bluuebunny/crossref_metadata_2025 huggingface dataset:
Intercropping with Sorghum in Nigeria
Authors: Andrews D. J.
Published: October 2008

At Samaru (11° 10′N, 7° 39′E) the growing season for rain-fed annual crops is 180 to 200days. Sole cropping, relay cropping and intercropping of long season sorghum, early millet or maize and late planted cowpeas were evaluated for most effective use of this period, all crops being cultivated mechanically. Relay cropping and intercropping gave 59 and 80 per cent more return per acre respectively than a sole crop of sorghum, the increases coming mainly from higher cereal yields. Some criteria applicable to intercropping are recognized.
White Stripe Disorder of Oil Palm (Elaeis guineensis) in Malaysia
Authors: Rajaratnam J. A.
Published: October 2008

Oil palms with white stripe have greatly reduced yields. In the chlorotic areas of the leaflets, columnar palisade cells fail to develop and there is a reduction in air-space volume of the spongy mesophyll. Leaf area and photosynthetic activity are also reduced. Recovery of palms showing symptoms was spasmodic. The condition is discussed in relation to boron, to N/K ratio, polyphenols and availability of photosynthate.
Effects of Nitrogen Fertilization on the Growth, Composition and Yield of Upland and Lowland Taro (Colocasia esculenta)
Authors: de la Pena Ramon S. , Plucknett Donald L.
Published: October 2008

The effects of nitrogen fertilization on growth, nutrient uptake and yields of upland and lowland taro were studied on the island of Kauai, applying o, 280, 560 and 1120 kg./ha. N. Nitrogen concentrations of upland and lowland taro leaves were significantly correlated with yields, although regression analysis showed that per cent N in both blades and petioles decreased with age. Higher yields were obtained from the lowland than from the upland crop, regardless of amounts of N fertilizer applied. The highest yield obtained from lowland taro was at 1120 kg./ha. N harvested at fifteen months (57·6 tons/ha.) and from upland taro the highest yield was obtained at 560 kg./ha. N harvested also at fifteen months (25·5 tons/ha.).
Effects of Soil and Management Factors on Fertilizer Responses and Yield of Irrigated Wheat in Iran
Authors: Abraham T. P. , Hoobakht A.
Published: October 2008

The yield data obtained from fertilizer experiments conducted at 195 locations for three years were examined to study the relations between yield, response to nitrogen and phosphorus, soil test values, and number of irrigations, using multiple regression technique. Irrigation accounted for 20–36 per cent of the yield variation, whereas soil factors did not show appreciable effects. Nitrogen response was influenced by irrigation, while some soil factors affected response to phosphorus.
Effects of Night Temperature on Growth and Development of IR8 Rice
Authors: Owen P. C.
Published: October 2008

Under controlled environment conditions rice variety IR8 was subjected to night temperatures of 15, 20 and 25°C during each of the three periods (a) sowing to floral initiation, (b) initiation to panicle emergence, and (c) panicle emergence to maturity, with day temperatures of 30°C throughout. Night temperatures of 15°C prevented floral initiation throughout the experiment, an effect partly overcome by transfer to higher temperatures after 102 days but not without yield loss. The optimum night temperature was 20–25°C, with some evidence of change of temperature effects, as distinct from the effect of actual temperature levels. As IR8 was developed under relatively stress-free conditions, its sensitivity to temperatures below 15°C may be greater than in varieties developed elsewhere.
Heterosis for Grain Yield and its Components in Spring Wheat Crosses
Authors: Chowdhry A. Rehman , Mohammad Amir , Qazi Mohammad Zarif
Published: October 2008

Ten wheat crosses between tall local varieties C228 and C591, a short local variety C271, and short Mexican varieties Penjamo, Nainari 60, Pitic 62 and Sonora 64, were field-tested under irrigation for heterosis for plant height, grain yield, spikes per plant and kernels per spike. Heterosis occurred to a greater degree for the last three attributes in some of the crosses, with the greatest heterotic expression in crosses involving Penjamo and Pitic 62 and the local variety C591.
Effects of Plant Population and Fertilizer Nitrogen on Growth and Components of Yield of Maize Grown for Silage in Nigeria
Authors: Haggar R. J. , Couper D. C.
Published: October 2008

Weekly measurements in a maize silage crop grown at three populations, each at three levels of nitrogen, showed that leaf area index, crop growth rate and total whole plant yield were greatest at the highest plant population (430,000/ha.) and lowest at the low population (47,000/ha.). At the former maximum yields of dry matter and crude protein occurred approximately seventy-five days from sowing, when the cob contribution was small. With wider spacing maximum yields occurred later. At the intermediate population (107,000/ha.), and with adequate nitrogen, sowing on the square was superior to sowing in wide rows. Nitrogen did not preferentially affect the relative dry matter yield of any growth component; plant population had a greater influence on total whole plant yield than nitrogen.
Effects of Cool Periods (15° C) at Night on Taichung (Native) No. 1 Rice
Authors: Owen P. C.
Published: October 2008

Taichung (Native) No. 1 rice was grown under controlled conditions with a basic temperature regime of 30°C by day and 20°C by night. Periods of 2, 4 and 12 hours at 15°C (59°F) were imposed during darkness for the first or second 40 days, or for the first 80 days after sowing. Floral initiation was delayed by cool periods of 2 hours at night or longer, and delay from this cause was always accompanied by reduced grain yields, resulting from fewer spikelets per panicle or increased tiller sterility. This effect was not overcome when the cool periods ceased after floral initiation. Cool periods longer than 4 hours had a greater effect when they were given in the first 40 days.
A Long Term Experiment on Soil Fertility and Cotton Yield in Tanzania
Authors: Le Mare P. H.
Published: October 2008

Compost or ammonium sulphate improved and maintained cotton yield for 6 years but both, together with triple superphosphate, were needed to maintain it for 9 years, after which yield declined and lime was necessary. Compost supplied necessary but insufficient phosphorus, potassium, calcium and nitrogen. Manganese toxicity was severe when potassium chloride was used on very acid soil. At suitable soil pH and with adequate phosphorus and cations, response to nitrogen was large, but for it to be most effective, calcium seemed necessary to maintain the cation: anion ratio. Without lime, yields declined with heavy rain; with it they were largest in the wettest seasons.
Estimation of the Area of Rubber Leaves (Hevea brasiliensis Muell. arg.) Using Two Leaflet Parameters
Authors: Lim T. M. , Narayanan R.
Published: October 2008

A rapid, simple method is described for estimating the area of rubber leaves from two measurements on the middle and one of the side leaflets. The relationship between the area of a leaflet (A) and its length × breadth (LB), described by the expression A = 0.654 LB, does not vary between the three leaflets or between leaves of different ages, and clonal differences are slight.
Effects of Nitrogen, Phosphorus, Potassium and Magnesium on Growth of the Oil Palm
Authors: Corley R. H. V. , Mok C. K.
Published: October 2008

Potassium application appeared to increase dry matter production and yield of oil palms, primarily by increasing leaf area, while nitrogen increased both leaf area and net assimilation rate. Responses to phosphorus and magnesium were harder to interpret. Production of vegetative dry matter attained a fairly constant level at the higher rates of fertilizer application, while the ratio of bunch yield to total dry matter production was little affected by fertilizer treatments. The importance of these results for oil palm breeding, and their possible value in diagnosing fertilizer requirements, are briefly discussed.
Time of Application of Nitrogen Fertilizer to Maize at Samaru, Nigeria
Authors: Jones M. J.
Published: October 2008

Maize was grown for three years at three levels of nitrogen, 56, 112 and 224 kg. N ha.−1, involving altogether nine different timing and splitting treatments. Measurements were made of grain yield, plant nitrogen status and total-N-uptake, and, in one year, movement of nitrate-N in control plot soils. Where only 56 kg. N ha.−1was applied, its time of application made very little difference to yield; at higher rates of nitrogen an unsplit application as late as seven weeks was very inefficient, but only at the highest rate did a split application give any appreciable yield increase over an unsplit application to the seed bed. Consideration of the soil nitrate-N data and the long-term pattern of rainfall distribution leads to the conclusion that leaching is unlikely to be a serious problem in the nitrogen nutrition of early-planted maize.
Effects of Soil Moisture Stress on Two Varieties of Upland Cotton in Israel IV. Effects of Periods of Stress Occurrence, Correlations and Regressions
Authors: Marani A.
Published: October 2008

Effects of moisture stress during different stages of cotton development were evaluated by using correlation and regression methods on data of six irrigation experiments from three different climatic regions. Significant negative correlations were found between the number of days in which soil moisture was below a threshold level, and several plant traits. Flower number was usually affected adversely by stress at the beginning of flowering; boll number, boll retention, boll weight, lint yield, lint length and seed index by stress at the end of flowering; earliness and lint fineness by stress during early boll development. Lint index, per cent and strength were affected by stress at different periods and effects of stress on lint yield were correlated with its effects on boll number, boll weight, lint length and early maturity.
Application, Absorption and Translocation of Boron in Oil Palm
Authors: Rajaratnam J. A.
Published: October 2008

Four methods of applying boron to the oil palm were studied and the results indicated that applications to the soil or to leaf axils were best. Tests of five sources of boron showed that alkaline borate fertilizers were superior to boric acid.
Trials of Spraying and Cultural Practices on Cotton in Uganda. I. Agronomic and Spraying Implications
Authors: Davies J. C. , Wheater R. O.
Published: October 2008

Four trials are described on the effects of spraying and cultural practices on pests and yields of seed cotton. Precropping with sorghum or beans after opening from a ley did not reduce yields of cotton compared to the recommended practice of ploughing a ley 6 weeks before sowing, but late ploughing and late sowing reduced yields. Nitrogenous fertilizer after a successful ley did not increase yields, but multiple sprays (up to twelve) significantly increased them over the recommended standard four spray regime, and reduced the percentage of stained seed cotton. In general cultural practices did not affect the level of pest attack, but DDT spraying gave excellent control of Heliothis armigera, while dimethoate prevented the build up of red mite (Tetranychus telarius) and gave excellent control of tea mite (Polyphagotarsonemus latus) in the multiple spray regimes.
Components Analysis of Yield Responses to Drought of Sorghum Hybrids
Authors: Blum A.
Published: October 2008

Drought resistance in terms of yield and its components was studied in the field in twenty-one agronomically-adapted high-performance grain sorghum (Sorghum bicolorMoench) hybrids. Resistance was considered to be indicated by a minimal decrease in yield under stress as compared with non-stress conditions. Water stress, imposed by a decreasing amount of stored soil moisture during the growing season, decreased grain yield and number of panicles per unit area, increased the number of grains per panicle, the number of branches per whorl and the number of grains per branch, and decreased the number of whorls per panicle. Thus a compensatory effect was observed in some components for reduction in tillering under stress. Resistant hybrids performed better than susceptible ones under stress by producing a relatively higher number of panicles per unit area, and more grains per panicle branch. Susceptible hybrids performed better than resistant ones under non-stress (irrigated) conditions due to the relatively higher number of panicles per unit area and larger 1000-grain weight. Some of the implications regarding selection for yield performance under drought are discussed.
Effects of Brackish Irrigation Water and Fertilizers on Millet and Corn
Authors: Ravikovitch S.
Published: October 2008

A field experiment was conducted to study the effect of irrigation with brackish water on the growth and composition of millet and corn, fertilized with various combinations of N and P. Millet irrigated with water of EC 3.30 mmho/cm. produced yields 79 to 93 per cent of the control (tap water of 0.61 mmho/cm.), depending on the N and P treatment applied. With water of EC 5.05 mmho/cm. yields equivalent to 52–72 per cent were obtained. Corn yields were 78–90 per cent of the control with irrigation water of 4.60 mmho/cm., and 55–64 per cent when irrigated with water of 7.06 mmho/cm. The N and P contents were mostly higher in plants grown on plots irrigated with brackish water.
Interactions of Genotype and Temperature on Cotton Boll Period and their Implication in Breeding
Authors: Yfoulis A. , Fasoulas A.
Published: October 2008

Effects of environmental temperature on boll maturation period of cotton and the genotype response, investigated in a 3-year field experiment, showed a negative correlation between period and mean temperature and revealed genotypic differences regarding degree of temperature influence and sensibility to temperature changes. The observed genotype × temperature interactions may help cotton breeders in establishing breeding centres and in creating desirable gene combinations for wider adaptability to temperature.
Redistribution of Fungicides in Coffee Trees
Authors: Pereira J. L. , Mapother H. R. , Cooke B. K. , Griffiths Ellis
Published: October 2008

Using coffee trees sprayed with cuprous oxide and captafol it has been shown that both fungicides are redistributed within the tree canopy by rain. Under conditions of light rain fungicides are removed from upper parts of trees and redeposited at lower levels within the canopy in amounts capable of providing effective protection against coffee berry disease (CBD). With heavy rainfall, however, redeposition of fungicide at effective levels is less likely to occur. The results are discussed in relation to the success of overhead boom sprayers in controlling CBD and the observations that shoots in the upper parts of coffee trees are an important source of spores of the CBD strain of Colletotrichum coffeanum.
Nature of Competition between Weeds and Rice for Nitrogen Under Dry Land Conditions
Authors: Chakraborty T.
Published: October 2008

The nitrogen content of weeds was significantly higher than that of Dular rice-straw, but with Taichung Native I rice in winter there was no significant difference between the nitrogen in weed samples and rice plants at the tillering stage. Rice straw contained a higher proportion of nitrogen where there were three hand weedings. The total dry matter of rice was much reduced by weed competition. Weed species contained much nitrogen at the vegetative, flowering and post-flowering stages, indicating severe competition for nitrogen by weeds throughout the growth of rice under dry land conditions.
Effects of N and K Fertilizers on Cynodon IB.8 and on Soil K in Southern Nigeria
Authors: Chheda H. R. , Saleem M. A. Mohamed
Published: October 2008

Cynodon IB.8 was subjected to (i) various levels of N under cutting management, and (ii) various levels of K under grazing management. The results indicated significantly higher DM and CP production with 168 kg./ha. of N under cutting management, with resultant significant reduction in exchangeable and non-exchangeable soil K. Under grazing management, increased K application increased K content in the herbage, but showed a negative correlation with Ca uptake. Results indicated that the initial soil K status was adequate to supply the requirements of Cynodon, and that under grazing management the soil K status could be maintained at adequate levels to support lengthy cropping.
Application, Absorption and Translocation of Boron in Oil Palm. III. Leaf Analysis for Diagnosing Boron Requirements
Authors: Rajaratnam J. A.
Published: October 2008

A method is described for estimating boron requirements of the oil palm, and factors influencing leaf boron concentration of the palm are discussed.
Competitive Effects ofCynodon dactylon, Sorghum halepenseandCyperus rotunduson Cotton and Mustard
Authors: Horowitz Menashe
Published: October 2008

In a short-term competition experiment in large containers, growth of cotton planted 3 weeks after bermudagrass (Cynodon dactylon), johnsongrass (Sorghum halepense) or purple nutsedge (Cyperus rotundus), was severely reduced; after 10 weeks of competition, weedy cotton weighed only 15 per cent of the weed-free control. Cotton sown before weeds, or weeds planted before cotton, were only slightly affected by competition. Highly significant negative correlations were found between growth parameters of cotton and weeds. Inhibiting effects, and in some cases transitory stimulation, were produced on mustard seedlings by leachate from weed-infested soil and by extracts from subterranean weed parts, suggesting that the competitive effects of perennial weeds are due to nutrient depletion and to biologically active substances.
A Rapid Laboratory Method of Assessing Susceptibility of Hevea Clones to Oidium Heveae
Authors: Lim T. M.
Published: October 2008

A detached-leaf technique is described for assessing susceptibility of Hevea clones to Oidium heveae, based on intensity of sporulation. This offers a rapid, systematic method of screening clones in vitro against the disease, in place of the current nursery and field methods.
Fertility Studies on a Sandy Loam in Semi-Arid Tanzania
Authors: Anderson G. D.
Published: October 2008

N and P fertilizers applied to maize had considerable effects over a five-year period, especially when both were given. Initial applications of 47 lb/acre/P2O5with annual dressings of 58 lb N, produced a mean yield increase of 55 per cent above the control. K gave little response in the first three years, but thereafter became more important. 1120 lb ammonium sulphate nitrate caused striking reductions in soil pH, Ca, Mg, K, total and organic P but increases in exch. Mn and soluble P. 112 lb double superphosphate increased the total and organic P and 65 lb K2O reduced organic P. Organic carbon suffered a mean loss of 33 per cent over five years. Recommendations are made regarding P2O5, N and K on this soil.
A Preliminary Survey of Cocoa Nutrition in Relation to Dieback Disease in Papua–New Guinea
Authors: Drover D. P.
Published: October 2008

Cocoa leaves were analysed for potassium, calcium, magnesium, manganese, iron, copper and zinc to assess the nutritional status of this crop in Papua–New Guinea, as part of a study into a dieback disease. Potassium and manganese contents of the leaves were generally high, whilst magnesium, iron and copper were often low. Some exchangeable cation data from soils is presented. Nutrient imbalances, toxicities and deficiencies, may make cocoa more susceptible to dieback.
Variability of Potential Evaporation in East Africa
Authors: Woodhead T. , Waweru E. S.
Published: October 2008

Monthly and annual totals for the Penman estimate of potential evaporation have been reliably determined, for periods varying from 7 to 11 years, at 14 East African observatories. At each site, these annual and monthly totals are normally distributed, with coefficients of variation of the order of 5 and 10 per cent, respectively. Meteorological stations established for the sole purpose of supporting evaporation surveys should therefore be relocated at 5- or 6-year intervals so as to derive maximum benefit from the valuable instruments. The results of these variability analyses were applied in the evaluation of confidence limits for monthly and annual potential evaporation rates, and reference is made to recent compilations of such limits for 137 sites in Kenya and Tanzania.
Growth and Flowering of Mango (Mangifera Indica L)
Authors: Teaotia S. S. , Pandey I. C. , Upadhyay S. K.
Published: October 2008

Growth and flowering studies were made for three years on the mango varieties Dashehari Langra and Nisar Pasand. The main growth periods were March July, March July and February-November respectively, with a peak in June for Dashehari and May for Langra, but Nisar Pasand showed no such peak. Flowering on shoots within one year of the previous flowering was recorded on 73 per cent of Nisar Pasand shoots, 38 per cent with Langra and 6 per cent with Dashehari. Nisar Pasand was shown to be a regular bearer.
Heterosis and Combining Ability in Wheat under Irrigation and Moisture Stress
Authors: Sinolinding K. P. , Chowdhry A. Rehman
Published: October 2008

Analysis of a 4-parent diallel cross showed marked heterosis for yield and its components in two crosses (Mexipak × Dirk and C273 × AU49) under irrigation, while little or negative heterosis occurred under moisture stress. A large part of the genetic variation among crosses for yield, and most components of yield, was attributed to the general combining ability, indicating that the additive effects were important. Reciprocal effects and various interactions were insignificant except for kernel weight, which suggests that effective selection could be made under irrigation of genotypes adaptable to moisture stress.
Effect of Molybdenum on the Nitrogen Metabolism of Rice
Authors: Gupta D. K. Das , Basuchaudhuri P.
Published: October 2008

The application of molybdenum, as ammonium molybdate at 40 gm./ha. as a foliar spray, alone or in combination with 400 kg./ha. of N, as ammonium sulphate, significantly increased total and soluble nitrogen in the leaves, stem and grains of the high-yielding rice cultivar IR8. The significant increase in protein content of grains was associated with a corresponding increase in most of the protein-bound amino acids, viz. leucine, phenylalanine, methionine and valine, alanine, threonine, glutamic acid, serine and glycine, aspartic acid, lysine, arginine and histidine, asparagine and proline. Nitrogen itself considerably increased the protein content, but nitrogen in combination with molybdenum was more effective.
Studies on Fractional Application of Nitrogen to Hybrid Maize in India
Authors: Nair K. P. Prabhakaran , Singh R. P.
Published: October 2008

Field experiments conducted over 2 years to evaluate the merits of fractional application of N to hybrid maize unequivocally established its utility in circumventing leaching losses and consequently boosting grain yield. Combinations of fractional application need to be phased to minimize leaching losses and also to correspond to crop needs. Fractional application improved yields even in years when the incident rainfall was evenly distributed.
Farmers' Options in Low-Income Rural Areas of the Tropics: A Conflict of Priorities
Authors: Haswell Margaret
Published: October 2008

The world grain situation and shortages of fertilizer place the agricultural industry even more to the forefront of policy and planning in low-income tropical farming areas. Planning must be positively directed toward eliminating the major constraint of inaccessibility to markets. The narrowing of alternative agricultural opportunities as accessibility decreases is indicated for a sample of farm-family households; low-income farmers isolated from the services sector arc particularly susceptible to the constraint of ‘scarcity of season’ which in turn is aggravated by the economic cost of ill-health when this coincides with the period of heaviest agricultural work. The problem which arises is one in which farmers rely on topping-up farm income with income from non-farm activities. Unless a two-to-threefold net income over any other combination of income-earning opportunities can be assured, small-scale producers largely persist in treating farming simply as a way of life by which the subsistence needs of the family can be met without recourse to new input forms.
Effects of Close Spacing on Cowpeas (Vigna Unguiculata) in Southern Nigeria
Authors: Ezedinma F. O. C.
Published: October 2008

Close spacing between and within rows significantly increased the biological and agricultural yields of cowpea without exerting clearly differential effects on the three test cultivars of different forms. It is suggested that low yields of cowpeas commonly observed in southern Nigeria could be due largely to low planting density. A six-fold increase in yield of beans can be achieved by halving the current spacing of 90 by 30 cm. provided the crop is protected from field pest damage.
Growth, Yield and Quality of Cotton under Three Water Regimes in the Sudan
Authors: Nadi A. H. El
Published: October 2008

The effects of three irrigation regimes on growth, yield and quality of cotton were investigated for two seasons in relation to earliness, quality and water-use efficiency, expressed as m. of water/kg. cotton produced. Light irrigations of cotton, at 75 mm. per irrigation every ten days, were economically better than the traditionally-accepted practice of irrigating every 14 days, and markedly better than prolonging the irrigation cycle to 20 days, mainly due to increased market value of the crop. The results also showed that irrigation intervals of 20 days, besides depressing yield, had a deleterious effect on fibre strength, though the different water regimes did not seem to affect other quality tests.
Interspecific Hybrids between Tea (Camellia sinensis) and Wilson's Camellia (C. irrawadiensis) I. Morphology and Cytology of F1 Hybrids
Authors: Bezbaruah H. P.
Published: October 2008

Crosses were made between tea (Camellia sinensis L.) and Wilson's camellia (C. irrawadiensis Barua), using tea as the female parent, but reciprocal crosses were not successful. The F1 hybrids were intermediate in morphological and anatomical characters between the parents. Regular meiosis and high pollen fertility in the hybrids clearly indicate a close relationship between the parental genomes.
Effects of Inoculation and Nitrogen Fertilizer on Soybean in Western Nigeria
Authors: Kang B. T.
Published: October 2008

The effect of inoculation and added nitrogen fertilizer on soybean variety TK-5 were studied in pot and field experiments. In the former bean yields with IARI and CB 1809 inoculants were better than with Nitragin-S. In the field experiment, inoculation alone was inadequate to supply the nitrogen need of the crop, 30 kg. N/ha. being needed with inoculation, and 60 kg. N/ha. without inoculation, for maximum yield. Higher nitrogen application, combined with inoculation, increased dry matter, N-uptake, bean yield, pod number, bean weight and nitrogen content of seed. Oil content of the seeds decreased with inoculation and nitrogen application.
Effects of Low-Temperature Stress on Fertility and Fruiting of Eggplant (Solanum melongena) in a Subtropical Climate
Authors: Nothmann J. , Koller D.
Published: October 2008

Low-temperature stress in eggplant during the cool season causes gradual loss of pollen fertility and leads to the development of seedless fruit, but female fertility is not similarly affected. The temperature-induced male sterility is transient, and full pollen fertility is regained with normal seed development, as temperature conditions improve.
Yield and Yield Components of Six Sweet Potato (Ipomoea batatas) Cultivars I. Contribution of Yield Components to Tuber Yield
Authors: Lowe S. B. , Wilson L. A.
Published: October 2008

Total yield and yield components (tuber numbers and mean tuber weights) of six local sweet potato cultivars were compared in wet and dry season crops. There were significant negative correlations between tuber number and mean tuber weight in five of the six cultivars, and positive correlations between these yield components and total yield, suggesting that cultivars may be grouped into ‘tuber number-tuber weight’ and ‘tuber weight’ types, as well as a ‘random type’ in which yield is related to neither component. Marketable yield tended to be directly related to both components, and cultivars with lower tuber numbers usually produced a higher percentage of marketable yields. The significance of these findings for sweet potato yield improvement is discussed.
Effect of Boron Nutrition on Intensity of Red Spider Mite Attack on Oil Palm Seedlings
Authors: Rajaratnam J. A. , Hock Law Ing
Published: October 2008

The effect of boron nutrition on the susceptibility of young tenera oil palm seedlings to red spider mite attack was studied. Highest concentrations of mites were recorded in seedlings which had received little or no boron in the growing media. Injuries by mites were greatest when the leaves had the highest number of mites per unit area, the lowest boron concentration and the lowest concentration of cyanidin.
Growth and Productivity of Tapioca (Manihot utilissima) IV. Devlopment and Yield of Tubers
Authors: Williams C. N.
Published: October 2008

Root measurements on three Malayan varieties of tapioca (high, medium and low-yielding clones) showed that the onset of tuberization brings about a slowing-down or cessation of growth in root length, but no changes in stem growth rate were associated with the onset of tuber growth. High yield was associated with high tuber weight rather than with tuber number, which could be related to the size of storage tissue cells formed by the root cambium. The process of tuberization in tapioca is discussed generally.
Effects of Spacing, Sett Weight and Fertilizers on Yield and Yield Components in Yams
Authors: Gurnah A. M.
Published: October 2008

The effects of plant population on yield and its components were investigated in three experiments in 1969, 1970 and 1971. Increasing populations from 9000 to 36,000 plants/ha. increased yield linearly. The number of tubers produced per plant was not affected by population, but an increase in plant density decreased average tuber weights. Increasing sett weight from 203 to 608 gm increased tuber yields/ha. and the number of tubers per plant but did not affect average tuber weights in two experiments. In 1971 compound fertilizers increased yield up to the highest rates of 90 kg./ha. each of N, P2O5and K2O respectively.
Effects of Season on Parthenocarpic and Fertilized Summer Squash (Cucumis pepo L.)
Authors: Rylski Irena
Published: October 2008

The effect was investigated of seasonal differences between winter and spring on the development of parthenocarpic and fertilized fruits in two squash cultivars, Zucchini Elite F1 and Bushy White. The former had stronger parthenocarpic characteristics than the latter. The effect of night temperature on growth of the parthenocarpic fruits was most pronounced, both rate of growth and final weight increasing with decreasing temperature. Whereas long days inhibited development of parthenocarpic fruits, the heaviest and longest fruits were obtained under normal day-length conditions.
Nodulation of Legumes in the Sudan III. Response of Haricot Bean to Inoculation
Authors: Habish H. A. , Ishag Hassan M.
Published: October 2008

Field experiments conducted in two localities in two growing seasons on the effect of inoculating haricot bean showed that a local strain of Rhizobium significantly improved nodulation and usually increased the nitrogen content of plants. In three out of four experiments, increases in seed yield were obtained ranging from 20–145 Per cent (significant in two cases). Inoculation was better than 43 kg. N/ha. of combined nitrogen but not better than 86 kg. N. Soil inoculation gave better early nodulation than seed inoculation, but the difference diminished in the later stages of plant growth.
Physiological Studies of Stored Wad Ramli Onions
Authors: Musa Sulafa K. , Adlan A. B. , Abdalla A. A.
Published: October 2008

The Sudanese local onion cultivar Wad Ramli has a markedly long rest period (60 days) and a long dormant period of up to six months. It has high dry matter (16 per cent), high soluble solids (15 per cent) and strong pungency, factors which contribute to its good storability under conditions that are usually adverse for good storage.
Responses of Sorghum Varieties to Intercropping
Authors: Andrews D. J.
Published: October 2008

Tall local sorghum and new dwarf varieties were compared, both as sole crops and when intercropped with an early cereal, in a replicated experiment, and at five sites in observation plots. Dwarf varieties were superior both as intercrops and as sole crops, and intercropping was better than sole cropping for all varieties. In the experiment 27 per cent more total grain yield (sorghum + early cereal) was obtained when dwarf varieties were used instead of tall. When the sorghum was intercropped, increased yields per plant came largely because there were more grains per head.
Growth and Yield of Irrigated Sesame I. Effects of Population and Variety on Vegetative Growth
Authors: Lazim M. H. , El Nadi A. H.
Published: October 2008

Four sesame varieties were tested at three plant populations to study varietal and population effects on some attributes of vegetative growth. Significant differences between varieties were detected and planting density was found to modify both areas and dry weights of leaves.
Growth and Yield of Irrigated Sesame II. Effects of Population and Variety on Reproductive Growth and Seed Yield
Authors: El Nadi A. H. , Lazim M. H.
Published: October 2008

Four local sesame varieties were tested at three plant populations. Increase in plant density increased seed yield, which was positively related to number of pods per plant, seeds per pod, 1000-seed weight, heights of main stems and numbers of nodes per plant. Changes in soil moisture did not affect relative turgidity, whereas stomatal openness decreased as the irrigation interval became longer.
Effects of Humidity on Losses of Bulb Onions (Allium cepa) Stored at High Temperature
Authors: Stow J. R.
Published: October 2008

Onion bulbs were stored at 30°C at relative humidities of 50, 80 and 95 per cent in 1971–72 and at the same temperature at 35, 50, 60 and 70 per cent RH in 1972–73. Losses from rotting, sprouting and desiccation were recorded. The latter were lowest at 95 per cent RH and not correlated with humidity in the range 35–80 per cent RH. Rotting losses similarly were not correlated with humidity but were highest at the highest humidity.
A Preliminary Trial of the Pearl Lupin in England
Authors: Masefield G. B.
Published: October 2008

Introductions were made to Oxford, England, of a number of strains of the pearl lupin (Lupinus mutabilis Sweet) from South America. In the first season of growth, two of these strains showed considerable promise for development as a field crop in England. Analysis of the seeds confirmed that they are comparable to the soya bean in their content of protein and oil. The chief disadvantage of the species is that the seeds contain toxic alkaloids. Alkaloid-free strains of this species have twice been bred in the past; the seed of these strains has been lost, but such work could be done again. (It is regretted that there is no surplus seed available for distribution from Oxford at present.)
Sorghum Grain Hybrids in Nigeria
Authors: Andrews D. J.
Published: October 2008

Hybrids made for the first time on six experimental photosensitive sorghum seed parents (whose breeding is described) were tested with their pollen parents, which included good dwarf varieties, in replicated small plot trials at Samaru in 1972. Grain yields of up to 5000 kg./ha. were recorded from hybrids with acceptable plant types and grain qualities, which was 40 per cent more than from the best varieties. Some hybrids, though giving over 6000 kg./ha., were unacceptable due to excessive plant height or poor grain appearance. Seed parent yields, determined in an adjacent trial, ranged from 1700 to 2900 kg./ha.
Epidemics and Chemical Control of Leaf Curl Virus Disease of Tomato in the Sudan
Authors: Yassin A. M.
Published: October 2008

Tomato leaf curl virus disease (TLC) was checked by frequent and early applications of Anthio, Folimat, Malathion and Phosdrin against the aleyrodid vector, Bemisia tabaci. Conversely, up to two-fold increases of fruit yield resulted from such applications of the insecticides. Though seed-bed or field applications, separately, gave satisfactory results on occasions, treatments of the plants in the seed-bed and the field were often both essential. Field observations during the experimental period, over four consecutive seasons, showed peak infection rates within the first 8–12 weeks of tomato planting. There were marked inter-seasonal fluctuations of disease incidence, ranging from < 50 to 100 per cent. There was no clear correlation between spread of the disease and the wind direction. Epidemiological behaviour of the disease is discussed in relation to its chemical control.
Effects of Rainfall on Yield of Grain Sorghum in the Sudan
Authors: Ali Faisal M.
Published: October 2008

The effects of rainfall on yield of rainfed grain sorghum in a rotation experiment have been investigated over six years. There was a positive association between yield and rainfall during May and from the beginning of July to the first half of September, but a negative association at other times of the year. Total rainfall in August and September, and the annual total, were positively related to yield, while the totals of June and July were inversely related. Variation in monthly rainfall accounted for up to 86 per cent of the variation in yield, while the total rainfall in August and September accounted for up to 96 per cent.
Effects of Defoliation on Pigeon Peas (Cajanus Cajan)
Authors: Hammerton John L.
Published: October 2008

Mild manual defoliation of pigeon pea plants had little effect on pod numbers, pod weights, or number of seeds per pod in two experiments. The effects of severe defoliation depended on timing and differed between pigeon pea cultivars. Late severe defoliation reduced pod numbers in both experiments, but early and intermediate severe defoliation also differed in their effects. Some physiological implications of these results are suggested.
Weather and the Yield of a Crop
Authors: Devanathan M. A. V.
Published: October 2008

The growth of plants is controlled by the availability of photosynthesized carbohydrates. Since both rainfall and sunshine are needed for photosynthesis an empirical expression is proposed which relates vegetative growth to the product of rainfall and bright sunshine hours over a specified period. Tea is a crop in which the yield is entirely vegetative and harvested throughout the year. Laycock's data for tea yields from constant treatment plots in Malawi show that yield was strongly correlated with the product of rainfall per month (R) and average daily hours of sunshine per month (S) for the previous month (r=0·972). The graph of yield vs RS for the previous month gives a straight line passing through the origin. This empirical weather parameter RS appears suitable for the study of vegetative harvests.
Susceptibility of two Cocoa Progenies to Attack by Insect Species
Authors: Bigger M.
Published: October 2008

Two cocoa progenies, T85/799×T17/359 and E1:C43/291×T63/967 (Series IIB hybrid), were compared for degree of infestation by 17 insect species comprising a Coccid, an Aphis, a Mirid and six ants. A significantly greater proportion of trees of the second variety was infested by the mealybugs Planococcus citri Risso and Pseudococcus hargreavesi Laing, by the Lecaniid scale Gascardia sp. nr. zonatus Newst., by the aphis Toxoptera aurantii Boys, by attendant ants Camponotus spp., and Crematogaster spp., and by the ant Polyrhachis laboriosa F. Smith. Because of differences in habitat requirement between the four Hemiptera, it is postulated that it is more likely that the response is due to a physiological difference between the two progenies than to a purely environmental difference.
Susceptibility of two Cocoa Progenies to Attack by Insect Species. II—Effects of Canopy Size on Numbers of Mealybugs
Authors: Bigger M.
Published: October 2008

The main axis of a Principal Components Analysis, based on measurements of width and depth of canopy of two cocoa progenies was shown to be an index of canopy size and the second axis an index of shape. Mean scores of the progenies T85/799×T17/359 and E1:C43/291×T63/967 (Series IIB hybrid) on these axes showed that their canopies did not differ significantly in shape, but that the canopy size of Series IIB trees was on average greater than that of T85/799×T17/359. Regression lines of log numbers per tree of Planococcus citri Risso against canopy size of the two progenies were parallel, indicating that for a given canopy size P. citri was 2·3 times more prevalent in trees of Series IIB than in T85/799×T17/359. A similar analysis with the combined numbers per tree of seven mealybug species showed that they were 1·9 times more prevalent in Series IIB than in T85/799×T17/359 trees of the same size.
Effects of Planting Date and Seeding Rate on Egyptian Cotton (Gossypium barbadense)
Authors: El Fawal M. A. , El Okkia A. F. , Abdel-Bary A. A. , El-Khishen A. A.
Published: October 2008

Work was conducted in Alexandria and Sakha districts, Egypt, to study the influence of planting dates and seeding rates on yield of seed cotton, yield components and fibre properties of Egyptian cotton, Menoufi variety, during 1970–1972. Four planting dates were studied, together with four seeding rates. The number of lost plants decreased as planting date was delayed, and the highest yield of seed cotton resulted from the third date of planting (20–23 March) using hand-drilling. Neither planting dates nor seeding rates had significant effects on most of the other characteristics studied.
Responses of Soybean to Symbiosis and Nitrogen Fertilization Under Humid Sub-Tropical Conditions
Authors: Pal U. R. , Saxena M. C.
Published: October 2008

Responses of nodulating and non-nodulating isolines of Clark and Harosoy to applications of N were studied, to evaluate the suitability of symbiosis versus N fertilization for soybean. Nodulating lines did not respond to N when they were either effectively inoculated or raised on a field which had been under inoculated soybean in the past. On a field brought under soybean for the first time, uninoculated Clark and Harosoy needed 300 and 235 kg. N/ha. respectively to give maximum yields. Symbiosis proved better than N fertilization for the N nutrition of soybean.
Effects of Growth Regulators on Pigeon Pea (Cajanus cajan)
Authors: Hammerton John L.
Published: October 2008

Ethephon substantially increased pod numbers of a rust-susceptible cultivar, by inducing leaf fall and a second flowering, but had no such effect on a rust-resistant cultivar. The treatment reduced seed number per pod in both cultivars. B-9 increased pod number in the rust-resistant cv. but reduced mean pod weight and seed number per pod.
Establishing a Mixed Pasture under Maize in Malawi. I. Time of Sowing
Authors: Thomas D. , Bennett A. J.
Published: October 2008

The results are reported of an experiment on the Lilongwe Plain to investigate the effects of under-sowing maize with a mixture of Rhodes grass and silverleaf desmodium. Undersowing caused no significant reduction in any component of maize yield, and mixed swards with a good legume content were established. Nitrogen application had no significant effect on yields of grain or pasture, but in the following year undersown swards outyielded those directly seeded. Some practical advantages of undersowing are discussed.
Effects of Ground Rock Phosphate-Sulphur Mixture on Yield and Nutrient Uptake of Groundnuts (Arachis hypogaea) in Northern Nigeria
Authors: Bromfield A. R.
Published: October 2008

Groundnuts given a mixture of S35-labelled ground rock phosphate and sulphur at planting were radioactive 14 days later, when go per cent of the seedlings had emerged. Forty days after planting one-third of the total plant-S was from the fertilizer, and the mean recovery of fertilizer-S was 18 per cent by harvest. In field experiments the mixture outyielded ground rock phosphate and was as good as single superphosphate, though drought diminished yields generally. At three sites which were harvested the percentages of applied-S recovered were 12, 20 and 27 per cent. Significantly more P was taken up by the crop receiving the mixture than was recovered from the ground rock phosphate alone.
Establishing a Mixed Pasture under Maize in Malawi. II. Method of Sowing
Authors: Thomas D. , Bennett A. J.
Published: October 2008

Different methods of undersowing maize with a mixture of Rhodes grass and silverleaf desmodium were compared, together with the effects of applied nitrogen, in an experiment on the Lilongwe Plain. Drilling the legume on the ridge or in the furrow was superior to broadcasting, and caused no substantial reductions in maize yield. Nitrogen application increased all aspects of maize production but slightly reduced legume yield. The data generally confirm previous findings that undersowing causes no appreciable and consistent reduction in maize yield, and results in the establishment of mixed swards with a high legume content.
A Development Plan for Semi-Arid Areas in Western Sudan
Authors: Adams Martin E.
Published: October 2008

This paper, concerned with agricultural development planning problems in the Sahelian and Sudanian (semi-desert and savanna) zones in Africa between 10 and 16° North, describes a plan for Darfur, Western Sudan. This aims to modernize a stagnant and primitive technology and out-dated land rights which, in the face of rapid population increase and climatic change, are reducing the long-term carrying capacity of the land. The development plan (H.T.S., 1974) has been based on a 2-year (1972–73) survey by a team of physical and social scientists, financed by the Overseas Development Administration of the United Kingdom and the Ministry of Agriculture in the Sudan.
Moisture Conservation by Fallowing in Botswana
Authors: Whiteman P. T. S.
Published: October 2008

Low and unreliable rainfall, combined with high summer evaporation rates, frequently lead to poor yields and crop failure in Botswana agriculture. Over three test years it has been shown that the soil can store up to 100 mm. of available moisture at planting time, which represents about half the water requirement of a crop of sorghum, and the balance is likely to be met (P = 0.05) during the current growing season. Sorghum grain yields have been doubled (2007 kg./ha.) after fallow compared with 1028 kg./ha. after non-fallowed pre-treatments. The advantages of a farming system based on a bare summer fallow are discussed, and reference is made to the implications of its wider adoption.
Factors Affecting Plant Stand in Pigeon Pea
Authors: Khan T. N. , Ashley J. M.
Published: October 2008

Effects are reported of some factors which may influence emergence and establishment of pigeon pea (Cajanus cajan (L.) Millsp.), including seeding depth, seed dressing, seed grading, seeding rate, variety and temperature. The effect of seeding rate was dependent on mean germination percentage in the field, but circumstantial observations on other factors of possible consequence in determining plant stand are also discussed.