bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled Environments as an Adjunct to Field Research on Lentils (Lens culinaris) I. Perspectives, Tenets and Objectives
Authors: Summerfield R. J. , Muehlbauer F. J. 
Published: October 2008

SUMMARYOur experience with potentially tropic-adapted grain legumes leads us to hypothesize that ‘with appropriate and sufficiently proven technology, developed specifically for the purpose, controlled environment facilities can be a powerful adjunct to field research and so assist in the attainment of crop improvement objectives in lentils’. This contribution comments on the ‘adaptation’ of grain legume crops to their environments, describes current lentil production in the USA and elsewhere, and discusses the tenets and objectives of a programme of research devoted to the ultimate release of lentil genotypes that are well adapted to the environments for which they are intended.
Effects of Ground Rock Phosphate and Elemental S on Yield and P Uptake of Maize in Western Kenya
Authors: Bromfield A. R. , Hancock I. R. , Debenham D. F. 
Published: October 2008

SUMMARYThe effect on maize yields of ground rock phosphate, alone or mixed with sulphur in either of two proportions, and of single-superphosphate, was measured at five consecutive harvests. At the first harvest single-superphosphate increased yield by 1.54 t and the best of the mixtures by 0.56 t grain/ha. Ground rock phosphate alone had no effect on yield. At the third harvest there were no yield differences between sources; because yields produced by rock phosphate and the mixtures improved. The cumulative increase in yield produced by single-superphosphate was 3.58 t/ha and by rock phosphate 2.69 t grain/ha, but because the fertilizer cost ratio was 3:1, additional grain produced by rock phosphate cost half as much. The apparent P recovery ranged from 5.40 to 8.28 kg/ha, with most from single-superphosphate and least from the mixture containing most elemental-S.
Boron Nutrition of Amazon Cocoa (Cacao theobroma) in Nigeria. I. Early Results of Fertilizer Trials
Authors: Ojeniyi S. O. , Egbe N. E. , Omotosho T. I. 
Published: October 2008

SUMMARYBoron treatment was superimposed on half of 48 Amazon cocoa NK-treated plots in four locations across Southern Nigeria. Boron was deficient in soil and leaves of untreated 12-year-old Amazon cocoa, but boron treatment increased bean yield from 13 to 70%. Application of N and K fertilizers reduced the impact of soil-applied boron.
Influence of Flooding and Soil Moisture Content on Elongation of Sugar cane in Trinidad
Authors: Gumbs F. A. , Simpson L. A. 
Published: October 2008

SUMMARYThe total growth increment of sugar cane stalks from 13 to 22 weeks after planting was 55% greater in elevated than depressed areas in fields flooded intermittently during the period of measurement. The weekly growth increments were 137–9% greater in elevated than depressed areas, especially when soil moisture was high. The cane was on top of high ridges but water stood up to 10 cm deep over the top of the ridges in depressed areas for up to 5 or 6 days after rain and at varying depths below the top for several more days. Provided the soil was not submerged, tillers elongated most when the soil profile was saturated or nearly so; mere waterlogging without submergence seems not to damage cane. Tiller elongation and soil moisture were well correlated regardless of depth of sampling between 0 and 45 cm, but different relations were obtained for elevated drained areas and depressed areas subject to submergence.
Effects of Nitrophoska and Atrazine on relations betweenSorghum bicolorandStriga hermonthica
Authors: Bebawi F. F. , Farah A. F. 
Published: October 2008

SUMMARYNitrogen-atrazine combinations were significantly more effective in stimulating higher yield components of sorghum and depressing yield components of striga than sole treatments of either nitrogen or atrazine. Over all treatments nitrophoska at 129 kg N/ha in combination with atrazine at 1.75 kg/ha gave 224, 180, 155 and 151% increases in yield components over the control for head, straw, 1000 grain weights and plant height of sorghum, and a decrease in 83, 88 and 90% of striga density at 8, 12, and 16 weeks from sowing the sorghum. The synergistic effect of nitrogen-atrazine is demonstrated.
Designing Experiments for Intercropping Research
Authors: Mead R. , Stern R. D. 
Published: October 2008

SUMMARYThe efficiency of many intercropping research programmes could be improved if research workers made fuller use of modern statistical knowledge about experimental design. Important statistical considerations for experimental design and plot sampling are reviewed and their relevance to intercropping research assessed. The general philosophy of factorial structure and blocking, and specific ideas on the use of systematic designs and monocrop plots, are discussed.
Phenology of Chickpeas (Cicer Arietinum) in Contrasting Aerial Environments
Authors: Roberts E. H. , Summerfield R. J. , Minchin F. R. , Hadley P. 
Published: October 2008

SUMMARYEffectively nodulated plants of 3 cultivars of chickpea, classified as early, mid-late and late-maturing, were grown to reproductive maturity in 12 factorial combinations of simulated tropical environments in growth cabinets. Cultivars varied in sensitivity but all responded as quantitative long-day plants and flowered earlier in longer photoperiods. Differences in temperature had important consequences, especially on the duration of the reproductive phase and overall crop longevity; they also induced plants to flower at the same time in different photo-periods. Early flowering plants did not necessarily mature early; others taking twice as long to come into flower had short reproductive periods and came to maturity at the same time. Relations between phenology, morphology and seed yield are described and compared with similar data for field-grown plants. Screening for ‘adaptation to environment’ in chickpeas is discussed.
Effects of Single-crop Agri-silviculture on Soil Analysis
Authors: Ojeniyi S. O. , Agbede O. O. 
Published: October 2008

SUMMARYExperiments were carried out to examine the effects of agri-silviculture in three different ecological zones of Southern Nigeria. The four treatments considered were Gmelina arborea (forest tree crop) alone, Gmelina + maize, Gmelina + yam, and Gmelina + cassava, each treatment being replicated 8 times in each location. Composite soil samples, collected from two surface layers of each treatment plot, were analysed. Inter-planting young forest plantations with food crops usually increased soil N and P, at the slight expense of soil organic carbon. However, exchangeable Ca, Mg and K contents, pH, and soil N and P contents, were not statistically different among the treatment plots.
Growth and Resource Use of Maize, Pigeonpea and Maize/Pigeonpea Intercrop in an Operational Research Watershed
Authors: Sivakumar M. V. K. , Virmani S. M. 
Published: October 2008

SUMMARYGrowth and interception of Photosynthetically Active Radiation (PAR) in a maize/pigeonpea intercrop and sole maize and sole pigeonpea crops grown in large plots in an operational research watershed at ICRISAT research centre were compared. Growth and yield of the maize crop, in pure stands and in intercrop, were not significantly different. Efficiency of dry matter production, calculated from the relations between dry matter production and cumulative intercepted PAR, was highest for the maize/pigeonpea intercrop, followed by sole maize and sole pigeon-pea, proving the utility of such intercrops in making better use of resources in the Semi-Arid Tropics (SAT).
Effects of Plant and Canopy Density on Seed Yield and Oil Content in White Lupin (Lupinus albus)
Authors: McGibbon R. , Williams Watkin 
Published: October 2008

SUMMARYHigh plant populations caused a reduction in pod set and consequently in seed yield. Removal of axillary branches reduced the average weight of seed and percentage seed oil on primary racemes, indicating transport of photosynthate from branch leaves to storage sites in pods on primary racemes. Debranching at low densities was also associated with premature senescence of leaves and desiccation of immature pods, suggesting that branch removal need not have an exclusively simple nutritional basis. High canopy density reduced oil content, and seeds borne on primary racemes had lower oil levels than those on axillary branches.
Fertilizer Response of Napier Grass under Different Soil Conditions in Brunei
Authors: Williams C. N. 
Published: October 2008

SUMMARYSeasonal fertilizer response of napier grass (Pennisetum purpureum) was measured on various soils in Brunei. Climate was moderately humid over the three-year experimental period, with the longest dry spell about 4 months. Optimal fertilizer N levels (balanced with other nutrients) ranged from about 240 to 900 kg/ha/yr on the different soil types and under different moisture conditions. Dry forage yields at the optimum fertilizer levels ranged from 5 t/ha/yr on sandy soil under dry conditions, to 55 t/ha/yr on a sandy clay loam with adequate water. Moderate production of about 20 t/ha/yr was obtained on acid sulphate soil with fertilizer and lime. Digestible nutrient and protein levels of 60-day forage were about 55 and 10% respectively.
Effects of Temperature and Preflooding on Rice Yields in Kenya
Authors: Young L. H. 
Published: October 2008

SUMMARYAn investigation was made at the Mwea Irrigation Settlement, Kenya, to discover the reason why rice units which were transplanted earlier gave higher yields. Yields over an 11-year period were examined in relation to meteorological data and cultivation activities. It was found that the period during which the units were flooded prior to transplanting correlated with the date of transplanting, with longer preflooding periods causing higher yields and not the transplanting date. A yield/temperature relationship was also established.
Intercropped Corn–Soyabean Density Studies. I. Yield Complementarity
Authors: Putnam D. H. , Herbert S. J. , Vargas A. 
Published: October 2008

SUMMARYIntercropped corn and soyabean were grown in a randomized block design (RBD) and a systematic design (SD) in 1981 and 1982 to evaluate total yield, yield complementarity, crop competition and land-use efficiency as affected by corn and soyabean densities. In the RBD, three corn density treatments were applied to corn–corn–soyabean–soyabean, corn–corn–soyabean, and corn–soyabean intercrop row patterns and to monocultures. In the SD, 9 or 10 corn densities were factorially combined with up to 13 soyabean densities in a corn–soyabean row pattern (91 cm spacing). In the RBD, total intercrop yields were similar to corn monoculture yields (60.8 to 62.7 t ha−1 in 1981) in the corn–corn–soyabean and corn–soyabean patterns at high corn densities but were less at low density. The corn–corn–soyabean–soyabean pattern yielded 87% of the corn monoculture at high density in 1982. These results were confirmed in the SD, where total intercrop yields were highly responsive to corn density and poorly responsive to soyabean densities. Both experiments indicated that high corn row densities are needed to maintain yields in corn–soyabean intercrops, possibly higher than the levels studied. Land equivalent ratios were above 1.0 for all but the low density corn–corn–soyabean–soyabean pattern in the RBD. The ability of an intercrop with as many as half the corn rows replaced by soyabean to produce yields similar to corn monoculture indicates a biological complementarity for dry matter production in the mixtures.
Influence of Seedbed Tilth on Emergence and Root and Shoot Growth of Seedlings of Some Crops
Authors: Malik R. S. , Jhorar B. S. , Dahiya I. S. 
Published: October 2008

SUMMARYWheat (Triticum aestivum), mustard (Brassica juncea), gram (Cicer arietinum) and barley (Hordeum vulgare) seedlings were raised in soils of different tilth created in microplots during 1981 and 1982. Amplitude in diurnal seed-zone temperature and soil moisture content increased with tilth coarseness. At low soil moisture levels, seedling emergence of wheat and mustard decreased with increasing clod size while that of gram and barley increased. These effects were not significant at high soil moisture levels. Shoot growth of all the crops was higher under coarse tilth than under fine tilth at both moisture levels. Root growth of wheat and mustard decreased with increasing clod size while that of gram and barley increased, at both moisture levels. Mustard had the highest seedling emergence at the low moisture level. Seedling emergence and shoot growth were higher under high moisture than under low moisture for all crops. Root growth varied depending upon the type of crop.
Evaluation of Fertilizer Placement Methods for White Yam (Dioscorea rotundata)
Authors: Nwinyi S. C. O. , Enwezor W. O. 
Published: October 2008

SUMMARYFour fertilizer placement methods (ring, sideband, broadcast and furrow) applied ten weeks after planting were compared in nine experiments to determine the best method for fertiliza- tion of white yam (Dioscorea rotundata). Significant yield differences due to the treatments were observed at Mbato, Umudike and Igbariam in 1980 and at Nsukka and Igbariam in 1981. Best yields overall were obtained with the sideband method, followed by broadcast, ring and furrow in that order. However, man-days taken to fertilize one hectare by ring, sideband, furrow and broadcast methods were 11.2, 10.9, 2.8 and 1.5, respectively, so that in this regard, broadcast is preferable to the other placement methods.
Evolution of Grain Legumes. III. Pulses in the GenusVigna
Authors: Smartt J. 
Published: October 2008

SUMMARYThe genusVignaincludes seven species of pulse, two African and five Asian. While the Asian species are within the subgenusCeratotropis, the two African species are in different sections of the subgenusVigna, namelyCatjang(V. unguiculata) andVigna(V. subterranea). Limited gene flow is possible within subgenusCeratotropis, but none has as yet been demonstrated between subgenera nor between sections within subgenusVigna. Parallel evolutionary trends are apparent in all species, with considerable increase in seed and pod size. Erect bush forms have evolved in all cultigens exceptV. aconitifoliaandV. subterranea. The former has not apparently changed much in vegetative form under domestication, while the geocarpy of the latter precludes erect growth. Future prospects for the Asiatic grams would be better if yield levels could be improved. The cowpea is likely to remain an important crop at present levels of performance although there is room for improvement. There seems little immediate prospect of expanded ground bean production under existing conditions.
Soil Movement in Long-term Field Experiments as a Result of Cultivations I. A Model for Approximating Soil Movement in One Horizontal Dimension by Repeated Tillage
Authors: Sibbesen E. , Andersen C. E. , Andersen S. , Flensted-Jensen M. 
Published: October 2008

SUMMARYA serious problem in long-term field experiments is that soil is moved from plot to plot as a result of cultivations. The problem is often overlooked and very few attempts have been made to quantify this movement under varying conditions.A simple, mathematical model for approximating the movement of soil in one horizontal dimension by repeated tillage with one or more tillage implements is presented. The model describes the development with time of a concentration gradient of substance, by means of the solution of a diffusion equation. The model is in agreement with ‘the central limit theorem’, when it is used for the situation where the same cultivations are repeated many times in alternating directions.The model fitted well to data taken from the literature.
Soil Movement in Long-term Field Experiments as a Result of Cultivations. II. How to Estimate the Two-Dimensional Movement of Substances Accumulating in the Soil
Authors: Sibbesen E. , Andersen C. E. 
Published: October 2008

SUMMARYA previously presented model for one-dimensional soil movement by repeated tillage is extended for use under the more complex conditions of long-term field experiments, for (i) following the two-dimensional movement (along and across the plots) of accumulating substances (nutrients, disease organisms, etc.) caused by tillage; (ii) determining the smallest acceptable plot size from given conditions, when planning new long-term field experiments and (iii) determining the size of the discard relative to the size of the treated plot.Diagrams are given from which rough estimations can be made of both the movement of accumulating substances in long-term field experiments and the smallest acceptable plot size, when a computer with the necessary facilities is not available.
Evaluation and Presentation of Intercropping Advantages
Authors: Willey R. W. 
Published: October 2008

SUMMARYIt is proposed that two distinct objectives should be recognized in the evaluation of intercropping advantages: (i) a biological objective to determine the increased biological efficiency of intercropping and (ii) a practical objective to determine the advantages that are likely to be obtained by a farmer. The sole crop systems with which intercropping must be compared to satisfy these objectives are defined. Evaluation in relative, absolute, monetary and nutritional units is discussed and some aspects of presenting intercropping data in graphical form are illustrated.
Effects of Intercropping, Mulching and Staking on Growth and Yield of Tomatoes
Authors: Olasantan F. O. 
Published: October 2008

SUMMARYThe effects of intercropping, mulching and staking on growth and yield of three tomato varieties were evaluated in four field trials in 1982 and 1983. Fruit yields of the improved varieties were significantly reduced by intercropping with okra but the yield of a local variety was unaffected. Though the yield of okra when grown with tomato varieties was less than that of a sole crop, the combined yield of the two crops in mixtures was more than the means of the species in monoculture. Relative Yield Totals (RYT) increased to maxima of about 1.42 and 1.39 when the local variety was grown with okra in 1982 and 1983 trials, respectively. Mulching and staking significantly increased vegetative growth, yield and yield components of the tomato plants. Mulched plants grew taller and had more branches and a greater number and weight of fruits than staked plants. Improved varieties responded better to mulching and staking than the local variety. Growing improved varieties of tomato in sole stands with proper mulching and staking is therefore recommended.
Grain Yield Potential of Some Diverse Maize (Zea mays L.) Morphotypes Intercropped with Cocoyam (Xanthosoma sagittifolium)
Authors: Ayuk-Takem J. A. , Chhedda H. R. 
Published: October 2008

SUMMARYThree maize cultivars, BACOA, SAW and COCA, were evaluated when intercropped with cocoyams at a density of 50 000 maize plants and 10 000 cocoyam stands ha−1. BACOA which matures in 120 days, and SAW (130 days) transmitted significantly more light to the lower canopy than COCA, which has spreading leaves and matures in 150 days. Relative yields for BACOA, SAW and COCA in pure stands were 72, 100 and 85%, respectively, while those for cocoyams in BACOA/cocoyam, SAW/cocoyam and COCA/cocoyam mixtures were 82, 58 and 54%, respectively, showing that COCA significantly suppressed the yield of cocoyam when intercropped.Yields of a COCA type with erect leaves increased as plant density increased from 20 000 to 50 000 plants ha−1 in pure stands, while yields of COCA with spreading leaves increased as plant density increased from 20 000 to 40 000 plants ha−1 but decreased when plant population increased to 50 000 plants ha−1. When COCA with erect leaves was intercropped with cocoyams, cocoyam tuber yields were fairly stable and maize yields continued to increase significantly as plant density increased from 20 000 to 50 000 plants ha−1, whereas the yields of COCA with spreading leaves and cocoyams were greatly reduced when intercropped and when the plant population increased from 20 000 to 50 000 plants ha−1.
Effect of Shoot Removal on Shoot and Root Yields of Sweet Potato
Authors: Dahniya M. T. , Hahn S. K. , Oputa C. O. 
Published: October 2008

SUMMARYExperiments on harvesting sweet potato as a green vegetable and as a root crop are described. Whole shoots yielded 62% more than shoot tips. Similar total shoot yields were harvested whether tip removal was at two, three or four week intervals. Root yield was decreased by 31 to 48% by removing shoot tips, while removing whole shoots led to root yield decreases of 48 to 62%. Harvesting shoots at two week intervals gave 72% reduction in root yield, compared with 50% with four week intervals. There were fewer and smaller tubers as the frequency of shoot harvests increased. There were varietal differences in response to shoot removal For reasonable yields of both shoot tips and tuberous roots harvesting shoot tips at four week intervals is recommended.
Evolution of Grain Legumes. IV. Pulses in the Genus Phaseolus
Authors: Smartt J. 
Published: October 2008

SUMMARYThe genus Phaseolus as currently recognized contains four pulses: common bean (P. vulgaris), runner bean (P. coccineus), lima bean (P. lunatus) and tepary bean (P. acutifolius). Although these all have their origins in tropical and sub-tropical latitudes, they have evolved in different ecological zones. The runner bean has evolved at higher altitudes, the common bean at intermediate levels and the lima bean at lower altitudes. The tepary has a specialized desert-annual life-form. The occurrence of day neutral genotypes in all species has permitted their spread into cool and worm temperate zones (the common and runner beans) and the warm temperate zone (lima bean). It is possible therefore to grow one or other Phaseolus species in most areas of the world where cultivation can be practised. The common bean has evolved the widest range of growth forms, seed and pod sizes, pod forms and textures, and seed and pod colors. World-wide an enormous primary gene pool has been produced. The common bean pool is the secondary gene pool for the runner bean and vice versa, since partially fertile interspecific species produce sterile or inviable F1 hybrids so that potential for interspecific gene transfer is limited. Thus no known secondary gene pools exist for Phaseolus species other than P. vulgaris and P. coccineus.
The Role of Fertilizer Management in the Development and Expression of Crop Drought Stress in Cereals under Mediterranean Environmental Conditions
Authors: Keatinge J. D. H. , Neate P. J. H. , Shepherd K. D. 
Published: October 2008

SUMMARYThe development and influence of crop drought stress was examined in winter-planted small-grain cereals under Mediterranean environmental conditions. In two average or wetter than average years crop drought stress in the grain-filling period was greatly exacerbated by the addition of fertilizer (N and P) and this usually resulted in significantly lower kernel weights. Yet this reduction was not so substantial as to seriously affect crop yields. Total grain yields were largest in treatments receiving fertilizer, due to greater spike numbers and numbers of kernels per spike. But heavy nitrogen applications may promote the risk of a large proportion of small or shrivelled grains in a dry year.