with increase in its own population and it was the dominant crop at high chickpea/low safflower populations. An initial increase in safflower population caused an increase in chickpea yield at the 1:1 row arrangement; otherwise increasing safflower population decreased chickpea yield. LERs at 2:1 indicated no real evidence of yield advantages for intercropping. At 1:1 advantages ranged up to 19%, with a maximum where the highest chickpea population was combined with a low safflower one. This optimum combination could not have been identified with earlier designs.
Effects of Weeding and Row Spacing on Sugar Cane at the Kenya Coast
Authors: Abubaker A. S. , Gurnah A. M.
Published: October 2008

Using the sugar cane cultivar Co 421, competition from weeds for the whole growing season was compared at three row spacings with competition for periods ranging from 15–120 days at the start of the season or later, and weed-free conditions all through the season. The critical period for weed competition was the first three months, since weeding during the remaining 11 months did not improve yields, which were similar at row spacings of 1, 1·25 or 1·5 m. There were no interactions between the weeding and spacing treatments.
Physical Measurements in Crop Physiology I. Growth and Gas Exchange
Authors: Monteith J. L. , Gregory P. J. , Marshall B. , Ong C. K. , Saffell R. A. , Squire G. R.
Published: October 2008

Instruments and techniques are described for measuring the interception of light by the canopy of a crop, the CO2 exchange of individual leaves, leaf extension rate, and root distribution. Suitable systems for recording are also reviewed. Names and addresses of manufacturers are cited for a few representative models.
The Use of Saline Groundwater in Arid Areas
Authors: Hallsworth† E. G.
Published: October 2008

An account is given of large-scale trials of the use of saline water for the trickle irrigation of forest trees in the desert areas of Abu Dhabi, in eastern Arabia. Water of salinities up to an equivalent of 16,000 ppm have been used on Casuarine glauca and Eucalyptus camaldulensis. Growth rates ranged from 1.7 m in 7 years on salinities of 16,000 ppm to 10–12 m in 8 years on salinities of 2000–2500 ppm. Trickle irrigation appears to allow the use of more saline water than can be used with other systems, perhaps because plant roots are not subject to the fluctuations in moisture stress that occur under all other systems.
The Banjhi (Dormancy) Cycle in Tea (camellia sinensis)
Authors: Tanton T. W.
Published: October 2008

The ‘banjhi’ or dormancy cycle in free-growing tea trees appears to be the result of an endogenous rhythm. However, in harvested tea apical dominance causes dormant shoots to be produced under conditions favourable to growth, and the synchronized flushing cycle causes periods of apical shoot (active terminal bud) and secondary shoot (dormant terminal bud) production.
Influence of Liming and Soil pH on Sorghum (S. Bicolor) and Groundnut (Arachis Hypogaea) in Acid Tropical Malaysian Peat
Authors: Chew W. Y. , Joseph K. T. , Ramli K.
Published: October 2008

In three field experiments, peat pH increased in parabolic relation to liming at the rate of 0.0544 pH unit/t/ha between 0–40 t/ha lime, but only 0.0224/t/ha between 40–72 t/ha. Groundnut and sorghum seed yield and crop residue also showed parabolic responses to peat pH and liming, but groundnut seed yield correlated poorly with soil pH (r2 = 0.38, P = 0.05), compared with its crop residue as well as with sorghum seed and residue (r2 = 0.75, 0.76 and 0.79, respectively, P = 0.01). Groundnut was generally more tolerant of peat acidity (pH 3.35–3.65) than sorghum, giving higher plant survival in unlimed plots, optimum seed and residue at pH 4.60 compared with 5.70 for sorghum, and reduced responsiveness to pH increase. Seed and residue of both crops decreased with continuous cropping, probably because of increasing pest and disease incidence and depletion of available soil nutrients.
Influence of Liming and Soil pH on Cassava (manihot esculenta) in Tropical Oligotrophic Peat
Authors: Chew W. Y. , Joseph K. T. , Ramli K. , Majid A. B. A.
Published: October 2008

In three field experiments studying the liming needs of cassava on peat, optimum tuber DM was obtained at pH 3.8 and optimum top DM at pH 4.2; liming to higher pH values decreased tuber DM while maintaining top DM. Consequently, the Harvest Index decreased over the whole range of soil pH studied (3.49–5.50). Increases in tuber DM per hectare with liming, and with an increasing growth period, were associated with mean tuber weight (r = 0.86) and with Harvest Index (r = 0.65) rather than with tuber number (r = 0.37).
Physical Measurements in Crop Physiology II. Water Relations
Authors: Squire G. R. , Black C. R. , Gregory P. J.
Published: October 2008

Instruments and techniques are reviewed for measuring the content and potential of water in the soil, the water potential and solute potential of plant tissue, and the diffusive resistance of leaves. Emphasis is placed on difficulties encountered in the field and in the interpretation of measurements. References are given to recent technical papers and reviews dealing with the principles and construction of individual instruments.
Field Plans: Why the Biometrician Finds them Useful
Authors: Ryder K.
Published: October 2008

When agricultural experimenters send data to a statistics unit for analysis, they do not usually include a field plan of the experimental site unless specially requested to do so. But such a plan can be a great help to a biometrician: he can use it to check that the design used in the field was correctly described, and to arrange the plot residuals in the field layout as a way of detecting a fertility trend in the site and of relating anomalous values to particular locations on the ground. This paper gives examples of how a field plan can be used to the benefit of the experimenter.
A Technique for Using Permanent Neutron Meter Access Tubes in Cultivated Soils
Authors: Howse K. R.
Published: October 2008

A technique is described that allows neutron meter access tubes to be reinstated in tilled soil without disturbance below the depth of ploughing or tine cultivation. In a test there was no evidence of greater water movement to depth around reinstated access tubes compared with newly inserted ones.
Effects of Formulation and Method of Applying Gibberellic Acid on Flower Promotion in Cocoyam
Authors: Wilson Jill E.
Published: October 2008

Gibberellic acid (GA) at 1500 ppm, applied as foliar spray or pre-plant soak, effectively promoted flowering in Nigerian clones of the cocoyams Xanthosoma and Colocasia. A foliar spray (technical grade GA) applied with 0.25% surfactant gave better results than with 0.01% surfactant or than a foliar spray of Pro-Gibb Plus (commercial GA formulation). A pre-plant soak of Pro-Gibb Plus was least effective but could be useful in poorly equipped research stations.
Growth and Yield of the Tea Bush
Authors: Tanton T. W.
Published: October 2008

Changes in growth rate of tea shoots cause yield fluctuations between seasons, but the size of the basal shoot population remains constant throughout the year. The proportion of shoots with dormant apical buds does not influence the mean weight of shoots harvested. Models of shoot extension are discussed.
Effects of Urea Spray on Wheat in Iraq
Authors: Seth Jagdish , Mosluh K. I.
Published: October 2008

An experiment on wheat (variety Mexipak) was undertaken for two years at the Experimental Farm to study the effects of soil and foliar application of urea. The results indicated appreciable increases in grain yields due to foliar sprays of urea during both years of the experiment; the spray helped to increase yield-contributing factors such as thousand-grain weight, weight of grains per plant, plant height and dry weight.
The Misuse of Methematicians, Statisticians and Computers in Agricultural Research
Authors: Finney D. J.
Published: October 2008

The paper outlines ways in which agricultural scientists fail to benefit fully from collaboration with statisticians and mathematicians and from the use of computers. These result mainly from misunderstandings and wrong attitudes; the aim here is to correct them by frank examination. A statistician can easily point comment on how his attempts to cooperate with others are rendered ineffective, and many examples are quoted. He must also recognize and seek to correct his own weaknesses; the paper has no intention of minimizing these, though its chief concern is with other matters. The emphasis throughout is on statisticians and mathematicians being collaborators in research, not merely purveyors of specialized services, on computer use being coherently planned, and on scientific management being concerned with priorities.