bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Cowpea (Vigna Unguiculata) to Spacing in the Savanna and Rainforest Zones of Nigeria: Response Surface Analysis
Authors: Odulaja A. , Kayode G. O.
Published: October 2008

A re-analysis of a two-year study designed to investigate the effect of spacing on the yield of two cowpea cultivars in the savanna and rainforest zones of Nigeria confirms plant density and spacing recommendations for the savanna zone while contradicting all but intra-row spacing recommendations for the forest zone. An inter-row spacing of 60 cm and intra-row spacing of 9 cm or closer could be used for improved seed yield in the savanna zone, while a plant density between 120 000 and 166 666 plants ha−1with an inter-row spacing of 30 cm would be optimum for cowpea production in the forest zone.
The Effect of High Yielding Perennial Herbage Crops on Biological Degradation and Nitrate Accumulation in Peat Soil
Authors: Levanon D. , Levin I. , Kipnis T. , Cohen U.
Published: October 2008

Perennial crops, guinea grass and alfalfa, and annual crops, wheat and cotton, were grown in the reclaimed Hula Valley swamp. The aim was to find ways to preserve the peat soil from aerobic oxidation, wind and water erosion; to minimize nitrate accumulation, which causes pollution of the waters draining into the Kinneret Lake (Sea of Galilee); and to select high yielding crops that both fulfilled these needs and ensured a good income for the farmers. Our results showed that high dry matter yields of guinea grass and alfalfa could be obtained. A significant decrease in peat soil erosion and nitrate accumulation was also recorded under these perennial crops, so growing them has both economic and ecological advantages.
Techniques for Planting Sugarbeet to Advance the Harvest Date in North Indian Conditions
Authors: Narang R. S. , Bains B. S.
Published: October 2008

Results of a two-year field study show that even under hot northern Indian conditions, sugar-beet planting dates can be advanced to 20 September to permit an early harvest from mid-March onwards. Seeding the crop on the northern side of east-west ridges gave root yields of 45–50 t ha−1 with a sucrose content of 12–14%. Transplanting gave the highest tonnage but led to a high incidence of branched tap roots. For timely planting during October, direct seeding in north–south rows was also satisfactory. Such staggered seeding and harvest schedules could help extend the milling period to 90–100 days as against the present 45–50 days.
The IBSNAT Project and Agricultural Experimentation in Developing Countries
Authors: Harrison S. R. , Thornton P. K. , Dent J. B.
Published: October 2008

The International Benchmark Sites Network for Agrotechnology Transfer (IBSNAT) project has established an international network of co-operating farming systems researchers. A decision support system that includes a number of crop models and databases has been developed to assist in the evaluation of new agrotechnology packages in the tropics and sub-tropics. Standards have been established for the recording of ‘minumum data sets’ from field experiments to allow the crop models to be validated for specific sites. The decision support system, still under active development, has the potential to reduce substantially the time and cost of field experimentation necessary for adequate evaluation of new cultivars and new crop management systems.
Response of Beans to Fertilizer and Seed Treatment in Central Province, Zambia
Authors: Bezuneh M. , Olsen F. J.
Published: October 2008

On-farm research was conducted in Zambia between 1984 and 1987 to examine the performance of an imported bean variety and identify management practices that could result in higher and more stable yields and to examine their economic feasibility for risk averse smallholder farmers. Results showed that the Brazilian bean variety Carioca was superior to the local variety tested in terms of yield, net economic returns and reliability of performance, especially when used in combination with fertilizer and insecticide.
Genotype Effects in Millet/Cowpea Intercropping in the Semi-arid Tropics of Niger
Authors: Reddy K. C. , van der Ploeg J. , Maga I.
Published: October 2008

Three pearl millet and three cowpea genotypes were examined in intercropping systems on deep sandy soils in Niger between 1984 and 1987. The intercropped pearl millet genotypes usually produced at least 80% of their sole crop yields when the cowpea was planted two or more weeks after the pearl millet. The early maturing and spreading cowpea genotype contributed most to LER. All cowpea genotypes yielded more when planted in association with dwarf rather than the traditional tall pearl millet genotypes because they received more light.
The Effect of Photoperiod on the Reproductive Development of a Photoperiod Sensitive Groundnut (Arachis hypogaea L.) Cv. NC Ac 17090
Authors: Flohr Marie-Luise , Williams J. H. , Lenz F.
Published: October 2008

The physiological basis for responses to daylength of a photoperiod sensitive groundnut genotype (NC Ac 17090) was investigated by comparing its growth and development in natural daylength with that in an artificially manipulated photoperiod in three field experiments. Photoperiod did not influence the thermal time to flowering, or the subsequent appearance of flowers until 900–950 flowers m−2 had appeared. Thereafter flowers continued to appear in short, but not in long, days. In each experiment, long days increased the thermal time between the initiation of each peg and pod, and the thermal time required for each fruit to mature. These fruit initiation and developmental changes were reflected in the partitioning of assimilates to pods, this being substantially less in long days than in short. Changes in pod initiation rate, partitioning co-efficient, and the thermal time taken for a pod to mature were related to mean daylength.
Effects of Intercropping Oilseeds and Pulses in Roselle (Hibiscus sabdariffa)
Authors: Roy A. R. , Sasmal B. C. , Bhattacharjee A. K.
Published: October 2008

The effects of intercropping roselle with blackgram, cowpea, soyabean, groundnut and sesame under single, double and triple row planting patterns and at three different intercrop sowing dates were studied from 1983 to 1985. The fibre yield of roselle was reduced by intercropping. The reduction was least with groundnut and greatest with cowpea but was compensated for by the yield of the intercrops. Double and triple row planting systems favoured the productivity of both roselle and the intercrops, increasing the Land Equivalent Ratio (LER) of the cropping system. The best yields of roselle were obtained when the intercrops were sown 15 days after the roselle.
Light Use, Water Uptake and Performance of Individual Components of a Sorghum/Groundnut Intercrop
Authors: Azam-Ali S. N. , Matthews R. B. , Williams J. H. , Peacock J. M.
Published: October 2008

The productivity of each component of a sorghum/groundnut intercrop and its constituent sole crops is determined in terms of a ‘Crop Performance Ratio’ (CPR) defined as the productivity of an intercrop per unit area of ground compared with that expected from sole crops sown in the same proportions. The CPR allows productivity, intercepted radiation and seasonal transpiration to be compared so that conversion coefficients for radiation (e; g MJ−1) and dry matter/water ratios (q; g kg−1) can be calculated for each intercrop component and its constituent sole crops. In this experiment, CPR for total dry weight in the intercrop was 1.08 and that for reproductive yield was 1.27. These advantages in overall productivity and yield were typical of those reported elsewhere for sorghum/groundnut intercrops. The proportional increase in total dry matter in the intercrop was largely a result of its greater interception of radiation. The further advantage in reproductive yield was a consequence of an improved harvest index in the sorghum component of the intercrop (0.64) compared with that of its sole crop counterpart (0.55).
Simulation of the Seed Bank Dynamics of Orobanche crenata Forsk. in some Crop Rotations Common in Northern Syria
Authors: Schnell H. , Kunisch M. , Saxena M. C. , Sauerborn J.
Published: October 2008

Simulations of the dynamics of the seed bank of Orobanche crenata Forsk. under different crop rotations are presented. Rotations studied involved four host species, lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.) and woolly-pod vetch (Vicia villosa subsp. dasycarpa (Ten.) Cavill.), and non-host species. Simulation showed that the Orobanche seed bank dynamics in three-course crop rotations would result in a high Orobanche seed population and hence in low yields of the respective crops. Replacing the susceptible by resistant legumes such as woolly-pod vetch in some of the cycles of the rotations would keep the Orobanche infestation at a low level without reducing the proportion of legumes. A three-course crop rotation with faba bean would have to be changed to a 12-coursc rotation in which faba bean was grown every twelfth year but was replaced by woolly-pod vetch or other resistant legumes in seasons 3, 6, 9; 15, 18, 21; and so on. In the three-course rotations with chickpea or lentil, these susceptible legumes would be grown every ninth year but would have to be replaced in seasons 3 and 6; 12 and 15; 21 and 24; and so on, thus changing these three-course rotations into nine-course rotations.
Optimization of Mineral Nutrition in a Coconut Plantation Taking an Experimental Approach in situ
Authors: Bonneau X.
Published: October 2008

Over several decades agronomists have developed a mineral nutrition management method for perennial oil crops based on leaf analysis combined with reference field trials. This method has been used in a coconut plantation on the peats of the east coast of Sumatra to optimize mineral nutrition in a very short time, at minimum cost and with maximum reliability, through successive adjustments of the fertilizer schedules. Two reference trials were set up to study a wide range of mineral nutrients assumed to be deficient on this area. Further experiments were set up as new nutritional problems occurred at the plantation, and as soon as the first results were obtained from these two trials. In this way, the iron and copper deficiency problems at the plantation were dealt with satisfactorily taking an experimental approach. New experiments were set up recently to test the hypothesis of a silicon deficiency. The fertilization schedules for the commercial plantation were developed by successive adjustments based on the trial results. Leaf analysis data showed that the coconut palms in the commercial plots always complied with the experimental models. In addition to being rapid and reliable, this method was also cost-effective, especially when larger areas were involved.
Production of Seedling Tubers Derived from True Potato Seed and Their Use as Seed Tubers in the Sudan
Authors: El-Amin S. M. , Adam B. , Varis E. , Pehu E.
Published: October 2008

Seedling tubers of three true potato seed (TPS) crosses raised in a seedbed soil mixture of clay, sand and dry leaves produced about 3.1 kg of seedling tubers m−2 in the growing season of 1988–89 and between 4.3 and 5.1 kg m−2 in 1989/90. The seedling tubers produced were stored and their use as seed tubers was subsequently compared with the locally popular variety Alpha. The mean tuber yields of the hybrids ranged between 9.4 and 11 t ha−1 in 1990/91 and between 21.9 and 22.9 t ha−1 in 1991/92. Mean tuber yields of cultivar Alpha were 14.3 t ha−1 in 1990/91 and 24.1 t ha−1 in 1991/92, showing that tuber yields comparable to those of imported seed tubers could be obtained from seedling tubers of TPS origin.
Long-term Comparison of the Agronomic Efficiency and Residual Benefits of Organic and Inorganic Nitrogen Sources for Tropical Lowland Rice
Authors: Cassman K. G. , de Datta S. K. , Amarante S. T. , Liboon S. P. , Samson M. I. , Dizon M. A.
Published: October 2008

Nitrogen efficiency fromAzolla microphyllaorSesbania rostratagreen manure, rice straw, and inorganic fertilizer-N was compared in two long-term experiments with irrigated lowland rice (Oryza sativaL.). Treatments included a control and each nitrogen source alone or in combinations that provided 50% of the total applied nitrogen from an organic and inorganic nitrogen source. All nitrogen sources were applied at equivalent nitrogen rates to 19–22 consecutive rice crops. Residual effects were assessed in two subsequent cropping seasons at one site. Lower grain yield, agronomic efficiency (Δgrain per kg total applied nitrogen), and apparent nitrogen uptake were obtained from green manure and rice straw nitrogen as sole or dual nitrogen sources rather than from a standard split application of prilled urea. Compared to prilled urea, residual effects from green manure or rice straw included a significant increase in soil organic carbon and total nitrogen, and greater extractable soil nitrogen in the vegetative growth period. After panicle initiation there was no residual effect on the rate of crop nitrogen accumulation, and final grain yields were similar regardless of previous nitrogen source. Recycling of rice straw appeared to have greater potential for reducing fertilizer-N requirements than use of green manure because rice straw is often a wasted resource in irrigated rice systems of the humid tropics, the efficiency of rice straw nitrogen in combination with prilled urea is comparable to green manure nitrogen, and the increase in soil nitrogen from rice straw was 50–150% greater than from green manure.
The Photosynthesis and Transpiration of Crops
Authors: Monteith J. L.
Published: October 2008

When a leaf absorbs radiant energy, only a small fraction is stored chemically in photosynthesis. In sunlight, this fraction is at most one-fifth of the energy in the visible spectrum, decreasing with increasing light intensity because of the finite resistance to the diffusion of carbon dioxide through the leaf to the chloroplasts. Energy absorbed but not stored in photosynthesis is dissipated by transpiration and convection.

The potential or maximum photosynthesis of a crop canopy can be estimated from a set of six parameters describing the photosynthesis-light curve of single leaves, the arrangement of leaves in the canopy, and radiation climate. Comparing estimates of potential photosynthesis with measurements of carbon dioxide exchange over a field of sugar beet, the estimated rate of respiration was 2 gm carbohydrate per m2 leaf area per day, equivalent to 44 per cent of gross photosynthesis over the whole growing season. Over the season, the foliage lost 34 per cent of incident radiation by transmission to the soil.

The potential rate of transpiration can be found from Penman's formula assuming values of external (aerodynamic) and internal (mainly stomatal) resistance for the canopy as a whole. In south-east England, the energy for potential transpiration is almost equal to net heat H in summer and is therefore about half the energy of incoming solar radiation. For a real crop of grass subject to moisture stress, transpiration was less than the potential rate at about 0·8 H on average and 0·3 H in very dry weather.

During the summer, cumulative photosynthesis increases linearly with cumulative transpiration to give a production ratio (gross photosynthesis/transpiration) of 1/100 in the Thames Valley and 1/200 in the Sacramento Valley. The production ratio is expected to change with crop type as well as with climate.
Effect of Planting-Date on Nodulation and Dry-matter Yield of Cowpea in Nigeria
Authors: Tewari G. P.
Published: October 2008

A split-plot field experiment was conducted to investigate the influence of planting dates on the formation of nodules in a variety of cowpea (Paraguay 6). Results indicated that the principal factor influencing both nodulation and yield was day-length, the highest number of effective nodules being produced from the June planting.
The Influence of Plant Density on the Morphological Characters and Seed Production of Common Vetch (Vicia sativa L.)
Authors: Blum A.
Published: October 2008

Plant population studies were carried out in 1963 and 1964, including row spacing of 75 cm at different within-row densities, for purposes of comparison with the common practice of drilling at 15 cm spacing. Planting in spaced rows 75 cm apart, with increasing intra-row density from 55 to 175 seeds per metre of row, increased seed yield compared with drilling and a high intra-row density was better than low intra-row density for seed yield. The increase in seed yield was due to a higher number of stems, flowers and pods per unit area, and to a higher number of flowers forming mature pods. Seed set was better in spaced rows than at drill-spacing. Flowering took place over a shorter period, and the peak was attained earlier, at higher within-row density. Plant competition influenced plant branching as early as sixteen days after emergence. The relation between seedling development and seed yield is discussed.
Methods of Recording Data in the Laboratory and Field
Authors: Berry G. , Cleaver T. J. , Nelder J. A. , Salter P. J.
Published: October 2008

Methods of recording experimental data in the laboratory and field are discussed. Use of specially designed record sheets, punch cards and punched paper tape in conjunction with an electronic computer extends the scope of experimental work and leads to improved efficiency and accuracy.
Irrigation Frequencies for Lucerne on Shallow Granite Sand in Low Rainfall Areas of Rhodesia
Authors: Landsberg J. J.
Published: October 2008

Mature lucerne on shallow granite sand was irrigated at different intervals, determined by four factors, 0·4, 0·6, 0·8 and 1·0, applied to daily evaporation (E0) as measured by a USWB Class A pan. Moisture balances were calculated for each treatment, and when the accumulated sum of daily evaporation, multiplied by the appropriate factor, reached 1·2 inches, which was about 50 per cent of the available moisture in the top 2 feet of soil, this amount of water was applied to the plots of the treatment concerned. Irrigation on the basis of 0·8 E0 gave the but overall results, although the highest yield from a single cut was obtained with the irrigation frequency defined by 1·0 E0. During the rainy season yields from all treatments declined markedly, those from the most frequently irrigated treatment showing the greatest drop. The lucerne under the irrigation regimes defined by 0·4 and 0·6 E0, although subjected to considerable moisture stress in the dry weather, suffered no lasting ill effects and yielded well during the rains. The experimental area was almost certainly subject to advective energy but the results are considered valid for local conditions.
Agronomic Factors Influencing Yield and Quality of Groundnuts in the Sudan Gezira
Authors: Tahir W. M. , Misovic M. S.
Published: October 2008

An early upright-bunch variety of groundnut, Barberton, and a medium-late spreading-bunch variety, Ashford, were compared at 7·5, 15·0 and 30·0 cm. intra-row spacings planted at one and two kernels per hill on 60 cm. ridges in the irrigated heavy clay soil of the Sudan Gezira in 1963 and 1964. Barberton was harvested on days 95, 110 and 125, and Ashford on days 125, 140 and 155 after planting in July–August. Ashford outyielded Barberton at the lower densities, and the best pod yields were obtained on day 125 harvest at a population of 55,000–60,000 plants per acre. A higher plant population depressed the yield of Ashford while the increased pod yield of Barberton was not significant. Field germination of kernels increased more in Barberton with delay in harvest and with decrease in plant population than in Ashford. Mean pod and kernel weights and shelling out-turn of Barberton increased with delay in harvest. Barberton gave higher oil content and shelling out-turn, and lower proportion of pods with single kernels than Ashford. The highest population of Barberton gave the best oil content in early harvests. In general, the arrangement of plants within rows at similar populations had only small effects except on the quality of nuts, which was improved by planting single kernels at close spacing (7·5 cm.) with the variety Barberton and two kernels at wide spacing (15·0 cm.) with Ashford, at optimum plant populations.
Responses of Mature Tea to Phosphate and Potash in North-East India
Authors: Sen A. R.
Published: October 2008

This paper summarizes the results of a series of NPK experiments conducted in the past on mature tea in north-east India.
A Note on the Grafting and Anatomy of Black Pepper
Authors: Garner R. J. , Beakbane A. Beryl
Published: October 2008

Some early attempts to graft black pepper are described. Good unions have formed between different clones of Piper nigrum L., and between different species of Piper grown in a glasshouse in the United Kingdom. The structure of pepper stems is considered in relation to the apparent impermanence, in the tropics, of unions that initially appear to be successful.
The Potential Availability of Organic Nitrogen Fractions in Some West Indian Soils
Authors: Cornforth I. S.
Published: October 2008

The effect of four crops of maize on the distribution of organic nitrogen in ten West Indian soils, given either lime, P, K, Mg and trace elements or no fertilizers, was studied in a greenhouse experiment. The soils were also analysed for ‘available N’ by incubation and chemical methods. Variations in the redistribution of organic N fractions during the greenhouse experiment did not permit conclusions to be drawn on the source of N used by the maize, although the amount of hydrolysable N, particularly hexosamine, amino and hydroxy-amino N, in the initial samples was closely related to N uptake. Part of the chemically stable, non-hydrolysable organic N was broken down by soil organisms during the experiment; this was increased by liming acid soils.
Effects of Rhizobium-Inoculum Placement on Peanut Inoculation
Authors: Schiffmann J. , Alper Y.
Published: October 2008

An experiment was conducted on peanut inoculation with Rhizobium inoculum, introduced below the planting level at three different soil depths (8, 12 and 15 cm.), to ensure more favourable moisture conditions for proliferation of the root nodule bacteria, and to obviate the need for frequent irrigation. Inoculation on both sides of the peanut rows, after the plants had emerged, was also tested. The number and weight of nodules per plant decreased with increase in placement depth. Side inoculation after emergence of the plants resulted in significantly less plant infection than placement of the inoculum at 8 and 12 cm. depths. Peanut yield and quality after inoculation at 15 cm. depth were significantly lower than at 8 cm. inoculation.
Inoculation of Peanuts by Application of Rhizobium Suspension into the Planting Furrows
Authors: Schiffmann J. , Alper Y.
Published: October 2008

Soil inoculation was tried in field experiments during two seasons using different concentrations and amounts of bacterial suspension and compared with direct seed inoculation of chemically protected and unprotected peanut seed. Soil inoculation gave significantly better results than direct inoculation of chemically protected or unprotected seed.

Large yields of high quality peanuts, which compared favourably with highly nitrogen-fertilized peanuts, were obtained after the application of relatively small amounts (10–40 gm.) of enriched peat inoculant in 5 litres of water per dunam (1/10 ha).
Nodulation of Tropical Legumes I. Specificity in the Rhizobium Symbiosis of Leucaena leucocephala
Authors: Trinick M. J.
Published: October 2008

Leucaena leucocephala (Lam.) de Wit. failed to nodulate with 94 of the 99 strains of Rhizobium tested, representing the seven recognized cross-inoculation groups of nodule bacteria. A group of legumes including L. leucocephala, Mimosa invisa Mart., M. pudica L., Acacia farnesiana (L.) Willd. and Sesbania spp. showed the properties of a cross-inoculation group of plants. Rhizobia isolated from these legumes were all fast-growers and nodulate L. leucocephala, often effectively, and also many other tropical legumes, including Vigna sinensis (L.) Savi ex Hassk., which are usually nodulated effectively with slow-growing root-nodule bacteria. The taxonomic significance of the results is discussed.
Timing and Frequency of Spraying for Control of Coffee Leaf Rust in Southern India
Authors: Ananth K. C.
Published: October 2008

To study control of Hemileia vastatrix leaf disease in Coffea arabica L., an experiment was run for a year in Coorg District of Mysore State. Three and four early-season sprays coupled with two mid-season ones gave a reasonable control, as evaluated by leaf spot counts, but a high proportion of rust-affected leaves were retained on the bushes. Infection commenced in the hot weather, immediately after showers, and the number of infected leaves appears to have been more important than the average leaf spot counts. Control of leaf disease up to December, and a late incidence of the rust during January, may not affect crop prospects appreciably. It is suggested that reduced early sprays coupled with pre-monsoon and timely mid-season schedules should reasonably control the incidence of rust.
Effects of Moisture and Nitrogen on Growth, Yield and Mineral Content of Rice
Authors: Pande H. K. , Singh Panjab
Published: October 2008

Limited moisture supply caused reduction in leaf area, number of effective tillers, ratio of sound to unsound grains and the nitrogen, phosphorus, iron and manganese content of rice. Crop yield was adversely affected in the absence of standing water. Two levels of nitrogen (40 and 60 kg.N/ha.) caused no significant difference in yield in 1965, but in 1966, when 30 and 60 kg. N/ha. were used, the latter gave better yields.
Fertilizer Responses by Coconuts (Cocos nucifera) on Two Contrasting Jamaican Soils
Authors: Smith R. W.
Published: October 2008

The results from a 33 and two 25 factorial fertilizer experiments are presented. N-deficiency limited female flower production, rate of bunch production, and yield; K-deficiency reduced the setting of flowers and yield; nuts were larger where P was applied. The results are interpreted in the light of foliar analyses, and the concept of independant critical levels of the major nutrients is challenged. It is suggested that yield is related to the ratios between foliar N and K, but that the K level should in turn be interpreted in the light of a balance between the monovalent and divalent cations. Female flower production and setting can be used as a ready field guide to nutrient requirements.
Effects of Planting Date and Spacing on Yields of Onion Seed under Hot Arid Conditions in the Sudan
Authors: Abdalla Abdalla Ahmed
Published: October 2008

Experiments in two successive seasons showed that planting date and spacing of bulbs affected the seed yield of Sudanese onions, but not the number of branches and seed heads produced by bulbs. Yield per plant increased with increase in spacing, but closer spacing gave the highest yield per unit area. Later sowing depressed seed size, weight and yield.
Component Analysis: An Aid to the Interpretation of Data
Authors: Holland D. A.
Published: October 2008

Principal component analysis is a mathematical technique for summarizing a set of related measurements as a set of derived variates, frequently fewer in number, which are definable as independent linear functions of the original measurements. Consideration of their mathematical nature shows that they do not, themselves, necessarily correspond to sensible biological concepts, though they are more amenable to statistical study than the original measurements. Further, by assessing the extent to which they are in accordance with biological hypotheses, or with the results of other, similar, analyses, they can be transformed into other linear functions which are meaningful in the biological sense, or consistent with other results. Thus the specific technique of principal component analysis is developed into a more general component analysis approach. With proper regard for the purpose the analysis is intended to serve and for the mathematical restrictions involved, this approach can lead to a useful condensation of a mass of data, a better under-standing of the observed individuals as entities rather than collections of isolated measurements, and to the formulation of new hypotheses for subsequent examination.
The Available-Water Capacity of Barbados Soils
Authors: Hudson J. C.
Published: October 2008

Large soil monoliths, extracted undisturbed in 44-gallon oil drums, have been used to assess the available-water capacity, and the relation between the growth of sugarcane and soil water deficit for agricultural soils in Barbados. Constancy of field capacity was studied and the effect of cultivation on the storage of available soil water. Deep montmorillonite clays and oceanic soils had storage capacities greater than 20 cm. of water in an 80 cm. profile, whereas sandy or stony montmorillonite clays and most soils developed from kaolinite clays had capacities less than 11 cm. Cultivation significantly increased the water holding capacity of soils but this was rarely as great as for fabricated composts and the water was never so freely available. The data have been used in decisions about cultivation and irrigation, and as the basis for an ecological grouping of sugar estates according to their probable water balance.
Effects of Sea Water on Growth of Reyong-20 Rice in Malaysia
Authors: Kathirgamaraj Sivanadyan , Williams C. N. , Joseph K. T.
Published: October 2008

Pot experiments with Malaysian rice variety Reyong-20 showed that sea water supplied at a concentration of 3 per cent increased yields of both grain and straw; a 6 per cent solution increased straw but not grain yields; yields were depressed at 9 and 12 per cent but tolerance of higher concentrations of sea water increased with age of the plants.
Long-Term Effects of Fertilizers and Manure on Soil and Leaves of Cotton in Nigeria
Authors: Bache B. W. , Heathcote R. G.
Published: October 2008

On a site in the Sudan Savanna, chemical properties of soils (except for phosphate) and the composition of cotton leaves were determined after fifteen annual treatments including dung, ammonium sulphate, single superphosphate and potassium chloride, in all combinations of three levels. In the soils dung increased C, N, cation exchange capacity, exchangeable Ca and Mg and pH, and decreased soluble Al and Mn; ammonium sulphate decreased pH, increased soluble Al and Mn, and decreased exchangeable Ca and Mg; potassium chloride had no obvious effects. In the plants dung increased P and reduced Mn; ammonium sulphate reduced Ca and Mg, and increased Mn; superphosphate increased P, Ca and Mg, and reduced K; potassium chloride increased K slightly. The most important results were the ability of ammonium sulphate to acidify the soil, as shown by soil properties and reflected in tissue composition, and the ability of dung to ameliorate these effects. Reduction of crop yield in the presence of adequate nutrient supply seems to have been due to excessive soil acidity.
Pod Development and Germination of Bhindi (Abelmoschus esculentus)
Authors: Manohar Man Singh
Published: October 2008

Pods of bhindi (Abelmoschus esculentus) developed most rapidly for the first 11 days after the opening of bhindi flowers, after which development slowed down. Seeds matured in about 21 days after flower opening and attained up to 97 per cent germinability. Water potentials lower than −500 joules/kg. in the germination medium adversely affected germination of bhindi seeds. Seeds up to two years old but of > 1 density (i.e. those which sink in water) germinated better than lighter seeds which float.
Coffee Berry Disease: Epidemiology in Relation to Control
Authors: Nutman F. J. , Roberts F. M.
Published: October 2008

In many instances measures developed for the control of coffee berry disease in East Africa have become less effective since 1961. Changes in the flowering and fruiting patterns of the coffee tree have recently become evident, ascribed in part to the onset of a wetter and cooler climatic cycle in 1961–62, and in part to the effect of the disease itself which, by removing crop, stimulates out-of-season flowering. Consequently, instead of a single main crop in which susceptible and highly infective ripe berries are present for a short time only, a series of over-lapping crops results in ripe berries being on the trees for most of the year. This has changed the disease epidemiology: formerly the main source of infection was conidia from the maturing wood, but now conidia from the berries are often predominant. This has greatly affected the efficiency of control measures, and means are suggested for restoring the previous situation.
Leguminous Cover Crops for Maintaining Soil Fertility in Sisal in Tanzania I. Effects on Growth and Yield
Authors: Hopkinson D.
Published: October 2008

Sisal was grown in double rows with broad-interrow covers of Pueraria phaseoloides, controlled volunteer vegetation or clean weeding. Clean weeding gave the best yield over one cycle, but Pueraria cover was best in the second cycle. Pueraria was better than volunteer vegetation in all trials, with the greatest margin on soils low in nitrogen, or where there were pernicious weeds. On an exhausted soil, sisal with a Pueraria cover responded to fertilizer nitrogen applied in the early or late part of the cycle. Manuring sisal growing with a volunteer vegetation cover with 50 tons sisal waste/ha. improved growth to the same extent as replacing the cover with one of Pueraria. In the absence of manures, yields declined from cycle to cycle with all the covers. At the level of manuring which maintained yields with a volunteer vegetation cover, yields declined slightly with clean cultivation, and improved considerably with a Pueraria cover.
Effects of Environment and Cultural Conditions on Potassium, Calcium and Magnesium in Coffee Leaves
Authors: Robinson J. B. D.
Published: October 2008

Potassium, calcium and magnesium in coffee leaves are presented as total K + Ca + Mg in dry matter and as percentages (proportions) of this sum. Brazilian coffee and leaf samples collected in different parts of Kenya generally fell within the normal ranges of values reported from the Kivu area in the Congo Republic. Data for Kenya coffee leaves are examined for the influence of season, cultural treatments such as organic mulch and fertilizers, and cropping level, on the concentration and balance of the nutrients.
Preliminary Investigations into the use of Systemics for Control of Red Ring Disease of Coconuts
Authors: Hoyle J. C.
Published: October 2008

Trials were carried out to ascertain which of four systemic insecticide/nematicides were absorbed by young coconut palms (Cocos nucifera L.) using three different methods of application. Stem injection of Bidrin and Nemacur are impractical because the chemicals break down too quickly and frequent retreatment would result in too much physical damage to the young trees. Lannate was not absorbed from leaf axil placement, and broke down too quickly when absorbed from the soil to be of practical use. Nemacur was not absorbed through the leaf axil, but was from the soil and lasted up to 14 weeks in the plant. Temik, absorbed both through the leaf axil and from the soil, lasted up to 14 weeks. The possibility of controlling red ring disease of coconuts with Nemacur or Temik is considered.
Effects of Time and Method of Applying Nitrogen to Dwarf Wheats
Authors: Jain N. K. , Maurya D. P. , Singh H. P.
Published: October 2008

Linear regression of grain and straw yield of dwarf wheats on level of fertilizer nitrogen was significant, but the efficiency of fertilizer nitrogen was determined by the time and method of its application. A single application as a basal dressing was the least productive for grain yield, while split fertilization at sowing and at first irrigation increased the efficiency of applied nitrogen. Further splitting in three doses did not benefit wheat. Foliar application of nitrogen to replace top dressing at the heading stage was of no advantage while replacement of a top dressing at first irrigation by urea spray at heading was definitely deleterious.
Variability in Commercial Sweet Potatoes (Ipomoea Batatas—L. Lam) in Trinidad
Authors: Haynes P. H. , Wholey D. W.
Published: October 2008

The variation in number and yield of tubers from three commercial fields of sweet potato was measured over three seasons. Sources of variation were attributed to factors external to the plant, such as soil, management and climatic differences, and to inherent plant factors, including type of planting material. It is suggested that a reduction in variability could lead to increases in productivity, and may also increase the precision of field experimentation.
Responses of a Semi-dwarf Wheat to Temperatures Representing a Tropical Dry Season. I. Non-Extreme Temperatures
Authors: Owen P. C.
Published: October 2008

Under controlled environment conditions a semi-dwarf wheat, Mexico 120, was subjected to day temperatures of 32 and 27°C, with night temperatures of 21 or 16°C, which are similar to those occurring for a large part of the dry (winter) season of the Ord River valley area of northern Australia. Temperature differences imposed only during the 23 days between sowing and floral initiation produced effects which persisted throughout later growth, when all plants were grown under one temperature regime. The effects of temperature differences before floral initiation were greater than those of similar temperature differences imposed after ear emergence began. The maximum temperatures occurring even in the coolest months probably limit maximum potential grain yields in an environment similar to that of the Ord River valley.
Responses of a Semi-dwarf Wheat to Temperatures Representing a Tropical Dry Season. II. Extreme Temperatures
Authors: Owen P. C.
Published: October 2008

Under controlled environment conditions a semi-dwarf wheat, Mexico 120, was subjected to temperature regimes representative of the extremes that occur during the dry (winter) season of the Ord River valley in northern Australia. High temperatures (35°C by day: 18°C by night) such as occur at the beginning and end of the dry season were compared with low temperatures (30°C by day: 13°C by night) such as occur in mid-season. Day length was constant at 12 hours. High temperatures from floral initiation onwards adversely affected floret development, and after ear emergence reduced grain filling to nil. Net assimilation rates were reduced by high temperatures. Major effects on yields were caused by high temperatures well before anthesis. The critical temperature after anthesis is apparently between 32° and 35°C.
Effects of Fruiting, Defoliation and Ring-Barking on the Accumulation and Distribution of Dry Matter in Branches of Coffea Arabica L. in Kenya
Authors: Cannell M. G. R.
Published: October 2008

Whole branches were removed from trees in the field, at regular intervals, to follow the increase in dry weight of fruits and new vegetative growth. Information on the partition of carbohydrates was gained by comparing the growth of untreated, defoliated, de-blossomed and ring-barked branches. Untreated branches increased in weight rapidly when their fruits began to expand, probably because they imported carbohydrates, and their net photosynthetic capacity increased. More young fruits were shed from defoliated than from untreated branches, thus partially compensating for loss of leaf. Non-fruiting, and sometimes fruiting, branches exported a considerable amount of assimilate during the dry seasons, when the trunk-root system was a relatively important dry matter sink. When there were many fruitless branches on fruiting trees, the fruiting branches imported carbohydrates from them during the whole period of fruit growth, whereas fruitless branches imported carbohydrates only when there was a ‘flush’ of shoot growth.
Border Effects in Rice Experimental Plots I. Unplanted Borders
Authors: Gomez Kwanchai A. , De Datta S. K.
Published: October 2008

In experiments with transplanted rice, the first row next to the unplanted alley consistently gave significantly higher grain yields than the centre rows. The increase was progressively higher as the width of the unplanted alley between plots was increased up to 100 cm., but where the increase was very large, yields of the second outermost row were significantly decreased. No evidence was found that border effects reach beyond the second outermost row. Varieties that differed in tillering capacity, plant height, or both responded differently to the unplanted borders.
Losses of Nitrogen from Urea in Some Soils of East Pakistan
Authors: Khan D. H. , Rashid G. H.
Published: October 2008

An appreciable loss of gaseous N from added urea was recorded in two sub-tropical soils of East Pakistan under laboratory controlled conditions, markedly accentuated by the presence of decomposable organic materials which increased ammonification and tended to decrease nitrate accumulation. The addition of bonemeal to the soils had little effect.
Some Micronutrient Deficiencies in Sisal (Agave Sisalana)
Authors: Pinkerton A.
Published: October 2008

Visual symptoms of deficiencies of manganese, copper, zinc, iron, molybdenum and boron on sisal are described, and compared with those observed previously with deficiencies of macronutrients. The diagnostic value of symptoms is discussed, and tentative suggestions made for micronutrient concentrations in leaves for adequacy and deficiency.
The Root Nodulation of Tall and Dwarf Peas and Beans
Authors: Masefield G. B.
Published: October 2008

Observations on the relative degree of root nodulation were made for three successive years on tall and short cultivars of Pisum sativum and Phaseolus vulgaris sown at dates appropriate to each cultivar and grown under conditions of ordinary horticultural practice. In P. sativum, it was found that the shorter the cultivar, the greater were the number and weight of nodules per plant and the weight of nodules as a percentage of plant weight; dwarf cultivars also produced a greater weight of nodules per square metre of ground occupied and per square metre per day of crop growth. In Ph. vulgaris, differences in number and weight of nodules per plant between dwarf and climbing cultivars were not consistent between years. In a single comparison between Ph. uulgaris and Ph. multiflorus (scarlet runner beans), numbers and weights of nodules per plant were almost identical. Some agronomic implications of these findings are discussed.
Productivity of the Oil Palm (Elaeis guineensis Jacq.) in Malaysia
Authors: Corley R. H. V. , Gray B. S. , Kee Ng Siew
Published: October 2008

Crop Growth Rate, Leaf Area Index, Net Assimilation Rate and Harvest Index were estimated for oil palms in nine age groups growing on coastal alluvial soils in Malaysia. The mean Crop Growth Rate of mature palms was 29·83 t./ha./yr, with a Leaf Area Index of 3·61, and Net Assimilation Rate was 0·16 gm./dm.2/wk. Photosynthetic efficiency was about 2·2 per cent. Oil constituted about 17 per cent of total dry matter production. Possibilities for improving the yield of oil are briefly discussed.
Breeding Tomatoes for Resistance to Leaf Mould (Cladosporium fulvum) in Western Nigeria
Authors: Bliss F. A. , Arny D. C.
Published: October 2008

Seedling tests for reaction of tomato cultivars to leaf mould (Cladosporium fulvum) showed that a single race 1·3, or a mixture of races 1 and 3, was present at four sites in the Western State of Nigeria sampled at different times during 1967 and 1968. Vetomold, Vantage, Vinequeen, Astronaut, Floradel, and Tarran were immune and Purdue 135 was resistant. Genetic tests showed that theCf2, gene conditioned immunity and that theCf4gene provided resistance.
Effects of Pollination on Set and Growth of Summer Squash (Cucumis pepo) in Israel
Authors: Globerson D.
Published: October 2008

The effects of pollination on set and growth of summer squash var. Zucchini were investigated. In winter, parthenocarpic fruits developed and pollination had no effect, but in summer only pollinated fruits continued to grow. Partial pollination in summer caused ovary abortion of some fruits, and a reduced rate of fruit growth in those which continued to grow. The ovary was 8·8 cm. long at anthesis in winter but only 8·2 cm. long in summer.
Mineralization of Soil Nitrogen at a Savanna Site in Nigeria
Authors: Wild A.
Published: October 2008

The mineral N (NH4 + NO8) in soils at a savanna site was low at the time of crop planting except after groundnuts and when dung had been used. Nitrification occurred whatever the previous crop, but the numbers of nitrifying bacteria were small and varied with the level of substrate ammonium.
Studies on White Yam (Dioscorea rotundata) II. Changes in Nutrient Content with Age
Authors: Sobulo R. A.
Published: October 2008

Variation in the percentage of nitrogen, phosphorus and potassium content of a variety of white yam, grown without fertilizer, and the nutrients removed per acre by various portions of the plant, were determined. The time to apply fertilizers, and the most suitable portion of the plant for foliar analysis, were deduced from the changes in nutrients with age. The effect of nitrogen fertilizer on yield, and the nutrient content of the harvested tuber, were studied. The influence of a yam crop in a rotation is discussed.
Overhead Application of Fungicide for the Control of Coffee Berry Disease
Authors: Pereira J. L. , Mapother H. R.
Published: October 2008

Comparison of an overhead boom sprayer (Monica Mist) with a conventional air-assisted sprayer (Conomist) showed that the former gave relatively poor cover, but control of coffee berry disease (CBD) was equally good with both machines. It is suggested that the success of overhead spraying is dependent upon effective redistribution of fungicide within the tree canopy during rain.
Effects of Pod Maturity on Bean Development, Viability, Mucilage Content and Seedling Vigour in Cacao
Authors: Adenikinju S. A.
Published: October 2008

Hand-pollinated pods of the Crin Elite establishment cocoa progeny C77 X C23 showed that pod maturity, based on pod age, significantly affected bean viability as well as leaf area, leaf number, plant height and plant girth of the seedlings produced. Beans extracted from immature unripe cocoa pods only 15 weeks from hand-pollination were more than 50 per cent viable and produced seedlings vigorous enough for transplanting to the field after 20 weeks in the nursery compared with beans from 25-week-old normal, mature-ripe cocoa pods. Loss by black pod disease (Phytopthora palmivora Butl) could therefore be avoided and time of waiting for pods to attain normal maturity and ripening saved, by early harvesting.
Persistence of Gamma BHC (Lindane) and Malathion Residues on Fruits of Bhindi (Abelmoschus esculantus L.) under Indian Conditions
Authors: Kavadia V. S. , Gupta H. C. L. , Jain P. C.
Published: October 2008

The persistence of residues of gamma BHC and malathion on bhindi fruits was estimated by bioassay using 1-day-old male Drosophila flies. Although the initial deposits were heavy, they dissipated quickly, with half-lives of approximately 4 and 2 days for gamma BHC and malathion respectively.
Aflatoxin in Haricot Bean and Other Pulses
Authors: Habish H. A.
Published: October 2008

Aflatoxin was found in forty-one out of seventy-four samples of various pulses, whereasAspergillus flavusoccurred in all samples, and there was an apparent correlation between the occurrence of the fungus and the level of the toxin in haricot beans. There was evidence that the toxin was produced in haricot beans after harvest, and drying the pods immediately after harvest is therefore suggested as a method of controlling mould growth and the formation of aflatoxin.