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The medium from which seedlings are transplanted influences seedling growth and survival on the field. The objective of the experiment was to compare how growing media affect the growth and survival of cocoa seedlings under field conditions. The seedlings were raised in both soil and soilless media and were transplanted on the field in June, when they were six months old. The experimental design was a randomized complete block design with three different growing media: 1. top soil, 2. sawdust + poultry manure + rice husk biochar (70%:25%:5%), and 3. sawdust + poultry manure + municipal solid waste compost (50%:35%:15%). The cocoa seedlings were transplanted at a spacing of 3 m × 3 m at 12 plants per plot and each plot size measured 45 m × 45 m. Data were collected on plant height, leaf number, stem girth, leaf chlorophyll content, percentage of plants that shed their leaves, and percentage of survival. Results indicated that seedling survival at the onset and end of the dry season was significantly (P < 0.05) higher for seedlings transplanted from soilless media compared to those from the top soil treatment. Irrigation will be necessary to maintain high seedling survival when seedlings are transplanted from the top soil for a well-established plantation.

Copyright of African Crop Science Journal is the property of African Crop Science Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of African Crop Science Journal is the property of African Crop Science Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of African Crop Science Journal is the property of African Crop Science Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fungal mycotoxins are important contaminants of agricultural commodities that pose serious concerns to producers, consumers and exporters. Aflatoxin is a carcinogenic metabolite produced by the fungi Aspergillus flavus and A. parasiticus. These fungi and other mould species living in the soil contaminate several crops including maize. This study was undertaken with the following objectives: (i) to assess the presence of A. flavus and other moulds in Ghanaian soil; (ii) to determine the distribution and density of A. flavus under three agro‐ecologies noted for major maize production; and (iii) to assess the effect of percentage of carbon (C) and nitrogen (N) and soil pH on A. flavus population densities and diversity in the isolates found across the agro‐ecologies. The data showed seven moulds that were common across the agro‐ecologies. Significant differences (P < 0.05) were observed in the A. flavus density and distribution within and across these agro‐ecologies. Fumesua soils recorded the highest levels of A. flavus (1.185 × 103 cfu g−1) while Akomadan recorded the least (9.76 × 102 cfu g−1). Percentage available C, N and soil pH did not significantly influence A. flavus density. The A. flavus isolates identified in this study varied in genetic sequence within the aflatoxin gene cluster, but these differences were not distinguishable by origin. [ABSTRACT FROM AUTHOR]

Sweetpotato (Ipomoea batatas Lam) is a staple food globally, but it has remained underutilised resource in Ghana due to lack of consumer preferred cultivars. There is the need to develop staple-type sweetpotato cultivars which are preferred by consumers to increase sweetpotato use as a food security, health and industrial crop commodity in Ghana. This study was conducted to evaluate the breeding potential of sweetpotato germplasm for the development of farmer and consumer preferred varieties in Ghana. A total of 115 sweetpotato accessions were evaluated for genetic variability. Significant (P<0.01) differences were observed indicating genetic diversity. G x E was significant for all traits, except dry matter, sucrose, total sugar, and starch content. Phenotypic Coefficient of Variation (PCV) ranged from 4.78% for starch content to 63.40% for marketable root weight. Genotypic Coefficient of Variation (GCV) ranged from 4.07% for starch content to 55.35% for marketable root weight. Broad-sense heritability estimates varied from medium (0.61) to high (0.90) for all the traits, except for sucrose content. Predicted improvement over the means is 10 up to 105% for all traits, except starch (7.13%). This indicates sufficient useful genetic variation prospect which could be used to provide substantial improvement through selection of superior genotypes. The strong positive genetic association between dry matter and starch (r = 0.71), and strong negative relationship for sugar and dry matter (r = -0.77) and starch content (r = -0.99) indicates the possibility of developing non-sweet high dry matter sweetpotatoes, which are the preferred varieties in Ghana. [ABSTRACT FROM AUTHOR]

Analyses of the results of calibration of survey meters carried out at the Secondary Standards Dosimetry Laboratory (SSDL) in Ghana over a period of 4 y (2008–2011) are reported. The calibration factors (CFs) of the set of survey meters indicated that ∼91.04 % were within the acceptable limit of ±20.0 %. A higher percentage of the survey meters indicated CFs in the range of 0.95–1.15 except a few of them which indicated values <0.55. Some of the survey meters also recorded CFs >1.15. The degree of uncertainty in the measurements ranged from 0.03 to 17 % with the majority of them ranging from 0.03 to 6.0 % and a few of them >6.0 %. The results show that most of the survey meters calibrated were within the requirements of the regulations and may provide data for future development of calibration techniques in the country. [ABSTRACT FROM AUTHOR]

Soil population densities of Helicotylenchus multicinctus (Cobb) Golden were assessed under Flemingia macrophylla [(Willd.) Merrill] and Pueraria phaseoloides (Roxb.) Benth, and natural bush fallows over 24 months in three villages in southern Cameroon. Also assessed was the effect of H. multicinctus on yield of plantain. Trials were set up in four to five year-old Chromolaena odorata (L.) R. M. King & H. Rob. dominated natural bush fallow. Initial H. multicinctus population density at Ngoumou (512 100 cm-3 soil) was (p < 0.05) higher than at Mfou (241 100 cm-3 soil) and Nkometou (70 100 cm-3 soil). H. multicinctus population was correlated with (i) total annual rainfall (r = 0.79; p = 0.01) and (ii) clay content (r = 0.95; p < 0.001). At 12 months after planting (MAP), P. phaseoloides and F. macrophylla supported (p < 0.01) lower population densities of H. multicinctus (88 and 152 100 cm-3 soil, respectively) compared with the natural regrowth (287 100 cm-3 soil). Comparing the initial population with that at 12 MAP for each of the three fallow systems, both P. phaseoloides and F. macrophylla reduced density of H. multicinctus (p < 0.05). However, when the initial population density was compared with that at 24 MAP only under P. phaseoloides was the reduction maintained. Contrarily, population density under F. macrophylla was comparable between the initial and 24 MAP. This is the first report of the nematode reducing effect of P. phaseoloides. Plantain flowering and subsequent harvesting was earliest under P. phaseoloides, different from that under F. macrophylla (p < 0.05). Plant bunch weight was positively correlated with the length of the fruit filling period (r = 0.67) which in turn was positively correlated with the non damaged root index (NDRI) (r = 0.58). Plantain under P. phaseoloides had the highest NDRI and consequently recorded the greatest yield (p < 0.05). There was no difference in plantain yield between the natural regrowth and F. macrophylla. Pueraria phaseoloides could be used as one component for the biological control of H. multicinctus. [ABSTRACT FROM AUTHOR]

Abstract: Growth and fruit yield of scarlet eggplant were examined under intercropping with an erect and semi-spreading early maturing cultivars of cowpea in an additive intercropping model with scarlet eggplant as the main crop, in two dry seasons, under irrigation. Cowpea was planted simultaneously with scarlet eggplant, 2 and 4 weeks ahead of scarlet eggplant. Land equivalent ratio (LER) of the intercrops ranged from 1.38 to 1.94, indicating that the intercrops were more productive than the pure crops. Reduction in fruit yield of the main crop, when intercropped with the semi-spreading cowpea cultivar was significantly (p &#60;0.01) greater than with the erect cowpea cultivar. Simultaneous planting of cowpea and scarlet eggplant produced 90–99% the fruit yield of sole scarlet eggplant, while planting cowpea 2 and 4 weeks ahead produced 65–80% and 58–60% of sole crop yield, respectively. Competition between component crops was however most favourable for both cultivars of cowpea when planted 2 weeks ahead of scarlet eggplant. Planting cowpea 2 weeks ahead of the main crop also produced the highest LER most likely due to more efficient utilization of sunlight, water and soil nutrients. Simultaneously planting cowpea and transplanting scarlet eggplant, is recommended for such additive intercropping system, aimed at full yield of scarlet eggplant with additional cowpea for food, income or fodder. [Copyright &y& Elsevier]

Aflatoxins are carcinogenic secondary metabolites produced mainly by two species of Aspergillus fungi, (A. flavus and A. parasiticus). The toxin contaminates maize grains during the developmental stage as well as in storage. Grains with contamination levels above 20 ng/g are usually destroyed in the USA while the European Union and Japan allow 2–4 ng/g and nil respectively. Ghana lacks regulatory infrastructure for monitoring fungal contamination and detection of aflatoxin in grains prior to market. Therefore, this study assessed the extent of A. flavus contamination together with other mould on maize and total aflatoxin accumulation among stored maize grains across 34 towns and villages under three agro-ecologies in Ghana during the minor crop season of 2015–2016. A. flavus, was identified as the most predominant contaminant and recorded average percentage contamination of 56.7%, 30.6%, 53.5% and 45.6% on grains sampled across four communities (Fumesua, Wenchi, Ejura and Akomadan), respectively. Total aflatoxins recorded in the samples per community were in the range of below limit of detection (LOD) to 692 ng/g, 23 ng/g, 945 ng/g and 112 ng/g for Fumesua, Wenchi, Ejura and Akomadan, respectively. These dangerous upper limits demand urgent attention in the area of aflatoxin resistance breeding in maize to help address the aflatoxin menace in Ghana. • Aflatoxin contamination of maize grains is wide-spread in Ghana. • Wide adaptation of Aspergillus flavus across different agro-ecologies in Ghana. • Aspergillus flavus is the leading mould contaminant of stored maize across three agro-ecologies in Ghana. • Aflatoxin levels in stored grains are highly varied per district. • Low corroboration between Aspergillus flavus contamination and aflatoxin levels. [ABSTRACT FROM AUTHOR]