African Journals Online
Ghana Journal of Agricultural Science

VOLUME 32 (1999) PART ONE
ABSTRACTS

VARIABILITY STUDIES IN SOME QUALITATIVE CHARACTERS OF COWPEA (VIGNA UNGUICULATA (L.) WALP) ACCESSIONS FROM FOUR COWPEA-GROWING REGIONS OF GHANA

(S. O. B.-L.: Plant Genetic Resources Centre, P. O. Box 7, Bunso, Ghana; I.O.: Department of Crop Science, University of Ghana, Legon, Ghana)

Forty-five cowpea accessions, randomly selected from cowpea germplasm from four cowpea-growing regions Of Ghana, namely, Upper East, Upper West, Northern, and Eastern Regions, were characterized and evaluated to determine the range of variability in qualitative characters in the samples. Variability was observed in growth habit, twining tendency, plant and pod pigmentation, and raceme position. Accessions from the Upper West, Northern and Eastern Regions showed three types of growth habit: prostrate, semi-prostrate and intermediate, with the semi-prostrate type in the majority, whilst and Upper East Region showed only the semi-prostrate type. Accessions from the Northern and Eastern Regions showed three types of twining tendency, namely, no twining, slight, and intermediate twining, whilst the Upper East Region accessions showed only none twining types. Majority of the accessions showed the no twining type. All the regions showed great variability in plant and immature pod pigmentation in the cowpea accessions. Two types of flower colour were observed, purple and white. With the exception of the Upper East Region accessions which showed only white flower colour, accessions from all the other regions showed both white and purple colours with the accessions with purple colour in the majority. In most of the accessions from the Upper West, Northern and Eastern Regions, the racemes were held above the canopy.

Original scientific paper. Received 4 Apr 97; revised2 Jan 99.

DIPLODIA NATALENSIS POLE EVANS, THE CAUSAL AGENT OF CITRUS GUMMOSIS DISEASE IN GHANA

(M. K. A. &K. A. O.: Department of Crop Science, University of Ghana, Legon, Ghana; K. G. O.-B.: University of Ghana Agricultural Research Station, Kade, Ghana)

Isolations were made from the barks of gummosis-infected citrus trees from orchards of the University of Ghana Agricultural Research Station at Kade. The isolation media used were 1.5 per cent water agar, 1.5 per cent water agar + nystatin, and 1.5 per cent water agar + benomyl. Four isolates including Diplodia natalensis Pole Evans, Fusarium solani Appel + Wr., and two other identified fungi were obtained. The two fungi were unidentified on Potato Dextrose Agar (PDA). When the isolates were tested for pathogenicity, only D. natalensis induced the disease symptoms in the inoculated 18-month-old rough lemon seedlings which were incubated after inoculation in a screenhouse of 30-37 oC and 55-75 percent relative humidity. This result strongly suggests that D. natalensis is one of the pathogens causing citrus gummosis disease in Ghana.

Original scientific paper. Received 2 Apr 97; revised 18 Jan 99.

STUDIES ON PERFORMANCE OF SOME OPEN-POLLINATED MAIZE CULTIVARS IN THE GUINEA SAVANNA. III. NITROGEN USE EFFICIENCIES OF FOUR CULTIVARS

Crops Research Institute, Council for Scientific and Industrial Research, P.O. Box 3785, Kumasi, Ghana

Nitrogen use efficiency (NUE), defined as grain produced per unit of fertilizer nitrogen (N) applied, is a highly desirable agronomic character of non-leguminous crop varieties. This study was conducted to compare the NUEs of one local maize (Zea mays L.) variety and three improved composites released in Ghana since 1972, and determine the effects of breeding for improved agronomic performance on the NUEs of the improved cultivars. The four late-maturing maize cultivars (local, Composite 4,Dobidi, and Okomasa) were evaluated at 0, 80, and 160 kg N ha-1 and under three plant densities at Nyankpala and Damongo in 1992 and 1993. Across environment analysis for grain yield showed environment, plant density, nitrogen, and cultivar effects were significant (P<0.05). The environment W cultivar, environment W nitrogen, density W nitrogen, and nitrogen W cultivar interactions were also significant. Mean grain yields for the improved cultivars were 3.5, 4.7, and 5.3 t ha-1 at 0, 80, and 160 kg N ha-1, respectively. Yields for the local variety were lower by 40.0, 42.2, and 51.4 per cent at 0, 80, and 160 kg N ha-1, respectively. NUEs for the local variety, Composite 4, Dobidi, and Okomasa were 9.8, 16.4, 15.7, and 15.1 at 80 kg N ha-1, and 6.4,11.0, 11.3, and 11.4 at 160 kg N ha-1, respectively. The NUEs over the two N levels were 8.1, 13.7, 13.5, and 13.1 for the four cultivars, respectively. NUE increased linearly at 0.15 yr-1 in improved cultivars over the local variety at both N levels. It was concluded that improved maize cultivars were more efficient in using fertilizer N than the local variety, NUEs did not differ among the improved cultivars, and that breeding resulted in 1.8 per cent yr-1 improvement in NUE over the local variety.

Original scientific paper. Received 12 Aug 97; revised 18 Jan 99.

(S. O. B.-L.: Plant Genetic Resources Centre, CSIR, P.O. Box 7, Bunso, Ghana; K.O.: Department of Crop Science, University of Ghana, Legon, Ghana)

Four crosses involving five local accessions of cowpea were evaluated to determine the amount of heterosis for maturity date, seed yield, and components of yield. Heterosis for seed yield plant-1 was greater than that for other characters with a high-parent heterosis of 2.4 to 72.1 per cent. Number of pods plant-1 was the most heterotic of the yield components. The cross between high-yielding parents produced the highest heterosis above the mid-parent and high parent for seed yield plant-1. Seed yield may be improved by crossing among local landraces of cowpea through improving the number of pods plant-1.

Original scientific paper. Received 4 Apr 97; revised 22 Jan 99.

A COMPARISON OF DIFFERENT MODELS TO CHARACTERIZE LACTATION CURVES OF FRIESIANS IN A HUMID FOREST ZONE

(B. K. A.: Department of Animal Science, University of Ghana, Legon, Ghana; J. D. K.: Department of Animal Science, KNUST, Kumasi, Ghana; P. K. K.: Dairy Beef Cattle Research Station, KNUST, Kumasi, Ghana)

A study was undertaken of 110 lactations of a herd of Friesians in the humid tropical zone of Ghana to investigate the goodness of fit and other milk production variables estimates by six published lactation curves. These were Yn = a - bn + cn ln (n), (Singh); Yn = n/(a + bn + cn2), (Nelder); Yn = a -bn - ae-cn, (Cobby); Yn = anbe-cn, (Wood); Yn = anb/cosh (cn), (Papajcsik); and Yn = n/ae-bn, (Jenkins); where Yn is the milk yield on day n and a, b and c are the parameters estimated iteratively from the solution to the equations. Season of freshening did not influence peak day, but significantly influenced peak production and 300-day lactation in favour of cows freshening in the major rainy season. Lactation yield was best estimated by Wood model which also gave the highest average R2 values as well as the closest estimate of day of peak production. However, Wood model overestimated peak yields and required the highest number of iterations for convergence. The Jenkins equation imposed a lactation curve that was mostly inconsistent with the data. Except for Jenkins, all models estimated mid to late lactation very well, but differed significantly in their abilities to estimate initial lactation. The relative rankings of the six models by various indexes ranked Singh and Wood models favourably with Nelder as intermediate while the models of Cobby, Papajcsik and Jenkins were ranked poorly.

Original scientific paper. Received 19 May 97; revised 25 Jan 99.

A SURVEY ON PROCESSING AND MARKETING CHARACTERISTICS OF PERI-URBAN AGROPASTORAL DAIRYING IN GHANA

S. A. OKANTAH, F. Y. OBESE, E. O. K. ODDOYE, P. GYAWU & Y. ASANTE

(S. A. O., F. Y. O. & E. O. K. O.: Animal Research Institute, Council for Scientific and Industrial Research, P. O. Box 20, Achimota, Ghana; P. G.: Department of Animal Science, KNUST, Kumasi, Ghana; Y. A.: Department of Economics, University of Ghana, Legon, Ghana)

A survey was conducted in five districts on the Accra plains to characterize the peri-urban dairy system. Results from the survey indicated that sale of milk (fresh or processed) by farmers as well as the amount marketed varied according to districts. A high percentage of farmers in Ga Rural (82.4 per cent), Tema (85.7 per cent), and Ewutu-Effutu-Senya (91 percent) districts which are close to marketing centres mainly sold fresh milk, while farmers in the North Tongu and Dangbe West districts farther away from marketing centres mainly sold processed milk, 76.2 and 66.7 per cent, respectively. Consumption of processed milk by farmers in the various districts was significantly (P<0.05) different, but not the consumption of fresh. milk. Consumption of processed milk by farmers in the Dangbe West and the North Tongu districts was high, over 70 per cent, while in the remaining districts the percentages were lower, 57.1 per cent for Tema, 37.5 percent for Awutu-Effutu-Senya, and 23 per cent for Ga Rural. There was no significant association between fresh or processed milk consumed at home and the ethnic group of household head.

Original scientific paper. Received 14 Oct 96; revised 10 Mar 99.

FORAGE YIELD AND SOIL IMPROVEMENT POTENTIAL OF SOME ANNUAL AND SHORT-TERM PERENNIAL LEGUMES AT TWO SITES IN GHANA

Animal Research Institute, Council for Scientific and Industrial Research, P.O. Box 20, Achimota, Ghana

Six annual and semi-perennial legumes were evaluated for forage production and their effect on soil properties at two sites, Pokoase (transition zone) and Nyankpala (Guinea savanna zone). The common legumes evaluated at the two sites were Lablab purpureus, Desmodium distortum, Crotalaria ochroleuca, and Macroptilium lathyroides, whilst Clitoria ternatea was additionally evaluated at Nyankpala and Mucuna pruriens was additionally evaluated at Pokoase. Herbage yields and herbage chemical composition were determined at the two sites. Soils under the different legumes at Pokoase were also analysed for nitrogen, extractable phosphorus, exchangeable potassium, and organic carbon contents. The large-leaved climbing and decumbent species L. purpureus and M. pruriens as well as the erect M. lathyroides showed very good attributes in forage production and soil improvement properties. Herbage yields in the three species at the Pokoase siteexceeded 6 t/ha and produced high crude protein contents in the range 14.71 to 17.38 per cent. The soils under L. purpureus and M. pruriens showed high N contents (> 0.5 per cent) whilst M. lathyroides improved soil organic carbon best. Macroptilium lathyroides also showed the highest contents of available P and exchangeable K in soil under it compared to the other legumes.

Original scientific paper. Received 17 Jun 97; revised 4 Feb 99.

A SURVEY ON LIVESTOCK AND MILK PRODUCTION CHARACTERISTICS OF PERI-URBAN AGROPASTORAL DAIRYING IN GHANA

S. A. OKANTAH, F. Y. OBESE, E. O. K. ODDOYE, P. GYAWU & Y. ASANTE

(S. A. O., F. Y. O. & E. O. K. O. : Animal Research

Institute, Council for Scientific and Industrial Research, P. O. Box 20, Achimota, Ghana; P. G.: Department of Animal Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Y. A.: Department of Economics, University of Ghana, Legon, Ghana)

A survey was conducted in five districts on the Accra plains to characterize the peri-urban dairy production system. Results from the survey indicated that farmers were keeping cattle, sheep, goats, and poultry (Guinea fowl, turkey, chicken, and duck), cattle being the only species milked. The mean flock size was 73.6 TLU with a coefficient of variation of 103 per cent. The average cattle herd size was 133. Farmers made limited use of agro-industrial by-products. Cultivation of pastures, improved fodder, and multipurpose trees was non-existent, and neither was any system of cut and carry practised. The use of concentrate and protein supplementation was also negligible. The mean length of the dry season was 5.2 1 0.7 months. Offtake was low at 8.9 per cent per annum. Replacement and calving rates were 0.7 and 0.67, respectively. The mean age at first calving and calving interval were 36 and 14.4 months, respectively. The mean lactation length was 8.5 months. There were no crossbreds of the type 'exotic W local'. The Sanga was the predominant breed of cattle and constituted over 76 per cent of cattle kept on the Accra plains. Feeding of calves was by suckling residual milk from dams after partial milking. Calves were allowed to suckle until the cow was nearly dry, leading to a long mean calf weaning age of 8.4 months. Cows were milked once daily usually in the mornings. The mean daily partial milk yield per cow was 1.55 1 0.22 l. Mean partial annual milk yield per farm was 10,040 1 2952 l. It was concluded that the system required substantial transfer of improved technologies to increase milk production.

Original scientific paper. Received 14 Oct 96; revised 3 Feb 99.

INDIGENOUS KNOWLEDGE ON 'SIELLA' AND ITS ROLE IN THE FARMING SYSTEMS OF NORTHERN GHANA

N. KARBO, J. BRUCE, A. LANGYINTUO, S. DITTOH & J. YIDANA

(N. K. & J. B.: Animal Research Institute, Council for Scientific and Industrial Research, P. O. Box 52, Nyankpala - Tamale, Ghana; A. L.: Savannah Agricultural Research Institute, Council for Scientific and Industrial Research, P. O. Box 52, Nyankpala - Tamale, Ghana; S. D. & J. Y.: University of Development Studies, Nyankpala - Tamale, Ghana)

An informal survey covering 32 villages in the Northern, Upper East, and Upper West Regions and involving over 250 men, women, and children was conducted to ascertain the indigenous knowledge on 'siella', a soil type licked by domestic animals and wild life. Samples of the soil were collected in several locations and analyzed for available macro- and micro-mineral content. The soil was found to be alkaline. Sodium and potassium content was 10-15 times higher than that in ordinary soils of the zone. Variation in mineral content was high across locations ranging from 0.0 to 6.83 mg/kg for phosphorus, and 64.97 to 7,485.5 mg/kg for calcium. The soils were found to be totally devoid of phosphorus in locations within the Upper West, and micro-mineral concentration was low in all locations. The soil is well known in the northern part of Ghana and is believed to play a vital role in the health and productivity of animals. Cows on 'siella' give birth to heavier calves and milk better. The soil has curative properties and stops diarrhoea. It is also believed to give good health and strength to aged humans.

Original scientific paper. Received 19 Dec 97; revised 30 Mar 99.

EVALUATION OF BARE-ROOT METHODS FOR TRANSPLANTING COCOA SEEDLINGS

F. M. AMOAH, K. OPOKU-AMEYAW, K. OSEI-BONSU & F. K. OPPONG

Cocoa Research Institute of Ghana, P.O. Box 8, New Tafo, Ghana

Studies were carried out to evaluate various bare-root methods for transplanting cocoa seedlings. The objective was to find alternative methods to the ball-of-earth (polyethylene bag) method of transplanting cocoa seedling which is known to give very good establishment but is very expensive. The experiment involved three factors: (i) length of time after lifting seedlings from the soil (1, 2 or 3 days), (ii) with or without the application of clay-slurry to the roots, and (iii) eight different methods for packaging the uprooted seedlings in a 3 W 2 W 8 factorial experiment with the ball-of-earth method as a control. Seedling mortality was determined at 3-month intervals up to the 12th month whilst growth was measured at 12 months after transplanting. The experiment was repeated each year for 4 years. At the end of each year, less promising treatments assessed by percentage survival were eliminated. The following five bare-root treatments with a success range of 63 - 78 per cent were selected besides the ball-of-earth treatment which consistently had the highest mean survival of 92.5 per cent over the 4-year period: (i) roots wrapped in moist sack, leaves enveloped in clear polythene bag and seedlings planted on the same day; (ii) roots and leaves pruned, roots wrapped in moist sack, and seedlings planted on the same day; (iii) roots wrapped in moist sack and seedlings left in the shade and planted on the 2nd day; (iv) roots wrapped in moist sack, leaves enveloped in clear polyethylene bag, and seedlings left in the shade and planted on the 3^rd day; and (v) roots and leaves pruned, roots wrapped in moist sack, and seedlings left in the shade and planted on the 3rd day. Verification of these treatments with farmer participation will help to determine their acceptance or whether to modify the different packages.

Original scientific paper. Received 30 Apr 98; revised 30 Mar 99.

THE EFFECT OF TIME OF PLANTING AT STAKE ON COCOA SEEDLING SURVIVAL

  F. K. OPPONG, K. OPOKU-AMEYAW, K. OSEI-BONSU, F. M. AMOAH, K. M. BREW & K. ACHEAMPONG

Cocoa Research Institute of Ghana (CRIG), P. O. Box 8, New Tafo, Ghana

Studies were conducted at the Cocoa Research Institute of Ghana, Tafo and its sub-station at Bunso, from 1994 to 1997 to re-appraise the success of cocoa etablishment from seeds sown at stake at specified times of the year before the onset of the dry season. The treatments consisted of four times within the year when seeds were sown at stake, namely April, June, and September. Seedlings raised in polyethylene bags were transplanted to serve as the control. The experiments were repeated every year for 3 years. During the 1995/96 season, the experiments were set up either under shade established one year earlier, or established in the same year as the cocoa seeds were sown at stake. Emergence of germinated cocoa seeds from the soil was generally high and independent of the time of sowing. However, survival of cocoa seedlings from seeds sown in April, June, and July was higher than when seeds were sown in September. Establishing shade one year ahead of sowing seeds at stake improved the survival rate of the cocoa seedlings. Seedling losses due to mammalian or accidental damage during weeding was minimal. The results show that inspite of the unreliable rainfall pattern in Ghana, planting at stake is still feasible in cocoa-growing areas of Ghana with similar climatic conditions as the locations used for this experiment. However, for high percentage survival of seedlings, adequate shade must be established at least one year in advance to protect the young seedlings during the dry season.

Original scientific paper. Received 20 Nov 97; revised 21 Apr 99.

EFFECT OF PROPICONAZOLE (TILT) AND PRUNING ON SEVERITY OF BLACK SIGATOKA DISEASE AND YIELD OF PLANTAIN

  C. K. BODAKPUI, K. A. ODURO & K. AFREH-NUAMAH

(C. K. B. & K. A. O.: Department of Crop Science, University of Ghana, Legon, Ghana; K. A.-N.: University of Ghana Agricultural Research Station, Kade, Ghana)

The use of Propiconazole (Tilt) and pruning to control Black Sigatoka disease in plantain was tested from March 1995 to April 1997 at Kade, Ghana. There were four treatments: Tilt application alone, Pruning alone, Tilt + Pruning, and Control in a randomised complete block design. Expressed as percentage total leaf area attacked, disease severity was 16 (13.1-19) for the control treatment while it was 4.6 (2.9-6.2), 5.1 (3.7-6.4), and 3.8 (2.5-5.0) for Tilt, Pruning, and Tilt plus Pruning, respectively. The control was significantly different from the other three treatments which were, however, not different from each other at P = 0.05. At the 44th week after transplanting, the youngest leaf with symptom (YLWS) was on the average the 6th leaf for Tilt while it was 4th, 5th, and 3rd for Pruning, Tilt + Pruning, and Control, respectively. It meant that the plants treated with Tilt appeared healthier than the control. The total number of bunches harvested after 66 weeks were 47, 54, 50, and 52 with bunch weights of 249.1, 453.0, 392.2, and 405.0 kg for Control, Tilt, Pruning, and Tilt + Pruning, respectively. The Control was significantly different from the other treatments which were, however, not different from each other at P = 0.05. Correlation analysis indicated a negative but significant association (r = -0.96) between severity of disease and yield. The results show that pruning and burning of diseased leaves can be used as an alternative to fungicide application to control Black Sigatoka on plantain.

Original scientific paper. Received 9 Oct 97; revised 27 Apr 99.

PERIPARTURIENT BEHAVIOUR OF THE WEST AFRICAN DWARF GOAT

E. K. AWOTWI, S. AGBODZA, K. OPPONG-ANANE & F. K. FIANU

(E. K. A., S. A. & F. K. F.: Department of Animal Science, University of Ghana, Legon, Ghana; K.O.-A.: Department of Animal Production, Ministry of Food and Agriculture, Kintampo, Ghana)

  ABSTRACT

The periparturient behaviour of 63 pregnant does and their kids was studied. The behavioural characteristics investigated were incidence of prepartum isolation and restlessness, time taken for new born kids to stand and to start sucking. Apart from these behavioural parameters, the time of parturition, duration of labour, and duration of grooming were also investigated. The results were analyzed for the effects of parity of dam and type of birth on these characteristics. All the does showed prepartum restlessness and about 90 per cent of them actively isolated themselves. Most parturitions (82.per cent) occurred during daytime. Labour on the average lasted for about 10 min. On the average, it took kids about 13 min after birth to stand up and an additional 2 min to start sucking. Parity of the damand the type of birth did not significantly affect any of the characteristics studied.

Original scientific paper. Received 17 Sep 98; revised 19 May 99.

DISTRIBUTION OF FREE AND TOTAL ALUMINIUM IN SOME COCOA-GROWING SOILS OF GHANA

  K. OFORI-FRIMPONG, G. K. ASAMOAH & M. R. APPIAH

(K. O.-F. & M. R. A.: Cocoa Research Institute of Ghana, P. O. Box 8, Tafo-Akim, Ghana; G. K. A. : School of Agriculture, University of Cape Coast, Ghana)

The Western Region of Ghana is currently carrying the bulk of Ghana's cocoa, and so it is important to investigate the amounts and distribution of total and free Al oxides in some cocoa-growing soils from the region. Six soil series belonging to one major compound association of soils occurring in a toposequence, the Yakasi-Elubo/Oda Compound Association, was used. Soil profile pits of 1 m2 and to different depths were prepared for each soil series, and soil sampled from different genetic horizons of the profiles and analysed for total and free Al oxide contents and other soil properties. The amount of total and free Al oxide in the profiles increased with depth. The mean values for total and free Al oxides for the surface soils (A-horizons) were 505.7 and 194.3 mmoles Al2O3/kg soil, respectively, and those for the B-horizons were 648.9 and 289.5 mmoles Al2O3/kg soil, respectively. The pattern of distribution of total and free Al oxides were similar and closely related to the distribution of clay. Except in the lowland soil where pH was higher in the A-horizon, pH generally decreased with depth where there was maximum accumulation of Al oxides. The upland soils contained higher amounts of Al than the lowland soils of the catena. The higher amounts of Al in the soils may limit cocoa cultivation.

Original scientific paper. Received 29 Apr 98; revised 24 May 99.

EFFECT OF VARIETY, PLANTING DENSITY, AND FERTILIZER ON THE YIELD AND THE RELATIVE COMPETITIVE ABILITY OF INTERCROPPED MAIZE AND CASSAVA

( J. N. A.-A.: Crops Research Institute, CSIR, P. O. Box 3785, Kumasi, Ghana; D.M.O.: Department of Crop Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana)

Different stands of two each of contrasting maize (Zea mays L.) and cassava (Manihot esculenta Cranz) varieties were established as intercrops in experiments at Fumesua and Kwadaso near Kumasi (60 43' N, 10 36' W), from 1986 to 1989. The objective was to identify the factors that play crucial role as determinants of yield of maize and cassava grown as intercrops. Genotype, planting density, and fertilizer application proved important in the performance of both intercrops. Each intercrop had a depressive effect on the other, maize being about two and half times more competitive than cassava. Interspecific superiority was, however, not constant for variety, planting density, and fertilizer application. Suitable combinations of genotypes of maize and cassava are suggested based on land equivalent ratio (LER) and competitive ratio (CR) values and suitable planting densities of the intercrops recommended.

Original scientific paper. Received 18 Aug 97; revised 30 May 99.

PRELIMINARY STUDIES IN RICE-FISH CULTURE IN A RAINFED LOWLAND ECOLOGY IN GHANA

Crops Research Institute, Council for Scientific and Industrial Research, P.O. Box 3785, Kumasi, Ghana

Mixed farms of rice and fish are yet to receive attention in Ghana, despite lowland rice being grown under inundation in most areas nationwide. In a preliminary study, Nile tilapia (Oreochromis niloticus) was successfully cultured in a rainfed lowland rice farm, although no additional care was provided for fishes. The highest yielding rice variety produced 4.8 t/ha (480 kg/1000 m2) which was commensurate with previous yields at the same location. Parent fish yield of 121 g/fish for a period of 139 days was also commensurate with yield from fish ponds. This excluded yield of fish progeny. With proper management, fish yields would greatly complement that of rice.

Provisional communication. Received 18 Feb 97; revised 24 Jan 99.