The sesame seed contains oil, protein, dietary fibre, and several minerals and it is also a store of lignans. Lignans are key selection factors for sesame quality due to their health, nutritive and market value. In Ghana sesame growers rely on wild or undocumented planting seeds which are of mixed colouration and its lignan content is ambiguous. The objective of this study was to segregate street sesame seeds into component colour fractions and subsequently evaluate the consistency of lignans in the seed fractions. Sesame seeds were collected from street vendors in northern Ghana and were segregated into seed fractions based on the pericarp colour. The viability of seed fractions stored at different temperatures (ambient, 5 °C, 0 °C) over time and lignan contents of single or bulk mixed seeds were verified. The collected seeds were of mixed colouration with approximately 4 % debris, 40 % white, 36 % cream, and 20 % dark coloured seeds by weight. The viability of the seeds was 67-85 % depending on pericarp colour. White seed fractions which had the highest proportion by weight had a significantly (p = 0.0275) higher viability (85 %) than the dark seeds which had the least viability (67 %). The seeds lost viability over time. However, seeds stored at 0 °C maintained a viability of 77 % at the fourth year. There were differences in the relative abundance of lignans for both bulk seeds and, single seeds with different pericarp colours. The most abundant occurring lignans in the seeds were sesamin, sesamolin and sesaminol and its downstream glucosides. The source of seed or pericarp colour was not predictive of seed viability or lignan composition. These findings provide baseline data on seed quality including an improved storability under cold environments. It also gives an insight into how mixed seeds of variable pericarp colours can have distinct characteristics. Although the mixed coloured seeds had no implications for varied quality including lignan content, the international market for sesame requires that seeds are of consistent colour.

Synthetic chemicals continue to play an important role in reducing storage losses attributable to insect pest activities. However, the adverse effects associated with some patented chemicals make synthetic pesticides less attractive and have given the drive to search for alternative methods of pest control. This study evaluated the effects of a traditional gin, akpeteshie crude extracts made of four timber species, neem (Azadirachta indica), mahogany (Khaya senegalensis), teak (Tectona grandis) and cedrela (Cedrela odorata) on the maize weevil Sitophilus zeamais on stored maize grains in the laboratory. Home-made extracts of the test tree plants at concentrations of 0.5, 1.0 and 2% were tested as grain protectants or as insect poisons. All tested extracts in their respective concentrations performed well in the reduction of live insects during maize storage as compared to a non-extract treatment. The mode of action of all the extracts was generally concentration and time-dependent. On average neem extract was the most effective followed by mahogany, teak, and cedrela in that order. Neem and mahogany extracts performed well in reducing grain damage at a concentration of 2% and at 0.5% concentration of cedrela extract respectively. All extracts reduced progeny emergence and acted both as a repellent or a toxicant. The extracts performed better as compared to the untreated control in the viability of maize seeds leading to germination, and subsequent seedling emergence. The relatively low weight loss of the stored grains treated with these crude extracts during the 90-day experimental period at a maximum concentration of 2% is predictive that they can be adopted as safe and alternative grain protectants against weevils in store. The unknown phytochemicals in these akpeteshie hardwood extracts may be responsible for the insecticidal properties against the weevils. For some concentrations of the extracts, germination was inconsistent which led to the suspicion of allelopathy.

The status of Bactrocera dorsalis as a destructive pest of fruits including mango continues to be a challenge among farmers at Ghana. Although chemical insecticides have been employed to manage its incidence and damage, there still exist gaps that need be addressed including concerns on toxic residues on fruits and the possibility of resistance evolvement by this pest to insecticides. The alternate management for the fruit fly should therefore be environmentally friendly and with minimal side effects. The objective was to compare the attractiveness of homemade lures of aqueous leaf extract of Pimenta racemosa and a commercial attractant containing methyl eugenol. The research involved the use of leaf extracts of Pimenta racemosa to trap Bactrocera dorsalis was conducted in five mango orchards in two agro-ecological zones in Ghana during the major mango fruiting season of 2017. Three experimental orchards were each sectioned into five blocks of 20 trees each. Four trees in each block formed the sampling trees making 20 sampling trees per orchard received the lures as treatments. The lures were dispensed in homemade traps made of PET containers. A total of 174,388 individual arthropods were captured of which 171,412 were identified as B. dorsalis and 2,976 identified as non-target arthropods. There was a significant difference between the performance of the commercial lure and the leaf extracts (P < 0.05) which was expected. The ability of the Pimenta extracts in the homemade traps to capture some fruit flies is an indication of its potential as a low-cost option to complement the more expensive commercial for small farm holdings.

The pest status of Cosmopolites sordidus has been related to farm sanitation, environmental conditions and local weevil biotypes. This study was to confirm the inherent fecundity of endemic weevils, soil moisture effect and planting material health status that may contribute to weevil behaviour. Adult banana weevils were confined to plantain rhizomes, which were then subjected to four soil moisture regimens for 65 days. In another experiment to measure potential fecundity, weevils collected from the farmer’s field were dissected to determine the internal egg follicles. Planting material with different initial weevil egg infestations on the pseudostem were confined below insect screening net in growing pots. Larva damage and stage populations were determined after 22 weeks. The results showed that weevils confined to plants under moisture stress had higher corm damage than irrigated and vigorously growing plants. A lower number of weevils were associated with plants under moisture stress than vigorously growing plants. The maximum number of mature egg follicles present in the ovaries of female weevils was 17. In general, the mean number of mature egg follicles was 4 per female adult weevil. Infested planting material with initial estimated number of 0.3 eggs per sucker resulted in 2.3 adult emergence and ≈ 34% corm cross section damage after 154 days. The potential egg follicles albeit slow weevil population build-up reiterates the k-selected nature of the banana weevil. The egg follicles in adult female ovaries were high and comparable with weevils in other banana growing regions. The default health status of planting material was confirmed to be a contributing factor to weevil build-up in confinement. Soil moisture increased weevil survival but the improved plant vigour compensated for weevil damage.

Sesame is an oilseed crop which can be grown on marginal lands. Selection of stable sesame cultivars that can adapt to local environmental conditions can be a very important food security strategy. A set of 21 high yielding sesame accessions that have been selected for a temperate region were grown in the transitional zone of Ghana during the major season of 2014. The seeds were sown after the first rain in the year in a completely randomized design, with three replications. The objective was to evaluate the effect of the contrasting environment on sesame phenology and to select cultivars with yield potential that can be accepted into local farming systems in the new environment. Morphological, physiological and agronomic traits, leading to yield were recorded in this study. Number of capsules per plant had the strongest association (72%) with seed yield. Five accessions showed a combination of early maturity < 12 weeks with high overall mean seed yield (> 20 g per plant) and good harvest index (0.29). Based on their mean performance these cultivars have been selected as promising exotic cultivars for the new locality.

In the search for alternatives to sawdust as growing media in commercial mushroom cultivation, three organic substrates obtainable as crop residue, maize husk, maize cob, and maize stalk, with each being supplemented with rice bran, were evaluated as growth media for the oyster mushroom, Pleurotus ostreatus (Kummer). For the tested alternatives to sawdust, the harvested weight of fruiting bodies that sprouted on a kilogram maize husk media per crop (32.99 g) was the highest. Sawdust media supported significantly (P<0.001) heavier fruiting bodies (42.18) than the maize residues. The peak mushroom harvests for the various substrates were obtained between the first and seventh fruiting body flushes. The biological efficiency of the substrates, which measured usable nutrients indicated that maize stalk supplemented with rice bran, was 39% compared to that of the sawdust media (60%). The maize husk media and the maize cob media had biological efficiencies of 32% and 9.5%, respectively. These results indicate that two of the tested growing media (maize stalk or husk) produced mushrooms with yield characteristics that were comparable to the well-used sawdust in the cultivation of oyster mushrooms. The environmental and economic parameters involved in the use and carting of sawdust make these on-farm crop residues a viable alternative for mushroom cultivation in especially nonforest zones of Ghana.

Sesame (Sesamum indicum L.) Pedaliaceae is produced mainly in developing countries where abundant and inexpensive labour is available and usually by small holders. It is cultivated for its edible seeds which is high in nutritious fatty acids. In Africa sesame has in recent years been promoted to diversify agricultural production especially in the Sahel region. It has the potential to become an important field crop in Ghana especially in the drier regions. Unavailable field data on constraints to sesame production including its insect pests may be the reason for its non-commercial cultivation in Ghana. A preliminary survey of arthropods associated with sesame, was conducted in the transitional zone of Ghana during the 2009 growing season. In order to achieve maximum natural infestation, no conscious control measure was adopted. A wide spectrum of arthropods including chewers, suckers, pollinators, scavengers and predators were found. In all 60 insect species and 11 spiders were collected and identified at least to family level. It appears that, Araneae, Coleopterans, Hemipterans, Hymenopterans, Lepidopterans and Orthopterans may be important. These arthropods recorded on sesame in Ghana have several implications for the future. This includes several scenarios where these endemic insects will prefer sesame in a host shift situation; the beneficial populations could be exploited and incorporated as field banker crops in local farming systems, sesame could be used as a trap crop or it could be adopted as an attractor for insect pollinators in tree crop plantations. The description, incidence and dynamics of these important insects and spiders of sesame are discussed.

This study was conducted with the primary objective of comparing the attractiveness of crude aqueous leaf extracts of an exotic spice plant Pimenta dioica L. with two commonly used attractants: methyl eugenol and sweet orange citrus (Citrus sinensis Osbeck) juice for the Africa invader fruit fly Bactrocera invadens Drew, Tsuruta & White (Diptera: Tephritidae) in a citrus plantation. No significant differences were observed among the tested concentrations (5, 10, 15 and 20% wt/vol) for most of the sampling days indicating that none of the concentrations was superior over the other in attracting B. invadens. The performance of the extracts was comparable with the synthetic methyl eugenol, particularly, during the first four days of placing the attractants in the field. Traps baited with synthetic methyl eugenol lure mixed with cypermethrin technical grade in a ratio of 4:1 v/v captured and killed significantly more adult B. invadens compared with traps baited with matured sweet orange citrus juice of about 10% brix. We have therefore shown for the first time that field populations of adult male B. invadens can be attracted to crude aqueous leaf extracts of P. dioica. These results suggest that leaf extracts of P. dioica can be used to detect and control B. invadens in citrus plantations.

Three diverse insects, a polyphagous "leaf chewer" (Atractomorpha lata), a polyphagous "sap feeder" (Myzus persicae), and a "restrictive feeder" (Plutella xylostella) responded differently when fed with eight cultivars of sesame either as whole leaf or via artificial diet. There was limited or no correlation in induction between detoxifying enzyme substrates (esterase, glutathione s-transferase [GST], and mixed function oxidase [MFO] activities) when activity toward various substrates α-naphthyl acetate, 1-chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene, and p-nitroanisole (pNA), were compared although they were generally elevated in the tissues from insects on sesame than a reference fed with radish seedlings. In A. lata, esterase activity for the cultivar 11Pusan and 45Laos were three-fold higher compared to the reference, while other cultivars, 24Nanbu-twasaki and 56S-radiatum were--two- to three-fold lower than the reference. In M. persicae, the esterase activity was as much as five-fold higher than the reference in one test cultivar. GST activities of the sesame cultivars were generally higher (≈two-fold) than the reference in all insects and at variable ratios among the cultivars. The MFO activity toward pNA in grasshoppers feeding on these sesame cultivars was either highly expressed or nonexistent. These results indicate that although the cultivars belong to the same species, they might have undergone changes in secondary phytochemicals in response to varying biogeographical distribution. Each insect species is suspected to target a specific plant chemical burden that it tries to overcome in each cultivar through enzyme activation.

The effects of extracts of sesame, Sesamum indicum L. (Liamiales: Pedaliaceae), and whole leaves of some selected cultivars of sesame were tested using a natural host Spodoptera litura (F.) (Lepidoptera: Noctuidae). Indices taken using the immature stages include; diet utilization, growth and development and induction of detoxification enzymes. The results indicate that S. litura generally selects its food amongst cultivars within 6 hours after food presentation. Growth and development of the insect is controlled also by plant acceptability and quality. Although all the cultivars tested significantly limit insect growth and development the variety 56S-radiatum did not allow a complete life cycle as pupation from first instar stage was 0%. Generally the crucial period for immature S. litura was the larval period, especially the first two instars where the weight of an insect fed on an experimental diet was three times lower than that of a control diet. The larval developmental period was greater than 40 days as compared to 17 days for insects fed a control diet. S. litura also had lowered efficiency in utilizing ingested food, from a low of 13% in a sesame cultivar to 45% in the control diet. The key detoxification enzyme was a glutathione s-transferase that was confirmed by a 6-fold increase between S. litura fed a plant cultivar vs. a control diet towards the substrate 1,2-dichloro-4-nitrobenzene. First and second instars of S. litura have a relatively reduced detoxification of enzymes in response to plant cultivar diets leading to low survival. A 3% v/w crude extract of the cultivars increased enzyme induction towards all the tested substrates.