bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of Maize to Planting Dates in a Tropical Rainforest Location
Authors: Fakorede M. A. B. 
Published: October 2008

SUMMARYGrain yield of maize (Zea mays L.) was decreased by 30, 38 and 34 kg ha−1 for each day by which sowing was delayed after the first planting in March in 1978, 1980 and 1981, respectively. Yield reduction was associated with reduced plant size (plant and ear heights, tassel weight and branch numbers), ear number, ear weight, grain weight, ear length, ear diameter and kernel weight. High yields can thus be obtained by planting with the first rains of the year, especially if a good rate of emergence and seedling vigour under relatively hot, dry soil conditions can be ensured either culturally or genetically.
Weather Factors Affecting the Response of Maize to Planting Dates in a Tropical Rainforest Location
Authors: Fakorede M. A. B. , Opeke B. O. 
Published: October 2008

SUMMARYSimple linear correlations, stepwise multiple regressions and path-coefficient analyses were used to determine the relation between grain yield of maize (Zea mays L.) and weather factors in a three year study involving several planting dates within each year. Maximum and minimum relative humidity, which demonstrated negative relationships with yield, were the most reliable factors, both directly and indirectly, for predicting yield. Temperature (including accumulated heat units), sunshine hours and total and effective rainfall generally showed negligible direct effects on yield. Potential evaporation, which showed positive correlation, had a negative direct influence on grain yield. We conclude that, whenever possible, path analysis should be used as well as correlation and regression analyses in explaining the complex multiple interactions of yield and weather factors in crop production.
Genotype Environment Interactions and the Identification of Adaptable Cultivars of Upland Rice (Oryza Sativa) in South-Western Nigeria
Authors: Oyedokun J. B. 
Published: October 2008

SUMMARYTwenty improved upland rice cultivars were evaluated in yield trials at three locations for three successive years in south-western Nigeria. Highly significant genotype x environment interactions were observed, indicating that some cultivars yielded better in some locations than others. The use of regression analysis adequately identified the cultivars best suited to each environment. S2d values (measures of stability) for the cultivars ranged from 0.0007 to 0.2196, the cultivars with smaller values being more stable at the respective locations. The more adaptable cultivars have high mean yields and a deviation from regression as small as possible. The cultivar best adapted to good environments was code 3 (an improved selection from the cross Lac 23 x IR 528) with a yield of 3.36 t ha−1, while code 9 (a sister selection from the same cross) was best adapted to poor environments. Code 8 (a selection from the cross IR 154/O.S. 6 and 63–83) showed general adaptability. Once grain quality has been evaluated some of these cultivars might therefore replace code 18, the currently recommended upland rice cultivar, in the rain-forest zone.
The Effect of Pruning at Different Heights on Yields, Dry Matter Production and Partitioning in Clonal Tea (Camellia Sinensis) in Kenya
Authors: Magambo M. J. S. , Waithaka Kimani 
Published: October 2008

SUMMARYDry matter production and partitioning in old clonal tea bushes pruned and maintained at different heights were investigated. New tissues (leaves, new branches and small roots) consti- tuted a small fraction of the total dry matter in all bushes pruned and initially maintained at 70, 40, 25 and 10 cm high, 36 months after pruning. Leaf/frame dry matter ratio was larger and the shoot/root and frame/root ratios were smaller in the bushes initially maintained at 10 cm than in the bushes maintained at other heights. Yields per unit area of the plucking surface were greatest in the smallest bushes initially maintained at 10 cm in 42 months of recording but on the basis of the available space they were greatest in the large bushes initially maintained at 70 cm.
An Agronomic and Economic Study of Intercropping Brussels Sprouts and Summer Cabbage
Authors: Salter P. J. , Akehurst Jayne M. , Morris G. E. L. 
Published: October 2008

SUMMARYIntercropping Brussels sprouts with cabbage was studied in two experiments comparing four different intercropping systems with sole crop production. Intercropping presented no agronomic or management problems because both crops had compatible cultural and crop protection requirements. Analysis of Land Equivalent Ratios and Relative Value Totals showed that the four intercropping systems gave consistently larger yields than the sole crops. In one experiment profitability, measured by the gross margin, was higher from all of the intercropping systems and costs per unit of produce were reduced. Similar results were obtained with one intercropping system in the other experiment. Alternative methods of evaluating the results in economic terms are discussed, together with the implications of intercropping in high-input systems of vegetable production.
On the Use of Stigter's Ratio in Expressing the Thermal Efficiency of Grass Mulches
Authors: Othieno C. O. , Stigter C. J. , Mwampaja A. R. 
Published: October 2008

SUMMARYData from mulched tea show that an earlier defined ratio of temperature fluctuations in thermally homogeneous soil can be successfully used in rating the thermal efficiency of artificial grass mulches. The efficiency of a natural mulch of growing grass is also determined for comparison. It is demonstrated that the use of the ratio is more precise than using average temperatures in assessing the effects of the mulches.
Response of Pearl Millet Cultivars to Inoculation with Nitrogen-fixing Bacteria
Authors: Wani S. P. , Chandrapalaiah S. , Dart P. J. 
Published: October 2008

SUMMARYThe results of field experiments conducted with millet cultivars inoculated with different nitrogen-fixing bacteria at the ICRISAT Centre, Hyderabad, India are described. Significant interactions were observed between host cultivars and bacterial strains, but some cultivars showed consistently increased grain and dry matter yields, suggesting the possibility of exploiting suitable plant and nitrogen-fixing bacterial associations for increasing grain yield. Inoculation also resulted in increased nitrogen uptake up to 14.9 kg ha−1, and larger grain nitrogen contents.
Stomatal Responses to Environmental Variables in Shade and Sun Grown Coffee Plants in Mexico
Authors: Fanjul Luis , Arreola-Rodriguez R. , Mendez-Castrejon M. P. 
Published: October 2008

SUMMARYThe influence of air temperature (T), vapour pressure deficit (vpd), irradiance (Q) and leaf water potential (ψ) on diurnal stomatal movement of coffee plants was examined under field and controlled environmental conditions. Leaves of plants grown under shade had larger stomatal conductance (g) values than plants grown in open sun. Stomatal responses to vpd under constant temperature conditions were very strong, indicating that ambient humidity could play a major role in controlling stomatal aperture. Changes in g as vpd increased probably contributed to observed reductions in the rate of net photosynthesis (Pn), though the effect of vpd on Pn was smaller.
Response of Cowpea (Vigna unguiculata) to Spacing in the Savanna and Rainforest Zones of Nigeria
Authors: Kayode G. O. , Odulaja A. 
Published: October 2008

SUMMARYA two year field study designed to investigate the effect of spacing on yield of two cowpea cultivars in the savanna and forest zones of Nigeria showed that cowpea yields were larger in the savanna than in the forest zone at all spacings employed. Inter-row spacing wider than 60 cm and intra-row spacing closer than 10 cm could be used for improved seed yield in the savanna zone, while 60 × 20 cm (83 333 plants ha−1) would be optimum for cowpea production in the forest zone.
Development of Mixed Tree and Food Crop Systems in the Humid Tropics: A Response to Population Pressure and De-forestation
Authors: Watson G. A. 
Published: October 2008

SUMMARYMixed tree and food crop farming systems are being developed in the humid tropics. They offer one solution to the problems caused by population pressure and de-forestation, since they can provide a satisfactory income to the subsistence farmer, while adequately protecting the environment In seeking to develop optimal systems, examples and information can be drawn from traditional mixed cropping systems, from taungya systems of forestation, and from other systems developed within the commodity cropping sector. However, the full potential of mixtures involving perennials and food crops can only be realised within the limitations of local socio-economic and political circumstances.
Effects of Maturation Environment on Seed Size and Subsequent Plant Growth in Peas (Pisum sativum)
Authors: Kant K. , Sharma B. , Tyagi M. C. 
Published: October 2008

SUMMARYMaturation of peas in cool temperatures (mean 17.5°C) at Dalang Maidan, Lahaul (in the Himalayas) led to the development of larger seeds in comparison to those of the same varieties which had matured in warmer temperatures (mean 24.5°C) at Delhi, India. The larger seeds from Lahaul, when sown at Delhi, gave rise to taller plants which came into flower earlier compared with those from the seeds matured at Delhi. Significant location ′ variety interactions were recorded for germination and plant height. Inherent variation in days to flowering could have been a major factor in these interactions. These data are of direct importance to breeders using seeds developed at more than a single location if environmental conditions differ appreciably.
Effects of Cropping Seasons and Temperatures on the Dormancy of Rice (Oryza sativa) Seeds
Authors: Sikder H. P. 
Published: October 2008

SUMMARYThe Boro (dry) and Kharif (wet) seasons of West Bengal differ appreciably in respect of atmospheric temperature, relative humidity and hours of bright sunshine each day. Post-harvest hot temperature (31°C) either in controlled conditions (in the Kharif season) or in natural (31.5°C) conditions (in the Boro season) had a more significant effect than post-harvest cool air temperature (20.4°C) in the Kharif season on the early breaking of dormancy of paddy rice seeds. However, the pre-harvest hot air temperature (31.4°C) of the Boro season was no more effective in breaking dormancy than the pre-harvest cool air temperature (20.9°C) of the Kharif season. With a mean air temperature of 20.4°C the post-harvest exposure of the seeds to the sun from sunrise to sunset during the Kharif season was much more effective in breaking dormancy than the post-harvest mean air temperature of 31.5°C during the Boro season.
Weather, Physiology and Seasonality of Tea (Camellia sinensis) Yields in Malawi
Authors: Squire G. R. 
Published: October 2008

SUMMARYField measurements with a pressure chamber showed that the water potential of tea shoots was more closely related to the atmospheric saturation deficit than to the amount of water in the soil. Records for shoot growth and weather then revealed that, within a narrow range of mean temperature, the weekly rate of shoot extension was inversely related to mean saturation deficit measured at 1400 h. During periods when saturation deficit did not rise above 20 mbar, the rate of shoot extension varied linearly with mean temperature above a base temperature of 12.5–13.0°C. These correlations suggested that seasonality of shoot growth in tea can be explained largely by the independent effects of temperature and humidity. The effect of mean air temperature on the rate of shoot extension was confirmed in a glasshouse built over an established crop.
Factors Affecting Yields of Dark Fire-cured Tobacco in Malawi
Authors: Tanton T. W. , Abington J. B. 
Published: October 2008

SUMMARYThe yield data from a series of fire-cured variety × fertilizer trials in Malawi are presented. Variety was not important in determining total yields though it was in influencing the distribution of grades. Fertilizer had a large effect upon yields, particularly upon the Cutter and Leaf grades, but environment had by far the greatest influence. High levels of applied fertilizer could not be relied upon to replenish a depleted soil so that it produced yields comparable to those from a soil with well-maintained fertility. Application of fertilizer produced a beneficial change in the grade distribution within the crop.
Measuring Leaf-water Potential in Chickpea with a Pressure Chamber
Authors: Sivakumar M. V. K. , Virmani S. M. 
Published: October 2008

SUMMARYThe pressure-chamber technique has been used for the first time to measure leaf-water potentials in chickpea under field conditions. Available soil-water contents at different depths for irrigated and non-irrigated crops are presented along with the diurnal variation in leaf-water status, to show that pressure-chamber measurements correspond closely with available soil water. Leaf-water potential has also shown differences in leaf-water status among different cultivars. The rapidity and ease with which measurements can be made in the field make the technique suitable for quick measurements of leaf-water status for chickpea.
Seed Characters and Germination in Soyabean
Authors: Nangju D. 
Published: October 2008

SUMMARYTwenty-five cultivars of soyabean (Glycine max (L.) Merr.), differing in their origin, crop duration and seed size, were planted four times at bi-weekly intervals during the major rainy season at Ibadan, Nigeria and harvested at optimum maturity or two weeks later. Delayed harvest and intense rainfall during pod maturation were essential for selecting for resistance to field weathering, but 2 weeks' delay enabled susceptible and resistant cultivars to be identified. Percentage of infected seed had the highest correlation with potential germination at harvest (r=−0·869**) but may not be a suitable criterion for use in a screening programme. An alternative would be to screen cultivars for resistance to weathering on the basis of seed size and the proportion of smooth and clean seed, since these characters were highly correlated to potential germination (r=−0·562** and 0·632** respectively).
Estimation of Hydrogen Cyanide Released from Cassava by Organic Solvents
Authors: Williams Hugh J. 
Published: October 2008

SUMMARYMethods are described for releasing HCN from cassava leaves and tubers by organic solvents and its spectrophotometric estimation as the red complex formed with alkaline picrate. Chloroform was the most efficient solvent, with toluene an acceptable alternative, using enough solvent to wet samples thoroughly to maximize cyanide yield. Cyanide content was concentrated in the veins and towards the base of leaves and declined linearly with leaf age. Release of HCN with solvent compared favourably with traditional homogenization/steam distillation with leaves and parenchymal tissue, but was unsatisfactory for tuber peel. The effective removal of HCN from cooked cassava leaves depends chiefly on release of enzymes by efficiently chopping them before boiling, which only slowly destroyed potential cyanide content of unchopped leaves.
Short Day Induction of Flowering in Pearl Millet (Pennisetum typhoides) and its Effect on Plant Morphology
Authors: Ong C. K. , Everard A. 
Published: October 2008

SUMMARYFour hybrids of pearl millet (Pennisetutn typhoides) were screened for photoperiod sensitivity in a heated temperate glasshouse and the effects of 12 h short day induction on the reproductive development and plant morphology were examined. All the hybrids (BK 560, MBH 104, MBH 110 and ICH 105) responded to 14 short days by a considerable reduction in the time to anthesis, plant height and the final number of leaves produced, without any adverse effect on head development. In another experiment BK 560 required at least four short days for floral initiation and another four for subsequent development. Short day induction had no apparent effect on the rate of leaf appearance. The results were compared to those reported for millets in general and to millets grown in the tropics.
Effects of Maturity on Oil Yield of Brassica juncea
Authors: Gambhir P. N. , Narain A. , Tiwari P. N. 
Published: October 2008

SUMMARYThe change in seed oil percentage and 100-seed weight of Brassica juncea Varuna was studied as the crop matured during rabi 1977–78. Statistically, the oil percentage reached its highest value at 55 days from flowering, whereas the 100-seed weight was highest about 20 days later, when the pods were fully yellow. Oil yield (the product of oil percentage and seed weight) also reached its highest value when the pods were fully yellow. This information should enable the crop to be harvested at the proper physiological stage (yellow-podded) for maximum oil yield.
Evolution of Grain Legumes. V. The Oilseeds
Authors: Smartt J. 
Published: October 2008

SUMMARYAlthough the groundnut and soyabean are not close taxonomic relatives they have a number of features in common. Both are polyploid (2n= 4x= 40 chromosomes) and have arisen from the domestication of wild polyploids. Polyploidy has occurred independently at least twice in the genusArachis, while inGlycinethe genus includes both tetraploids and octoploids, an unusually high ploidy level in a legume. Both crops are oilseeds although oil content varies widely between the two species, ±50% in groundnut and ±20% in the soyabean. The soyabean produces ±35% protein content of good quality whereas that of the groundnut is ±30% and less well balanced nutritionally. The soyabean originated in the Far East whereas the groundnut originated in the eastern Andes foothills (N.W. Argentina to S. Bolivia). The evolutionary changes under domestication in the soyabean are typical; the cultigen has become a compact, erect, self-supporting plant with reduced pod dehiscence and loss of seed dormancy. The evolutionary response pattern of the groundnut is similar but modified on account of its geocarpy. This necessitates the maintenance of adequate contact between basal branches of the plant and the soil for effective fruiting. Notwithstanding this, strongly ascending growth forms have become established. The greatest contrast between the two species is in photoperiod sensitivity; the groundnut is day-neutral while the soyabean is a short-day plant with genotypes varying widely in the day length tolerated without inhibition of flowering.
Studies on Row Arrangement and Population Densities of Potato Cultivars in a Sugarcane and Potato Intercropping System in North Central India
Authors: Verma R. S. , Chauhan R. S. , Singh R. N. 
Published: October 2008

SUMMARYFour plant densities and two genotypes of potato intercropped with sugarcane were examined at Lucknow, India and compared with potato–sugarcane sequential cropping. The best yields and monetary returns were obtained with one sugarcane row to two rows of potato (Kufri Chandramukhi) at 80 × 103 potato plants ha−1; this treatment combination gave virtually a full yield of both potato and cane. Sequential cropping of potato and sugarcane with 80 × 103 potato plants ha−1 in rows 50 cm apart gave better yields than intercropping potato with sugarcane in a 1:1 row arrangement. Kufri Chandramukhi, a short duration variety of potato, was more suitable for intercropping with sugarcane than the long duration Kufri Sindhuri. Growing potato either in sequence or as an intercrop with sugarcane decreased soil bulk density and increased its available nitrogen content.
Effect of Iron Pyrites, Organic Materials and Micronutrients on Yield of Rice and Wheat and on Amelioration of Sodic Soil
Authors: Tiwari K. N. , Kumar Anil 
Published: October 2008

SUMMARYThe effects of iron pyrites, organic materials and micronutrients on the yield of rice and wheat and on the amelioration of saline sodic soil were studied at Kanpur. The grain yield of the first crop of rice increased from 1.37 to 2.97 t ha−1 following application of pyrites at 50% of the estimated gypsum requirement. The grain yield of succeeding wheat and rice crops also increased significantly with pyrites treatment. These increases were associated with marked decreases in pH, electrical conductivity, exchangeable and soluble sodium content and bulk density of the soil and with an increase in its hydraulic conductivity. The beneficial effect of pyrites was increased with the application of rice straw, Sesbania as green manure and micronutrients, the pyrites plus Sesbania green manure treatment being the most effective.
Harvesting Policies For Tea in Malawi
Authors: Palmer-Jones R. W. 
Published: October 2008

SUMMARYThe information collected from an experiment on tea, in which two plucking intervals and three plucking standards were imposed, allowed analysis of the effects on the total value of output (Cloughley et al., 1983; Cloughley, 1983). The analysis can be extended and its practical relevance improved by incorporating harvesting and manufacturing costs. Using information collected in another experiment and readily available economic information the effects of incorporating these costs are presented. A method of simultaneously determining optimal plucking interval and standard is described.
Effects of NPK Fertilizer on Tuber Yield, Starch Content and Dry Matter Accumulation of White Guinea Yam (Dioscorea rotundata) in a Forest Alfisol of South Western Nigeria
Authors: Kayode G. O. 
Published: October 2008

SUMMARYField trials designed to investigate the effects of nitrogen, phosphorus and potassium on the yield, starch and dry matter content of white guinea yam were conducted over a four year period in south western Nigeria. The optimum level of nitrogen for successful production of white guinea yam was 35 kg ha−1in a forest Alfisol that had been under cultivation for at least two years. Nitrogen, phosphorus and potassium had no significant effect on starch content, but large applications of phosphorus and potassium significantly decreased dry matter accumulation.
Controlled Environments as an Adjunct to Field Research on Lentils (Lens culinaris). II. Research Strategy
Authors: Summerfield R. J. , Muehlbauer F. J. 
Published: October 2008

SUMMARYThe strategy and associated practical details are described of a research programme which seeks to make effective use of controlled environment facilities in providing information and screening techniques useful to lentil breeders. Two principal objectives were (a) that genotypes grown in artificial climates should respond to whatever factors are being investigated in a manner which reflects their responses and relative sensitivity to different agroclimates in the field, and (b) to deploy controlled environment facilities for the longest period which is feasible during each calendar year and with maximum benefit:cost ratio.
Inducing Orthotropic Shoots in Coffee with the Morphactin Chlorflurenolmethylester
Authors: Stemmer W. P. C. , Van Adrichem J. C. J. , Roorda F. A. 
Published: October 2008

SUMMARYThe auxin-transport-inhibiting morphactin chlorflurenolmethylester (CFM; Methyl 2-chloro-9-hydroxyfluorene-9-carboxylate) breaks the dormancy of axillary buds in young coffee plants and produces orthotropic shoots. A concentration of CFM as low as 50 mg/litre induced an average of 24 orthotropic shoots per 6-month-old seedling. This approach could provide a fast and inexpensive method of vegetative propagation for raising disease-resistant cultivars if adult clones respond similarly to the seedlings used here and the treatment does not adversely affect the propagation of induced shoots.