Industrial Crops
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Browsing Industrial Crops by Author "Aduayi, E.A."
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Item Automated Methods for Nitrogen, Phosphorus and Potassium Determination in Coffee Plant and Mulching Materials(1972) Kimeu, B.S.; Aduayi, E.A.In order to cope more accurately and rapidly with the chemical analyses of the massive influx of samples, as a result of the introduction of a leaf analysis service for coffee growers by the Coffee Research Station in 1971, the application of automated chemical analyses was employed. Automated methods adapted for the determination of nitrogen and phosphorus on the Technicon Autoanalyser and potassium on the Unicam Atomic Absorption Spectrophotometer using the same digest solution are described and the results are compared to manual determinations. A better agreement between replicated automated determinations was established for each element analysed than in the non-automated determinations.Item Coffee Board of Kenya Monthly Bulletins February 1971(1971) Aduayi, E.A.; Bould, C.; Kimeu, B.S.; Coffee Board of KenyaFertilizer programmes for Coffee (at present) are based largely on past experience, or on field manurial trials, or soil analysis data, or a combination of all three. In general, crop yield responses are obtained from nitrogenous fertilizers only, although there are indications that in certain areas yields have been improved by phosphatic fertilizers (Mehlich, 1968). There appears to be little critical data on yield responses to other major nutrients or to trace elements, although magnesium and iron appear to be associated with bean quality. It should be emphasized, however, that little information is available from critical experiments in which the nutrients under test were known to be the only limiting factors, or in which the applied nutrients were shown to be taken up by the trees (as reflected in a changed nutrient status).Item Coffee Board of Kenya Monthly Bulletins January 1971(1971) Aduayi, E.A.; Coffee Board of KenyaStudies on the effects of copper on Coffea arabica L. seedlings show that copper (as Cu20 or CUS04) when applied in high concentrations affects root development, the general growth and nutrient composition of the plant and produces toxicity (Castillo and Parra, 1959; Nag Raj and George, 1960). Baker (1964) sprayed detached leaves of Coffea arabica with different concentrations of copper oxychloride and found that copper, up to 474 ppm, was absorbed by the leaves.Item Effect of Copper Sprays on the Mineral Nutrient Content and Growth of Arabica Coffee Seedlings in Kenya(1972) Aduayi, E.A.Coffea arabica L. seedlings (cv. S.L.34) were sprayed with varying concentrations of cuprous oxide at 0.0, 0.25, 0.50 and 0.75% for 30 days. Significant increases in the total mean fresh and dry weight; rate of transpiration; stomatal apertures; the total leaf area and plant vigor were observed on the seedlings with increasing concentrations of Cu treatments. The content of N, K, Ca and Cu were significantly increased in the seedlings at Cu spray treatments of 0.50 and 0.75% It is possible that the growth promoting effects produced in coffee by spraying high concentrations of copper is partly nutritional. This is brought about by the catalysing effects of the absorbed Cu ions, by accelerating enzymatic activities within the plant and hence increasing nutrient uptake.Item Effects of Cuprous Oxide (Copper) on the Growth and Mineral Composition of Coffee Seedlings Grown in Nutrient Solutions(1972) Aduayi, E.A.Copper fungicides are used frequently on Coffea arabica L. in Kenya to control coffee berry disease (Colletotrichum coffeanul1l Noack) and leaf rust (Hemileia vastatrix Berk. and Br.) and sometimes as "tonic sprays" for leaf retention. Cuprous oxide sprays, containing about 50 percent copper, are particularly recommended for leaf rust control when applied before the onset of the long and short rains (Griffiths 1970; Wallis and Firman 1967; Vermeulen and Patwa 1966).Item Observations on the Water Culture Technique For Studying the Effects of Copper Concentrations On Arabica Coffee Seedlings(1972) Aduayi, E.A.The technique and procedure of growing coffee seedlings in water cultures for experimental purposes at the Coffee Research Station, Ruiru, are discussed. It was observed that this method would provide a basic and accurate guide for the study of the role of nutrient elements and their interactions and would assist with an efficient fertilizer programme. The water culture method was suitable for a short-term (less than a year) investigation and did not require any expensive systematic aeration and set-up. Results obtained from this technique Could provide valuable nutritional information on the growth, yield and quality of mature coffee in the field.Item Observations on the Water Culture Technique for Studying the Effects of Copper Concentrations on Arabica Coffee Seedlings(1972) Aduayi, E.A.The technique of growing plants in soil-less cultures is not new. However, modifications are often made to this technique to suit a particular plant species, the climatic conditions of the area and the availability of facilities and equipment. Ulrich (1956), Fernandez and Childers (1960), Hoagland and Chandler (1932),Hoagland (1940) and Hewitt (1963, 1966), have grown various crops in water cultures, another soil-less media in order to provide basic information on the role and interactions of nutrient elements before conducting field and other long-term experiments. Coffee species and perennial fruit crops, (citrus, cacao, apples)have been similarly grown for the same purpose, (Laue, 1957. 1961; Malavolta andGomes, 1961; Malavolta et al 1962; Bould,1961; Bolle-Jones, 1954; Lewis and Kenworthy,1962). Sholto-Douglas (1955), speculated on the possibility of soil-less cultivation of Arabica coffee in Kenya. He thought that such a technique, apart from saving time, labour and Space, would expose plants to adequate nutrition, free from the interference of soil colloids.Item Soil pH as Measured in Different Solutions and the Nutrient Content with of Water Some Coffee Soils(1972) Aduayi, E.A.Soil-pH measurement in various dilutions with water and with O.OIM CaCl2, and the determination of total and available soil-Cu and some nutrient elements were carried out in sites that had undergone various treatments and cultural practices for over ten years at the Coffee Research Station. PH measured in 1: 1, and 1:2.5 dilutions with O.OIM CaCl2 solution was more consistent when compared to pH measured in water. Napier grass (Pel1nisetum pur pureum) cultivation produced low soil-K (1.48 me per cent), and high soil - Mg and - Ca (2.02 and 8.98 me per cent respectively) compared to high soil-K (2.36 me per cent), low Mg (1.94 me per cent) and Ca (8.14 me per cent) in sites in which coffee had been cultivated and mulched with Napier grass. Available Cu was about 10 per cent of the total Cu, and increased in sites with copper spray treatments. Available P was low in all sites sampled. There was a better correlation established in soil pH measured in O.OIM CaCl2 solution and the values were more consistent than pH measured in water.Item Soil-plant Nutrient Relationships in Tree Crops with Special Reference to Coffee(1970) Aduayi, E.A.The use of soil and foliar analyses for studying soil-plant nutrient relationships as a basis for fertilizer programmes is discussed. Experimental evidence is given on the availability and interactions of N, P, K, Ca and Mg in soils and plants, and their effect on coffee in Kenya.
