bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Roguing on Yield and Smut of Sugarcane
Authors: James G. L. 
Published: October 2008

SUMMARYSugarcane yields and smut incidence levels were observed in three successive crops. The effect of pathogen upon host was primarily one of stress, as smut infection was shown to increase sucrose content of cane whilst depressing yields in tonnes of cane per ha. Where infection levels were high, roguing was shown to increase disease incidence. However, smut whip removal was confirmed as the best roguing treatment for commercial fields. Disease control and yield responses related to roguing effort were much better in NCo 376 than NCo 310; and, therefore, continued cultivation of NCo 310 fields with high smut incidence was concluded to be a major hazard to the industry.
Effects of Intercropping Maize or Sorghum with Cowpeas, Pigeon Peas or Beans
Authors: Enyi B. A. C. 
Published: October 2008

SUMMARYIntercropping maize or sorghum with pigeon peas, cowpeas or beans led to a reduction in leaf area indices, fresh weight yield at time of anthesis, straw yield at harvest and grain yield of the cereal crops. In sorghum, pigeon peas and cowpeas had a greater adverse effect on grain yield than beans, but with maize, beans and cowpeas had a more adverse effect on grain yield than pigeon peas. While intercropping maize with either beans or cowpeas decreased total yield of grain (cereal and legume) per hectare, intercropping sorghum with pigeon peas increased total grain yield per hectare.
Towards the Reliable Prediction of Time to Flowering in Six Annual Crops. III. Cowpea Vigna unguiculata
Authors: Ellis R. H. , Lawn R. J. , Summerfield R. J. , Qi A. , Roberts E. H. , Chay P. M. , Brouwer J. B. , Rose J. L. , Yeates S. J. 
Published: October 2008

SummarySix genotypes of cowpea (Vigna unguiculata) of diverse origin were sown on various dates at five locations in Australia in order to provide a range of photothermal environments. Times from sowing to first flowering (f) ranged between 36 d and 145 d; pre-flowering temperature and photoperiod means varied from 15.7° to 29.2°C and from 11.6 to 15.5 h d−1. In five genotypes there was no effect of photoperiod on rate of progress towards flowering (1/f), but the relation between 1/f and mean temperature was always positive. The base temperatures (at which 1/f = 0) varied between 8.1° and 10.4°C. The rankings of parameter estimates among four photoperiod-insensitive genotypes common to this study and earlier research in controlled environments were almost identical, and there was generally good agreement between field observations and predictions from controlled environments once hourly temperatures were used to describe the natural environment. When cowpea plants were exposed to temperatures below 3°C, flowering was delayed beyond expected values, presumably as a result of chilling damage. In one genotype, rate of progress towards flowering was affected by both temperature and photoperiod, and relations between 1/f and the photothermal environment were described by a two-plane linear model of similar form to that determined in an earlier controlled environment study. These latest findings support the utility of such linear models for the prediction of crop phenology in the field and for the genetic characterization of photothermal flowering response in annual crops.
The Effect of Tillage on Topsoil Temperature and Strength in Coarse-grained Sands with Special Reference to a Tied Ridging System
Authors: Vogel H. 
Published: October 2008

SummaryTillage trials on sandy soils in Zimbabwe have shown that sheet erosion from arable fields under a no-till tied ridging treatment is negligible but that the system generates environmental conditions that have an adverse effect on crop potential. Tied ridging improves crop production by preventing waterlogging in high rainfall years and improving rooting depth when adequate water supply prevents soils from setting hard, but it causes high temperatures in the ridges and rapid drying during dry weather, resulting in poor or delayed emergence and thus in low and uneven crop stands. New strategies need to be developed to minimize these effects.
The Effects of Sole and Traditional Intercropping of Millet and Cowpea on Soil and Crop Productivity
Authors: Reddy K. C. , Visser P. L. , Klaij M. C. , Renard C. 
Published: October 2008

SummaryThe after effects of three years' continuous cropping with sole millet, sole cowpea or a traditional millet/cowpea intercrop were compared using five levels of nitrogen fertilizer. The continuous sole cowpea system had reduced the carbon to nitrogen ratio more than the continuous sole millet or the traditional intercrop. The test crop millet yielded much more, and its uptake of nitrogen and phosphorus was greater, when it followed sole cowpea than when it followed sole millet or the traditional millet/cowpea intercrop. The three years' continuous sole cowpea had an effect equivalent to the application of 205 kg N ha−1on the test crop of millet. It also caused the greatest reduction inStrigainfestation in the test crop. It is therefore recommended that cowpea cultivation be increased in the Sahel.
Influence of Tree Training and Plant Density on Yields of an Improved Cultivar of Coffea arabica
Authors: Njoroge J. M. , Kimemia J. K. 
Published: October 2008

SummaryThe effect on Coffea arabica cv. Ruiru 11 of training the trees on a single or two stem system at planting densities of between 1600 and 4800 trees ha−1 during the first production cycle after establishment was studied at three contrasting sites in Kenya. Training tree growth in the two stem system significantly depressed yields from the first two crops at all sites, irrespective of plant density, but yields caught up with the production levels of the single stem system faster in the wetter than in the drier zone. Yields of clean coffee increased with tree density up to 4000 trees ha−1 at all sites, irrespective of tree training method, but increased more slowly at populations of more than 4000 trees ha−1, especially in the drier zone. The proportion of large, grade A, coffee beans was not significantly influenced by the treatments studied.
Propagating Cassava (Manihot esculenta) by Sexual Seed
Authors: Iglesias Carlos , Hershey Clair , Calle Fernando , Bolaños Ana 
Published: October 2008

SUMMARYCommercial cassava production from true cassava seeds (TCS) appears to be a promising option for reducing or eliminating several of the production constraints associated with vegetative propagation. The most important contribution of TCS would be to reduce virus build-up in vegetative material and to resolve the problems of stake storage, low multiplication rate and the long growth cycle. Preliminary results suggest that the root yield potential of TCS is comparable with that of traditional vegetative propagation. Improvements in the capacity of true seed progenies to germinate and establish in the field can be achieved either genetically or through pre-planting seed treatments such as coating the seed with rock phosphate. Development of a successful TCS technology will require a multidisciplinary approach, involving basic studies in cassava breeding, physiology, agronomy, socio-economics and other fields.
Unpacking a Technical Package: Flexible Messages for Dynamic Situations
Authors: Okali C. , Sumberg J. E. , Reddy K. C. 
Published: October 2008

SUMMARYThis paper describes an attempt to develop and evaluate agricultural extension materials that support farmers' use of flexible management strategies. On the basis of experiment station and on-farm research results relating to millet and cowpea intercropping in Niger, a series of recommendations was developed, taking the form of a decision tree. The process of testing this format at the level of field extension agents and the implications of this experience for both research and extension workers are described.
Forage Yield of Sorghum and Winter Clovers as Affected by Biological and Chemical Reclamation of a Highly Alkaline Soil
Authors: Kumar Ashok , Batra Lalita , Chhabra R. 
Published: October 2008

SUMMARYA field experiment was conducted on a highly alkaline soil (pH 10.6, exchangeable sodium 95%) to compare biological reclamation using Leptochloa fusca with chemical reclamation using gypsum. Rice gave satisfactory yields in the first year of gypsum application but sorghum and Sesbania gave extremely poor yields. The yield of Leptochloa was not affected by gypsum application. Trifolium resupinatum yielded more than T. alexandrinum when sown in the winter season. The green forage yield of sorghum was greatest when the sorghum followed Leptochloa grown for two years, with the harvested grass allowed to decompose on the site. The results show that biological reclamation with Leptochloa is a good substitute for chemical reclamation with gypsum.
Sink-Source Relations in Cassava: Effects of Reciprocal Grafting on Yield and Leaf Photosynthesis
Authors: Pellet Didier , El-Sharkawy Mabrouk A. 
Published: October 2008

SUMMARYTwo contrasting clones of cassava (Manihot esculenta) were reciprocally grafted to test the hypothesis that the yield of cassava is limited by the number of storage roots. Effects of the root sink on leaf gas exchange were also tested under field conditions using a portable infra-red gas analyzer. Storage root number and root yield were affected by stock size and root yield was associated with the number of storage roots. The harvest index and sink-source ratio (root numberz/leaf area index) were correlated with root number. A feedback effect of root number on single-leaf photosynthesis was observed in one clone. It is concluded that the number of storage roots may be used as an indicator of sink strength.
The Water Relations of Barley Grown Continually or After Fallow Under Semi-Arid Conditions
Authors: Orphanos P. I. , Metochis C. 
Published: October 2008

SUMMARYGrain barley was grown either continually or in rotation with fallow in a 12-year experiment. Annual rainfall ranged from 120 to 297 mm. As the water requirement of the crop is 240 mm, growth in most seasons occurred under water stress. The amount of water conserved under fallow was only significant (75–100 mm) in three of the 12 years and only once did the water conserved increase barley yield in the following year. The total grain yield over the experimental period was twice as high in the barley–barley sequence as in the barley–fallow sequence.Cultiuo continuo de cebada o después de barbecho
Problems and Perspectives on the Use of a Crop Simulation Model in an African Research Station
Authors: Mbabaliye T. , Wojtkowski P. A. 
Published: October 2008

SUMMARYCrop simulation models have been proposed as tools for the transfer of technology in less developed countries. Using a validation exercise as a framework for evaluation, this study looked at the ease of use of a simulation model in a small African research station. Although the model did not accurately predict grain yield of the local maize hybrid, the procedure did highlight some of the problems involved in applying the model. The constraints to the use of such models at small research stations are discussed and improvements that could facilitate model use are suggested.Uso de model de cultivo para la investigación en Africa
Influence of Nitrogen Application and Stage of Harvesting on the Dry Matter Production of Sorghum Sudanense-Lablab purpureus Mixtures in Central Sudan
Authors: Ibrahim A. E. S. 
Published: October 2008

SUMMARYThe effects of cropping system, nitrogen application and harvesting stage on the quantity and quality of the forage produced by Sudan grass-lablab mixtures were studied in central Sudan. Mixing increased the number of tillers plant-1 of Sudan grass and the plant dry weight of both crops. Application of nitrogen increased the number of tillers and dry weight plant-1 of Sudan grass but had no significant effect on the growth parameters of lablab. Growth parameters of both crops were appreciably increased by harvesting at the milk-ripe stage of Sudan grass. The largest total dry matter yield was obtained from a mixture of 20 kg Sudan grass and 40 kg lablab ha-l, but the largest protein yield was obtained from sole lablab.Nitrógeno en combinaciones de sorgo sudanés y Lablab purpureus
Development of Leaves in Oil Palm (Elaeis Guineensis) and Determination of Leaf Opening Rate
Authors: Breure C. J. 
Published: October 2008

SUMMARYOil palm rachis length was determined on primordia dissected from palms planted at four densities. It started to increase rapidly in leaf–10, that is, about ten leaves younger than the spear leaf in all density treatments. The mean number of leaf primordia at the three higher palm densities was 47.7 compared with 51.5 at the lowest density of 56 palms ha-1. Some of the palms planted at the highest density were thinned to identify the stage at which the amount of light affected the rate of leaf opening. A sudden increment of light accelerated leaf production at both the rapid expansion stage and the preceding slow expansion stage. The greatest acceleration of leaf production began 24 months after thinning, probably because of the effect of the extra light on the rate of leaf initiation. The response of leaf production to thinning may apply to other related cultural practices.Desarrollo de hojas en la palma aceitera(Elaeis guineensis)y determination de la tasa de apertura de las hojas
Evapotranspiration of Onion in Sahelian Niger
Authors: Prashar Chit R. K. , Sharma Govind C. , Gandah Mohamadou 
Published: October 2008

SUMMARYIrrigation responses of three locally adapted onion cultivars were studied in drainage type lysimeters and under field conditions on a deep sandy loam soil, free of salinity problems, at Maradi in Niger. Evapotranspiration (Et) was established by the water balance method, and used to establish the rate of water use. The peak rate of water use was 7.5 mm per day during the bulb formation stage. Irrigating onions when the available soil moisture to a depth of 20 cm had been depleted by 40% increased the yield more than irrigation at 60 or 80% depletion. The mean yield from plots receiving frequent irrigation was 33 t ha−1.Evapotranspiratión de la cebolla en el sahel nigeriano
Selection of Dry Pea (Pisum Sativum) Varieties and their Performance by Comparison with Barley and Wheat in Mediterranean Environments
Authors: Hadjicristodoulou A. 
Published: October 2008

SUMMARYThe possibility of growing dry peas in the semi-arid areas of Mediterranean countries was assessed by comparing dry pea (Pisum sativum L.) varieties with the highest yielding barley and durum wheat varieties under rainfed conditions and with supplementary irrigation in Cyprus. The yield of barley cv. Kantara was greater than that of the best pea variety selected, PS 210713, especially under the driest conditions, but the differences between cereals and dry pea varieties were smaller when grown in areas where there was more rain or where supplementary irrigation was supplied. The protein content of the dry seeds and straw of the peas was higher than those of the cereals. It is concluded that selected varieties of dry peas could be grown in dry Mediterranean areas, particularly in rotation with barley or wheat.Pisum sativum L. para zonas mediterráneas
Non-destructive Measurements of Biomass in Millet, Cowpea, Groundnut, Weeds and Grass Swards using Reflectance, and their Application for Growth Analysis
Authors: Buerkert A. , Lawrence P. R. , Williams J. H. , Marschner H. 
Published: October 2008

SummaryA simple hand-held reflectometer was used to estimate the shoot dry matter of pearl millet (Pennisetum glaucum), groundnut (Arachis hypogaea), cowpea (Vigna unguiculata), weeds and grass swards non-destructively. While the instrument was able to predict shoot dry matter well for single, standing millet and cowpea plants and proved useful for a growth analysis of millet, its reliability was unsatisfactory for groundnut. For millet, the slope of two separate regressions between the difference of reflectance ratios and shoot dry matter, taken 10 days apart, was almost identical. This suggests a possible simplification in future crop growth models. The usefulness of the instrument for estimating dry matter in natural species mixtures such as weeds and grasses depended on the homogeneity of the mixture and the uniformity of their physiological state.Medición de la biomasa utilizando la reflexión
Response of Azolla Caroliniana and Rice to Phosphorus Enrichment of the Azolla Inoculum and Phosphorus Fertilization During Intercropping
Authors: Singh D. P. , Singh P. K. 
Published: October 2008

SummaryThe effects of phosphorus enrichment of Azolla inoculum and phosphorus fertilization during intercropping on the growth, nitrogen fixation and phosphorus content of Azolla caroliniana and the grain yield, straw yield and nitrogen uptake of rice were studied for four consecutive seasons. The phosphorus-enriched Azolla maintained a higher plant phosphorus content and produced a greater biomass and nitrogen yield than the unenriched Azolla. Application of phosphorus during intercropping significantly increased the dry weight, nitrogen yield and phosphorus content of both unenriched and phosphorus-enriched Azolla. The differences between the enriched and unenriched Azolla declined as increasing levels of phosphorus were applied during intercropping. The grain and straw yields and nitrogen uptake of rice were increased both by phosphorus-enrichment of Azolla inoculum and by phosphorus fertilization during intercropping.La gestión de fósforos para la siembra simultánea del Azolla y el arroz
Sensitivity (Stability) Analysis of Multiple Variety Trials, with Special Reference to Data Expressed as Proportions or Percentages
Authors: Dyke G. V. , Lane P. W. , Jenkyn J. F. 
Published: October 2008

SummaryThe literature on ‘stability analysis’, which is better called ‘sensitivity analysis’, leaves much to be desired. This paper attempts to clarify the issues, particularly the effect of the non-linearity of the standard model relating variety yields to mean yields over sites. The model is extended from its original applications in the analysis of crop yields to the analysis of measurements that cannot be considered Normally distributed, such as disease assessments expressed as percentages or proportions. Modern computer software offers a method that is theoretically sound and can be applied routinely to data of many different distributional types. Graphical methods of displaying the results of the analysis of non-Normal data are discussed.Análisis de la sensibilidad de ensayos con variedades
Towards the Reliable Prediction of Time to Flowering in Six Annual Crops. VI. Applications in Crop Improvement
Authors: Lawn R. J. , Summerfield R. J. , Ellis R. H. , Qi A. , Roberts E. H. , Chay P. M. , Brouwer J. B. , Rose J. L. , Yeates S. J. 
Published: October 2008

SummaryVariation in time from sowing to flowering (f) was examined for 44 cultivars of soyabean, mungbean, black gram, ricebean, cowpea, chickpea, lentil and barley, when grown in up to 21 diverse environments obtained by making one or more sowings at each of six locations spanning tropical, sub-tropical and temperate climates in Australia. The utility of simple linear models, relating rate of development (l/f) towards flowering to mean photoperiod and temperature prevailing between sowing and flowering, was evaluated. The models were highly efficient, explaining most (86.7%) of the variation observed across species, cultivars and environments. They were particularly efficient in describing responses where cultivars were relatively well-adapted, in agronomic terms, and least efficient where cultivars were exposed to unfavourable temperature and, to a lesser extent, photoperiod. Opportunities for exploiting the models in applied crop improvement include their use in interpretation of G × E interaction, genotypic characterization and selection of parental genotypes, selection of test environments, designing screening procedures, and more efficiently matching genotypes to target environments. The main strengths of these linear, additive rate models in crop improvement are their wide applicability across species and genotypes, their relative simplicity, and the requirement for few genotype-specific response parameters. Their main weakness is their lack of precision in describing responses when plants are exposed to unfavourable photothermal extremes, albeit in circumstances that are sometimes unrealistic for cropping those particular genotypes.Predicciones del tiempo que ha de transcurrir hanta la floración. VI.
Analysis of Water Budgets in Semi-Arid Lands from Soil Water Records
Authors: Pilbeam C. J. , Daamen C. C. , Simmonds L. P. 
Published: October 2008

SUMMARYFour components of the water budget for a growing season, namely storage, drainage, transpiration and direct evaporation from the soil surface, were estimated using a suite of techniques. The only data requirements were rainfall, neutron probe measurements of soil water content and microlysimeter measurements of evaporation from the soil. Data from four growing seasons at Kiboko, Kenya between 1990 and 1992 were used to provide examples of the estimations. Drainage was significant (about 10% of rainfall) in one season only; in the other seasons, total evaporation comprised at least 95% of the seasonal rainfall.Drainage was determined using a relationship between unsaturated hydraulic conductivity and soil water content that was determined during the early part of the rainy season when water was penetrating to depth. This analysis made it possible to identify a critical water content at the base of the soil profile, above which there would be significant drainage. However, there are large errors associated with estimation of drainage if significant drainage occurs.Estimates of direct evaporation from the soil surface were used as the basis of distinguishing transpiration from total evaporation. Microlysimetry was used to develop a model of evaporation from these sandy soils, which was based on the assumption that the evaporation from the soil surface following heavy rainfall is a unique function of time from rainfall, and little influenced by the presence of a sparse crop. This method showed that direct evaporation from the soil accounted for between 70 and 85% of total evaporation in seasons when total evaporation estimates ranged from 150 to 325 mm.
Yield Gain and Risk Minimization in Maize (Zea Mays) through Cultivar Mixtures in Semi-arid Zones of the Rift Valley in Ethiopia
Authors: Tilahun Amede 
Published: October 2008

SUMMARYThe effect of mixtures of cultivars on yield and risk distribution in four maize cultivars grown at four different population levels was studied in semi-arid environments in Ethiopia. Mixtures yielded between 2 and 29% more than the pure stands, but late maturing pure stands produced more biomass than mixtures. Mixtures of cultivars with similar flowering periods yielded 60% more than the pure stands in dry growing seasons, but only 30% more when there was more rain. Yield gain was associated mainly with varietal synchrony of anthesis and silking. Mixtures composed of cultivars with different flowering times were less at risk from yield loss in the case of end-of-season drought and yielded 100% more than their late flowering component in pure stand. But in long growing seasons, with an early dry spell, pure stands of the late cultivar outyielded the mixtures whereas pure stands of the early flowering cultivars yielded less than the mixtures, except in years with a serious end-of-season drought. The results indicate that it would be profitable to grow mixtures in semi-arid regions if cultivars with similar height and synchronized flowering time were grown at populations of between 65 000 and 90 000 plants ha−1.