bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects and Interactions of ‘Package Deal’ Inputs on Yield and Labour Demand of Maize
Authors: Baker E. F. I. 
Published: October 2008

SUMMARYEffects of sowing dates, population, fertilizer, weeding and variety inputs on yield were measured, as well as labour required to apply the inputs. Sowing date was the most important, response to others being dependent upon this factor. Population was least important, but increased in value as fertilizer level was raised. Labour requirements were so increased by applying the ‘package’ that subsistence farmers, whose families are fully occupied as the sole source of labour, would be unable to cope without reducing the area under cultivation. Thus yield response to a package must be higher than hitherto considered acceptable, and the risk of not obtaining this increase probably contributes to the rejection of such recommendations by subsistence farmers.
Evaluation of Yield, Variability and Quality of Sweet Potato Cultivars in Sub-Tropical Australia
Authors: Huett D. O. 
Published: October 2008

SUMMARYThe yield, variability and quality of 16 sweet potato cultivars, harvested after 21 weeks growth, were evaluated in sub-tropical Australia. The coloured-flesh cultivars L8-92, Centennial, HAC-Pink, Copperskin Goldrush and Nemagold produced yields of marketable storage roots in excess of 19,000 kg ha−1, which was three to four times the yield of the local commercial cultivar, White Maltese. The high variability in mean yield per plant of all cultivars offers scope for selection within cultivars. Those with a deep orange flesh and high soluble solids content, i.e. L8-92, Copperskin Goldrush and Centennial, were preferred by members of a taste panel. A high carotene cultivar L8-92 has the greatest commercial potential because it produced the highest yield of marketable storage roots and had the highest taste panel rating for eating quality of stored roots.
Genotype-Environment Interactions in Wheat: Effects of Temperature on Coleoptile Length
Authors: Bhatt G. M. , Qualset C. O. 
Published: October 2008

SUMMARYTemperature effects on coleoptile development were studied in 18 genotypes of spring and semi-winter wheats, illustrating a simple experimental approach for choosing genotypes and management practices that would minimize genotype–environment interactions for stand establishment.
Manifestations of Heterosis in Grain Sorghum
Authors: Kambal A. E. , Abu-El-Gasim E. H. 
Published: October 2008

SUMMARYThe magnitude of heterosis for 15 characters was studied in ten sorghum hybrids, produced by crossing ten restorer varieties with male-sterile Combine Kafir 60 as a common female parent. The most evident expressions of heterosis were higher yield and increased vegetative growth, often associated with delay in flowering. The increase in yield of the hybrids over their superior parents, ranging from 35 to 238%, resulted mainly from an increase in number of grains per head, rather than from an increase in the weight of individual grains. The regressions of hybrids on male parents, and the correlations of yield with other characters were studied, and the prospects of producing adapted hybrids for the Sudan are briefly discussed.
Chemical Weed Control in Groundnuts in the Kenana Area of the Sudan
Authors: Hamdoun A. M. 
Published: October 2008

SUMMARYHerbicides tested at Kenana Agricultural Research Station (K.A.R.S.) from 1968 to 1972 showed that pre-emergence application of oxadiazon, nitrofen, linuron, phenobenzuron, prometryne, nitralin, diuron and fluorodifen gave satisfactory weed control. Applications of oxadiazon at 2·38 kg/ha, fluorodifen at 7·14 kg, nitrofen at 4·76 kg and nitralin at 3·8 kg had no adverse effect on growth of groundnuts, but prometryne, diuron, phenobenzuron and linuron at relatively lower rates caused phytotoxicity symptoms. Residues from treatment with 7·14 kg fluorodifen, 2·38 kg oxadiazon and 4·76 kg alachlor did not injure test crops, but growth of sorghum and maize was reduced 9 months after applying 3·8 kg nitralin. Phenobenzuron was persistent in soil and most test crops were injured following an application of only 1·9 kg.
Relative Efficiency of the Randomized Complete Block Design
Authors: Abou-el-Fittouh H. A. 
Published: October 2008

SUMMARYThe efficiency of the randomized complete block design, relative to the completely randomized design, is linearly expressed as: Relative efficiency=A+CF, where A and C are constants determined by the number of treatments (t) and blocks (b) and F=calculated F value for blocks in the ANOVA table. For values of t and b ranging from 2 to 10 the constants A and C are estimated. Curves of relative efficiency are given when o≤F≤10 for t values ranging from 2 to 10 when b=4, 6 and 8.
Effect of Split Application on N Uptake by Wheat from N15 Labelled Ammonium Nitrate and Urea
Authors: Hamid A. , Sarwar G. 
Published: October 2008

SUMMARYThe effect of split application of N on the uptake of N by wheat from N15 labelled ammonium nitrate and urea was studied in the field. Nitrogen fertilizers were applied at 120 kg N/ha in a single application (at seeding); two split applications (at seeding and tillering); and six split applications (at seeding, tillering, boot, heading, flowering and the milky stage). Nitrogen applied in two splits was most productive for grain yield for both the N sources, but six split applications significantly increased the protein content in grain compared with single or two split applications. The utilization of N from ammonium nitrate in grain was significantly higher than from urea when applied in six split applications.
Chemical Preservation of Partially Dried Potato Pulp
Authors: Lacey J. , Pirie N. W. 
Published: October 2008

SUMMARYMechanically dehydrated potato pulp containing up to 50% dry matter was stored, without visible deterioration, for up to 25 weeks after treatment with at least 0·3% of propionic acid. Wetter pulps required more acid for satisfactory preservation. Thorough mixing was important if maximum storage periods were to be achieved. Ammonia was less satisfactory as a preservative. No visible deterioration occurred while ammonia vapour was present, but bacterial growth was still found even after the addition of about 0·7% ammonia to pulp containing 40–45% dry matter.
Methods of Bringing Tea into Bearing in Relation to Water Status During Dry Weather
Authors: Carr M. K. V. 
Published: October 2008

SUMMARYDespite large visual differences in size and form of shoot and root systems of young clonal plants and of older seedlings, there was no convincing evidence that tea plants, brought into bearing by pegging, are necessarily more susceptible to water stress than similar plants that have been pruned, though the sap tension in pegged plants of one clone was often greater than in similar pruned plants. Further studies are needed to show whether this is the case in drier areas, but differences in responses to dry conditions by individual clones appear to be of greater significance.
The Stability of Rice Yields in Sri Lanka
Authors: Ganashan P. , Whittington W. J. 
Published: October 2008

SUMMARYThe stabilities of plant height and yield for rice varieties grown in Sri Lanka were calculated by regression analysis. High yields were produced by both stable and unstable varieties in the wet season, but in the dry season high-yielding varieties tended to be of above-average stability. The yield of the newer, shorter varieties exceeded those of older varieties except at low nitrogen levels, and the new varieties were of above-average stability.
Population × Environment Interactions in Maize Trials and their Implications on Testing Procedures
Authors: Obilana A. Tunde , Fatunla Tunde 
Published: October 2008

SUMMARYThe important interactions in a 2-year maize trial were population × location, location × year and population × year × location, and our analyses suggest that eight locations, two years and three replications will allow the detection of a 5% differential in yield. The most effective way of obtaining the true value of a variety is by increasing the number of years, and the least effective is by increasing the number of replications. Since locations can be effectively substituted for years, increasing the number of locations will expedite the release of improved cultivars.
Leaf Fall in Cassava
Authors: Rosas C. , Cock James H. , Sandoval G. 
Published: October 2008

SUMMARYTrials on leaf abscission of cassava led to the conclusion that the leaf lamina is necessary, and must receive light, to prevent abscission of the petiole. The abscission rate of old leaves is increased by the presence of an active apex, but is not affected by the carbohydrate requirements of the roots.
Effects of Grain Formation on Dry Matter Distribution and Forage Quality in Maize
Authors: Bunting E. S. 
Published: October 2008

SUMMARYPost-anthesis trends in yield and forage quality of dry matter in components of the maize shoot were studied in experiments with barren and fertile plants grown at 10 plants/m2. In fertile plants, which had a maximum shoot DW 6 or 7% higher than barren ones, the stems (including leaf sheaths) yielded 5 t/ha (42% shoot DW) 30 days after flowering, declining to 3·5 t/ha (26% DW) at final harvest 60 days later. During this period the ear increased by more than 4 t/ha, from 23 to 50% of shoot DW, whereas in barren plants there was little change in DM distribution, with the stem representing about 48% shoot DW, leaf and husk together 40–45% and the ear (rachis only) less than 10%. DM percentage of shoots was similar in barren and fertile plants until maximum DW was attained about 60 days after flowering, after which fertile plants dried more rapidly. In vitro dry matter digestibility was as high in barren as in fertile plants, and the analytical data on forage quality do not suggest that it was positively associated with grain content.
Effects of Rate and Time of Nitrogen Application on Yields of Cotton in Northern Nigeria
Authors: Smithson J. B. , Heathcote R. G. 
Published: October 2008

SUMMARYTrials to determine the optimal rate and time of nitrogen application to cotton were conducted at three sites for three seasons. The results indicate that nitrogen is used most efficiently when applied at relatively low rates, with at least half the application delayed until flowering. Early application leads to the incorporation of a greater proportion of the nitrogen into the vegetative structures which, at lower rates, may leave insufficient for fruit development. With late application a greater proportion of the nitrogen is utilized in reproductive growth, although full utilization may not be achieved at higher rates.
Research-based Recommendations versus Farmers' Practices: Some Lessons From Cotton-Spraying in Malawi
Authors: Farrington John 
Published: October 2008

SUMMARYThe discrepancy between farmers' performances and research-based recommendations in the control of cotton pests in Southern Malawi is discussed. Analysis of the former in two seasons revealed that the farmers' low levels of insecticide application approached the economic optimum, whereas several factors of economic importance were omitted from the research-based justification of high spraying levels. Recommendations for improving the applicability of research recommendations to smallholder farming are made, with particular reference to the farming risks that arise from uncertain rainfall, the wide range of farming ability encountered in practice, and the dangers of atypically high levels of management in research experiments.
Influence of Plant Density and Nitrogen on Yield and Milling Quality of Lowland Rice in Nigeria
Authors: Fagade S. O. , Ojo A. A. 
Published: October 2008

SUMMARYIn experiments conducted with three rice varieties at different plant populations and N levels, the non-lodging varieties responded to 150 kg N/ha. The highest yield in non-lodging varieties were at the highest transplanted density, but at the lowest density in the lodging variety. The percentage of total milled rice of all varieties was not significantly affected by N application, which improved head-rice recovery in chalky IR-8, but had no significant effect on non-chalky varieties. Competition for nutrients could be a major factor limiting head rice return at high densities.
Short-term Prediction of Cotton Yields in the Sudan Gezira
Authors: Bartsch Reinhart 
Published: October 2008

SUMMARYThis paper attempts to determine the relations between weather and cotton yields in the Gezira Scheme in the Sudan, and to establish a prediction function with climatic factors as variables. The precision of the function established to forecast the final yield in April will as yet be low, when based on the information available at the end of October, November or December. A significantly better yield forecast can be made at the end of January. Variables of the prediction function are temperature, humidity, radiation and evapotranspiration. A strategy is proposed to improve early forecasts step by step, by making further forecasts at later stages.
The Effects of Plucking Policies on the Yield of Tea in Malawi
Authors: Palmer-Jones R. W. 
Published: October 2008

SUMMARYThere have been conflicting reports of the effects of different plucking (harvesting) policies on yields of tea in Malawi. An experiment is reported which separates the effects of plucking round length from those of plucking standard, and is compared with the results of simulating those plucking policies. Between the experiment and the simulation the conflict is resolved, and the validity of the experiment and simulation model are thereby enhanced. The immediate practical implications of the work are limited because of the unquantified relations between plucking standard and quality and grade out-turn of made tea.
Effects of Dated Soil Moisture Stress on Crop Yields
Authors: Nairizi S. , Rydzewski J. R. 
Published: October 2008

SUMMARYCrop yield response to soil moisture deficiency varies for different crops and also depends on the time of its occurrence in the growth cycle. Many attempts have been made to derive a single relationship between total water consumption and yield for various crops, but this has proved of limited use, because the effect of time was omitted from such production functions. Jensen (1968) derived two expressions, for determinate and indeterminate crops, bringing the time element into his expressions indirectly by a parameter (λi) which defines the relative sensitivity of the crop to soil moisture stress at different growing stages. The usefulness of this approach depends on the accuracy with which this parameter can be determined. The aim of this paper is to derive λi for a number of crops from available experimental data and subsequently to find a way of computing the quantitative contribution of each single irrigation application to the crop yield. This should lead to a more rational use of irrigation water resources.
Combining Ability and Rank Correlations in a Diallel Cross of Indian Mustard (Brassica juncea)
Authors: Asthana A. N. , Pandey V. K. 
Published: October 2008

SUMMARYA diallel cross study on Indian mustard revealed a preponderance of additive gene action for seven characters out of the nine studied. Plant height and seeds per siliqua seemed to be controlled by both additive and non-additive gene action. Days to flower, number of secondary branches, length of main branch, number of siliquae on the main branch, length of siliqua and yield per plant were mainly controlled by additive gene action, whereas oil content was determined mainly by non-additive gene action. Heterosis was prevalent and the maternal effect was not generally apparent in the crosses. Rank correlations established a positive correlation between performance per se and GCA, and between heterosis and SCA.
Plant Husbandry and Management Techniques for Growing Grain Legumes Under Simulated Tropical Conditions in Controlled Environments
Authors: Summerfield R. J. , Huxley P. A. , Minchin F. R. 
Published: October 2008

SUMMARYPractical solutions are described to problems incurred in growing cultivars of cowpea, soyabean, lima bean and pigeon pea under simulated tropical conditions in controlled environments, namely (a) ‘Saxcil’ growth cabinets in which daylength, day and night temperatures, light intensity and quality, relative humidity and CO2, concentration are precisely controlled and can be varied over time; (b) compartmentalized glasshouses and adjoining dark compartments where daylength, and day and night temperatures are automatically controlled and night-break illumination can be provided, and (c) heated plastic film houses in which daylength-insensitive tropical legumes can be grown to maturity during the UK summer months since the environment of the wet tropics can be simulated in all respects other than daylength.
Agronomy of Linseed Oil Cultivars (Linum usitatissimum) in Northern Nigeria
Authors: Yayock J. Y. , Quinn J. G. 
Published: October 2008

SUMMARYForty-six cultivars of linseed oil (Linum usitatissimum L.) were grown under wet and dry season conditions in the Sudan Savanna of Nigeria. Only during the dry season was production good and cv Dunes consistently outyielded all other cultivars in terms of seed and oil content. Trials of sowing dates gave maximum seed yield and oil content from plots sown during late October. In row spacing trials, rows 15–22 cm apart and seed rates of 58–78 kg/ha were found to be the most practicable. There was a linear relation between increasing rates of nitrogen and seed yield, maximum production being obtained at 55–88 kg N/ha, but oil content was slightly depressed at levels above 33 kg N/ha.
Storage of Fresh Cassava (Manihot esculenta). II. Simple Storage Techniques
Authors: Booth Robert H. 
Published: October 2008

SUMMARYThe development of two simple techniques, box storage and field clamps, which allow curing and storage of fresh cassava roots for 1 and 2 month periods, is described. Consistent and acceptable results have been obtained following storage of roots in boxes packed in moist but not wet sawdust and kept at ambient temperatures. The design of field clamps that maintain internal temperature below 40°C, to allow successful curing and storage, varies in different seasons. Storage life of roots is enhanced by the selection of roots in good condition, and any delay in placing the roots in storage results in poorer out-turns.
Nitrogen Nutrition of Cowpea (Vigna unguiculata). I. Effects of Applied Nitrogen and Symbiotic Nitrogen Fixation on Growth and Seed Yield
Authors: Summerfield R. J. , Dart P. J. , Huxley P. A. , Eaglesham A. R. J. , Minchin F. R. , Day J. M. 
Published: October 2008

SUMMARYEffectively nodulated cowpea plants, grown in pots without applied nitrogen, were vegetatively equal to non-nodulated plants supplied with 60 ppm N throughout growth (88 days) and produced significantly greater seed yields. Supplying non-nodulated plants with 120 or 240 ppm N improved seed yields (but not significantly) compared with plants completely dependent on symbiotic fixation. Nodulation promoted branching, and improved pod set and/or retention compared with plants relying on applied N.
Effects of Monocrotophos on Insect Damage and Yield of Cowpea (Vigna unguiculata) in Southern Nigeria
Authors: Dina S. O. 
Published: October 2008

SUMMARYThe effect of one, two or three applications of monocrotophos at 1120 g ai/ha at weekly intervals was determined on cowpea var. Ife Brown. All regimes were equally effective in grain production in early 1974 but spray applications 35 and 42 days after planting gave the best result in the late crop. Grain production from two applications was not significantly different from three applications in 1975. The control plots in the late season of both years failed, due to moisture stress and lack of pest control measures. It is considered that two sprays at flowering is adequate to forestall a crop failure in this variety.
Studies in Mixed Cropping. I. Seasonal Differences in Relative Productivity of Crop Mixtures and Pure Stands in the Kenya Highlands
Authors: Fisher N. M. 
Published: October 2008

SUMMARYAn experiment is described in which the productivity of maize–bean and maize–potato mixtures in alternate rows was compared with pure stands of the component species in four cropping seasons. In seasons with low rainfall, yield from the mixtures fell short of that from pure stands, but in one exceptionally wet season a yield advantage was found for maize–bean mixtures. The poor performance of mixtures in low rainfall seasons appeared to result from large reductions in maize yield attributable to competition from the potato or bean. In the one high-rainfall season, no such reduction in maize yield occurred. An implication of these findings for farming systems with mixed cropping is discussed.
Diallel Analysis of Genetic Variation in Pigeon Pea (Cajanus cajan)
Authors: Dahiya B. S. , Brar J. S. 
Published: October 2008

SUMMARYA diallel analysis of flowering time, pod number, 100-seed weight and yield of six cultivars ofCajanus cajan(L.) Millsp. was studied. Additive inheritance was important in determining flowering time, but the dominance component was higher than the additive component, and over-dominance was observed for pod number, 100-seed weight and yield. Heritability estimates for all the traits except flowering time were quite low, and the bulk population method of breeding was suggested for early segregating generations. The graphical analysis of the diallel cross was in close agreement with the findings from variance component analysis. It is suggested that the best cross would be that between two parents chosen on the basis of their low g.c.a. for flowering time and their high g.c.a. for other traits.
Factors in a Package of Practices for High-production Maize in Northern Nigeria
Authors: Taylor B. R. 
Published: October 2008

SUMMARYIn trials over 2 years at five locations in Northern Nigeria single inputs were removed from a package of maize practices. The improved variety was most important and increased the yield of the otherwise complete package by 86%. Early sowing and high plant population were not important in all trials. The high fertilizer treatment (125–50–50 kg NPK/ha) consistently exceeded the half rate, with a mean increase of 31%. It was suggested that, with clean weeding, priority should be given to the improved variety, high fertilizer and early sowing. High populations, involving changes to traditional techniques, may be introduced gradually.
The Sulphur Nutrition of Coconut
Authors: Silva M. A. T. De , Anthonypillai Greta M. , Mathes D. T. 
Published: October 2008

SUMMARYThe sulphur content in the sixth leaf from the apex of coconut palms was found to be the most sensitive index to sulphur treatments. Although the S concentration in this leaf correlated negatively with applied levels of S, the response curve was concave. Sulphur treatments increased the total yield of fruits and weight of copra, but decreased the weight of kernel per nut. The derived curve for yield versus S concentration in the tissue was C-shaped, attributed to growth dilution effects caused by enhanced initial growth following the restoration of a nutrient in minimum.
Some Useful Equations for Biological Studies
Authors: Landsberg J. J. 
Published: October 2008

SUMMARYThe properties are discussed of a number of relatively simple equations that describe non-linear relations of the type which frequently occur in biology. Most of the equations can be linearized by applying simple transformations (e.g. logy, log (a–y), I/y) to either y or x, or both. Some approximate methods of fitting the equations to experimental data are given, but statistical methods are not discussed in any detail.