bluuebunny/crossref_metadata_2025 huggingface dataset:
Frost Injury and Performance of Coffee at 23° S in Brazil
Authors: Filho A. Androcioli , Siqueira R. , Caramori P. H. , Pavan M. A. , Sera T. , Soderholm P. K.
Published: October 2008

Eighteen arabica coffee introductions from the USDA germplasm collection were planted at 23° S latitude in Brazil from 1977 to 1982 to assess their yield potential and frost hardiness, compared with the cultivar Catuai Amarelo which is extensively planted in Brazil. Nine of the introductions had similar yields to Catuai Amarelo. Erecta T966 and Harrar yielded as well as Catuai Amarelo and were also more frost hardy. Tall, early maturing coffee varieties showed the least frost injury.
A Field Screening Technique for Drought Tolerance
Authors: Sagar Prem , Kapoor R. L.
Published: October 2008

A simple yet effective field screening technique for estimating drought tolerance is described. It involves growing plants in sloping plots which are opposite each other and connected to sub-channels lined with polyethylene sheet. The slopes are designed to achieve instant surface run-off and the sub-channels connected to a main channel for rapid drainage of rain-water. Stress is created at different stages of crop growth by manipulating the timing of irrigation and covering the soil surface with polyethylene sheeting. The technique proved effective even in the monsoon season which is characterized by irregular intensity and distribution of rainfall. Data on six characters for 80 genotypes of pearl millet grown in six artificially created environments representing different levels of moisture stress are discussed. The ‘slope’ technique was effective in creating different levels of moisture stress at various stages of crop growth and in distinguishing categories of genotypes by their relative drought tolerance.
Response of Wheat on Coarse Textured Soils to Mode and Time of Manganese Application
Authors: Takkar P. N. , Nayyar V. K. , Sadana U. S.
Published: October 2008

Two field experiments were conducted to evaluate the efficiency of rate, mode and time of application of manganese sulphate to irrigated wheat on manganese-deficient loamy sand (Ustipsamments) soils recently brought under rice. A significant increase in manganese uptake by wheat and marked increases in wheat grain and straw yields occurred following both soil (5, 10 and 20 kg Mn ha-1) and foliar (0.5, 1.0 and 2.0% MnSO4 solution) application of manganese, but foliar application was more effective. A series of sprays initiated before the wheat was first irrigated (26 days after sowing) gave significantly better results than application begun after the first irrigation (32 days after sowing); four sprays of 0.5% MnSO4 solution produced the largest grain yield, followed by three of a 1% solution.
Sesame Agronomy in South-east Tanzania. I. Plant Population and Sowing Method
Authors: Taylor B. R. , Chambi J. Y.
Published: October 2008

Field trials are described in which the seed yield response of row-sown sesame to increasing plant population was examined, and in which row-sowing was compared with broadcasting at different seed rates. Maximum yields were obtained at an intended 200 to 250 × 103plants ha−1but yields were not greatly affected by a wider range of populations. Broadcasting, the normal local practice, gave yields slightly higher than those from rows 50 cm apart, the un-thinned rate of 800 × 103viable seeds sown ha−1yielded as well as treatments thinned to the optimum population, and double this seed rate, unthinned, gave the lowest yields, especially in rows.
Effects of Sowing Pattern and Seed Rate on Green-chop Yield of Forage Sorghum
Authors: Bebawi F. F. , Mazloum A. E.
Published: October 2008

The effects of sowing pattern and seed rate on the green-chop yield of forage sorghum-sudangrass hybrid (cv. Pioneer 988) and forage sorghum (cv. Abu Sabeen) were investigated. In general, more green-chop yield was obtained from seed of both cultivars drilled in regular rows, double rows and triple rows than when traditionally sown as broadcast seed. Yields were greater when plants were sown at 70 kg seed ha−1 than when traditionally sown at 35 kg seed ha−1. These yield advantages were sustained through three successional harvests. Pioneer 988 generally yielded more than Abu Sabeen, especially when sown in January. Both cultivars gave minimum yield when sown in April, July or October.
Effect of Apical Debudding on Growth and Yield of Okra (Abelmoschus esculentus)
Authors: Olasantan F. O.
Published: October 2008

Field trials on okra over three seasons showed that the removal of the apical bud on the main stem at 3 or 4 weeks did not affect marketable fruit yield but that yield was reduced by about 39% when debudding was done at 5, 6 or 7 weeks. Apical debudding led to increased vegetative development, enhanced dry matter accumulation and reduced plant height. Removing the apical bud at weeks 3, 4 or 5 delayed the first harvest by 8, 15 or 18 days, respectively, compared to the undebudded control plants. It appears that okra can tolerate considerable apical damage during the vegetative stage, as can happen with insect attack, without serious loss of yield.
Significance of the Coupling between Saturation Vapour Pressure Deficit and Rainfall in Monsoon Climates
Authors: Monteith J. L.
Published: October 2008

In monsoon climates, the mean daytime saturation vapour pressure deficit (D), measured at screen height, decreases from a maximum of 3–4 kPa attained several months before rain arrives to a minimum of 0.5–1 kPa in the month of highest rainfall. Climatic records from India and West Africa were analysed to give the relation between D and precipitation (P mm month−1) as:

where n ranged from 0.5 to 0.9 between stations.

The dependence of dry matter production on D and therefore on P is evaluated when growth is restricted by rain and when this restriction is removed by irrigation. In the first case, the decrease in demand for water associated with a decrease in D is comparable in importance with the increase of water supply (P). The analysis has implications for the marginal response of crops to supplemental irrigation and for the interpretation of experiments with a line-source or rain-shelter.
Effect of the proportion of Species on the Yield and Quality of Forage Mixtures, and on the Yield of Barley in the Following Year
Authors: Osman A. E. , Nersoyan N.
Published: October 2008

Mixtures of legumes and cereals in various proportions (seed ratios) were evaluated in Northern Syria for forage production and quality and for yield of barley grain in the following year. Both a vetch-cereal and pea-cereal mix were tested in proportions of 0:100, 33:66, 50:50, 66:33 and 100:0. The study was carried out between 1982 and 1985, covering two seasons for forage production and two for grain production. Dry matter yields of the mixtures exceeded the yield of either one or both components of the mixture grown as pure stands, depending on the rainfall. The maximum overall yield and quality of forage was recorded for the 66:33 legume-cereal combination. The greatest benefit to subsequent barley grain yield was realized when the legume was grown in a pure stand or formed a high proportion (66:33) of the mixture. Herbage quality was better in forages containing vetch than in those containing pea.
Calibration of Experiments on Perennial Crops using Covariance Analysis: the Case of Coconut
Authors: Abeysinghe Tilak
Published: October 2008

The calibrating efficiency of the pre-experimental yield of coconuts was examined using ten years data from a calibration experiment. On the basis of a fully randomized design it was found that the two-year pooled pre-experimental yield on four-tree plots produces consistent calibration and reduces the experimental error mean square by about 73%. This brings down the mean coefficient of variation to 9.7% from its pre-calibration levels of 36 on one-tree plots and 18 on four-tree plots.
The Field Performance of Induced Uniculm Grain Sorghum (Sorghum bicolor) in South-east Queensland, Australia
Authors: Fukai S. , Liwa C. J. , Henderson C. W. L. , Maharjan B. B. , Hermus R. C. , Searle C. , Herbert S. W. , Foale M. A.
Published: October 2008

Reduction of leaf area in sorghum without tillers (uniculm sorghum) might result in conservation of water at early stages of growth and hence in stability of grain yield under dry conditions. In two experiments in south-east Queensland, Australia, tillers were removed by hand to examine the growth of uniculm sorghum. Tiller removal promoted root development at the flag leaf stage but significantly reduced shoot dry matter and lowered grain yield by about 20% in a wet season. The saving in soil water as a result of tiller removal was relatively small but statistically significant.
Quantifying and Valuing the Joint Production of Grain and Fodder from Maize Fields: Evidence from Northern Pakistan
Authors: Byerlee Derek , Iqbal Muzaffar , Fischer K. S.
Published: October 2008

Simple methods are proposed for measuring the relative importance of grain and fodder produced jointly from maize fields in four zones in northern Pakistan. These methods suggest that the joint production of grain and fodder from maize is important in all four zones and that fodder accounts for between one-third and one-half of the total value of the crop. The relative value of fodder production is particularly high in two of the zones (the irrigated mid-altitude Swat Valley and the rainfed low altitude Islamabad District), both characterized by a high ratio of animal numbers:maize area. The results suggest that maize research and extension recommendations that do not take into consideration the fact that farmers produce maize for fodder as well as grain will often not be accepted by farmers.
Growth, Nodulation and Nitrogen Fixation in Stylosanthes: Effect of Different Day/Night Root Temperatures
Authors: Date R. A.
Published: October 2008

Nodulated plants of six varieties of Stylosanthes were grown at a constant temperature of 30°C for 21 days in a controlled environment and then for a further 21 days at a range of day/night root temperatures. Dry matter and nitrogen content of S. hamata cv. Verano and CPI40264A were measured after growth at day/night root temperatures of 30/30, 40/30, 50/30, 60/30 and 60/35°C. Similarly, growth and nitrogen content were measured for Verano, CPI40264A, S. gvianensis cv. Oxley and cv. Cook, S. humilis cv. Lawson and S. scabra cv. Seca after growth at root temperatures of 25/20, 25/25, 30/25, 30/30, 35/30 and 40/30°C. There were strong interactions of root temperature with variety and harvest time (31 and 42 days) but all varieties grew well even at the highest temperatures (50–60°C) provided they were supplied with nitrogen. Symbiotically dependent plants of S. hamata cv. Verano were more tolerant of high root temperatures and maintained better growth and nitrogen fixation at 40/30°C than those of CPI40264A, especially after the 31 day harvest. All six varieties responded similarly, but to differing extents, to the lower range of root temperatures. Nitrogen fixation was more severely affected than dry weight by high root temperature.
A Comparison of the Use of Azolla and Blue-green Algal Bio-fertilizers with Green Manuring, Organic Manuring and Urea in Transplanted and Direct-seeded Rice
Authors: Singh A. L. , Singh P. K.
Published: October 2008

Azollaand blue-green algae (BGA) inoculated in a rice field produced a higher biomass and fixed more nitrogen in transplanted than in direct-seeded rice. Application ofAzolla, BGA, composts of Eichhomia andAzollaand green manuring withSesbaniaincreased tiller numbers, height, grain and straw yields, and nitrogen uptake by rice in both the transplanted and the direct-seeded crop. The growing and incorporating of threeAzollacrops with the rice crop produced more grain than the use of other nitrogen sources but the rice crops showed a poor response to inoculation with BGA. The yield of rice following green manuring withSesbaniaor the use of two crops ofAzollaafter transplanting was similar to that of a crop receiving 60 kg N ha−1as urea, but smaller yields resulted from the use of composts ofAzollaandEichhornia.
Effects of Green-stage Grazing on Rainfed Barley in Northern Syria. II. Yield and Economic Returns
Authors: Yau S. K. , Mekni M. S. , Naji I. , Srivastava J. P.
Published: October 2008

The effect of a single grazing at the tillering stage on barley yield and economic returns was studied with two widely grown local landraces over five seasons at Tel Hadya and two seasons at Breda in northern Syria. In general, grazing reduced both grain and straw yield, particularly the latter. The percentage of grain yield reduction was similar at the two sites. Grazing increased net revenue on average, though there were marked seasonal differences. This increase was higher at Breda, the drier site, a finding which contradicts the commonly-held belief that grazing is unprofitable in dry areas.
Effects of Component Densities and Nitrogen Fertilization on Efficiency and Yield of a Maize/Soyabean Intercrop
Authors: Russell J. T. , Caldwell R. M.
Published: October 2008

A field study was conducted in 1985 at two locations in Maryland, USA, to test the influence of environment (location), input level (N fertilization), management (component density combinations), and measure of performance on recommendations for a maize/soyabean intercrop. Location affected the degree of intercrop yield depression of each crop; the effect of N on relative competitive abilities; the maximum Land Equivalent Ratio (LER) and maximum modified Staple Land Equivalent Ratio (SLER); the difference between LER and SLER; the optimum density combinations and change in optima in response to N; and the N level at which the greatest land use efficiency was achieved. Given the complexity of the environmental effects, recommendations based on the trials have a very narrow range of applicability.
A Water Stress Index for Tea (Camellia sinensis)
Authors: Stephens William , Carr M. K. V.
Published: October 2008

A simple Stress Time Index (STI) for predicting yield loss in the tea crop due to drought is proposed, based on the daily summation of the difference between the potential soil water deficit and a specified limiting value. Validation of the technique with results from a line-source irrigation experiment with a single clone in the Southern Highlands of Tanzania suggests that there is a linear relationship between STI and relative yield loss during the warm dry season. As a result of changes in the composition of the shoot population at each harvest the apparent critical deficit at which shoot growth is restricted increases from below 20 to 300 mm as the dry season progresses. The rate of yield loss with increasing STI also varies through the dry season for the same reason.
A Large, Retractable, Low Cost and Re-Locatable Rain Out Shelter Design
Authors: Hatfield P. M. , Wright G. C. , Tapsall W. R.
Published: October 2008

The design of a low cost and relocatable rain out shelter used for drought studies in the field is described. This design, covering 162.5 m2, enables reasonable plot sizes to be used and minimizes aerial and sub-aerial edge effects. A fully retractable vinyl cover results in minimal modification of the surrounding crop environment.
Intercropping Short and Long Duration Groundnut (Arachis Hypogaea) Genotypes to Increase Productivity in Environments Prone to End-of-season Droughts
Authors: Rao R. C. Nageswara , Wadia K. D. R. , Williams J. H.
Published: October 2008

Three short duration and one long duration groundnut genotypes, grown either ‘sole’ or as intercrops (in 1:1 ratios of the short duration with the long duration genotypes), were compared in four trials. The intercrop treatments resulted in Land Equivalent Ratios (LERs) of up to 1.25 for pod yield and total biomass despite moderate or severe water deficits at the end of the season. Specific combinations of genotypes were necessary to maximize the LER. The results indicate there is scope for achieving greater productivity in environments with a variable season length by growing late and early genotypes together in an intercrop system.
Intercropping Experiments, Statistical Analysis, and Agricultural Practice
Authors: Finney D. J.
Published: October 2008

Much recent research has been directed at intercropping. Although the planning and analysis of these experiments often raises complicated statistical questions, many statisticians have concentrated on sophisticated graphical and numerical procedures for summarizing results, without considering what system of intercropping, if any, is on balance advantageous to the farmer and how its advantage is to be measured. This paper surveys aspects of intercropping that need examination before farmers can be advised, such as the value of produce, and the effects of intercropping on yields and costs. Any synergism of productivity occurring directly or in the longer term is a central but not necessarily decisive aspect of the problem. A recently described experiment is used as an example. The main conclusion is that experiments on these topics need to be large and well-designed, with repetition in several years, and that interpretation must allow for alternative sets of numerical values expressing values and costs.
Plant Breeders' Rights, an Equitable Legal System for New Plant Cultivars
Authors: Mastenbroek C.
Published: October 2008

As the art of plant breeding became a professional and increasingly expensive activity, legal protection was gradually provided in member states of UPOV (International Union for the Protection of Plant Varieties), at present 17 in number. The requirements and scope for protection by Plant Breeders' Rights (PBR) are reviewed and are considered to be favourable for plant breeders, growers and national agricultural productivity. Advantages and disadvantages of PBR and patent protection in connection with biotechnology, the rôle of multinationals as plant breeders and aspects of genetic erosion are discussed.
The Effects on Soil Temperature and Moisture Content and Crop Growth and Yield of Intercropping Maize with Melon (Colocynthis vulgaris)
Authors: Olasantan F. O.
Published: October 2008

The effects of various intercropping patterns of maize and melon on soil temperature and moisture content and crop growth and yield were compared in field trials over a two year period. Intercropping raised soil temperature in the upper 10 cm at 0600 h and reduced it at 1000, 1400 and 1800 h, and also increased soil moisture content by about 30%, compared with maize sole cropping. Melon biomass and seed yields were reduced by intercropping but maize growth characters were unaffected. However, the reduction in melon yields was less when grown with maize in widely spaced rows. Maize intercropped with melon in alternate pairs of rows (2:2) gave the best land equivalent ratio (LER).
Environmental Modulation of Flowering in Mung Bean (Vigna radiata): Further Reappraisal for Diverse Genotypes and Photothermal Regimes
Authors: Summerfield R. J. , Lawn R. J.
Published: October 2008

Genotypes of mung bean commence flowering at very different times depending on sowing date and location, but relatively little is known about the modulation of flowering by environmental factors. Previous and frequently cited conclusions have been that: (a) genotype, photo-period and temperature all interact to determine relative earliness to flower, and that (b) the genetic control of these photothermal responses is seemingly complex. However, our reanalyses of original data in terms of rates of progress towards flowering, 1/f, rather than the traditional approach based on days from sowing to flowering, f, show that the photothermal modulation of flowering in mung bean can be described by a series of simple, linear models, and that interaction terms involving photoperiod and temperature are often insignificant. The merits and implications of this alternative analysis and interpretation of original data are discussed.
Long-term Forage Yields of Five Tropical Grasses on an Extremely Sodic Soil and the Resultant Soil Amelioration
Authors: Kumar Ashok
Published: October 2008

A long-term field study was conducted from 1979 to 1985 in the Karnal district of Haryana, India to evaluate the effect of three rates of gypsum (0, 5.2 and 10.4 kg ha−1) on the performance of five grasses (Diplachne fusca, Panicum laevifolium, P. antidotale, Chloris gayana and Cynodon maritimus) on an extremely sodic soil with an initial pH of 10.6 and an exchangeable sodium percentage (ESP) of 94. Diplachne, Chloris and Cynodon usually gave their maximum yield in the second year of planting, P. antidotale in the third year and P. laevifolium in the fourth year. The results showed that Chloris can be recommended for such situations as it maintains a higher productivity over a longer period than the other grasses. Alternatively P. antidotale and P. laevifolium can be planted in association with Diplachne to provide a steady forage supply for a long time. Increasing doses of gypsum resulted in decreases in soil pH, exchangeable sodium and ESP and increases in calcium, magnesium, organic carbon and the infiltration rate of soil.
Effects of Different Green Manures and Fodder Crops on Crop Yields and Phosphorus Needs of Potato–Wheat Systems in the North-Western Plains of India
Authors: Sharma R. C. , Govindakrishnan P. M. , Singh R. P. , Sharma H. C.
Published: October 2008

The tuber yield of potatoes in a field experiment conducted at Jalandhar between 1981 and 1984 was greater following green manuring with either Crotalaria juncea or Sesbania aculeata than after fodder crops of Zea mays or Pennisetum typhoides. The residual effect of phosphorus applied to potato on subsequent wheat crops varied with the previous green manuring and fodder cropping treatments but was always sufficient for the wheat when applied at an economic rate; the lack of an application of phosphorus fertilizer to the wheat did not result in a decline in the availability of soil phosphorus. The use of C. juncea as a green manure increased the availability of phosphorus but decreased that of potassium. Pennisetum typhoides also depleted soil potassium reserves. Sesbania aculeata green manure improved the organic carbon status of soil whereas P. typhoides depleted it.
Causes of Irregular Clove Production in the Islands of Zanzibar and Pemba
Authors: Martin Peter J. , Butler David R. , Dabek Andrew J.
Published: October 2008

In spite of large year-to-year variations in clove yields, production in the islands of Zanzibar and Pemba is often in synchrony and the annual harvests of the two islands are correlated with similar variables. Clove harvests are positively correlated with rainfall in October to February two years before the harvest and negatively correlated with the harvest in the previous year and rainfall around July, and October to December of the year before the harvest. It is likely that rainfall in these periods affects vegetative growth of the clove tree and clove bud differentiation.
Minimizing Yield Losses of Sugarcane When Grown with a Wheat Companion Crop by Fertilizer and Water Management
Authors: Verma R. S. , Yadav R. L.
Published: October 2008

In sub-tropical India where 70% of the country's sugarcane is grown, companion cropping of wheat in autumn-planted sugarcane is beneficial. However, because the yield of sugarcane is reduced, farmers there are reluctant to adopt this cropping system in spite of the greater monetary gains compared with wheat-sugarcane sequential cropping. Application of 200 kg nitrogen ha−1 to sugarcane in two doses, two-thirds immediately after the wheat harvest and the remainder a month later, combined with irrigation at 75% available soil moisture during the summer months (April–June), produced cane yields similar to those from sole autumn-planted sugarcane, with an additional 4.8 t ha−1 of wheat.
Effect of Concentration and Time of Application of the Defoliant Harvade on the Lint, Seed, Protein and Oil Yields, and Oil Properties of Cottonseed
Authors: Sawan Z. M. , Hefni EL-S. H. M. , Allam M. A.
Published: October 2008

Field experiments were performed in 1981 and 1982 on the cotton cultivar Giza 75 to determine the effect of different concentrations and application dates of the defoliant Harvade on the lint, seed, protein and oil yields, and oil properties of cottonseed. Defoliant concentrations of 240, 360 and 480 ml ha−1 increased lint yield per plant but tended to decrease seed index. Cottonseed yield per hectare, seed oil and protein percentage and yield, oil refractive index, free fatty acids, saponification and iodine values were not significantly affected by the defoliant. Late application increased lint yield per plant and cottonseed, oil and protein yield per hectare. Date of application had no effect on seed index, seed oil and protein percentage and oil properties.
Effects of Phosphorus and Carbofuran on the Growth and Nitrogen Fixation of Azolla pinnata and the Yield of Rice
Authors: Singh D. P. , Singh P. K.
Published: October 2008

The effects of phosphorus fertilizer and the insecticide carbofuran on the growth and N2-fixation of Azolla pinnata and on the growth, grain yield and nitrogen uptake of intercropped rice were examined in a wet and a dry season. Treatment with phosphorus or carbofuran increased the biomass of Azolla and the amount of nitrogen fixed (nitrogen yield) in both seasons, but the response was much better in the dry season. Azolla inoculation at 1.0 t ha−1 resulted in a greater bio mass and nitrogen yield than inoculation at 0.5 t ha−1. In the dry season, a combination of phosphorus and carbofuran enhanced the growth and N2-fixation of Azolla more than either treatment alone. Carbofuran treatment slowed the rate of decomposition of Azolla, particularly in the dry season. The plant height, leaf area index and dry matter production of rice at flowering time were increased in the plots treated with phosphorus or carbofuran in the wet season and these treatments increased rice grain yield and nitrogen uptake in both the wet and dry seasons.
The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis Hypogaea) in Response to Drought. I. Dry Matter Production and Water Use
Authors: Matthews R. B. , Harris D. , Rao R. C. Nageswara , Williams J. H. , Wadia K. D. R.
Published: October 2008

Four genotypes of groundnut grown with limited irrigation in a medium depth Alfisol in Central India transpired similar total amounts of water (220–226 mm) over the season, but produced different amounts of shoot dry matter (390–490 g m−2). The extraction front of Kadiri 3 moved most rapidly down the soil profile which may have enabled it to maintain the fastest rates of transpiration when soil water depletion was greatest. Tap root extension rates of Kadiri 3 in the first 32 days after sowing were also the fastest. NC Ac 17090 was more efficient than the other genotypes in extracting water immediately after irrigation from the upper 40 cm of the soil, but this had little value in determining the pattern of water availability in this experiment. Differences in the water extraction characteristics of these genotypes explain little of the variation in dry matter:water ratio, and do not account for the major variation in harvest index associated with drought.
The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis hypogaea) in Response to Drought. II. Solar Radiation Interception and Leaf Movement
Authors: Matthews R. B. , Harris D. , Williams J. H. , Rao R. C. Nageswara
Published: October 2008

Four genotypes of groundnut grown with limited irrigation during the post-rainy season in Central India produced similar amounts of dry matter per unit of intercepted solar radiation (e) before pod-filling, although different e values were observed during pod-filling. The relation between cumulative transpiration and intercepted radiation was similar for all genotypes. When drought became severe, fractional radiation interception (f) was reduced by folding of leaves, with little decrease in leaf area (L). The ratio f/√L was used as an index of the degree of leaf folding and was correlated with leaf water potential. The degree of folding varied with genotype and may have contributed to the observed differences in e and the dry matter:water ratio (q). The genotype EC76446(292) had the smallest q and largest f/√L ratio (the poorest radiation avoidance), while Kadiri 3 had the largest q and smallest value of f/√L.
The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis Hypogaea) in Response to Drought. III. Developmental Processes
Authors: Harris D. , Matthews R. B. , Rao R. C. Nageswara , Williams J.H.
Published: October 2008

Rates of leaf development in four groundnut genotypes were found to depend primarily on temperature, although there was a linear relation between the thermal time to produce one leaf and mean leaf water potential below −0.6 MPa. Flower, peg and pod production was analysed in relation to leaf number, since this integrated effects of temperature and water status.

When water was not limited, the ratio of pod number: peg number was about 0.8 for all four genotypes. During drought only one genotype (TMV 2) maintained this value, while for the other genotypes the ratio was approximately 0.15. Genotypes also showed different patterns of development during recovery from drought. TMV 2 maintained relatively high values of partitioning factor throughout the pod-filling period, resulting in the largest harvest index and pod yield. Kadiri 3 achieved the second largest harvest index and pod yield by maintaining production of pegs during drought and only forming pods when stress was relieved.
Effects of Geographical Area of Production on the Composition of the Volatile Flavour Compounds in Kenyan Clonal Black CTC Teas
Authors: Owuor Philip O. , Tsushida Tojiro , Horita Hiroshi , Murai Toshinobu
Published: October 2008

The contents of the volatile flavour compounds and the flavour index of black teas vary with localities. The magnitude and order of the variations are clonally dependent, the relative performance of clones varying with location. For a comprehensive breeding programme to improve black tea quality, it is suggested that tea clones should be evaluated in the areas of potential release before they are made available to tea growers.
Technology Development and Farmer Groups: Experiences From Botswana
Authors: Norman D. , Baker D. , Heinrich G. , Worman F.
Published: October 2008

The Agricultural Technology Improvement Project (ATIP) has been conducting on-farm research in Botswana with the goal of identifying improved arable production technologies. In an effort to increase the role of farmers in technology design and assessment, ATIP set up farmer groups that meet on a regular basis to discuss farming problems and on-farm trials. This article reviews and evaluates ATIP's experiences with farmer groups. A typology of technology development groups is proposed and group management issues are discussed.
Was this in Your Statistics Textbook? II. Data Handling
Authors: Finney D. J.
Published: October 2008

Good data handling is a prerequisite for good statistical analysis and interpretation. This paper begins by distinguishing types of numerical data. Care for original data and the risks involved in any process of copying data are emphasized. After discussion of the entry of data into a computer file, problems of scrutiny and checking are discussed at length. An attempt is made to suggest what action should follow when such scrutiny discloses anomalies in some values; if explanations can be found, or if clear evidence indicates corrections that are needed, no problem arises, but otherwise various subjective responses need consideration. Advice is offered on the numbers of digits to be retained in computations and reports. A final section presents ideas on the filing of data and analyses from an experiment.
Evidence for Yield Stability in Selected Landraces of Bean (Phaseolus vulgaris)
Authors: Ayeh Eric
Published: October 2008

Yield stability in beans from diverse sources in Malawi was estimated using the statistical parameters of genotype X environment variance, slope and standard error from regression. The heterozygous F2 and the most complex synthetic mixture were very stable, although not significantly different from some pure genotypes. The mean yields of most mixtures were marginally higher than the average of their components. There was a linear relationship between magnitude of diversity and stability. Evidence for heterozygote advantage was demonstrated.
Sociological and Ecological Factors in Technology Adoption: Fodder Trees in Southeast Nigeria
Authors: Francis P. A. , Atta-Krah A. N.
Published: October 2008

Farmer-managed trials with browse trees were undertaken at two locations in southeast Nigeria. The fast-growing tree species Leucaena leucocephala and Gliricidia sepium were either inter-planted with crops as alley farms or planted in pure stands as intensive feed gardens. At both locations, most of the trees established successfully under farmer management. However, the quality of establishment was uneven, and the rate of utilization generally poor, especially at one site. The limited success of the trials is traced to a number of related sociological, institutional and edaphic factors. These include poor soil fertility; the incompatibility of established cropping patterns and rotation practices with the planting of trees on farms; the division of labour and organization of decision-making within the household; and land and tree tenure rules. It is argued that farmer-managed trials are necessary to reveal the importance of sociological and institutional factors in farmers' decision making, and that such trials require a high level of farmer autonomy in their management.
Effect of Inoculating Crops with Phospho-microbes
Authors: Tiwari V. N. , Lehri L. K. , Pathak A. N.
Published: October 2008

Seed inoculation with Bacillus polymyxa markedly increased the yields of rice and chickpea crops, while Pseudomonas striata caused a greater impact on crop production when used with rock phosphate or super-phosphate in a wheat crop. The effect of the phospho-microbe inoculants was greater in phosphorus-deficient soils.
Population, Water Use and Growth of Groundnut Maintained on Stored Water. II. Transpiration and Evaporation from Soil
Authors: Simmonds L. P. , Williams J. H.
Published: October 2008

Stands of groundnut were grown at four densities on water stored in a medium depth alfisol in central India. Evaporation was estimated from changes in soil water content, and partitioned between transpiration and evaporation from the soil surface. Seasonal transpiration was strongly influenced by plant population, and approached a maximum as the population density increased to 23 plants m−2. Evaporation from the soil surface was only a small component of the seasonal water balance in dense stands, and was little affected by planting density. Differences in transpiration rate between spacings were greatest early in the season, but diminished when the denser stands ran out of water. The denser stands extracted more water from deep in the profile. Plants in widely spaced rows preferentially extracted water from near the row; water mid-row was only used later in the season.
Population, Growth and Water Use of Groundnut Maintained on Stored Water. IV. The Influence of Population on Water Supply and Demand
Authors: Simmonds L. P. , Azam-Ali S. N.
Published: October 2008

The objective of this paper is to identify the major factors responsible for the differences in transpiration rate (T) between stands of groundnut grown at three row spacings on stored water in central India. A method of analysis is developed to distinguish between the impact on transpiration of ground cover (which varied threefold between spacings) and of root:shoot ratio, which was substantially greater in the wider row spacings. When the soil was wet, both T and the canopy conductance, gc, were approximately proportional to the fraction (f) of incident radiation intercepted by foliage. But when the soil water content decreased below a threshold value, T/f and gc/f decreased because of an increase in stomatal resistance. Stomatal closure in response to soil water stress occurred sooner in the denser stands, partly because of more rapid depletion of soil water. A second contributory factor was that the sparser stands (which had a relatively large root:shoot ratio) had a greater capacity to keep stomata open as the soil water deficit increased.
The Evaluation of Alternative Fodder Crops under African Highland Conditions
Authors: Potts Michael J. , Biranguza Evariste
Published: October 2008

Four forage bassicas, kale, rape, turnips and swede, and fodder beet were evaluated for adaptation to tropical highland conditions using small-plot experiments and field observations. In a short cropping season turnips were best adapted with a mean yield of 22 t ha−1. The crop was quick to establish and gave good ground cover. Kale and swedes were better adapted to a long season and yielded more than perennial forage grasses or maize. Yield was related to the length of growing season, exceeding 100 t ha−1 by about 250 days. Kale and swedes established poorly on soils high in aluminium. Direct sunlight appeared to damage swede roots, causing secondary soft rots. Rape showed no advantage over kale. Fodder beet failed to establish satisfactorily in any of the experiments.
Controlled Environments as an Adjunct to Field Research on Lentils (Lens culinaris). IV. Cultivar Responses to Above- and Below-average Temperatures during Vegetative Growth
Authors: Summerfield R. J. , Muehlbauer F. J. , Short R. W.
Published: October 2008

The climates to which lentil (Lens culinaris) crops are exposed can vary appreciably depending on location and date of sowing. The effects on growth, development and seed yield when three USA cultivars experienced relatively warmer or cooler day/night temperatures during the vegetative period were investigated in growth cabinets. Plants were nodulated and supplied with either 20 or 80 ppm inorganic N; they differed appreciably in morphology and vegetative vigour, and so in their potential for subsequent pod production, depending on pre-flowering temperature and on nitrogen nutrition. Variations in seed yield were largely a consequence of treatment and cultivar effects on pod number per plant, and a pre-flowering temperature regime of 21°/7°C (mean 14.9°C) was supra-optimal. The pre-flowering environment clearly affects potential pod production and has persistent effects on the capability of plants to fill the pods produced.
New Farming Systems Development in the Wetter Tropics
Authors: Juo A. S. R.
Published: October 2008

Farming systems in the wetter tropics may be divided into three simplified models: the irrigated paddy-rice multistorey homestead garden complex of Asia, the tree and cash crop plantations of Latin America, and the mixed root crop-bush fallow systems of Africa. In upland ecosystems, sustainable farming systems development rests on a delicate balance between conservation and utilization. To meet the basic food and nutritional needs of the indigenous population, there is great potential for the improvement and adaptation of multistorey homestead gardens and mixed systems which include trees and annual and perennial crops. The principle and practice of ‘alley cropping’ provide an ecologically sound basis for future farming systems research and development in the region.
Effect of Coated and Uncoated Urea on the Carry-over of Nitrogen from Jute to Paddy Rice in the Humid Sub-tropics
Authors: Sarkar Apurba
Published: October 2008

Paddy rice was grown without fertilizer after jute which had been supplied with nitrogen as neem cake coated urea (NCU), wax coated urea (WCU), ammonium sulphate or standard urea at rates of 0, 40, 80 or 120 kg N ha−1. NCU or WCU applied to jute increased the dry matter and grain yield of the rice, suggesting that enough nitrogen is left behind to grow a subsequent rice crop without further fertilizer application.
Long-term Effects of the Continuous Cultivation of a Tropical Ultisol in Southwestern Nigeria
Authors: Obi A. Olu
Published: October 2008

Continuous cropping of a tropical Ultisol with or without nitrogen fertilizer increased soil acidification and reduced soil organic matter and productivity. Addition of nitrogen fertilizer failed to increase yields. This was apparently due to the decline in soil pH, an increase in the amount of soluble aluminium, and consequent inefficient utilization of added nutrients. Continuous use of ammonium sulphate as a nitrogen source hastened the development of both surface and subsoil exchange acidity.
A Survey Methodology for Assessing Yield Potential and Coffee Berry Losses in Peasant Coffee
Authors: Browning Gordon , Dorward Andrew
Published: October 2008

The effects of coffee berry disease (CBD) on yield are usually estimated by counting infected berries on marked branches throughout fruit development. This method is impractical when surveys are required of yield losses over large areas of extensively cultivated peasant coffee. A survey method is described for estimating yield potentials and the loss in yields due to severe CBD infection under such conditions. The method exploits the relation between numbers of flowering nodes and yield per tree, and requires a single subjective estimate of disease incidence on young expanding berries. Yield losses are estimated from the changes in this relation resulting from berry infection. Results are presented for peasant coffee at different stages of rehabilitation in Ethiopia. They indicate that the method is suitable for estimating.production in agronomic improvement projects and for identifying areas where CBD incidence might economically justify fungicide spraying.
The Use of Azolla Pinnata Isolates as Organic Nitrogen Sources for Lowland Rice (Oryza Sativa)
Authors: Singh A. L. , Singh P. K.
Published: October 2008

Four isolates of Azolla pinnata collected from Bangkok, Bangladesh, Vietnam and India grew well when used in paddy fields both before and after transplanting with rice varieties of different heights and times to maturity. Azolla increased plant height, tillering, 1000-grain weight, grain and straw yields, nitrogen concentration and uptake, and soil fertility.

The response of rice to Azolla was similar to that obtained by applying 60 kg N ha−1 as urea in three split applications. The different Azolla isolates differed in their growth, N2-fixation and response to rice crops and soil fertility. All these characteristics were better in the isolates from Bangkok and Vietnam than in those from Bangladesh and India. Azolla growth and N2-fixation were better with short rice varieties (IR-36, Ratna and Kalinga-II) than with Mahsuri, a tall rice variety, but Mahsuri, having a longer growing season, showed a better response to Azolla.
Cultivar X Cropping System Interactions in relay and row Intercropping of Bush Beans with different Maize Plant Types
Authors: Woolley J. N. , Rodríguez W.
Published: October 2008

Bean yield at two sites in Costa Rica was affected by the interactions of maize and bush bean cultivars with cropping system (relay, row intercropping and sole cropping). The maize culti-vars were grouped according to leaf area index (LAI) and plant height. At a site with a severe weed problem, leafy maize of intermediate height allowed the most bean yield in relay but the least in intercropping. Tall, leafy maize allowed as much yield of intercropped beans as short, less leafy cultivars. In intercrops, tall maize plants shaded the beans less, while in relay crops leafy plants of intermediate height shaded and suppressed weed growth so benefiting the following bean crop. At the other site, all maize groups had the same effect on beans whether grown in relay or intercropped. Leafy maize cultivars of medium height are preferable for sole crops and for relay cropping of beans at physiological maturity when weeds are a problem, but less leafy types are better for bean intercropping or for relay crops where the beans are planted before maize maturity. Plant types selected for sole cropping are not necessarily best for poly-cultures and one crop may affect another even when their periods of active growth do not overlap.
Growth ofAmaranthus Hybridus(African Spinach) under diffferent Daylight Intensities in the Dry Season in Southern Nigeria
Authors: Eze J. M. O.
Published: October 2008

The growth ofAmaranthus hybridusunder different daylight intensities was assessed in terms of physical, morphological and biochemical parameters. Maximum growth in many respects was achieved at about 70% of full daylight. However, full daylight favoured chlorophyll stability and maximum accumulation of total dry matter, carbohydrate, chlorophyll and ascorbic acid. The leaf area ratio increased uniformly with decrease in light intensity. Ageing was accelerated by full daylight. Reduced light intensity reduced dry matter accumulation in the roots more than in the stems or leaves.
Cotton Leaf Reddening in the Irrigated Gezira
Authors: Ishag H. M. , Ayoub A. T. , Said M. B.
Published: October 2008

Cotton leaf reddening was studied in irrigated vertisols at the Gezira Research Farm over three seasons. The percentage leaf reddening was negatively correlated with seed cotton yield. Plants showing symptoms of reddening produced smaller and fewer leaves which did not persist long enough to sustain the reproductive parts. Deficiencies of nitrogen and phosphorus were found to be responsible for the reddening symptoms. Nitrogen application, late August sowing and frequent control of insect pests all significantly reduced the incidence of reddening. Other possible remedies are discussed.
Crop-Livestock Interactions in Sub-Saharan Africa and their Implications for Farming Systems Research
Authors: McIntire J. , Gryseels G.
Published: October 2008

Herding and farming environments in sub-Saharan Africa are described briefly. The relative importance of crops and livestock is described for each environment. A matrix of crop-livestock interactions is defined for each environment and the reasons for each type of relation are noted. Farming systems are defined as segregated or completely integrated, according to the degree of crop-livestock integration on the farm. Points at which farming systems research (FSR) might be undertaken to improve interactions between crops and livestock are noted for both systems.
Genetic Resource Conservation
Authors: Astley D.
Published: October 2008

The conservation of genetic resources is discussed in relation to the stages in the evolution of crop plants. Strategies for the collection and conservation of wild species, landraces and advanced cultivars are considered in relation to the pratical needs of plant breeders and other users.
Seasonal Variation in the Water Uptake and Leaf Water Potential of Intercropped and Monocropped Chillies
Authors: Hulugalle N. R. , Willatt S. T.
Published: October 2008

The seasonal water use patterns and leaf water potential of chillies (Capsicum annum var. annum) grown as a monocrop and as an intercrop between soyabeans (Glycine max) were studied under a weekly and two weekly irrigation regime on a red duplex soil in Northern Victoria, Australia. Irrigation at two weekly intervals resulted in a temporal stratification of water extraction over the growing season, the soyabeans making their maximum demand during the reproductive phase. Senescence of the soyabeans at the R6–R7, growth stage was accompanied by an increase in water uptake by the intercropped chillies. No corresponding increase in water uptake was observed in monocropped chillies irrigated every two weeks or in intercropped or monocropped chillies irrigated weekly. Leaf water potential of the intercropped chillies was, for the most part, greater than that of the corresponding monocrops.