bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prospects for Brassica Carinata as an Oilseed crop in India
Authors: Malik R. S. 
Published: October 2008

SUMMARYTwenty one strains of Brassica carinata were tested under irrigated, rainfed and saline soil conditions and five strains under late sowing conditions along with five varieties each of B. juncea, B. napus and B. campestris var. yellow sarson, brown sarson and toria. Brassica juncea had the largest seed and oil yield under irrigated conditions but B. carinata performed much better than other species under late sowing, rainfed and saline soil conditions.
A Review of Methods for Measuring Crop Production from Smallholder Producers
Authors: Poate Derek 
Published: October 2008

SUMMARYFour methods of measuring crop production are reviewed in the context of different survey objectives. A popular technique, crop cutting, tends to overestimate yields and does not produce good estimates of individual plots. For high accuracy, harvest of the whole plot is the best method. If statistics of regional production are required output can be sampled after harvest, or, if the farmer harvests in consistent units, his own estimate can be taken. Limited evidence shows that farmers' estimates may be no more biased than crop cutting, but require fewer resources and supervision. There is no best method. The method used must be chosen for the purpose of the study. Whichever method is chosen a distinction should be made between biological and economic yield and correction must be made for threshing and moisture content.
Sorghums in the Post-Rainy Season. I. Effect of Irrigation and Date of Sowing on the Grain and Stover Yields of Diverse Cultivars
Authors: Reddy Belum V. S. , Seetharama N. , House L. R. 
Published: October 2008

SUMMARYIn India, sorghum is grown during the post-rainy season on Vertisols with stored soil moisture. As water stress towards the end of the growing season is believed to be a major cause of poor yields in these crops, an experiment was carried out involving five sorghum genotypes and four sowing dates with and without irrigation.Supplementary irrigation with 40 mm of water in the earliest sown crop increased grain yields by 24 and 26% in 1979 and 1982, respectively, while irrigation with a total of 120mm water in the latest sown crop increased yields by 87 and 60% compared with the corresponding dryland crops. Early sowings always resulted in better stover and grain yields irrespective of irrigation treatment. Grain yields of hybrids were similar to those of the cultivars but their stover yields were less. The post-rainy season cultivar SPY 86 gave the best grain yield across sowing dates. The widely grown post-rainy season cultivar M 35–1 yielded less but produced more stover and its yields were more stable. The importance of the stability of grain and stover yields and of evaluating the materials for more than one date of sowing in selecting sorghums for the post-rainy season is discussed.
The Effect of Different Planting Densities on Yield Trends in Oil Palm
Authors: Breure C. J. 
Published: October 2008

SUMMARYSixteen years' yield and growth data from an oil palm planting experiment, comparing 56, 110, 148 and 186 palms ha−1, and additional records from a progeny experiment, were used to study the effect of palm age and planting density on carbohydrates incorporated in total above-ground dry matter production per palm (TDMc) and its components: fruit bunch yield (Yc) and vegetative growth (VDMc). The canopy efficiency (e), the amount of carbohydrate incorporated in dry matter production per unit of absorbed radiation per hectare, decreased from the fifth to eighth year then levelled off, but increased once crown expansion was completed. The decrease in e paralleled the expansion of the intercepting leaf surface, and might therefore be linked to an increase in maintenance respiration losses. These losses were apparently not compensated for by an increase in photosynthetic production. The subsequent increase in e in older palms appears to have been due to improved light distribution as a result of an increase in light penetration. The effects of changing levels of light interception and distribution on e were more pronounced at higher density, and resulted in marked differences in changes of TDMc with age between densities. Corresponding differences occurred with Yc, so that the optimum density for current yield decreased until 12 to 13 years from planting, then markedly increased. These findings are discussed in relation to the measures which might be used to increase yield per unit area.
The Effect of Palm Age and Planting Density on the Partitioning of Assimilates in Oil Palm (Elaeis guineensis)
Authors: Breure C. J. 
Published: October 2008

SUMMARYYield and growth records from an oil palm planting density experiment, comparing 56, 110, 148 and 186 palms ha−1, and a progeny experiment, planted at 115 and 143 palms ha−1, were used to estimate the partitioning of assimilates into those used for structural dry matter (DM) production, and those used for growth and maintenance respiration.Gross photosynthetic assimilation (A) for closed canopies was estimated from absorbed photosynthetically active radiation (PAR), derived from actual sunshine hours, and the assimilation-light response curve, to be 128 t CH2O ha−1year−1. A for non-closed canopies was calculated by correcting for the degree of light transmission, which in turn was estimated from recorded leaf area index values (L), i.e. the total leaf area per unit ground area.Forty-eight percent of gross assimilation was used for DM production, about half of this being lost in growth respiration. The remaining 52% was lost in maintenance respiration. These losses appeared to level off before crown expansion was completed, and since trunk biomass continued to increase, maintenance respiration per unit biomass (R) decreased with age.An increase in planting density reduced the assimilates available for bunch DM, had little effect on those for vegetative growth, but strongly reduced maintenance respiration and, since biomass was little affected, reduced R. Assimilates for bunch DM ha−1reached a maximum at L = 5.6.The observed trends in R as a function of palm age and planting density merit further study.
Strengthening Linkages in Agricultural Research through a Farming Systems Perspective: The Role of Social Scientists
Authors: Byerlee Derek , Tripp Robert 
Published: October 2008

SUMMARYThe principal contribution that the farming systems perspective brings to agricultural research is a farmer and problem-solving orientation. Development of this orientation helps strengthen linkages in national research systems between commodity programmes and between disciplines for both applied and adaptive research. It can also strengthen linkages between research and extension and between research and policy analysis. Issues in strengthening each of these linkages are briefly reviewed with particular emphasis on the socio-economic dimensions and the potential role of social scientists. It is argued that the farming systems perspective in agricultural research should be seen as performing an integrative role in research systems. This can often be developed without significant institutional reorganization.
Was this in your Statistics Textbook? I. Agricultural Scientist and Statistician
Authors: Finney D.J. 
Published: October 2008

SUMMARYThis is the first of several papers that will present ideas on statistical method in agricultural research, especially in relation to the planning and analysis of experiments, based upon experience but not found explicitly discussed in standard textbooks. Indeed, some of the contents of these papers may appear to conflict with what can be found in books: closer examination is likely to disclose lack of real disagreement with the better texts. The first paper outlines a plan for the series. Thereafter, it concentrates on relations between agricultural scientists and statisticians and on some of the issues that are too easily overlooked when one of the former, often for good reason, chooses to be his own statistician.
Performance of Varietal Mixtures in Sugarcane
Authors: Kapur Raman , Bhat S. R. , Tripathi B. K. 
Published: October 2008

SUMMARYSix sugarcane varieties grown alone and in mixtures containing equal proportions of two or three varieties were evaluated for the economically important traits of the first crop and subsequent ratoon crops over a three year period. An increase in the yield of cane and sugar of up to 25% more than the average for the pure components was observed in some mixtures. The number of millable canes, sucrose content and cane yield in the mixtures was more stable than in the pure varieties. The advantages of growing varietal mixtures of sugarcane are discussed.
Analysis of Experiments Involving Line Source Sprinkler Irrigation
Authors: Morgan D. D. V. , Carr M. K. V. 
Published: October 2008

SUMMARYThe line-source sprinkler irrigation system provides a continuously variable water application rate, which depends on distance from the line-source. The system is simple to set up and minimizes the amount of land required for experimental work. As the irrigation treatments are allocated systematically, the assumptions of analysis of variance are not satisfied. It is proposed that the effects of irrigation treatments be assessed using analysis of covariance, with distance from the sprinkler line as covariate, thus adjusting for a linear fertility trend. This method of analysis provides an approximate residual mean square for the fitting of response curves, but could be vulnerable to a quadratic fertility trend.
The Mineral Status of Soil, Forage and Cattle Tissues in the Middleveld of Swaziland
Authors: Ogwang B. H. 
Published: October 2008

SUMMARYThe mineral status of soil, native forage and cattle tissues in the Swaziland middleveld was investigated during the dry and wet seasons of 1985/86. In relation to beef cattle requirements, forage Mg, P, Na, Cu, Zn and crude protein were deficient during both seasons and K was low during the dry season. Cattle serum and liver samples were generally low or deficient in P, Zn, Cu and Mn, while their Fe content was in excess of normal requirements. The forage, liver and serum analyses indicate that cattle in the middleveld are likely to require supplementary Na, K, Cu, Zn, Mn and crude protein, but Ca, Mg and Fe levels appear to be adequate.
Responses of Some Turkish Wheat Cultivars to Vernalization and Photoperiod
Authors: Terzioğlu Serpil 
Published: October 2008

SUMMARYThe vernalization and photoperiodic response of six locally adapted bread wheat cultivars grown under natural daylength conditions during the summer or winter months was examined in glasshouse experiments. The wheat was vernalized by chilling imbibed grains at 2 ± 1°C for 0, 15 or 45 days. Vernalization for 45 days followed by long summer days led to floral initiation in all cultivars within 28 days but vernalization for 0 or 15 days only led to floral initiation in one cultivar. Vernalization followed by long days reduced the time from transplanting to anthesis, resulting in early ear emergence. Vernalization followed by short days accelerated the development of all the cultivars, but normal development could also occur without vernalization at this time of year. Apical differentiation of the primary shoot and its length and development gave the most reliable information on the period of vernalization required.
Frequency of Weeding Okra (Abelmoschus esculentus) for Optimum Growth and Yield
Authors: Iremiren G. O. 
Published: October 2008

SUMMARYField experiments were carried out during the rainy seasons of 1985 and 1986 to examine the frequency of weeding necessary for the optimum growth and yield of okra in Nigeria. Weed removal within 12 weeks of sowing generally resulted in significantly better crop growth and yield than that in the weedy check. Weeding once as early as four weeks was as beneficial to okra growth and yield as two or three weedings later in the 12 week period. Weed removal four times at 3, 6, 9 and 12 weeks significantly enhanced crop growth and pod yield over all other treatments. For good pod yields, protection from weed competition over most of the duration of crop growth is therefore essential. Such weed removal may enhance crop yield partly by increasing aeration and water movement in the soil.
The Yield Stability of Maize Genotypes across International Environments: Full Season Tropical Maize
Authors: Crossa J. , Westcott B. , Gonzalez C. 
Published: October 2008

SUMMARYEvaluation of the yield stability of a group of CIMMYT tropical maize populations across international environments, measured by the performance of varieties derived from them, showed that the populations Mezcla Tropical Blanca, La Posta and Amarillo Dentado produced the most stable varieties across environments. Mezcla Tropical Blanco and Amarillo Dentado produced selections with good stability in both low and high yielding environments while La Posta produced varieties with better performance in favourable environments. ‘Across-site’ varieties were not consistently more effective than ‘site-specific’ varieties in improving yield stability. Varieties selected for some specific population-environment combinations have been very stable in other areas of the world.
Farmer Participatory Research: Editorial Introduction
Authors: Farrington John 
Published: October 2008

SUMMARYThis paper places the participatory approaches to research presented in the six following papers into the broader debate on priorities in agricultural research and on the role of specific approaches to research. It reviews the principal features of the approaches outlined, the extent to which they have been incorporated into existing institutions such as national agricultural research services, and their implications for support services. Key issues which future participatory research should address are highlighted.
The Impact of Regular Research Field Hearings (RRFH) in On-farm Trials in Northeast Brazil
Authors: Baker Greg , Knipscheer Hendrik C. , De Souza Neto Jose 
Published: October 2008

SUMMARYThe study of livestock in farming systems research presents several challenges. Factors such as the small number of observations, high statistical variability in measurements, and the difficulty in valuing non-market inputs and outputs make it difficult to evaluate on-farm research. Regular Research Field Hearings (RRFH) can improve communication between scientists and farmers, thereby increasing mutual understanding, willingness to collaborate in evaluation, potential technologies, and also improving test results. Of three groups of sheep and goat farmers involved in on-farm testing in northeast Brazil, the group which participated in RRFH experienced a significantly higher level of success with the technology as measured according to performance criteria such as weight gains and farmers' perceptions of their animals' performance. The results confirm the importance of farmers' participation in agricultural research.
Developing a Partnership between Farmers and Scientists: the Example of Zambia's Adaptive Research Planning Team
Authors: Kean Stuart A. 
Published: October 2008

SUMMARYThe Adaptive Research Planning Team in Luapula Province (ARPT-LP) is one of nine provincial teams in Zambia conducting farming systems research within the Research Branch of the Ministry of Agriculture and Water Development. ARPT-LP has been relatively successful in developing a partnership with farmers, involving them in both the planning and implementation of the team's research programme. This paper examines the formal and informal occasions on which farmers have been involved in the team's activities, with examples to illustrate how farmers' opinions have influenced decisions made by ARPT-LP. The factors which have influenced the frequency and quality of the scientists' interaction with farmers are discussed.
A Participatory Method for Systems-Problem Research: Rehabilitating Marginal Uplands in the Philippines
Authors: Lightfoot C. , De Guia O. , Ocado F. 
Published: October 2008

SUMMARYA participatory method that promotes farmer involvement in systems-problem research was developed in response to the failure to adopt improved cropping patterns among upland farmers. Techniques to identify systems problems involved group and individual farmer meetings. Problems concerning the cultivation of marginal cogonal (Imperata cylindrica) uplands were identified. An informal random sample survey, guided by topics of inquiry and biological measurements that employed systems analytical tools, was used to obtain a farmers' perception of ‘systems-problems’. Systems diagrams also provided a framework for searching and screening solutions. A sequence of vining legumes was tested in rehabilitating the marginal uplands. For this experiment farmers elaborated hypotheses on control of Imperata, recovery of soil fertility, and reduced labour costs in re-cultivation. Extensive research activity among the farmers indicates the value of this participatory method.
Improved Livelihoods, Genetic Diversity and Farmer Participation: A Strategy for Rice Breeding in Rainfed Areas of India
Authors: Maurya D. M. , Bottrall A. , Farrington J. 
Published: October 2008

SUMMARYThe present structure of plant breeding and seed multiplication in India is highly centralized. Furthermore, only a small number of new varieties is officially released each year. The system therefore appears inappropriate for the requirements of the large proportion of Indian farmers located in risk-prone and highly diverse environments. An alternative strategy is described whose central feature is close matching of the characteristics of farmers' traditional rice varieties with those of advanced breeders' lines. A selection from these lines is then distributed in small quantities for on-farm trials managed by farmers themselves. If the success of these initial efforts is to be sustained, a more decentralized approach to breeding and multiplication will be necessary.
Farmers, On-farm Research and the Development of New Technology
Authors: Sumberg J. , Okali C. 
Published: October 2008

SUMMARYMost commonly, on-farm research has sought to validate and demonstrate technologies developed under controlled experimental conditions. It is argued here that on-farm research has a role in all stages of technology development, and that methodologies and objectives transplanted from the research station are inappropriate, particularly given the restrictions they impose on farmers' capacity to experiment with new technology. Drawing on experience with alley farming in W. Africa, it is shown how the farm and farm family can be incorporated fully throughout the process of technology development. The example is used to clarify the role of researchers in participatory technology development.
A Comparison of Thermocouple Psychrometer and Pressure Chamber Measurements of Leaf Water Potential in Peanuts
Authors: Wright G. C. , Rahmianna A. , Hatfield P. M. 
Published: October 2008

SUMMARYThe pressure chamber method for measuring leaf water potential in peanuts was compared with the thermocouple psychrometer technique. The pressure chamber over-estimated leaf water potential by an average of 0.4 MPa over the range −0.5 to −5.0 MPa. It is suggested that the pressure chamber technique may be appropriate in comparative studies of peanut water stress. However, where absolute measurements are required, as in the calculation of leaf turgor potential, either a correction factor should be applied or, preferably, the thermocouple psychrometer technique used. If no account is taken of the discrepancy between techniques, erroneously large negative turgor potentials will result.
A Simple Model for a Quantitative Comparison of the Regrowth of Perennial Fodder Crops
Authors: Kamidi R. E. , Wanjala J. B. W. 
Published: October 2008

SUMMARYThe rate of regrowth in realtion to total dry matter yield is important for smallholders fodder crop production. A simple regression technique is used to compare the rates of regrowth of eight perennial fodder crops cut at the same time. A brief interpretation and discussion of results from data illustrative of the model' use in given.
Soil Physical Properties of Tied Ridges in the Sudan Savannah of Burkina Faso
Authors: Hulugalle N. R. , Rodriguez M. S. 
Published: October 2008

SUMMARYThe soil physical properties of tied ridges were measured in a trial, established in 1983, comparing three treatments: handhoe cultivation and planting on the flat; planting directly without any cultivation on tied ridges constructed the previous year; and handhoe cultivation and remoulding of tied ridges constructed the previous year. Two maize varieties and two management levels were used. The soil properties monitored were particle size distribution, penetro-meter resistance in the surface 20 mm, bulk density, water infiltration, soil water retention and soil temperature.Soil physical properties were affected mainly by the type of seedbed. Clay content in the surface 0.05 m was greater with tied ridging, with that in the furrows being higher than that in the ridge slopes. Daily maximum soil temperature was greatest in the flat planted plots and in the ridge slopes of the tied ridged plots. Penetrometer resistance at a soil water content of 0.05 kg kg−1 was greater in the tied ridged plots. Cumulative infiltration after 2 h was greatest with flat planting. The bulk density of ridge slopes in tied ridged plots was less than that in the furrows and in the flat planted plots. Soil water retention was greatest in the furrows of the tied ridged plots. Clay content was the major factor determining all the soil physical properties measured.
Effect of Crop Geometry (Row Proportions) on the Water Balance of the Root Zone of a Pigeonpea and Rice Intercropping System
Authors: Jena D. , Misra C. 
Published: October 2008

SUMMARYRice, pigeonpea and rice + pigeonpea systems (in the row proportions of 1:2 and 2:5) were compared. Soil water depletion and percolation were determined during selected dry spells and yields ascertained after harvest. The mean evapotranspiration rates of rice, pigeonpea, rice + pigeonpea (1:2) and rice + pigeonpea (2:5) were 0.28, 0.79, 0.40 and 0.35 cm d−1, respectively, during a dry spell around 60 days after sowing. In general low rainfall intensity and frequent dry spells in the growing season increased pigeonpea yield but depressed that of rice. Intercropping thus ensured yield stability and hence the profitability of the system as a whole.
Was This in Your Statistics Textbook? IV. Frequency Data
Authors: Finney D. J. 
Published: October 2008

SUMMARYObservations that are frequencies rather than measurements often call for special types of statistical analysis. This paper comments on circumstances in which methods for one type of data can sensibly be used for the other. A section on two-way contingency tables emphasizes the proper role of χ2 a test statistic but not a measure of association; it mentions the distinction between one-tail and two-tail significance tests and reminds the reader of dangers. Multiway tables bring new complications, and the problems of interactions when additional classificatory factors are explicit or hidden are discussed at some length. A brief outline attempts to show how probit, logit, and similar techniques are related to the analysis of contingency tables. Finally, three unusual examples are described as illustrations of the care that is needed to avoid jumping to conclusions on how frequency data should be analysed.