Comparison of methods of field planting on cocoa seedling survival and early growth in a marginal cocoa-growing area of Ghana

Cocoa seeds were planted at stake at different times to determine the best time for optimum establishment at the Cocoa Research Institute of Ghana substation at Afosu, considered as a marginal cocoa-growing area owing to its prolonged dry season. The treatments evaluated were planting hybrid cocoa seeds at stake in either April, May, June, July or September; and polythene bag or bareroot transplanting of 5-month-old hybrid cocoa seedlings in May or June, respectively. The trial was laid out as randomized complete block with seven treatments and five replicates. Each plot measured 24 m × 18 m and contained 48 plants. The results recorded over 3 years (1999-2001) showed significantly higher (P< 0.01) seedling survival rates in the polythene bag-transplanted seedlings than in seedlings from seeds sown at stake. There were no significant differences between the survival rates of seedlings from seeds sown at stake from April to July. The average percentage seedling survival after the first dry season for seeds sown at stake from April to July over the 3-year period (1999-2001) was 60 per cent compared to 57 per cent for bare-root and 81 per cent for polythene bag-transplanted seedlings. There were no significant differences between the girth increments of the seedlings, implying that once established, there may be no differences in the rates of growth of transplanted seedlings and those sown at stake. It is concluded that bare-root transplanting of cocoa seedlings and planting cocoa seeds at stake are feasible options in marginal cocoa-growing areas if such activity is properly timed to coincide with the rains. However, the polythene bag method of transplanting cocoa seedlings remains the best option for field planting of cocoa in marginal cocoagrowing areas of Ghana.Les féves de cacao étaient semées et soutenues à l'aide d'un tuteur aux moments différents à Afosu, une sous-station de l'Institut de Recherche en Cacao du Ghana qui est considérée une zone marginale de la culture de cacao en raison de la longue durée de sa saison sèche pour déterminer le meilleur temps pour l'enracinement optimum. Les traitements évalués étaient; la plantation de fèves de cacao hybride soutenues à l'aide d'un tuteur soit en avril, mai, juin, juillet soit en septembre et le repiquage à sachet en plastique ou à racine-nue de semis de cacao hybride âgé de 5 mois respectivement en mai ou en juin. L'essai était dessiné comme un bloc complet choisi au hasard avec sept traitements et cinq replicatifs. Chaque lot avait une mesure de 24 m × 18 m et contenait quarante-huit plantes. Les résultats obtenus sur une période de trois ans (1999-2001) montraient un taux de survie de semis considérablement plus élevé (P £ 0.01) dans les semis repiqués à sachet en plastique que dans les semis de fèves semées et soutenues à l'aide d'un tuteur d'avril à juillet. Le pourcentage moyen de la survie de semis après la première saison sèche pour les fèves semèes et soutenues à l'aide d'un tuteur d'avril à juillet sur la pèriode de 3 ans (1999, 2000, 2001) était 60% comparé à 57% et 81% respectivement pour les semis repiqués à racine-nue et à sachet en plastique. Il n'y avaient pas des différences considérables entre les augmentations de circonférence des semis, signifiant qu'une fois établi, il n'y aura pas, peut-être, de différences entre les taux de croissance de semis repiqués et les semis semés et soutenus à l'aide d'un tuteur. La conclusion est tirée que le repiquage de semis de cacao à racine-nue et la plantation de fèves de cacao et soutenue à l'aide d'un tuteur sont des options faisables dans les zones marginales de la culture de cacao si cette activité est bien exécutée avec un bon timing pour coïncider avec la saison des pluies. Toutefois, le repiquage de semis de cacao par la méthode de sachet en plastique reste la meilleure option pour la plantation de cacao sur le terrain dans les zones marginales de la culture de cacao au Ghana. Ghana Journal of Agricultural Science Vol. 40 (2) 2008: pp. 199-20

Effect of polybag size and foliar application of urea on cocoa seedling growth

The effects of different polybag sizes and foliar application of urea on the growth of cocoa seedlings in the nursery were studied at the Cocoa Research Institute of Ghana substation at Afosu in the Eastern Region of Ghana between June 2004 and May 2005. Hybrid cocoa seeds were sown in polybags measuring 17.5 cm × 25 cm, 12.5 cm × 25 cm, 12.5 cm × 20 cm, and 12.5 cm × 15 cm filled with top soil. From the four-leaf stage, half of the seedlings in the different polybags received fortnightly foliar application of 2 per cent urea solution, while the other half did not receive foliar application of urea. Each treatment consisted of 50 cocoa seedlings. There were significant differences (P< 0.01) in girth and height between the cocoa seedlings in the different sizes of polybags at 3, 4 and 5 months after sowing. Leaf number and tap root length were also significantly influenced by polybag size at 4 and 5 months after sowing. Generally, seedlings raised in 17.5 cm × 25 cm polybags produced bigger and taller seedlings, more leaves, longer tap root length, and had significantly higher (P< 0.01) total dry matter per seedling than those raised in 12.5 cm × 15 cm polybags. Foliar application of 2 per cent urea improved the growth of cocoa seedlings in all the different polybag sizes. The results suggest that smaller polybag sizes (12.5 cm × 25 cm, 12.5 cm × 20 cm, and 12.5 cm × 15 cm) could be used to nurse cocoa seedlings and transplanted early at 3 months after sowing instead of the recommended practice of nursing in 17.5 cm × 25 cm polybags and transplanting at 5 to 6 months after sowing. More cocoa seedlings raised in smaller polybags could, therefore, be transported per trip for field planting at reduced cost to the farmer.Les effets de différentes dimensions de sac en plastique et d\'application foliaire d\'urée sur la croissance de semis de Cacao dans les pépinières étaient étudiés à Afosu, une sous-station de l\'Institut de Recherche en Cacao du Ghana dans la région de l\'Est du Ghana entre juin 2004 et mai 2005. Les fèves de cacao hybride étaient semées dans les sacs en plastique qui mesuraient 17.5 cm × 25 cm, 12.5 cm × 25 cm, 12.5 cm × 20 cm, et 12.5 cm × 15 cm remplis de couche arable. De la phase de 4-feuille, une demie de semis dans les différents sacs en plastique recevaient tous les quinze jours l\'application foliaire de 2% de solution d\'urée alors que l\'autre demie ne recevaient pas d\'application foliaire d\'urée. Chaque traitement consistait en cinquant de semis de cacao. Il y avaient des différences considérables (P £ 0.01) en circonférence et en taille entre les semis de cacao dans les différentes dimensions de sacs en plastique à 3, 4 et 5 mois après la semaille. Nombre de feuille et la longueur de racine pivotante étaient aussi considérablement influencés par la dimension du sac en plastique à 4 et 5 mois après la semaille. En général les semis élevés dans les sacs en plastique de 17.5 cm × 25 cm produisaient des semis plus gros et plus grands, plus de feuilles, de longueur de racine pivotante plus longue et avaient une totalité de matière sèche par semis considérablement plus élevées (P £ 0.01) que ceux élevés dans les sacs en plastique de 12.5 cm × 15 cm. L\'application foliaire de 2% d\'urée améliorait la croissance de semis de cac ao dans toutes les différentes dimensions de sacs en plastique. Les résultats suggèrent que les sacs en plastique de dimensions plus petites (12.5 cm × 25 cm, 12.5 cm × 20 cm, et 12.5 cm × 15 cm) pourraient être utilisés pour soigner les semis de cacao et repiqués précoces à 3 mois après la semaille plutôt que la pratique actuelle recommandée de soigner dans les sacs en plastique de 17.5 cm × 25 cm et repiquer à 5-6 mois après la semaille. Plus de semis de cacao élevés dans les plus petites sacs en plastique pourraient donc être transporter par trajet pour le repiquage sur le terrain à coût réduit à l\'agriculteur. Ghana Journal of Agricultural Science Vol. 40 (2) 2008: pp. 207-21

Effect of weed control methods on some soil properties of a newly planted cocoa farm

Weed control constitutes a high percentage of the total field maintenance cost of newly planted cocoa. Soil samples were collected from an experiment that was designed to evaluate some weed control methods during cocoa establishment. The objective of the experiment was to assess the effect of the weed control methods on microbial biomass and extractable N and P contents of the cocoa-growing soil during cocoa establishment. The weed control treatments were clean weeding, two times per year; clean weeding, three times per year; clean weeding, four times per year (recommended practice); high slashing, four times per year; clean weeding (1 m wide), three times per year plus Mucuna pruriens cover crop; clean weeding, three times per year plus Flemingia congesta mulch; Gramoxone 1.5 l ha-1, four times per year; and Roundup 1.5 l ha-1, three times per year arranged in a randomized complete block design. Microbial biomass N content ranged from 10.8 to 42.5 mg N kg–1 soil. Microbial biomass N was significantly higher (

Three-dimensional jamming and flows of soft glassy materials

Various disordered dense systems such as foams, gels, emulsions and colloidal suspensions, exhibit a jamming transition from a liquid state (they flow) to a solid state below a yield stress. Their structure, thoroughly studied with powerful means of 3D characterization, exhibits some analogy with that of glasses which led to call them soft glassy materials. However, despite its importance for geophysical and industrial applications, their rheological behavior, and its microscopic origin, is still poorly known, in particular because of its nonlinear nature. Here we show from two original experiments that a simple 3D continuum description of the behaviour of soft glassy materials can be built. We first show that when a flow is imposed in some direction there is no yield resistance to a secondary flow: these systems are always unjammed simultaneously in all directions of space. The 3D jamming criterion appears to be the plasticity criterion encountered in most solids. We also find that they behave as simple liquids in the direction orthogonal to that of the main flow; their viscosity is inversely proportional to the main flow shear rate, as a signature of shear-induced structural relaxation, in close similarity with the structural relaxations driven by temperature and density in other glassy systems.Comment: http://www.nature.com/nmat/journal/v9/n2/abs/nmat2615.htm

The efficacy of low volume application of roundup (glyphostate) on weed suppression in some plantation crops in Ghana

No Abstract. Journal of the Ghana Association Vol. 2 (3) 1999: pp

The effect of shade and spacing on the growth and yield of improved robusta coffee (coffea canephora) in Ghana

No Abstract. Journal of the Ghana Science Association Vol. 2 (2) 1999: pp.109-11

The establishment and early yield of cocoa intercropped with food crops in Ghana

A cocoa-food crop intercropping trial was set up in 1988 at the Cocoa Research Institute of Ghana, Tafo. The effects of plantain, cassava, and maize as intercrops with cocoa only and in their various combinations on the establishment, growth of the cocoa, and the profitability of the food crops were studied in a randomized block experiment with five replicates. Mixed hybrid cocoa seedlings were planted at 3 m W 3 m and Glyricidia maculata provided permanent shade in all plots. Three years after planting, the sole cocoa with Glyricidia maculata was inferior in growth to the cocoa interplanted with food crops. Cocoa in treatments which included maize showed superior growth and better precocity. Yield of each food intercrop with cocoa only was higher than when combined with other food crops. Sole cocoa gave less revenue equivalent to the operational costs during the establishment phase. The other food crop combinations with cocoa gave net revenue gain in the first 2 years after planting. The economic evaluation of the food crop combinations indicated that treatments which included cassava were the most profitable. Ghana Jnl agric. Sci. Vol.31(1) 1998: 45-5

Potential use of Flemingia macrophylla as mulch for managing weeds in young cocoa in Ghana

The prospects for using Flemingia macrophylla and Mucuna pruriens in combination with manual weeding during the establishment of young cocoa was investigated. The following treatments were compared: Clean weeding three times/annum + F. macrophylla planted in the inter-rows of cocoa and biomass used as mulch; clean weeding of cocoa lines (1 m wide) three times/annum + Mucuna cover crop; and clean weeding four times/annum. The use of Flemingia mulch in combination with manual clean weeding three times/annum resulted in large girths and taller cocoa plants than in plots where Mucuna was used as cover crop. The girth and height of the young cocoa seedlings in the Flemingia plots were, however, not significantly different from those in plots where weeds were manually clean-weeded four times/annum. Seedling mortality was lower in the plots with F. macrophylla (7 per cent) than in plots which had Mucuna cover crop (13 per cent). Flowering and jorquette formation occurred earlier in the Flemingia plots than in the other treatments. The potential biological benefits of using F. macrophylla in an integrated weed management programme in young cocoa and the application cost are discussed. Ghana Jnl agric. Sci. Vol.31(1) 1998: 67-7

Periparturient behaviour of the West African Dwarf goat

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. Ghana Jnl.agric. Sci Vol.32(1), 1999: 95-10

Evaluation of bare-root methods for transplanting cocoa seedlings

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 3rd 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. Ghana Jnl.agric. Sci Vol.32(1), 1999: 69-7