Browsing by Author "Hansford, C.G."
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Item Annotated Host List of Uganda Parasitic Fungi and Plant Diseases- Part I(1937) Hansford, C.G.; Department of Agriculture, UgandaThe last list of Uganda Fungi published was that of Miss Wakefield (KewBulletin. 1920. p. 289 et seq.)and since that publication the collection and identification of these organisms has proceeded steadily though at times not very rapidly. The result is that the list referred to is now much out of date. And the following represents an effort to collect together all the records available. A large number of purely saprophytic fungi have been recorded and identified in Uganda but most of these are omitted from the following list. Many new species are mentioned in it and it is hoped that the Latin descriptions of these will be published shortly. In some groups there is doubt as to the accuracy of the older records but no time has been available to revise these as efforts have been concentrated on keeping abreast of the more recent collections; in any case. The material of the older collections is at Kew Herbarium and no duplicates are available in Uganda.Item Annotated Host List of Uganda Parasitic Fungi and Plant Diseases—Part III.(1937) Hansford, C.G.; Department of Agriculture, Uganda Protectorate.These two further instalments of the author's list of parasitic fungi and plant diseases so far recorded in Uganda are on the same lines as the first [R.A.M., xvi, p. 550], and include hosts belonging to 37 families. Armillaria mellea is stated to cause the most important disease of tea in Uganda [ibid., viii, p. 202]. Cotton wilt (Verticillium albo-atrum) [ibid., xv, p. 150; xvi, p. 455] is now known from most cotton areas south of Lakes Albert and Kioga and is increasing every year. The fungus is distributed all over Uganda in seed obtained from diseased plants, and under present conditions dissemination by this means cannot be prevented. It is probable that V. albo-atrum is locally the chief cause of cotton wilt. The fungus was recently discovered attacking cassava at Bukalasa. Mycosphaerella areola, the ascigerous stage of Cercosporella gossypii (syn. Ramularia areola] [ibid., xiv, p. 629] was recorded in its ascigerous stage on cotton. Gibberella fujikuroi, a common saprophyte on dead cotton plants, causes a disease of cotton seedlings simulating sore shin. Cladosporium album [Erostrotheca multiformis: ibid., xvi, p. 322] is recorded on beans (Phaseolus) (on which it causes little damage) and peas.Item Black Arm Disease in Uganda(1935/1936) Hansford, C.G.There are no certain records of the occurrence of this disease in Uganda be fore 1925, though there are strong grounds for assummg that it was present here for some few years before that date. In 1925 Snowden definitely identified it as present, and stated that it was of com mon occurrence. In the following year the leaf form of the disease was almost universal east of the Nile, and extremely common in Buganda; the stem form was common at Suere Plantation, following a severe hailstorm in September. In the following s~ason the leaf spot form was practically universal, though the stem form was much less common than in the previous year. In 1 928- 29 the crop of parts of Teso District was severely at tacked by both forms of the disease, and a very poor crop was obtained. The 1 929-30 season is still referred to as the .. Black Arm Year". In this season the disease was very severe in T eso, Bug, were and Lango, and in more limited areas in Busoga and Buganda. The loss of crop is estimated at from 50,000 to 70,000 bales of cotton, but in the light of later research it is difficult to estimate what proportion of this loss is directly attributable to the disease. In the £ollow ing season the disease was much less severe. The seed supply for the areas severely affected during 1 929-30 was ob tained from the less severely attacked areas of Busoga. In spite of this change of seed, the leaf form of the disease was present in almost every plot shortly after germination, and gradually spread to every plant. The stem form was reported from many places, but never became severe, and in this season the disease had little effect on the crop. In 1931-32, in spite of prolonged wet weather in mostItem Host List of the Parasitic Fungi of Uganda : Part II(1943) Hansford, C.G.; Department of Agriculture, UgandaParasitic fungi are a significant threat to agricultural productivity in the region, causing a wide range of diseases that affect both staple and cash crops.Item A Probable Virus Disease of Sweet Potato(1944) Hansford, C.G.; UgandaIn March, 1944, what is suspected to be a virus disease of sweet potato was discovered at Kwanda by Mr. J. D. Jameson, amongst a collection of native varieties kept here for reference. A detailed survey of the distribution of the disease in Uganda has not yet been possible, but records have been obtained from widely separated areas and there is thus reason to suspect its general distribution. Recently reports have been received of its occurrence in Ruanda-Urundi and in the adjoining parts of Tanganyika. 1 am informed by the authorities of the Congo Beige that they suspect its occurrence in serious amounts in the area west of Lake Albert, where the crop has suffered severely and has virtually been abandoned as a food supply to the Kilo Mines. In view of these records the disease is thus potentially of serious importance in those parts of East Africa where the sweet potato is a major source of food supply. Hitherto investigations have been limited to field observations and detailed experimental research is only being commenced, so that no information is yet available on the possible origin of the disease, on its method of transmission from plant to plant, or on its relation to virus diseases of other crop plants in East Africa. Both in the Congo Beige and at Kawanda large numbers of white flies (Aleyrodidae) have been noticed in affected plots, and we suspect these as possible vectors of the disease. They have not yet been identified but appear to be close allies of the species of Bemisia known to be the vector of the mosaicItem Sugar Cane Diseases in Uganda(1935/1936) Hansford, C.G.This was first discovered on Lugazi Estate in 1927, At that time it was limited to about 100 acres of cane. The distribution of the disease indicated that it had probably been present for about a year, though inspection of the estate in late 1926 had failed to reveal it. No indication of infection of local grass weeds was found, and the origin of the disease in Uganda remains a complete mystery. It has since appeared on Kakira Estate, again of unknown origin, and, as far as present information is available, its distribution is still limited to these two estates and native cultivation's close by them. No cases have ever been noticed in other districts, nor has any case ever appeared in the sugar cane nursery at Kampala, on either the older varieties or those imported since my arrival in 1926. It is therefore quite certain that the disease has not been imported on the newer varieties of cane; in fact it was found at Lugazi before any of these were grown there.Item Vascular Diseases of Cotton in Uganda(January 1940) Hansford, C.G.; Department of Agriculture, UgandaThis group of diseases has become much more prevalent in Uganda during the last ten years, though even to-day in many districts they are limited to occasional attacks on individual plants. In other very limited areas they have reached the stage at which some effect on crop production is noticeable, as for instance at the Bukalasa Experiment Station. In Uganda the field officer and the plant breeder must deal with the whole group of diseases as a single entity, as there is no means of distinguishing between the causative organisms concerned in individual cases except isolation in the laboratory. An analysis of what may be termed the "Wilt Complex in Uganda" will be a useful arrangement under which to discuss the work carried out on the diseases and that now in progress.
