Browsing by Author "Robinson, J. B. D."
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Item Advisory Soil or Plant Analysis and Fertilizer Use Part IV-Evaluation of Plant Analysis with Maize Yield Data(1969) Robinson, J. B. D.Maize fertilizer trials carried out over two seasons in Western Tanzania were sampled for the purpose of carrying out leaf analysis. This paper presents and discusses relationships between maize leaf nitrogen or phosphorus figures, maize yield and maize yield responses to two rates of nitrogen and phosphorus fertilizers. The practical uses of the leaf analysis technique in this area are indicated.Item Camber Bed Cultivation of Ground-Water (Vlei) Soils I-Experimental Crop Yields(1959) Evans, H. R.; Robinson, J. B. D.; Brook, T. R.Ground-water (vlei) soils are capable of producing Both Napier grass for mulching coffee and good pineapple crops, when cultivated on the Camber Bed system as previously described (Robinson. ct ai., 1955).Item Camber Bed Cultivation of Groundwater (Vlei) Soils Ii-Modifications of the System(1959) Robinson, J. B. D.; Brook, T. R.Since the publication of a description of the camber-bed system of cultivation of vlei soils considerable area of vlei land has been treated in this way, and the experience gained brought out points which required further investigation. Observations during the past two years have shown that the run-off from camber beds can be very high, and it is clear that before the system is put into operation the area should be examined to see if the run-off can be safely discharged into protected drainage ways without risk of damage to roads, culverts, cultivated land etc.Item Chemical Index for Available Soil Nitrogen(1967) Robinson, J. B. D.A comparison has been made between two laboratory index tests for potentially available natural soil nitrogen, for a number of arable East African soils. The newer chemical test which is both simple and quick, was found to be equally as satisfactory as the incubation test developed at E.A.A.F.R.O. The new test will be adopted for all calibration work in the future and is recommended for advisory soil analysis.Item Coffee Board of Kenya Monthly Bulletins December 1957(1957) Robinson, J. B. D.; Coffee Board of KenyaItem Coffee Board of Kenya Monthly Bulletins February 1958(1958) Robinson, J. B. D.; Coffee Board of KenyaI can summarize briefly the analytical equipment which I saw' on my Study Tour of some Central and South American off, Research Centres during January to February, 1957, and which was being used in the several research and investigation programmes of ,leaf analysis, as :- (a) Equipment for colourimetric analysis colourimeters, spectrophotometers. (b) Equipment for flame analysis flame photometer type. (None of the laboratories that I visited were equipped with a spectrophotometeraph although this was considered desirable by Dr. Lott of the I.B.E.C. Research Institute, Brazil, Dr. Muller and Professor Hardy in Costa Rica, for the rapid and comprehensive analysis of large numbers of samples.)Item Coffee Board of Kenya Monthly Bulletins July 1958(1958) Coffee Board of Kenya; Robinson, J. B. D.It is recommended by the Coffee Research Station that coffee seedling should receive an application of ammonium sulphate (2 oz. per, seedling) soon after, they have become established in the field.The timing of this application should be between 3-5, weeks after planting out if suitable rainfall for establishment has been forthcoming.Item Coffee Board of Kenya Monthly Bulletins November 1957(1957) Coffee Board of Kenya; Robinson, J. B. D.During the course of soil-nitrogen studies on the Kikuyu red loam soils at the Coffee Research Station,Ruiru,it has become apparent that the soil pH reaction is being influenced very appreciably by treatments applied in the manure trials on the Station.A short-term investigation was undertaken to examine the effects of various manual Treatments on the soil pH reaction,with particular reference to the use of ammonium sulphate fertiliser and to the question of the position of application in relation to the coffee tree.Item Coffee Board of Kenya Monthly Bulletins October 1958(1958) Coffee Board of Kenya; Robinson, J. B. D.; McCrae, D. J.; Wallis J. A. NShort-term seasonal I deficiencies, or perhaps it is better to term them mineral imbalance conditions, do probably occur, and it has been shown by trials at the Coffee Research Station that nitrogen$ becomes growth and cropping during the wet seasons. It has also been demonstrate d that consistent mulching of coffee, particularly with Napier grass, will create an increase demand in the and the tree for magnesium, which have to be supplied as a fertilizer salt.Item The efficiency of Muguga standard potting soil(1969) Robinson, J. B. D.; Dyson, W. G.; Dickinson, P. J.; Howland, P.; Semb, G.Experiments to examine the need to age or mature the unsterilized Muguga standard potting mixture before use in forest nursery work have shown that a minimum period of two to four weeks ageing is necessary. An examination of the individual components in both sterilized and unsterilized potting mixtures has emphasized the value of the manure component and shown that in the nursery, coffee hulls are not a good substitute for peat but in the glasshouse, they have slight advantages provided fertilizer is added. The inclusion of the gravel component was of no value in the forest nursery trials but was beneficial in glasshouse trial mixtures. Whilst it is difficult to generalize, the best unsterilized mixture for nursery use would appear to be forest soil to which is added manure, peat and fertilizer. Under greenhouse conditions, using the components sterilized, gravel should also be added. Fertilizer addition is optional, though probably beneficial for long-term work.Item Incubation Methods for Determining Available Soil Nitrogen(1967) Robinson, J. B. D.Mineral - N obtained after aerobic incubation and NH4-N obtained after anaerobic incubation of maize fertilizer trial soils have been correlated one with another. The level of correlation was not as great as that reported in the original method. NH4-N was generally less well correlated with yield and leaf - N parameters than was 6mineral - N. Mineral - N has been adopted for the present, in preference to NH4- N, to define an index to plant available soil - N in East Africa.Item The Leaf Yellowing or Yellow Wilt sydrome of sugar cane at the Tanganyika planting company, Arusha Tanzania(1969) Robinson, J. B. D.This visit primarily made to follow up an earlier visit in May 1968 for the specific purpose inspecting the root systems of cane with and without the Yellowing syndrome. Field conditions were too wet during the earlier visit for this work to be undertakenItem Mineral Nutrition of Coffee Preliminary Results with the Leaf Analysis Technique(1961) Robinson, J. B. D.In recent years many investigations have been carried out in Coffea Arabica with the leaf analysis technique. Machada (1956, 1958)in Colombia, Medcalf et at (1955) and Lottet at (1956), in Brazil, have related fertilizer application and crop responses to leaf analysis values; Culot and Van Wambeke (1958) studied mineral deficiencies in the Kivu area of the Congo Republic and defined the normal range of adequacy and the upper deficiency threshold levels for a number of macro and micronutrients.Muller (1960) has studied the question of the age of the leaf sample in relation to the nutritional status of the coffee tree and has described the nutritional gradient along cropping and non-cropping branches for some of the macro-nutrients. He has emphasized the value of the technique of "differential analysis" on bearing trees when investigating the macronutrients which are limiting to crop productionItem Mineral Nutrition of Coffee. Preliminary Results with the Leaf Analysis Technique(1961) Robinson, J. B. D.In recent years many investigations have been carried out in Coffea arabica with the leaf analysis technique. Machada (1956. 1958) in Colombia. Medcalf et al (1955) and Lott et al (1956), in Brazil, have related fertilizer application and crop responses to leaf analysis values; Culot and Van Wambeke (1958) studied mineral deficiencies in the Kivu area of the Congo Republic and defined the normal range of adequacy and the upper deficiency threshold levels for a number of macro and micronutrients. Muller (1960) has studied the question of the age of the leaf sample in relation to the nutritional status of the coffee tree and has described the nutritional gradient along cropping and non-cropping branches for some of the macro-nutrients. He has emphasized the value of the technique of "differential analysis” on bearing trees when investigating the macronutrients which are limiting to crop production.Item A Note on green-vein chlorosis of coffee(1955) Robinson, J. B. D.The writer has frequently noticed a particular type of leaf symptom on mature coffee (Coffea arabica) which appears to be related to a temporary deficiency of available iron. Limited field observations indicate that this condition is not confined to coffee grown on red soils of volcanic origin in Kenya, i.e. Kikuyu Red Loam series, since the presence of a similar condition has been observed on mature coffee growing on soils of the Basement Complex.Item A Note on Magnesium Unbalance Symptoms in Avocado Pear Trees(1961) Robinson, J. B. D.From time to time Avocado pear leaf samples were collected from trees growing on the Coffee Research Station, Ruiru, which exhibited these symptoms and were analysed for their calcium potassium and magnesium contents. The age and type of leaf sample collected is shown in Plate I; young, green leaves are those designated "A" and old chlorotic/necrotic leaves are those designated "B". In Table I are shown some typical analytical values together with a summary of some comparable figures found in the literature and referring to work carried on outside Africa.Item Nutrition Of Coffee - Deriving Reliable Data For Advisory Purposes(1967) Robinson, J. B. D.It is necessary to develop a sound advisory service for the efficient use of fertilizers and soil amendments in the coffee crop based on soil and plant analysis. This can only be done effectively by undertaking extensive field calibration trials together with longer-term bench mark site trials. An approach is outlined and problems specific to the perennial coffee crop are discussed.Item Response Of Mature Napier Grass To Fertilizers And Cattle Manure In Kenya(1965) Jones, P. A.; Robinson, J. B. D.Trials with Napier grass grown for mulching were conducted from 1951 .to 1959 on two similar and adjacent soil types. On the more fertile soil no consistent response was recorded to nitrogen or phosphorus fertilizers applied seasonally and annually.Item Studies on the Effect of Mulch and Irrigation on Root and Stem Development in Coffe Arabica L. 3. The Effects of Mulch and Irrigation on Yield(1964) Mitchell H.W.; Robinson, J. B. D.THE effects of organic mulch and irrigation on the root and branch system development in mature, 20 years old coffee trees (Coffee Arabica L.) have been described by Bull (1, 2). In this paper the effects of these treatments on crop yield in the same experiment (No. 15) are reported.Item Yield And Response To Fungicide And Fertilizer Of Peasant-Grown Arabica Coffee On Mt. Kilimanjaro, Tanzania Effects Of Treatments And Seasons On Yield(1967) Robinson, J. B. D.The first of this series of papers [1] was an introduction to' the study and contained a description of the soils and climate over the experimental area, as well as the Location of the individual trial sites, the treatments applied and the field methods used in the investigation.
