bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of the Zinc Requirements of Different Crops
Authors: Tiwari K. N. , Pathak A. N.
Published: October 2008

A field experiment was conducted for two consecutive years commencing in 1979–80 on the Indo-Gangetic alluvial soil of Pura to investigate the requirements for zinc of wheat, chickpea, mustard and Egyptian clover. Chickpea and Egyptian clover were more sensitive to zinc deficiency than wheat and mustard, respectively. Average total dry matter production by Egyptian clover and wheat was larger than mustard and chickpea. Egyptian clover and wheat required more zinc to achieve maximum dry matter production but they also recovered from the soil a larger proportion of applied zinc than chickpea and mustard. Mustard produced the most dry matter per unit of zinc absorbed.
Investigating Source-Sink Relations in Cassava by Reciprocal Grafts
Authors: Dahniya M. T. , Oputa C. O. , Hahn S. K.
Published: October 2008

The relation between source potentials and sink capacities of four cassava (Manihot esculentaCrantz) varieties with different characteristics was investigated by means of reciprocal grafts. There were marked differences in the sink capacities (average stock effects) and source potentials (average scion effects) of the varieties.
Effects of Fertilizers and Plant Age on Distribution of Nutrients in Nigerian Cassava (Manihot esculenta)
Authors: Okeke J. E. , Kang B. T. , Obigbesan G. O.
Published: October 2008

The effects of soil fertilization and plant age on the nutrient composition of various parts of five Nigerian cassava varieties were studied to identify suitable index plant tissue(s), sensitive growth stage(s) and optimum nutrient concentrations, to develop better fertilizer practices for the crop. The third month from planting was the most sensitive stage for diagnostic sampling, when N status was best reflected in leaf blades and K in petioles. N and P were most concentrated in leaf blades and least in root tubers. The largest root tuber yields after 12 months were associated with leaf blade analyses of 5% N, 0.4% P and 2% K at 3 months after planting.
Relationship of Base Temperature to Development of Spring Wheat
Authors: Del Pozo Alejandro H. , García-Huidobro Jorge , Novoa Rafael , Villaseca Sergio
Published: October 2008

The base temperature and thermal time for different development stages of spring wheat cultivars were calculated using a linear relation between the rate of development and the mean temperature. The results show that germination, emergence, tillering and leaf elongation (the vegetative phase) have a base temperature around 2°C but the elongation of the culm and the reproductive phase (tillering-maturity) have a base temperature over 6°C. A general model to describe the time to maturity of spring wheats, which takes account of these different phases, is proposed.
Twenty Years' Results from a Shade and Fertilizer Trial on Amazon Cocoa (Theobroma cacao) in Ghana
Authors: Ahenkorah Y. , Halm B. J. , Appiah M. R. , Akrofi G. S. , Yirenkyi J. E. K.
Published: October 2008

The effects of three shade densities, NPK fertilizers and fertilizer-pest/disease relationship on Amazon cocoa (Theobroma cacao L.) over a 20-year period are reported. Yields equivalent to the mean yield from the unfertilized plots were achieved in about 3, 4 and 6 years in fertilized plots under the no shade (S0), medium shade (S1) and heavy shade (S2) treatments, respectively. There were three growth phases, each characterized by a different yield trend. No appreciable changes in the exchangeable Ca and Mg were observed during the experiments, but K dropped to 68% of its initial value while the available P of the unfertilized and the S0 plots fell by 38%. Fertilizer recommendations for P and K should take account of overhead shade. The effect of N application was often negative. No direct relationship was observed between fertilizer treatment and the incidence of pest/blackpod/swollen shoot virus (SSV) disease of cocoa. SSV infection was greatest under S0. Cocoa farms in Ghana cannot maintain high yields (above 1000 kg dry cocoa ha−1) beyond 15 years of intensive cropping.
Response of Chickpea Cultivars to Water Stress in a Semi-arid Environment
Authors: Sivakumar M. V. K. , Singh Piara
Published: October 2008

The combined effect of soil moisture stress in the root zone and atmospheric evaporative demand on the growth and yield of two chickpea cultivars was investigated using four sowing dates and three irrigation regimes within each sowing date during the 1980–81 and 1981–82 seasons at the ICRISAT research centre. Total water use was different for different irrigation regimes and sowing dates and there were differences in the total dry weight and seed yield of chickpea between the sowing dates and the irrigation regimes. The cultivars did not differ in dry matter production. However, cv. Annigeri yielded more than cv. L-550 under all irrigation regimes. Differences in seed weight were observed between irrigation regimes and sowing dates and there were interactions between sowing dates and cultivars and between irrigation regimes, sowing dates and cultivars. High air temperatures during the period from flowering to maturity reduced the time to maturity of late-sown chickpea and led to reduced seed size and lower yields. The efficiency of use of applied water was also low for the late-sown crop.
Yield Distribution in Irrigated tea (Camellia Sinensis) at Two Sites in Eastern Africa
Authors: Carr M. K. V. , Dale M. O. , Stephens William
Published: October 2008

The results of two tea irrigation experiments conducted independently in southern Tanzania and Malawi, where severe annual droughts of similar duration occur, were compared. There were marked differences in the dry season yield distributions between the two sites. These could be attributed to the adverse effects of large saturation deficits on plant water status and rates of shoot extension in Malawi. The implications for tea irrigation in particular and for irrigation agronomy experiments in general are discussed. The need to include detailed descriptions of the environment in which experiments are conducted is stressed.
Influence of Mode and Time of Chlormequat Chloride (CCC) Application on Groundnut (Arachis hypogaea) under Semi-arid Rainfed Conditions in North-West India
Authors: Giri Gajendra , Gangasaran
Published: October 2008

A field experiment was conducted during the monsoon seasons of 1982 to 1984 to investigate the effect of chlormequat chloride (CCC) and its mode and time of application on groundnut. Foliar application of CCC 60 days after sowing at the rate of 200 ppm reduced moisture loss and increased relative leaf water content and yield. Soaking seed in a 0.5% CCC solution also increased relative leaf water content, root nodulation and seed yield.
The Effects of Elemental Sulphur on Shoot Dry Weight, Nodulation and Pod Yield of Groundnut (Arachis hypogaea) under Irrigation
Authors: Hago Tageldin M. , Salama M. A.
Published: October 2008

Field experiments were carried out to study the effects of elemental sulphur on irrigated groundnut. The sulphur was applied at rates of 50, 100 or 150 kg ha−1, either at sowing, at flowering or in two equal splits at sowing and flowering. Shoot dry weight, total sulphur content of leaves, nodule number per plant and pod yield were all significantly increased by sulphur treatment, but nodule dry weight was unaffected. The greatest response lay at or below 50 kg ha−1 applied at sowing. There were no further increases in response above this level.
The Effect of Cumulative Erosion and Rainfall on Sorghum, Pearl Millet and Castor Bean Yields Under Dry Farming Conditions in Andhra Pradesh, India
Authors: Vittal K. P. R. , Vijayalakshmi K. , Rao U. M. B.
Published: October 2008

Topsoil depth and yields of sorghum, pearl millet and castor bean were found to be positively correlated when monitored over thirteen seasons under widely varying rainfall conditions on an Alfisol in Andhra Pradesh, India. Yields responded up to 2.5 times more to topsoil depth when rainfall in the critical period exceeded evapotranspiration than under drier conditions. Yield variations were explained by topsoil depth in cereals, and by the interaction between rainfall during the critical period and topsoil depth in cereals and castor bean (R2<0.72). The expected yield losses as a result of erosion, based on 56 years of rainfall data, were 138, 84 and 51 kg ha−1cm−1for sorghum, pearl millet and castor bean, respectively. Quadratic models explained the yield losses due to cumulative erosion under conditions of both poor and good rainfall during the critical period. Sorghum and pearl millet tended to produce no yield when erosion exceeded 34 cm and castor bean when it exceeded 40 cm. There was less reduction in yield when rainfall was poor, up to about 10 cm of erosion, than when rainfall was good. The results indicate that pearl millet and castor bean are more suitable than sorghum for low rainfall and eroded conditions.
An Agronomic and Economic Evaluation of Soyabean Planting Methods in the Central Province of Zambia
Authors: Chanda K. S. , Bezuneh M. , Gibson P. T. , Olsen F. J. , Hudgens R. E.
Published: October 2008

Soyabean (Glycine max) is a relatively new crop for small-scale farmers in Zambia which has been adopted following the introduction of new cultivars, greater opportunity to obtain credit, easier marketing and an attractive guaranteed price. However, low yields limit production partly due to the lack of a planting method that establishes optimal populations. The present method is to plough and plant in the same operation, dribbling the seed behind the ox-plough. This often leads to uneven depth of planting, and hence to poor seedling emergence and erratic stands. Alternative planting techniques evaluated on farmers' fields for three seasons (1985/86–1987/88) suggest that farmers should replace their practice of planting behind the plough with either hand seeding following a plough–harrow operation or the use of a modified ox-drawn planter (Taparia).
Responses of Young Tea (Camellia sinensis) Clones to Drought and Temperature. II. Dry Matter Production and Partitioning
Authors: Burgess P. J. , Carr M. K. V.
Published: October 2008

The physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning at a high altitude site in Southern Tanzania where there are marked seasonal variations in rainfall and temperature. The plant dry weights, including roots, were measured eight months after field planting and subsequently at intervals of three to four months, corresponding to the different seasons, during the following two years. Fully irrigated plants of one clone (S15/10) were also harvested after four years in the field. Clones differed in the rates of canopy spread and hence in their capacity to intercept solar radiation. The ‘radiation use efficiency’ (the net total dry matter production per unit of intercepted short-wave radiation) was similar for the four well-watered clones and ranged from 0.40 to 0.66 g MJ−1, which corresponds closely to values reported for other woody tropical plants. A 16-week drought treatment imposed two years after planting reduced the mean light interception of the four clones by about 25% and the mean radiation use efficiency by 78% to 0.09 g MJ−1. Clone S15/10, a cultivar from Kenya which produces large yields, partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones, and correspondingly less to large structural roots. This resulted in a maximum harvest index of 24%, substantially greater than other values reported in the literature. There were seasonal differences in partitioning, with more dry matter being diverted to roots and less to shoots during the cool season. Although the drought treatments had no significant effect on root growth, the amount of dry matter partitioned to leaves, stems and harvested shoots declined by 80–95%. The roots of all four clones extended in depth at similar rates (about 2 mm d−1), those of Clone S15/10 reaching 2.8m after four years. The results are discussed in terms of appropriate field cultural practices and possible selection criteria for high yielding clones.
Farmer Participatory Crop Improvement. I. Varietal Selection and Breeding Methods and Their Impact on Biodiversity
Authors: Witcombe J. R. , Joshi A. , Joshi K. D. , Sthapit B. R.
Published: October 2008

Farmer participatory approaches for the identification or breeding of improved crop cultivars can be usefully categorized into participatory varietal selection (PVS) and participatory plant breeding (PPB). Various PVS and PPB methods are reviewed. PVS is a more rapid and cost-effective way of identifying farmer-preferred cultivars if a suitable choice of cultivars exists. If this is impossible, then the more resource-consuming PPB is required. PPB can use, as parents, cultivars that were identified in successful PVS programmes. Compared with conventional plant breeding, PPB is more likely to produce farmer-acceptable products, particularly for marginal environments. The impact of farmer participatory research on biodiversity is considered. The long-term effect of PVS is to increase biodiversity, but where indigenous variability is high it can also reduce it. PPB has a greater effect on increasing biodiversity although its impact may be limited to smaller areas. PPB can be a dynamic form of in situ genetic conservation.
Farmer Participatory Crop Improvement. II. Participatory Varietal Selection, a Case Study in India
Authors: Joshi A. , Witcombe J. R.
Published: October 2008

Farmer participatory varietal selection (PVS) was used to identify farmer-acceptable cultivars of rice and chickpea. Farmers' requirements in new crop cultivars (varieties) were determined, a search was carried out for released and non-released cultivars that matched these needs, and they were tested in farmer-managed, participatory trials. Farmer-acceptable cultivars were found amongst released material, but not among the recommended material for the area. Lack of adoption is, therefore, because resource-poor farmers have not been recommended or exposed to the most appropriate cultivars under the existing system of varietal identification and popularization. Adoption rates of cultivars would be improved by increased farmer participation, the systematic testing in zonal trials of locally popular cultivars to define their domains properly, a more liberal release system, and a more open system of providing seeds of new cultivars to farmers.
Farmer Participatory Crop Improvement. III. Participatory Plant Breeding, a Case Study for Rice in Nepal
Authors: Sthapit B. R. , Joshi K. D. , Witcombe J. R.
Published: October 2008

A participatory plant breeding (PPB) programme was conducted for the high altitude areas of Nepal. The aim was to breed acceptable varieties with minimum use of resources and to utilize farmers' knowledge in the PPB programme. Farmer participation began at the F5 stage and progress was followed over two seasons in two villages. Farmers proved to be willing participants and made selections in the segregating material, often with great success. Large differences in farmers' preferences between the F5 bulks were found and the most preferred were adopted rapidly. The most adopted variety, Machhapuchhre-3, performed well in the formal trials system, and much better than the products from conventional centralized breeding. The PPB programme increased biodiversity in the two participating villages.
Nitrogen Fixing Capacity of Mucuna untilis
Authors: Oke O. L.
Published: October 2008

The fixation of nitrogen in root nodules of Mucuna untilis was studied, and its transfer to other parts of the plant. Fixation reached a maximum of 6 mg. per day per plant, and the rate of transfer of nitrogen from the nodules increased gradually until it almost equalled the rate of fixation. Older plants seem to be more efficient fixers of nitrogen than younger ones.
Factors which affect the Germination of Seeds of Six Common East African Weeds
Authors: Huxley Peter A. , Turk Alexander
Published: October 2008

Internal and external factors affecting the germination of seeds of six common East African weeds were studied by sowing the seeds in each of 13 different treatments chosen to provide a wide range of different germination environments. The results indicate how germination is regulated in each of these species and provide the basic information necessary for further field studies.
Studies on Browse Plants in Ghana
Authors: Mabey G. L. , Innes R. Rose
Published: October 2008

Digestibility of the herbage of the indigenous tree Antiaris africana was investigated. Digestion coefficients (%) were—organic matter 67, dry matter 64, crude protein 78, crude fibre 39, nitrogen-free extract 74, ether extract 36 and ash 36. Calculated nutritive values were—starch equivalent 23·2 and digestible crude protein 3·7, giving a nutritive ratio of about 1 : 6. The herbage was young and its palatability high.
Fertilizer Responses in Swamp Rice (Oryza sativa L.) in Northern Nigeria
Authors: Bredero Th. Y.
Published: October 2008

A series of N × P field experiments with irrigated rice, conducted over the period 1958–1962 on the same plots on alluvial soils considered representative for most of the bottom ‘fadama’ land in Niger and Ilorin Provinces, Northern Nigeria, showed small increases with medium dressings of P2O5 and large responses with high dressings of N. The N responses showed considerable variation between soil types and years. The variation between soil types was attributed to different cation exchange capacities, which resulted in NH4′ leaching from the root zone at different rates. The variation in N responses between years was probably due to different physiological timings of the top dressings. Results of chemical analyses of straw and grain samples of the 1961 crop were used to estimate the percentage of N and P2O5 recovered by the crop with the various treatments over the untreated plots in the previous years of the experiments on two soil types. The recovery percentages for the different levels of N on the clay ‘basin’ soils were moderate, about 18 per cent, whereas those for the sandy ‘levee’ soils were lower, averaging only 9 per cent. Recovery of P2O5 varied from good at medium N levels (14 per cent) to moderate at high N levels (9 per cent) on the basin soils. Recovery of P2O5 on the levee soils was poor. The utilisation of the recovered N (75 lb paddy/lb N) and P2O5 (42 lb paddy/lb P2O5) was very good for N and fair for P2O5.
Maize Growing in Nyasaland (Malawi) II. Fertilizer Requirements
Authors: Brown P.
Published: October 2008

The main nutrient deficiency in Malawi is a chronic lack of nitrogen, which is found on all but a few soils. Phosphorus also becomes limiting quite rapidly on certain soil types as a result of permanent cultivation, but there has so far been little response to potash or lime. Incipient sulphur shortage is automatically corrected by the use of sulphate of ammonia and single superphosphate to correct the major deficiencies. Trace elements have not been widely tested. Samples of organic manure vary widely in moisture and nutrient content, and their nitrogen status is frequently low, so it is safest to consider manure as primarily a source of P, K and minor nutrients, and to supplement it with fertilizer nitrogen. It should be possible, with good cultivation of synthetic varieties and improved selections, to obtain maize yields of 15–20 bags/acre with fertilizer dressings of up to 80 lb/acre of the limiting nutrients.
Stimulation of Latex Flow in Hevea brasiliensis
Authors: Abraham P. D. , Tayler R. S.
Published: October 2008

Latex flow can be stimulated by bark scraping and by the application of vegetable oils, auxins and some other substances to the bark, either above or below the tapping cut. Auxin preparations are now widely used in commercial rubber production, 2,4–D and 2,4–5–T being the most common. The response obtained depends upon the formulation, on the method of application, and on other factors such as the age and condition of the tree and the tapping system employed. The effect of stimulation is considered to be due to a dilution of the latex and an increased rate of flow. A larger area of bark is drained, and the duration of flow is prolonged, because plugging of the latex vessels is delayed. In young trees, the conflict between increased latex production and active tree growth requires the development of different and less intensive techniques.
Responses of Lucerne to Different Soil Moisture Regimes
Authors: Landsberg J. J.
Published: October 2008

An experiment in which irrigation intervals for lucerne were dictated by four factors applied to daily evaporation from a Class A pan has been reported by Landsberg (1966). This paper discusses data from a number of subsidiary measurements made during that experiment. An extensive soil sampling programme yielded data on the effects of treatments on soil moisture content, and plant height and per cent ground cover measurements enabled detailed evaluations to be made of crop responses. Both height and ground cover were decreased by soil moisture stress. Relative turgidity was closely related to soil moisture content in the early morning, dry treatments showing more rapid recovery of turgor than those where water was kept at more adequate levels. Radiation utilization by the crop was affected by soil moisture conditions, and also apparently by temperature.
Responses of Cereals to Fertilizers in Northern Nigeria. I. Sorghum
Authors: Goldsworthy P. R.
Published: October 2008

As part of a programme to improve production of the main food crops of Northern Nigeria, trials were carried out to investigate the effect of nitrogen and phosphate fertilizer on the grain yield of sorghum. Five fertilizer response areas have been defined and estimates have been made of the most profitable combinations and levels of phosphorus and nitrogen to use in each area. Fertilizers produced the greatest increase in yield in the two response areas which cover the north of the country.
Improvement of Permanent Pasture by Overdrilling and Oversowing
Authors: Warboys I. B.
Published: October 2008

The failure of overdrilling techniques to improve poor pasture and the development of the dipyridylium herbicides, particularly paraquat, for controlling grass species, prompted research into oversowing techniques in 1963 and 1964. Rotary cultivation, although giving better establishment than any other oversowing technique, did not always reduce the more persistent weed grasses such as Agrostis spp., and so failed to produce a perennial rye-grass dominant sward. This was believed to be due to various factors such as unsatisfactory herbicide pre-treatments, the interval between spraying and cultivation, the high moisture content of the soil when cultivated, as well as the greater resistance of rhizomatous grass species to paraquat. In the absence of paraquat, rotary cultivation was able to establish a satisfactory number of seedlings. In both experiments, however, the subsequent botanical composition was considerably influenced by pasture management.
Systematic Designs for Spacing Experiments
Authors: Bleasdale J. K. A.
Published: October 2008

Two types of design are described, in which the number of plants per unit area varies systematically within any one plot in the field, the plant arrangement being held constant. Any desired range of spacing can be covered in either design and the calculations necessary to establish specific sets of dimensions are given. In addition descriptions are given of the laying-out, planting (or sowing), management and recording of experiments using these designs.
A Second Stock-Scion Trial with Mango in Israel
Authors: Oppenheimer Ch.
Published: October 2008

In a second stock-scion trial with mango in Israel the influence of five rootstocks was investigated. In our first trial, two rootstocks—Sabre and 14·12—had been found suitable and unsuitable respectively. In the second trial, 14·6 and 14·7 were found to be not significantly different from Sabre, 3·2 was found to be somewhat inferior and 14·12 was again unsuitable. The important characters of the 22 varieties grown are described, and an evaluation is attempted of their yield and marketability.
Nodulation of Legumes in the Sudan: Cross-Inoculation Groups and the Associated Rhizobium Strains
Authors: Habish H. A. , Khairi Sh. M.
Published: October 2008

Cross-inoculation tests, based on nodule formation and nitrogen fixation, were made on 21 species of legumes commonly found in the Sudan. The results showed that they may be grouped according to the accepted system of classification, but there were some important inconsistencies in the cowpea group. For instance,Arachis hypogaeaandAcacia spp.have their own strains of Rhizobium. The cultural and physiological characters of the rhizobia studied were generally similar to those known for other species of the organisms.
Host Preference and Survival of the Dark-Headed Rice Stem Borer Chilotraea polychrysa(Meyr.) in Malaya
Authors: Kok L. T.
Published: October 2008

The polyphagous nature of the dark-headed rice stem borer, Chilotraea polychrysa (Meyr.), may contribute greatly to its ability to survive periods of food shortage when rice plants are scarce. Investigations on the preference and survival of C. polychrysa on seven selected hosts belonging to the Gramineae revealed that it oviposited on all the hosts tested, but showed a marked preference for its normal host, rice (Oryza sativa). Survival rates on rice and the alternate hosts did not differ significantly. The percentage of larvae surviving to the adult stage was generally low because of the high rate of mortality from larval to pupal stage, irrespective of host species. In rice, there was distinct ovipositional preference for plants at the maximum vegetative stage rather than for younger plants. The larval survival rate increased with the age of the host from 35 to 65 days, but dropped sharply when infestation occurred on plants 80 days old, by which time the inflorescence is beginning to emerge.
Screening Fungicides for Control of Coffee Berry Disease in Kenya
Authors: Vermeulen H.
Published: October 2008

Fourteen out of 43 fungicides were selected, after laboratory screening, for field trials against coffee berry disease. Each fungicide was compared with a commercial cuprous oxide formulation and an unsprayed control, by assessing conidial production of bearing coffee branches and by recording the percentage of healthy ripe berries picked. In assessments of fungicidal efficiency, healthy ripe berry counts gave more consistent results than those obtained by measuring conidial production. The results from berry counts indicate that in these experiments Ortho Difolatan (BSI ‘Captafol’) was equal, but not significantly superior, to the standard formulation used in estate spraying. The annual rhythm of conidial production seems to have changed over the past five years. The significance of this is discussed in relation to the control of coffee berry disease.
The Growth of Four Rice Varieties as Affected by Temperature and Photoperiod with Uniform Daily Periods of Daylight
Authors: Owen P. C.
Published: October 2008

The growth and grain production of four rice varieties were compared under controlled environment conditions at two minimum night temperatures (15 and 23°C) and at two daylengths (11½ and 13 hours) where the period of daylight for active photosynthesis was kept constant at 8 hours. The lower night temperature prevented flowering but at the higher one grain yields were associated with panicle weights rather than panicle numbers, and production of so-called photoperiod-insensitive varieties was affected by photoperiod. Although the periods of natural light were constant, and photoperiods were extended by low intensity incandescent light, in-creased total plant weights, not due to effects on tillering, were observed under longer days.
Uptake of Phosphorus and Other Nutrients by Maize in Western Nigeria
Authors: Bromfield A. R.
Published: October 2008

Uptake of the major nutrients by maize was determined throughout the growing season. Little phosphorus was accumulated, as reflected in its distribution within the plants, but uptake of labelled phosphorus showed two distinct peaks associated with root development. One fifth of the applied phosphorus was recovered by the plants.
Comparative Potential Yields of Rice Varieties in the Australian Tropics
Authors: Owen P. C.
Published: October 2008

During the wet summer season of northern tropical Australia higher yields were attained by introduced weakly photoperiod-sensitive short-duration rice varieties than by locally-bred strongly photoperiod-sensitive varieties resembling traditional tropical indicas. There was no clear relationship between growth durations and yields. Dry season yields were lower, associated with shortened durations (especially of the reproductive phase) and lower cumulative radiation totals in the late phases of growth. Dawn, a variety of U.S. origin imported from the Philippines, outyielded all other varieties. In both wet and dry seasons yields depended largely on panicle weights, which in turn depended on high seed numbers per panicle. Individual seed weights were of less importance. The results tended to confirm a prior interpretation of climatic data, i.e. that there is no environmental factor limiting wet season yields in the region to levels below those obtained elsewhere in the tropics, provided the crop receives a high standard of care and attention.
Sulphur Nutrition of Legumes
Authors: Oke O. L.
Published: October 2008

Application of S, alone or in combination with P, significantly increased the number, yield and nitrogen content of root nodules on pigeon pea and guar. Sulphur, applied at different levels with NPK, increased the methionine content and yield of plants significantly but had no significant effect on the N content. Sulphur at 20 p.p.m., alone or in combination with P, increased the methionine content of pigeon pea significantly but the effect decreased at higher levels of S. In general, higher values of methionine were obtained in the presence of S than when it was absent.
Growth and Productivity of Tapioca (Manihot utilissima)—I. Leaf Characteristics and Yield
Authors: Williams C. N. , Ghazali S. M.
Published: October 2008

The shoots of high, medium and low yielding clones of tapioca were examined to see whether yield was associated with morphological characteristics of the foliage and/or with leaf area development. The lowest yielding variety had the highest leaf area per stem, and vice versa, differences in leaf area being mainly due to differences in leaf size. Leaves of the highest yielding variety possessed attenuated lobes, which tended to have a more vertical mid-day orientation, whereas the lowest yielding variety possessed large broad-lobed leaves with more horizontal orientation. The intermediate variety had acutely attenuated lobes and showed a much more vertical day-time orientation. The relationship between the leaf properties and canopy efficiency is discussed.
Water Relations of Beans I. Effects of Water Stress on Growth and Flowering
Authors: Nadi A. H. El
Published: October 2008

Experiments were made in glasshouses, growth cabinets and growth rooms to study the differential responses of the broad bean to water stress during the vegetative and flowering phases of growth. Plants in the flowering phase proved to be more sensitive to drought than in the vegetative period, and there were different responses (Relative Growth Rate) to temperature at different stages of plant growth. Day length and temperature influenced the position of the earliest flower initials on the stem, and intensity of flower shedding was aggravated by high temperature.
Effects of Rainfall on Yield of Cocoa in Ghana
Authors: Ali Faisal M.
Published: October 2008

Effects of rainfall on yield of cocoa from a large-scale experiment has been investigated at 10 and 12 sites, over seven years, in the Eastern and Ashanti regions of Ghana. There was a positive association between yield and rainfall at certain times of year, but a negative association at other times. Variation due to the regression of yield on monthly rainfall varied up to 23 per cent, while a maximum variation of 31 per cent accounted for the regression of yield on the total rainfall of February to April in the Eastern region.
Effects of Nitrogen Fertilizer on Natural Pastures in Western Tanzania
Authors: Walker B.
Published: October 2008

At Ukiriguru, in Western Tanzania, three levels of sulphate of ammonia were compared on natural pastures on hardpan soils. Yields of dry matter were substantially increased by nitrogen fertilizer and at high stocking rates the growth of cattle on different treatments followed fairly closely the amounts of dry matter available.
Selection of Intercrops for Cotton in India
Authors: Varma Mahendra P. , Kanke M. S. Subba Rao
Published: October 2008

Results of an investigation to select intercrops showed that cotton can be grown with more profit with groundnut or gora paddy than when grown alone. Growing food or cash crops along with cotton enables an early crop to be produced and the practice may help to extend cotton cultivation in Chotanagpur and Santhal Parganas, a potential cotton belt of the future.
Changes in Yields and Fertilizer Responses with Continuous Cropping in Uganda
Authors: Stephens D.
Published: October 2008

In sixteen factorial field trials with N, P, K, Mg, trace element and farmyard manure treatments, yields declined during the first four years of cropping following a resting period under grass, responses to K and farmyard manure increased, and other treatments showed no significant changes. After a few years of continuous cropping potassium deficiency may seriously limit yields, especially of sweet potatoes. N, P and K fertilizers maintained yields as well as the farmyard manure treatment.
Genetic Variability and Path Coefficient Analysis of Components of Ragi (Eleusine Coracana)
Authors: Chaudhari L. B. , Acharya R. C.
Published: October 2008

The range, mean, genotypic and phenotypic coefficients of variation, heritability and genetic advance for various characters, of forty-seven varieties of ragi (Eleusine coracana) showed a wide range of variation and highly significant varietal differences. The genetic advance was highest for yield of straw and genotypic coefficients were higher than phenotypic coefficients for most characters. Path coefficient analysis indicated that the number of productive tillers and grain weight of main ears were the major components for seed yield.
Effects of Environment and Cultural Conditions on Nitrogen and Phosphorus in Coffee Leaves
Authors: Robinson J. B. D.
Published: October 2008

Analyses of total N and P in coffee leaves from different geographic areas have been compared. The levels of these nutrients are correlated with each other and the quadratic regression equation for leaf N on leaf P has been derived. The value of N/P ratio in the coffee leaf for diagnosing nutritional status is assessed. No correlations were observed between Mg and either N or P. Irrigation of coffee in Kenya on latosolic soils raises leaf P but not N levels, in the absence of organic mulch and fertilizers. Effects of organic mulch, N and P fertilizers on leaf levels of N or P are discussed.
Genetic Variability in Root Development in Relation to Drought Tolerance in Spring Wheats
Authors: Derera N. F. , Marshall D. R. , Balaam L. N.
Published: October 2008

Fifteen Australian and exotic wheat varieties revealed genotypic differences in their patterns of root development and drought tolerance. Earliness in plant maturity, which accounted for 40 to go per cent of the observed variation in drought tolerance, appeared to be by far the most important characteristic of tolerant genotypes, but there nevertheless appeared to be a measurable relationship between some parameters of root development, water use efficiency and drought tolerance. The impact of study of this kind on the problem of breeding for drought tolerance is briefly discussed.
Use of Aerial Sprays for Correcting Magnesium Deficiency in Orange Groves
Authors: Bar-Akiva A. , Tal D. , Hirsh J.
Published: October 2008

Field trials were carried out using an aerial spray of Magniosan 55 (55 per cent magnesium nitrate) for the correction of severe magnesium deficiency in a Valencia orange orchard. Two treatments were applied, in autumn and spring respectively, each containing 50 l. Magniosan 55 solution in 200 l. water per hectare. The spray did not cause damage to fruit or leaves, penetrated satisfactorily into the lower and interior part of the canopy, and increased the Mg content of the leaves of treated trees from 0·095 to 0·190 per cent.
Spacing and Space-planting Experiments on Sugar Beet in Israel
Authors: Dor Z. , Carmeli R. , Lachover D. , Zur M.
Published: October 2008

Root and sugar yield responses of the Polyrave variety were more favourable to the lower of two population levels (70,000 and 92,000 beets/ha.) and to the wider of two between-row distances (60 and 50 cm.). When the triploid Trirave variety was space planted and, for comparison, conventionally planted and thinned to 3 population levels at 60 cm. between-row distance, the intermediate (87,000 beets/ha.) level gave the highest sugar yield. The thinned treatments consistently outyielded the corresponding space-planted treatments. Space planting at 40 cm. between-row distance resulted in high beet populations (130,000 beets/ha.) which evoked unfavourable responses in root and sugar yield and even in sugar content.
Dormancy of Shallots in Ghana
Authors: Sinnadurai S. , Amuti S. K.
Published: October 2008

The shallot is a common crop in tropical areas where daylength and temperature conditions do not permit the growing of onions. Shallots are dormant for 70 days from the time of harvest to sprouting in bulbs stored at room temperature (75 to 95°F), during which period about 40 per cent of the bulbs are lost due to drying out and disease. Bulbs stored at lower temperatures (40 to 60°F) sprout more rapidly, with an optimum of about 50°F. Cool storage enables the farmer to use the previous season's crop for planting within 30 days of harvest.
Growth and Productivity of Tapioca (Manihot utilissima) II. Stomatal Functioning and Yield
Authors: Williams C. N.
Published: October 2008

The stomatal functioning of high, medium and low yielding clones of tapioca was examined to see whether yield could be associated with conductivity and/or resistance to moisture stress. A sensitive falling pressure porometer was used to measure stomatal conductivity to the viscous flow of air at small pressure differences. No marked differences were observed which could account for the large range in yields shown by the varieties, but stomatal functioning could be related to canopy type and to planting conditions. In general the conductivity values of all three varieties were very low compared to many other crop species, which suggests that increases in canopy efficiency and yield could be obtained in certain environments by an increase in leaf conductivity.
Distribution and Weight of Nodules in Tropical Pasture Legumes in The Field
Authors: Whiteman P. C.
Published: October 2008

In tropical legume-grass swards random core sampling recovered too few nodules to be a useful method. Core sampling of individual plants with a 5·0 cm. Stace tube showed similar changes in nodulation as total root excavation. However, the nodule distribution was different on the root systems of the two species studied, Desmodium uncinatum and Phaseolus atropurpureus. Nodule weights per plant on these species were much higher than any previously recorded in the literature. The direct contribution from nodule decay to the total end-of-season nitrogen release was estimated and shown to be small, approximately 14 per cent for D. uncinatum and 8 per cent for P. atropurpureus.
Mechanized Harvesting of Tree Crops
Authors: Folley R. R. W.
Published: October 2008

Among the processes in orchard fruit production, partial mechanization has done little to reduce the peak demand for labour during the year. The most welcome new machine would be a harvester which, if it is to displace labour, will above all have to be efficient in not damaging the fruit. As regards English apples and pears, a machine that is to replace labour that is no longer available would have to be almost equally efficient. Working back from an economic specification, it seems that an efficient machine will be expensive, and that an expensive machine will have to harvest hundreds of acres to be economic.
Effect of dry Organic Matter on Growth and Yield of Beans (Phaseolus vulgaris L.)
Authors: Magalhães A. C. , Montojos J. C. , Miyasaka S.
Published: October 2008

Incorporation of dry matter of perennial soybean into the soil, alone or with mineral fertilization, resulted in improved vegetative growth of common beans. Fairly high LAI was observed at flowering time where dry organic matter had been added, causing leaf self-shading and decreased growth in the later states of development. In contrast, both the control and mineral fertilized plots showed slower but continuous growth up to 50 days from plant emergence. Only slight differences in grain yield were noticed despite remarkable increases of Crop Growth Rate, Relative Growth Rate, Net Assimilation Rate, and Efficiency of Solar Energy Conversion that resulted from the application of dry organic matter.
Analysis of a Diallel Cross of Maize Varieties Grown at Three Altitudes in Tanzania
Authors: Bolton A.
Published: October 2008

The analysis is presented of a 17 variety maize diallel cross grown in Tanzania at 1300, 500 and 200 m. Thirteen of the varieties included Central American material, mainly Caribbean and Flint types, and four were derived from Eastern African Flat-White maizes. Variety cross performance was much affected by environmental conditions. At 200 and 1300 m., four of the top five varieties were the same, and selection of varieties for composite formation was not particularly critcal. At the 500 m. site, order of yields differed markedly from the other sites, and predicted composite yield was much more affected by the choice of varieties included. Criteria are discussed for selection of varieties to be included in composites at the three altitudes.
Effects of Cycocel on Lodging and Grain Yield of Upland and Swamp Rice in Sierra Leone
Authors: Gupta D. K. Das
Published: October 2008

In upland rice, seed soaked in CCC for 24 hours before sowing or sprayed with CCC 10, 21, 42 and 63 days after sowing, showed severe lodging. Effects of CCC on the number of paniclebearing tillers, number of good grains in 1000 grains, weight of 100 good grains and grain yield were not significant. On the other hand CCC prevented lodging in swamp rice, with the lowest percentage when foliar spray was given 21 days after transplanting. CCC failed to increase the number of panicle-bearing tillers and grain yield in swamp rice.
Water Use by Maize at Three Plant Densities
Authors: Downey Lloyd A.
Published: October 2008

Water use by maize at three densities was measured by a complete water balance, including soil moisture, rain, applied irrigation and deep drainage in crops irrigated so that relative turgidity at noon remained above 90 per cent (i.e. no-stress conditions). Total evapotranspiration between planting and harvest, 56 cm., was not significantly affected by density, but evapotranspiration was slightly higher at higher densities when ground cover was less than 50 per cent. Actual evapotranspiration rose to 1 cm. per day during anthesis and grain filling. A fifth of the water applied moved beyond the root zone, indicating that work on more permeable soils would be inaccurate if the deep drainage component was ignored.
Effects of Soil Moisture on Growth of Young Tea in Malawi
Authors: Fordham R.
Published: October 2008

Young tea plants were grown for eight months in large polythene bags of soil, with provision to prevent rain from running into the soil. After a preliminary period of establishment, in which all plants were kept well-watered, four soil moisture regimes were applied ranging from watering twice weekly to withholding irrigation until plants had been subjected to a soil moisture tension of 15 bar, as determined by gypsum resistance units, for a period of one week before rewatering. Plant survival and growth were significantly better under the wettest compared with the driest regime.
Studies on White Yam (Dioscorea rotundata) I. Growth Analysis
Authors: Sobulo R. A.
Published: October 2008

The growth of two varieties of white yam was analysed from planting in December to harvest in September. Four stages were recognized, viz.: dormancy, rapid growth of vine and root, rapid tuber development accompanied by leaf senescence and tuber maturity followed by reduction in tuber weight. The period of rapid growth coincident with maximum demand for nutrients was early June, suggesting that fertilizer should be applied in mid-May so that it is available in June.
Effects of N, P and K on Yield of Grain Sorghum in the Central Rainlands of the Sudan
Authors: Ali Faisal M. , Salih Farouk A.
Published: October 2008

Mechanized crop production schemes continue to be the main source of grain sorghum in the Sudan, where fertilizer experiments have shown that applications of NP and NPK significantly increase the grain yield of continuous sorghum, though economic increases could be obtained by the application of nitrogen.
Effects of Nitrogen Application on Nitrogen Content of Grains of Swamp Rice in Sierra Leone
Authors: Gupta D. K. Das
Published: October 2008

The total N uptake, crude protein content, and recovery of N in rice grains varied with varieties. Increased levels of N application gave increases in total N uptake and crude protein content in the grains, though recovery of N in the grains decreased with increased levels of nitrogen application. Irrespective of varieties and levels of application, three split dressings of nitrogenous fertilizer gave greater total N uptake, crude protein content, and recovery of N in the rice grains than where all the N was applied at the time of transplanting of seedlings.
Studies of the Drip Method of Irrigation
Authors: Abrol I. P. , Dixit S. P.
Published: October 2008

A comparison has been made of drip and conventional check basin methods of irrigation, using onions and ladies finger as test crops. Significant increases in yield and water use efficiency in drip irrigated over conventionally irrigated plots resulted from increased availability of soil moisture at low tensions and reduced surface evaporation losses. Reduced soil strength in drip irrigated plots was also a factor resulting in increased yield of onions.
Performance of Improved Rice Varieties in the Tropics with Special Reference to Tillering Capacity
Authors: Yoshida Shouichi , Parao F. T.
Published: October 2008

The growth of improved short varieties of rice with low and high tillering capacities was compared under a wide range of nitrogen levels and spacings. A high tillering variety performed better than a low tillering one under the experimental conditions tested. Leaf area index values as high as 10 to 12 were not detrimental to grain production unless the crop lodged.
Effects of Nitrogen, Sulphur, Phosphorus and Boron on Cotton in Malawi
Authors: Matthews G. A.
Published: October 2008

Eight trials, covering a wide range of conditions in Malawi, have assessed the effect of applying nitrogen (0, 45 and 90 kg. ha.−1), sulphur (0, 22, 45 kg. ha.−1), phosphorus (0, 15 kg. ha.−1) and boron (0, 0·63 kg. ha.−1) on growth and yield of cotton. A nitrogen × sulphur interaction was very highly significant at one site, and good responses to nitrogen were obtained at six sites. Phosphorus and boron gave significant increases at one site. Increased yields of seed cotton indicated that there is an overall need for a compound fertilizer to supply nitrogen, sulphur, boron and in some areas phosphorus.