Browsing by Author "Hemingway, J.S."
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Item East African Work on Breeding Maize Resistant to the Tropical American Rust, Puccinia Polysora(1957) Baldwin, B.J.T.; Audrie, K.H.; Storey, H.H.; Dixon, G.E.; Hemingway, J.S.; Jameson, J.D.; Thorpe, H.C.; East African Agricultural and Forestry Research Organization: Tanganyika Agricultural Corporation: Uganda Department of Agriculture: Kenya department of AgricultureSince 1952 Puccinia polysora under has become widespread in maize in the tropical areas of East Africa, and severe attacks have been shown to reduce yield greatly. Two physiologic races have been recognized, 'EA.I' being today the prevalent race in the field and 'EA.2' being known as yet only in the Muguga glasshouses. Experimental infection trials in glasshouses at Muguga, Kenya, failed to demonstrate resistance in any African maize variety; but among maize’s imported from Central America and the Caribbean plants were found that showed the hypersensitive type of resistance. From these, lines were bred that were pure for either of two genes: Rppl. conferred high resistance to Race EA.I but none to EA.2; while Rpp2 conferred a lesser, but effective, resistance equally to both rust races. Field breeding at three stations in East Africa was successful in incorporating each of these genes separately in locally adapted maize varieties; and considerable bulks of pure-breeding resistant maize’s were expected to become available during 1957 and later years.Item Effects of Population Density on Yield of Maize(1956/1957) Hemingway, J.S.The name "Katumbili" is used for white seeded maize grown over wide areas of East Africa. In its crude form, as grown largely in native cultivation, the stock contains a very great mixture of characters: dent- and flint seeded types, tall, intermediate and dwarf plants, variations of ear number and row number on the ear, a range of growth periods, other colored seeds, etc. Attempts have been made in many areas, particularly on experimental farms, to "clean up" this mixture by mass-selection and other simple techniques, in order to standardize strains which conform to local necessities (length of season, etc.), and preferences (dent or flint, "sugary" or "starchy" seed, etc.). As a consequence of these attempts a number of fairly distinct strains have been named, and these are in use in breeding programmes and in the East African co-operative maize variety trials currently being run on a number of experimental farms. Examples of such strains are "Katumbili wanza", "Katumbili Namulonge", "Katumbili Kilosa" and "Katumbili Nachingwea".
