bluuebunny/crossref_metadata_2025 huggingface dataset:
Crop and Soil Responses to Post-emergence Tillage and Weed Control in Lowland Rice
Authors: Siopongco Joel D. L. C. , Ingram Keith T. , Pablico Paquito P. , Moody Keith
Published: October 2008

Beusani is a rice crop management system practised in rainfed lowland areas of eastern India whereby rice is dry-seeded, then wet-ploughed at 30–50 days after emergence and the land levelled by drawing a board across the field. Field experiments showed that beusani enhances rooting, especially in shallow soil layers, as a result of reduced penetration resistance. Although beusani reduced weed biomass by 38%, it was not as effective as application of herbicide followed by hand weeding, which reduced biomass by 87%. Yields were directly related to weed control, so beusani treatments did not yield as much as the herbicide plus hand weeding treatments in these experiments.
Towards the Reliable Prediction of Time to Flowering in Six Annual Crops. V. Chickpea (Cicer arietinum)
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. , Sandover S.
Published: October 2008

Four genotypes of ‘desi’ and two of ‘kabuli’ chickpea (Cicer arietinum) were sown at six locations in Australia on various dates between 1986 and 1988, giving 22 combinations of site and sowing date with diverse photothermal environments. Times from sowing to first flowering (f) varied from 30 to 162 d, mean pre-flowering temperatures from 10.8° to 29.3°C and mean photoperiods from 11.3 to 15.6 h d−1. There was no evidence that any observation had been obtained in photoperiods shorter than the ceiling photoperiod (Pcc) or longer than the critical photoperiod (Pc). This suggests that, in typical agricultural environments, chickpea crops experience photoperiods (P) which should satisfy the condition Pcce < P < Pc. In one ‘kabuli’ and two ‘desi’ genotypes, 1/f was influenced by both temperature and photoperiod. The coefficient of determination (R2) for a linear, additive rate of development model ranged from 0.74 to 0.80, with no significant difference in either temperature sensitivity or photoperiod sensitivity among these three genotypes. In the remaining three genotypes, no significant response to temperature was detected between 10.8° and 29.2°C, so rate of progress to flowering was influenced solely by photoperiod. There was no significant difference in the sensitivity of 1/f to P among these three genotypes. The linear, additive rate model found here to be so satisfactory as a predictive tool for phenology, is also shown to have much wider general application.

Predicción del liempo de floración
Integration of Forage and Food Crops Grown Sequentially on Vertisols under Rainfed Conditions in the Mid-Altitude Ethiopian Highlands
Authors: Tedla Abate , Sherington J. , Mohamed-Saleem M. A.
Published: October 2008

Poor drainage of Vertisols in the Ethiopian mid-altitude highlands limits farming operations and cropping in the early rainy season (July–August). Traditional crops are grown on residual moisture late in the season (September–January) when waterlogging is less of a problem. Productivity is therefore below its potential. The recent introduction of a broadbed and furrow system for improved drainage on Vertisols allows full use of the growing period and provides scope for a wider variety of cropping systems and increased productivity. Trials using a sequential cropping system demonstrated that two crops a year can be grown when Vertisols are drained. The crops used in the trial were oats or an oat/vetch mixture forage in the early season followed by grasspea or chickpea food crops in the late season as the second crop. Further on-farm research on sequential cropping of forages and food crops in the mid-altitude highlands of Ethiopia is now needed.
RhizobiumInoculation Increases of Bean and Maize Yields in Intercrops on Farms in the Peruvian Sierra
Authors: Pineda P. , Kipe-Nolt J. A. , Rojas E.
Published: October 2008

Nitrogen deficiency severely limits production of the bean–maize association grown by small-scale farmers in upland Peru. Sixty-four beanRhizobiumisolates were evaluated for induction of a plant growth response in pots of soil from the area and 14 of the most promising strains of these were tested on farmers' fields in 13 trials over a three year period. Bean yields were increased by inoculation with at least oneRhizobiumstrain in seven of the trials, with increases ranging from 0.21 to 0.68 t ha−1. Bean yields were not increased by the application of 120 kg N ha−1to the intercrop. Maize yields were increased byRhizobiuminoculation in nine of the 13 trials by between 0.34 and 1.85 t ha−1. Maize responded to nitrogen fertilizer on the same nine farms. ThisRhizobiumselection strategy, although laborious, was effective in identifying strains that can be recommended for use as inoculants by farmers in the region.
Profitability of Alley Farming with and without Fallow in Southwest Nigeria
Authors: Jabbar M. A. , Larbi A. , Reynolds L.
Published: October 2008

The profitabilities of three land use systems in the humid zone of southwest Nigeria are compared using a capital budgeting procedure combining on-station and on-farm experimental data. The systems are: non-alley farming with fallow; alley farming with fallow; and continuous alley farming. The results indicate that: continuous alley cropping is more profitable than non-alley or alley cropping with fallow; short fallowing in alley cropping reduces the rate of mining soil fertility and thus helps preserve future productivity; alley farming with small ruminants enhances the profitability of alley systems and increases their advantage over the non-alley system; and alley systems remain profitable even when terminal clearing costs are internalized in the current project cycle.
A Wet Excavation Method for Root/Shoot Studies of Pearl Millet on the Sandy Soils of the Sahel
Authors: Sivakumar M. V. K. , Salaam S. A.
Published: October 2008

Root/shoot relations of two cultivars of pearl millet (Pennisetum glaucum) were studied on a sandy soil at Sadore in Niger using a wet excavation method. For the first 10 days after emergence (DAE), the length of the seminal root showed an exponential growth rate while plant height increased more or less linearly. The maximum rooting depth for millet was 168 cm and the maximum number of root axes and primary laterals, 172 per plant. Root length continued to increase up to 75 DAE, the maximum length exceeding 5000 cm per plant. The proportion of total day matter accumulated in the roots decreased from 30% in the early stages to less than 20% by maturity. The wet excavation method is a promising technique for the rapid removal of intact root systems of pearl millet from the sandy soils of the Sahel.
The Impact of Cashew (Anacardium Occidentale) on Forest Soil
Authors: Aweto A. O. , Ishola M. A.
Published: October 2008

The impact of a 20-year-old cashew plantation on a forest soil was evaluated by comparing the properties of soil under cashew with that under an adjoining logged rain forest. The levels of organic carbon, nitrogen, exchangeable calcium and magnesium, and available phosphorus were similar under logged forest and cashew, suggesting that organic matter and nutrient cycles in a cashew plantation are similar to those in a logged rain forest and that cashew has no significant adverse effect on soil organic matter and nutrient status.
Suppression of Striga hermonthica on Sorghum Using a Cowpea Intercrop
Authors: Carsky R. J. , Singh L. , Ndikawa R.
Published: October 2008

Intercropping with a spreading type of cowpea was studied as a technique for the control of Striga hermonthica on sorghum in northern Cameroon. Alternate rows of cowpea did not reduce Striga density but planting the cowpea and sorghum in the same row, in the same or alternating hills, reduced Striga density and numbers of Striga per sorghum stand. Yields of sorghum grain in the same-row planting treatments were not significantly less than sole sorghum yields, and 200 to 700 kg ha−1 of cowpea grain was produced. Alternating stands of sorghum and cowpea within the same row gave the best yield of sorghum and greater reduction of Striga. Production of mature Striga with capsules decreased with increasing cowpea ground cover, so that while cowpea may not reduce Striga emergence, it may hinder Striga development, possibly reducing the Striga seed bank over time.
Aspects of Statistical Technique and Presentation
Authors: Riley Janet
Published: October 2008

This paper offers guidelines for the presentation of statistical material in scientific journals and project reports. Emphasis is given to the importance of planning a study so that the various components of statistical material can be linked to ensure the full efficiency of the work; if this is done well, the presentation of the results of the study, including the statistical components, can be achieved with greater ease.
The Impact of the International Agricultural Centres: Measurement, Quantification and Interpretation
Authors: Collinson M. P. , Tollens E.
Published: October 2008

Impact assessment is important to agricultural research. It quantifies benefits from both proposed and past research, and allows comparisons of the cost effectiveness of different research investments as a basis for priority setting. Though there are important economies of scale in the global and regional level research done by the international centres of the Consultative Group for International Agricultural Research (CGIAR), this research covers only one small sector in the sequence of research and development reaching down into farmers' fields. CGIAR impact thus depends on the rest of the research and development (R&D) sequence operating effectively, something largely beyond its control. In deciding a strategy for impact assessment, the international centres need to resolve two dilemmas: first, how much impact assessment they should do, for their own programme planning and monitoring, and to satisfy their stakeholder constituencies; and secondly, how sophisticated this assessment should be. Impact measurement is itself research and, like all research, is very much concerned with how much is gained from the extra costs of collecting further information.

Centros agrícolas internacionales
Effects of Liming and Cultivation on the Establishment and Persistence of Rainfed Mediterranean Pastures
Authors: Moreira N. , Trindade H. , Coutinho J. , Almeida J. F.
Published: October 2008

The influence of liming and method of cultivation on the dry matter yield, botanical composition and seedling density of a rainfed pasture grown in a Mediterranean environment from a commercial seed mixture based on subterranean clover was investigated. Liming resulted in a 2.5-fold increase in pasture dry matter yield. Yields were greater when the soil was scarified before sowing than when it was ploughed, and when the lime was spread after cultivation rather than before. Liming and scarifying increased the proportion of sown species (subterranean clover, white clover and tall fescue) and reduced the proportion of native species and bare ground. Subterranean clover seedling density was higher after scarifying than after ploughing.

Uso de cal en pastos mediterráneos regados por precipitaciones
Intercropping Cotton and Groundnut in Low and High Rainfall Areas in Eastern Zambia
Authors: Waterworth J. V.
Published: October 2008

Yields of intercropped cotton and groundnuts grown on alternate ridges 75 cm apart were compared in areas of high (more than 1000 mm a year) and low (less than 800 mm a year) rainfall and in rainy seasons with a low and high frequency of drought periods. There was no advantage from intercropping in the low rainfall area but in the high rainfall area land equivalent ratios of about 1.4 were obtained, confirming that intercropping is more suited to wet conditions. These high land equivalent ratios were associated with enhanced yields per plant in the cotton and unsuppressed yields per plant in the groundnuts, suggesting that a crop such as cotton, which both tolerates a wide range of population density and has a late-developing leaf canopy, may be particularly well suited to intercropping.

Cultivo simultáneo de algodón y chufa en zonas con altas y bajas precipitaciones en el este de Zambia
The Effect of Frequency of Defoliation on the Productivity of Selected Forage Legumes (Stylosanthes hamata, Stylosanthes capitataand Centrosema pascuorum) in the Sub-humid Zone of Nigeria
Authors: Tarawali G. , Mohamed-Saleem M. A. , Chionuma P. C.
Published: October 2008

The dry matter yield, nutritive value and persistence of three legume species (Stylosanthes hamata Taub., S. capitata Vog. and Centrosema pascuorum Mart. ex. Benth.) cut at different frequencies during the growing season or only once at the end of the growing season were compared. The shorter cutting intervals enhanced regrowth, but very frequent cutting reduced total dry matter and seed yields. A defoliation interval of three to six weeks is recommended. Generally, S. hamata gave the best performance.

Efecto del deshoje en tres legumbres
Farmer Participation in On-Station Tree Species Selection for Agroforestry: a Case Study from Burundi
Authors: Franzel Steven , Hitimana Leonidas , Akyeampong Ekow
Published: October 2008

Surveys and on-farm trials are frequently used to facilitate farmer participation in agricultural research. This paper reports on a less common method-farmer involvement in on-station trials. Thirty-nine farmers were invited to multipurpose-tree screening trials in Burundi. Three different methods were used to determine which species the farmers wanted to test on their own farms. Private interviews and voting by a show of hands in plenary sessions gave very similar results whereas focus group interviews produced different and contradictory results. Researchers also learned what criteria farmers used to evaluate trees and the reasons for their choices. A supplementary survey of farmers’ preferences for trees grown on their own farms confirmed the findings and more clearly defined their criteria. In this survey, farmers used a local board game, Bao, to rate tree species across criteria they considered important. Overall, the visit to the trials and follow-up survey proved to be a useful and cost-effective method for getting farmer input and applying it in the screening process.

La participación de los agricultores en la selección de especies de árboles
Response of Chickpea to Nitrogen, and a Comparison of the Factors Affecting Chickpea Seed Yield with those Affecting Wheat Grain Yield
Authors: Bonfil D. J. , Pinthus M. J.
Published: October 2008

Chickpea yields in Israel are usually considerably lower than wheat yields under comparable conditions. This study aimed to examine the possible yield limiting factors in chickpeas. Increasing the availability of nitrogen during seed development by a pre-sowing application of nitrate or by nitrogen top dressing at the onset of flowering led to an increase in the percentage of nitrogen in the straw but had no significant effect on seed yield. Growth analysis of chickpeas and wheat grown in two adjacent field experiments revealed that during the fruiting period these crops accumulated similar amounts of dry matter. However, the proportion of total wheat dry matter accumulated in the wheat grains was twice the proportion of total chickpea dry matter accumulated in the chickpea seeds. It was concluded that the main intrinisic factor limiting the seed yield of chickpeas is the continuation of vegetative growth during the period of seed development, which reduces the amount of assimilate allocated to the seeds.

Los factores restrictivos del rendimiento en el garbanzo
Effects on the Yield and Growth of a Young Compact Arabica Coffee Hybrid of Intercropping with Food Crops in Three Agro-ecozones in Kenya
Authors: Njoroge J. M. , Kimemia J. K.
Published: October 2008

The intercropping of a young compact Arabica coffee hybrid with food crops was studied in three coffee growing areas in Kenya. Intercropping with Irish potatoes, dry beans, tomatoes, cabbages, kale, carrots, finger millet, sorghum or soyabeans was feasible in suitable coffee ecological zones. Intercropping with maize or sweet potatoes was not feasible because of their adverse effects on coffee growth in the early stages of coffee establishment, which led to substantial reductions in coffee yield.

Siembra simultánea de café arábica con cultivos de comestibles
Seed Imbibitation and Drying as a Technique in Evaluating Sorghum Lines for Adaption to Dry Sowing in the Semi-arid Tropics
Authors: Maiti R. K. , Moreno L. S.
Published: October 2008

Seeds of 50 sorghum genotypes were tested for emergence after imbibition in water for different times followed by up to 30 days of drying. The emergence of a large number of sorghum genotypes was then tested after 40 h imbibition in water followed by 10 h drying. Genotypes selected as resistant to 45 hours imbibition and 10 days drying regained turgor in the radicle and plumule when exposed to imbibition and drying injury. Genotypes showed significant difference both for emergence and seedling dry weight after exposure to this stress. The genotypes resistant to imbibition injury and drying had a specific protein of 33.0 KDa which was absent from those which were susceptible to such stress.

La adaptación del sorgo a la siembra seca
Estimating Potato Tuber Yield in a Sub-tropical Environment with Simple Radiation-Based Models
Authors: Prihar S. S. , Arora V. K. , Singh G. , Singh R.
Published: October 2008

Dry matter and tuber yields of potato grown in a sub-tropical environment were estimated employing simple radiation-based models which require meteorological information on air temperature and solar radiation. Two versions of the MacKerron and Waister (1985) model, in which estimation of dry matter accumulation relies on a single composite parameter, radiation use efficiency (RUE), were compared with the Versteeg and Van Keulen (1986) model, which explicitly accounts for temperature and radiation effects on dry matter accumulation. In the original version of the MacKerron and Waister model, a linear change in the radiation interception factor with leaf area index is assumed; in the modified version an exponential change in the interception factor with leaf area index is considered. The accumulation of dry matter estimated from all three models was close to the measured values throughout the growing season, but estimates of tuber yield differed widely. Our analysis showed that the best agreement with measured values was obtained using the MacKerron and Waister linear model with RUE values adjusted according to the incident radiation level.

Estimatión del rendimiento del tubérculo de la patata
Statistics for Environmental Change
Authors: Barnett Vic , Riley Janet
Published: October 2008

Major changes to the global environment and their impact upon statistical requirements are presented. The need for extensive yet accurate datasets is stressed and the difficulties of achieving appropriate sampling strategies are described. Examples are presented of environmental studies in use in diverse field such as global warming, sustainability, agroforestry and intercropping, and local community studies. The history of the use of environmental statistics is highlighted as is the need for modern methods to handle large, multivariate datasets likely to be subject to both spatial and temporal variability.
Relative Importance of Air and Floodwater Temperatures on the Development of Rice (Oryza Sativa)
Authors: Collinson S. T. , Ellis R. H. , Summerfield R. J. , Roberts E. H.
Published: October 2008

Plants of rice (Oryza sativa)cultivar IR36 were grown under flooded and free-draining conditions at a constant air temperature of 28°C with an 11.5 h d−1 photoperiod in both a growth cabinet and a glasshouse. The nutrient solution within flooded pots was maintained at 20°, 24° or 28°C, or was not controlled. Rate of floral development was enhanced by warmer nutrient solution temperatures at the same air temperature; times to panicle emergence were reduced by an average of 17 d with increase in the nutrient solution temperature from 20° to 28°C. In comparable treatments, plants grown in the growth cabinet reached panicle emergence later than those grown in the glasshouse, possibly because mean air temperature was on average 0.8°C cooler in the growth cabinet. An independent model, derived from a previous investigation, provided a good prediction of the times from sowing to panicle emergence for plants grown in both the glasshouse and the growth cabinet when based on the mean of the temperatures of the nutrient solution and the air, showing that it is important to determine water/root temperature as well as air temperature when investigating the effect of environment on development of the rice plant.
Effects of Variety, Altitude, and Undersowing with Legumes on the Nutritive Value of Wheat Straw
Authors: Schulthess Urs , Tedla Abate , Mohamed-Saleem M. A. , Said Abdullah N.
Published: October 2008

Wheat was planted at different altitudes in the Ethiopian highlands. Increased altitude led to a lower neutral detergent fibre (NDF) content and a higher in vitro organic matter digestibility (IVOMD) of the leaf blades, leaf sheaths and stems. The varieties tested did not differ in NDF content, however, because of the improved NDF digestibility of all three straw fractions. The semi-dwarf varieties had a higher IVOMD than the standard tall wheats. The local durum wheat variety showed a much higher sodium content and a more favourable Na:K ratio. Undersowing with an equal mixture of Trifolium ruepellianum (Fres.) and Trifolium steudneri (Schwf.) led to a small reduction in straw yield but increased the crude protein content of the crop residues from 2.3 to 7.1% and the IVOMD from 44 to 51% as compared to the sole wheat stand.
Some Design Problems in Crop Experimentation. I. The Use of Blocks
Authors: Pearce S. C.
Published: October 2008

Field experiments are commonly designed in blocks and there are sound reasons for using them, for example, control of unwanted environmental differences and administrative convenience. If used, they should be chosen to correspond to perceived differences in the site or to simplify farm operations and not merely to conform to statistical desiderata. Thus, it is not essential that each must contain one plot for each treatment, though there are advantages if they do. Some of the consequences of using other block sizes are examined, it being borne in mind that modern computer packages will perform most of the tiresome arithmetic. The effectiveness of blocks is considered and it is noted that they sometimes do harm rather than good. The analysis of variance is explained in terms of strata as used in many modern computer programs and is extended to include the recovery of information and resolvability. Recommendations are made as to randomization.
Effect of the Treatment of Wheat Seeds with Vegetable Oils on Germination and Emergence
Authors: Klein Joshua D. , Hebbe Yonit
Published: October 2008

Seeds of wheat (Triticum aestivum L.) were coated with a range of vegetable oils before sowing, in an effort to provide a hydrophobic coating that would only dissolve or wash away in the presence of sufficient water to maintain continued seedling growth. Germination of oil-treated seeds was reduced by 20–50% and time to 50% emergence was increased by two to five days. Treating pesticide-coated seeds with vegetable oil further decreased germination and extended time to emergence. Oil treatment did not decrease water uptake or affect seed respiration. Degree of saturation and linoleic acid:oleic acid ratio were not correlated with the effects of the various oils. The decreased germination and delayed emergence associated with the oil treatment were probably due to physiological rather than physical factors.
On-Farm Evaluation of Nitrate-Nitrogen Dynamics Under Maize in the Northern Guinea Savanna of Nigeria
Authors: Webert G. , Chude V. , Pleysier J. , Oikeh S.
Published: October 2008

Nitrate-nitrogen was analysed over two cropping seasons in 57 farmers' fields in the northern Guinea savanna of Nigeria. Differences between fields were at least five-fold and often ten-fold irrespective of fertilization rates. Average concentrations were highest at the beginning of the rainy season. Loamy soils had a later peak for nitrate release and maintained high concentrations for a longer period after the start of the rains than the more sandy soils. Nitrate-N was not correlated with soil organic carbon or total nitrogen content. Grain yield of maize was closely associated with nitrate-N in the soil but not with organic carbon or total N. Four patterns of nitrate-N release over the season could he differentiated using cluster analysis. Soil texture, soil pH, soil organic carbon, stover management and cropping history contributed most to a differentiation of the four cluster groups in a discriminant model. There was wide variability in the inherent soil-nitrate level and in its importance in explaining differences in yield among farmers' fields. The development of technologies resulting in improved nitrogen availability or better nitrogen utilization should be based on research of inherent soil processes. For the transfer of such technologies, recommendation domains should be defined based on different native patterns of soil-nitrogen availability.
Morphological Development and Yield Potential in Hesperaloe Funifera (AGAVACEAE), An Experimental Fibre Crop for Dry Regions
Authors: McLaughlin Steven P.
Published: October 2008

Hesperaloe funifera (Agavaceae) is an experimental fibre crop which produces strong, fine fibres with potential uses in the specialty-paper industry. Hesperaloe's agronomic potential was evaluated in two long-term studies. The plant is a perennial with a rosette habit. Growth occurred by production of new leaves from the primary rosette until Year 3 and from secondary rosettes from Year 3 on. Rates of biomass growth increased over the five years studied. High-density stands (27 000 plants ha-l) produced 190 t fresh weight ha-1 after five years. Plots harvested once, after Year 5, produced more biomass than plots harvested twice, after Years 3 and 5. Increased biomass production can be achieved by improved stand establishment and nutrient management.
Development in Cowpea (Vigna unguiculata). I. The Influence of Temperature on Seed Germination and Seedling Emergence
Authors: Craufurd P. Q. , Ellis R. H. , Summerfield R. R. J. , Menin L.
Published: October 2008

The base (Tb), optimum (To) and ceiling (Tce) temperature for 50% seed germination and seedling emergence, and the thermal time at sub-optimal temperatures (θ1), were examined in experiments with a range of cowpea genotypes from different habitats and latitudes. There was substantial genotypic variation in seed germination for Tband To, but not for Tce. There was no evidence that genotypes from semi-arid habitats had higher values of Toor Tce, but estimates of Tbfor seed germination were related to latitude and were highest in genotypes originating from close to the equator. The significance of these responses as a component of developmental plasticity in relation to the adaptation of cowpeas is discussed.
Development in Cowpea (Vigna unguiculata). III. Effects of Temperature and Photoperiod on Time to Flowering in Photoperiod-sensitive Genotypes and Screening for Photothermal Responses
Authors: Craufurd P. Q. , Qi A. , Summerfield R. J. , Ellis R. H. , Roberts E. H.
Published: October 2008

Seventeen photoperiod-sensitive genotypes of cowpea (Vigna unguiculata) were grown in approximately 30 photothermal environments in Nigeria. Photoperiods ranged from 10 to 16 h d−1, mean temperatures from 19° to 30°C and times from sowing to flowering (f) from 32 to 140 d. Rate of progress towards flowering (1/f) was related to mean pre-flowering values of temperature and photoperiod using simple linear rate models comprising one, two or three planes (thermal, photothermal and insensitive). There were no significant differences (p > 0.25) among genotypes in response to temperature within the thermal plane and the common base temperature was estimated to be 7.6°C. Photoperiod-sensitivity varied by a factor of 15 among genotypes, and the critical and ceiling photoperiods varied from 12.2 to 13.4 and from 13.8 to more than 16 h d−1 at a mean temperature of 27°C, respectively. These simple models satisfactorily predicted f in an independent data set (R2 = 0.62) for plants grown in the main cowpea growing seasons at latitudes between 7° and 13°N. The utility of photothermal models and methods to screen for photothermal responses are discussed.
Effect of Leaf Stripping, De-tasselling and Topping of Maize on the Yield of Maize and Relay Intercropped Finger Millet
Authors: Subedi K. D.
Published: October 2008

A field experiment was conducted to study the effect of leaf stripping, de-tasselling and topping on the yield of maize and finger millet in a maize/finger millet intercropping system at Lumle in Nepal. De-tasselling of maize before pollen shedding reduced the number of barren plants, and increased test weight and grain yield but de-tasselling after pollination had no significant effect. Defoliation of maize by removal of leaves below and above the ear, or by topping 30 days after 50% silking, had no effect on either maize grain yield or on that of the relay planted finger millet. This contradicts the hypothesis that increased light penetration due to reduced shading improves the yield of millet under maize.
The Influence of Time of Planting and Spacing on the Production of Fodder and Fuelwood in Associations of Calliandra calothyrsus and Pennisetum purpureum Grown on Contour Bunds in the Highlands of Burundi
Authors: Akyeampong Ekow
Published: October 2008

The best time to plant Calliandra calothyrsus in association with Pennisetum purpureum and the appropriate in-row spacing of Calliandra for fodder and fuelwood production when grown on contour bunds were investigated. Main plot treatments were Pennisetum planted in November 1988 and associated with Calliandra in February 1989, Calliandra planted in November 1988 and associated with Pennisetum in February 1989, and both species planted simultaneously in November 1988. Sub-plot treatments were three within-row spacings of Calliandra. Survival of neither species was affected by time of planting. Total treatment yields of the second and third years were not influenced by time of planting but lower yields of leaf and wood were obtained from the later-planted Calliandra. Total yields were not significantly influenced by the spacing, but leaf and wood yields of the Calliandra at the 25 cm spacing were greater than those at the 100 cm spacing although not significantly different from those at the 50 cm spacing. Neither the time of planting nor the spacing of Calliandra affected the yield of maize or beans grown in the interbund areas. Simultaneous planting of Calliandra and Pennisetum is recommended.
Rainfall Erosivity and Erodibility of Inceptisols in the Southwest Colombian Andes
Authors: Ruppenthal M. , Leihner D. E. , Hilger T. H. , Castillo F. J. A.
Published: October 2008

The rainfall erosivity (R) and soil erodibility (K) factors of the Universal Soil Loss Equation (USLE) were determined on two sites in the Colombian Cauca Department over a five year period when rainfall was mostly lower than average. The results showed that the high erosion potential of the soils can be attributed more to high rain erosivity than soil erodibility. The R factor explained between 59 and 81% of the variation in soil loss recorded on continuously clean-tilled fallow plots. The erodibility of Inceptisols in the study region is classified as low. Values for soil erodibility (K) ranged from 0.012 to 0.015 (measured in SI units) in the fifth year of permanent bare fallowing. K factors were higher in the rainy than in the dry season. Soils, previously under grass vegetation, were very resistant to erosion in the first two years of bare fallowing. In the third year erodibility increased sharply and continued to increase steadily until the sixth year. K factors predicted by the USLE nomograph underestimated the empirically-determined erodibility of these highly aggregated clay soils.
Physiological and Morphological Features Determining the Performance of the Sorghum Landraces of Northern Nigeria
Authors: Flower D. J.
Published: October 2008

Sorghum landraces from contrasting districts of northern Nigeria were grown during the 1990 rainy season to describe their physiological and morphological features. Changes in their dry matter production and yield could be predicted from thermal time to flowering (based on response to a fixed daylength) and partitioning indices. Many other morphological and physiological features, such as light-extinction coefficient, light-use efficiency, plant height, leaf area and leaf number, were either stable or varied systematically with time to flowering. Grain yields of early maturing lines were limited by low light interception from flowering to physiological maturity and those of later maturing lines by highly site-specific drought stress.
Problems Associated with Phalaris minor and Other Grass Weeds in India and Pakistan
Authors: Shad Rashid A. , Siddiqui Sadar Uddin
Published: October 2008

The composition and control of the grass weed flora of India and Pakistan are discussed, and the losses caused by the weeds are reviewed. The most important perennial weeds are Cynodon dactylon and Sorghum halepense and the most important annual weeds Echinochloa crusgalli and E. colona in the summer (kharif) crops and wild oats (Avena spp.) and Phalaris minor in the winter (rabi) crops. Losses caused by these weeds can be considerably reduced by the use of selective herbicides but these may be too expensive for many farmers. The problems and control of Phalaris minor are considered in detail.
Adoption of Improved Cultivars of Pearl Millet in an Arid Environment: Straw Yield and Quality Considerations in Western Rajasthan
Authors: Kelley T. G. , Parthasarathy Rao P. , Weltzien R. E. , Purohit M. L.
Published: October 2008

The role of straw yield and quality in farmers' decisions about the adoption of pearl millet cultivars in western Rajasthan was examined using farm household surveys. Information on the relative importance of grain versus straw yield, the perceived risks associated with the use of new cultivars under variable climatic conditions and perceptions of straw quality indicated that improved cultivars of pearl millet were not adopted primarily because of poor grain yield in years with low rainfall, though poor straw yield in such years was also important. These results are particularly pertinent in the light of farmers' perceptions of the likelihood of experiencing drought or low rainfall. If new cultivars of pearl millet are to replace the traditional ones, they must perform better under conditions of limited rainfall.
Soil Fertility Decline and Fallow Effects in Ferralsols and Acrisols of Sisal Plantations in Tanzania
Authors: Hartemink Alfred E. , Osborne J. F. , Kips Ph. A.
Published: October 2008

Soil fertility decline and fallow effects were studied in Ferralsol-Acrisol catenas of plantations of sisal (Agave sisalana) in north-east Tanzania. The fertility of Ferralsols that had been subject to continuous sisal cultivation in the absence of fertilizers was extremely low but that of Ferralsols that had been under 18 years of bush fallow or under secondary forest was slightly better. Acrisols that had been under continuous sisal cultivation were less depleted than the Ferralsols because of greater intrinsic fertility. A comparison of soil analytical data from the 1950s and 1960s with recent data from the same sisal fields showed that the topsoil pH of the Ferralsols had decreased by 1.5 (r2= 0.807) and that of the Acrisols by 1.2 (r2= 0.494) under continuous sisal cultivation. Thus there had been a serious decline in soil fertility under sisal cultivation, and this decline was not adequately reversed by fallowing.
Efficient Control of Spatial Variation in Yield Trials Using Neighbour Plot Residuals
Authors: Vollmann J. , Buerstmayr H. , Ruckenbauer P.
Published: October 2008

The effect of spatial variation on experimental error variance and the significance of differences between genetic entries was evaluated in five performance trials. A significant portion of spatial variation could be detected in all the experiments investigated and various neighbour plot residuals were applied to adjust for local field trends. Neighbour plot adjustment was clearly more efficient than the randomized complete block design in reducing error variance and in detecting significant differences between entries. It was also more efficient than lattice designs in trial fields exhibiting short distance trends, which could not be covered efficiently by incomplete blocks. In most experiments with long and narrow plots, longitudinal adjustment using two neighbours at each side of a test plot was superior to adjustment by only one ‘nearest’ neighbour.
Pest and Disease Hazards and Sustainability in African Agriculture
Authors: Goldman Abe
Published: October 2008

Surveys of the relationship between pests and diseases and crop sustainability in several areas of Kenya, Nigeria, and other regions of Africa indicate that the production of numerous crops has declined sharply as a result of major pest and disease outbreaks, and others are threatened with major decline because of a surge in virulence of an endemic pest or disease, the introduction of a virulent exotic pest or pathogen, or because a system of control used previously has collapsed. Many of the crops that have declined were already experiencing reduced economic demand. In other cases, crop sustainability has been preserved by vigorous farmer responses or by the intervention of national and international research institutions. Most pests and pathogens, however, remain within tolerable bounds most of the time, though this often requires the use of chemical or cultural controls, or the availability of adequate land to compensate for losses. As land availability declines, more strenuous management efforts may be needed to sustain productivity.
Nitrogen Fertilization of Sugarcane in an Intercropping System with Maize and Potato in the Humid Tropical Climate of Mauritius
Authors: Kwong K. F. Ng Kee , Umrit G. , Deville J.
Published: October 2008

The competition for fertilizer nitrogen between sugarcane and a companion crop (maize or potato) grown between the sugarcane rows was studied using nitrogen-15 labelled nitrogen in three field experiments in Mauritius. The effect of the timing of nitrogen application on nitrogen recovery by sugarcane was also investigated. Not more than 15 kg ha−1 of the 120 kg ha−1 nitrogen applied to the sugarcane was taken up by the companion crop but this was compensated for by the uptake of 8 kg ha−1 nitrogen applied to maize or potato. The present recommendations for nitrogen fertilization of pure stand sugarcane were found to be applicable to sugarcane intercropped with non-leguminous food crops. Though fertilizer nitrogen uptake by sugarcane was increased by delaying nitrogen application until after the harvest of the maize and potato, this was not accompanied by an increase in sugarcane yields.
Fitting Short Duration Cowpea into a Cotton-Based Cropping System in Tanzania: Effect of Planting Pattern, Time of Planting Cowpea, and Insecticide Application to the Cotton
Authors: Myaka Fidelis A. , Kabissa Joe C. B.
Published: October 2008

An experiment to investigate the effect of planting pattern, time of planting the cowpea, and insecticide application on the yield of intercropped cotton and cowpea showed that insecticide applied to the cotton controlled cowpea pests best when the crops were planted in alternating single rows. I n wet seasons, delayed planting of the cowpea reduced its yield but its performance was better in alternating single rows than in other planting patterns. In drier seasons, cowpea yield was unaffected by time of planting and yields were similar with alternating single or double rows. Cotton yield was reduced by 47% when the planting pattern was changed to a one cotton:two cowpea row configuration.
Is Water-harvesting in Valley Floors a Viable Option for Increasing Cereal Production in Highland Balochistan, Pakistan?
Authors: Rodríguez A. , Shah N. A. , Afzal M. , Mustafa U. , Ali I.
Published: October 2008

Preparation of small catchment areas on rainfed valley floor soils in highland Balochistan, Pakistan, is a low-cost method of generating run-off and increasing crop yields within the cropped areas. The effect of different proportions of water catchment area to cropped area were investigated by comparing a control treatment with the entire area planted to the crop (traditional rainfed agriculture); a 1:1 treatment, with one half of the area used for water catchment and one half for planting; and a 2:1 treatment, with two thirds of the area used for water catchment and one third for planting. Results from six seasons of trials using wheat (Triticum aestivum) showed that the 1:1 treatment had 23% higher net benefits than the control, with a 19% reduction in the coefficient of variation. The 2:1 treatment had 29% lower net benefits than the control and reduced the variation in net benefits by 8%. By contrast, four seasons of trials using barley (Hordeum vulgare) showed that the l: l treatment yielded 25% lower net benefits than the control but increased by 4% the variation in net benefits. Treatment 2:1 had 36% lower net benefits than the control and 18% more variation. Even though the gross revenue from wheat under the 1:1 treatment was less than that from the control, the reduction in total costs in the 1:1 treatment resulted in larger net benefits than the control. Water-harvesting in the valley floors is not a net yield-increasing technology. Land suitable for cultivation is limited and the increases in yields in the cropped area resulting from water-harvesting are offset by the opportunity costs of the catchment area. However, wheat grown in a 1:1 ratio of cropped to catchment area can increase farmers' income and decrease its variation. For barley, farmers are better off using their traditional management practice than giving up part of their cropped area to create water catchments.
Biomass Production, and Feed and Economic Value of Fodder Weeds as By-products of Millet Cropping in a Sahelian Farming System
Authors: Lamers J. , Buerkert A. , Makkar H. P. S. , Von Oppen M. , Becker K.
Published: October 2008

Weeds are generally considered to be undesirable plants as they can cause yield losses but fodder weeds are traded as a valuable feed in Niger, Vest Africa. In vitro analyses of fodder weeds indicated that they are a suitable crude protein supplement to low quality millet stover, a major feed during the dry season. Dry matter production of fodder weeds increased with a crop residue mulch. When weeds are used as feed, farmers may generate additional income through an increased availability of energy for animal traction or for dairy and beef production. Species with the highest crude protein content, usually the most limiting factor in feed for animal production, had the highest market prices. The sale of fodder weeds may provide farmers with cash. Agricultural research programmes should be encouraged to consider the use of fodder weeds to improve both the quality and quantity of feed in the West African Sahel.
Yields of Cereal Grain and Protein
Authors: Simmonds N. W.
Published: October 2008

Earlier work has shown that, in cereals in general, grain yield (Y) and protein content (P) are strongly negatively related. It is shown here that the expected positive expected relationship between grain yield and protein yield also holds, with (YP) given approximately by YP = 0.141 + 0.0969 Y. All cereal breeding in which high protein content is desired therefore faces a compromise with grain yield.
Effect of Supplementary Saline Irrigation and Applied Nitrogen on the Performance of Dryland Seeded Indian Mustard (Brassica juncea)
Authors: Dayal Bhu , Minhas P. S. , Chauhan C. P. S. , Gupta R. K.
Published: October 2008

Field experiments were conducted for two years to evaluate the effects of combinations of saline irrigation (ECw 14.0 ds m-1) and nitrogen levels on the yield, seasonal water use and nitrogen use efficiencies of mustard. These showed that the use of saline water can boost the growth and yield of dryland mustard and that, within certain limits, a non-saline water supply can be substituted by applying nitrogen and saline water. It is suggested that fertilizer nitrogen rates should be adjusted in relation to the supply of water and its predicted salinity.

Irrigación salina y los efectos del nitrógeno en la mostaza sembrada en las tierras de secano
Effects of Crop Residue and Phosphorus Application on the Spatial Variability of Non-destructively Measured Millet Growth in the Sahel
Authors: Buerkert A. , Stern R.D.
Published: October 2008

Spatial variability in soil parameters and plant growth in the Sahel are still poorly understood and may hamper the interpretation of experimental results. This paper examines whether or not soil amendments such as phosphorus and crop residues affect the variability of final dry matter production in pearl millet (Pennisetum glaucum). Within- and between-plot variation in millet growth was studied in a three-year experiment with three levels of crop residues and four levels of phosphorus. The effects of different rates of application on within-plot variation in number of tillers, number of heads, maximum tiller height, and total above-ground dry matter of single mature millet plant stands (pockets) were calculated. Above-ground dry matter, estimated non-destructively using an equation derived from numbers of tillers and heads and from maximum plant height, gave good predictions of total dry matter for a range of genotypes across the 12 treatments. Crop residue and phosphorus application reduced the number of missing pockets, leading to a more uniform stand with fewer pockets which did not produce grain. With amendments, pockets were also taller and of more uniform height but a decrease in variability of total dry matter production only became evident after standardization of the data. The results show the need for a clear definition of ‘growth variability’ in millet and indicate that both chemical and non-chemical factors govern its expression in the Sahel.

Efectos de los residuos de las cosechas y del fósforo en la variabilidad del mijo
The Role of Rhizobial Biodiversity in Legume Crop Productivity in the West Asian Highlands
Authors: Keatinge J. D. H. , Materon L. A. , Beck D. P. , Yurtsever N. , Karuc K. , Altuntas S.
Published: October 2008

The numbers of bacteria and the nitrogen fixing efficiency of isolates ofRhizobium leguminosarum, R. ciceriandR. melilotiwith appropriate legume crop species were determined from soils collected from a wide range of locations in Turkey with elevations between 500 and 2200 m. For vetch and lentil nodulated byR. leguminosarum, many native rhizobia are present in most locations but they often have limited nitrogen fixation capacity. However, for chickpea nodulated byR. ciceri, relatively small numbers of bacteria and the almost universal ineffectiveness of fixation capacity point to a need for artificial seed inoculation of chickpea crops as a future agronomic priority. The wide range of bacterial numbers, considerable geographic inconsistency and generally low effectiveness of the indigenous rhizobia associated with the annualMedicagospp. suggest that inoculation would initially be a sensible precaution for all sowings.

Biodiversidad del rhizobium en Asia occidental