11 research outputs found
Build-up of insect pests and their natural enemies on rotated and non-rotated okra (Abelmoschus esculentus (L.) Moench), tomato (Lycopersicon esculentus Mill) and egg plant (Solanum melongena (L.) Moench.) fields
Objective: The quest for increased food production requires crops to be protected from pests and diseases. The readily available means of controlling pests is the application of chemical pesticides, with its attendant negative effects on humans and the environment. The study was conducted to assess the effectiveness of crop rotation as a pest control measure and how this affects the population of natural enemies of the pests.Methodology and Results: The build-up of insect pests’ of tomato, okra and eggplant and their natural enemies on rotated and non-rotated fields were studied. The rotated and non-rotated fields were each replicated 3 times. The different insect pests that infested the crops were identified and counted. Aphids and whiteflies were assessed using a scoring scale from 0 to 5. Natural enemies of the pests were also identified and counted. Significantly, larger numbers of Bemisia tabaci, Aphis gossypii, Podagrica uniforma, Zonocerus variegatus and Locusta migratoria were sampled on the crops on the non-rotated than the rotated fields. Numbers of natural enemies, Dictynia sp Coccinella sp and Camponotus sp were not significantly different on the rotated and non-rotated fields but crop yields were significantly higher on the rotated field.Conclusion and application of findings: The results of the study indicated that rotating crops on the same piece of land resulted in reduction in pests’ numbers and an increase in crop yields. The reliance on pesticides alone to manage pests may not be the best option to reduce pests because of the negative effects of pesticides on the environment. Crop rotation can therefore be adopted as a cultural control option in the overall management of pests
Occurrence of entomopathogenic nematodes (Steinernematidae, heterorhabditidae) as potential biocontrol agents against Spodoptera frugiperda infesting Zea mays
Synthetic insecticides are used worldwide to manage invasive fall armyworm (Spodoptera frugiperda) in cereals, in spite of the chemical’s prohibitive cost and threats to environmental health. In Ghana, little attention has been given to entomopathogenic nematodes as insect pest biocontrol agents, due to the existence of dismal expertise in the field. This study evaluated maize (Zea mays L.) farms for endemic entomopathogenic nematodes as potential biological control agents against fall armyworms infesting maize in Ghana. Entomopathogenic nematode juveniles were extracted using an insect baiting technique, White traps. These Rhabditid nematodes (Heterorhabditis; Steinernema) were found in 75% of 200 soil samples; and 92.5% of 40 districts targeted by this study. The Greater Accra region recorded the greatest population density (1,820 juveniles per 5 fall armyworm larvae cadavers); while; the Central region recorded the lowest density (81 juveniles per 5 fall armyworm larvae cadavers). There was high presence of entomopathogenic nematodes across the study areas. Therefore, entomopathogenic nematodes offer a promising alternative strategy for managing fall armyworm infestation of maize in Ghana to minimise over-reliance on synthetic insecticides.
 
Storage rot of seed yam resulting from speargrass injuries
Postharvest rot due to injury is a major contributing factor to the
declining quality of stored seed yams ( Dioscorea spp.). Among the
several known injuries, the piercing effect of speargrass rhizomes has
become a serious constraint for yam production in Ghana. The objective
of this study was to assess injuries on seed yams resulting from
piercing of speargrass rhizomes and their effects on postharvest rots
in Ghana. Eighty farmer fields from Mem, Watro, Asanteboa and Abour in
the Atebubu-Amantin Municipal in the Bono East Region of Ghana were
screened for speargrass incidence and injury on harvested tubers, for
laboratory analysis of pathogens in 2016 and 2017. The tubers were
sorted into four categories of seed yam based on weight. Thirty seed
yams each of two selected white yam cultivars (Dente and Kpamyo) with
visible speargrass rhizome-pierced-tubers (VSRPT) and non-speargrass
rhizome pierced healthy tubers (NSRPHT) were randomly selected and
stored in a ban for weekly assessment of rot. The rotten tissues from
the localised area of VPSRT were subjected to pathological
investigations in the laboratory. The incidence of injury seemingly
increased with increasing tuber weight. It was 0% for < 100 g
samples and averagely 14% for > 1 kg samples, irrespective of
cultivars and locations. Incidence of rot from NSRPHT sample was
observed 5 weeks after storage (WAS) for both cultivars; and 2 WAS from
the VSRPT sample and 40% higher than NSRPHT at 8 WAS. Eight and six
known rot pathogens were isolated from the rotten tissues of VSRPT of
Dente and Kpamyo, respectively. Injury from the piercing of speargrass
rhizome significantly contributed to hastening of tuber rots; while
tuber injury increased with increasing speargrass density. Appropriate
management of speargrass is essential for commercial seed yam growers
to reduce tuber damage which affects yam quality, storage and
marketing.La pourriture post-r\ue9colte due \ue0 une d\ue9chirure est un
facteur majeur contribuant \ue0 la baisse de la qualit\ue9 des
ignames des semences stock\ue9es ( Dioscorea spp.). Parmi les
nombreuses d\ue9chirures connues, l\u2019effet per\ue7ant des
rhizomes de la gerbe d\u2019herbe est devenu une contrainte
s\ue9rieuse pour la production d\u2019igname au Ghana.
L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer
les d\ue9chirures sur les ignames de semence r\ue9sultant du
per\ue7age des rhizomes de gerbe d\u2019herbe et leurs effets sur
les pourritures post-r\ue9colte au Ghana. Quatre-vingts champs
d\u2019agriculteurs de Mem, Watro, Asanteboa et Abour dans la
municipalit\ue9 d\u2019Atebubu-Amantin dans la region de l\u2018
Est de Bono au Ghana ont \ue9t\ue9 examin\ue9s pour
d\ue9terminer l\u2019incidence et les dommages de la gerbe
d\u2019herbe sur les tubercules r\ue9colt\ue9s, pour une analyse
en laboratoire des agents pathog\ue8nes en 2016 et 2017. Les
tubercules ont \ue9t\ue9 tri\ue9s en quatre cat\ue9gories
d\u2019igname de semence en fonction du poids. Trente ignames de
semence de chacun des deux cultivars s\ue9lectionn\ue9s
d\u2019igname blanche (Dente et Kpamyo) avec des tubercules
perc\ue9s de rhizome de gerbe d\u2019herbe (VSRPT) et des tubercules
sains perc\ue9s de rhizome non- gerbe d\u2019herbe (NSRPHT) ont
\ue9t\ue9 s\ue9lectionn\ue9s au hasard et stock\ue9s dans une
interdiction pour une \ue9valuation hebdomadaire de la pourriture .
Les tissus pourris de la zone localis\ue9e de VPSRT ont \ue9t\ue9
soumis \ue0 des investigations pathologiques en laboratoire.
L\u2019incidence des d\ue9chirures a apparemment augment\ue9 avec
l\u2019augmentation du poids des tubercules. Il \ue9tait de 0% pour
les \ue9chantillons <100 g et de 14% en moyenne pour les
\ue9chantillons > 1 kg, quels que soient les cultivars et les
emplacements. L\u2019incidence de pourriture de
l\u2019\ue9chantillon NSRPHT a \ue9t\ue9 observ\ue9e 5
semaines apr\ue8s stockage (WAS) pour les deux cultivars; et 2 WAS de
l\u2019\ue9chantillon VSRPT et 40% plus \ue9lev\ue9s que NSRPHT
\ue0 8 WAS. Huit et six agents pathog\ue8nes de la pourriture
connus ont \ue9t\ue9 isol\ue9s respectivement dans les tissus
pourris du VSRPT de Dente et de Kpamyo. Les d\ue9chirures
caus\ue9es par le per\ue7age du rhizome de gerbe d\u2019herbe ont
consid\ue9rablement contribu\ue9 \ue0 acc\ue9l\ue9rer la
pourriture des tubercules; tandis que les dommages aux tubercules
augmentaient avec l\u2019augmentation de la densit\ue9 de la gerbe
d\u2019herbe. Une gestion appropri\ue9e de la groseille verte est
essentielle pour les producteurs commerciaux d\u2019ignames de semence
afin de r\ue9duire les dommages aux tubercules qui affectent la
qualit\ue9, le stockage et la commercialisation des ignames
Enhancing productivity of farmer-saved seed yam in Ghana: Positive selection and neem leaf powder factors
Recycling of diseased and pests infested seed yam ( Dioscorea spp.)
has resulted in drastic yield reductions in yam production. The
objective of this study was to determine the effect of positive
selection on the quality of farmer-saved seed yam and also evaluate the
effect of neem leaf powder in managing plant parasitic nematodes damage
to yam. Two farming systems namely; Positive selection (PS) and Farmer
practice (FP) and two soil amendment regimes; neem leaf powder at 20 g
stand-1 (NA20) and no neem amendment (NA0) were tested on one variety
of yam (Dente). A 2 x 2 x 1 factorial study, mounted on a randomised
complete block design in a split plot arrangement was conducted in four
replications. Positive selection occupied main plots; while Farmer
practice occupied sub-plots. The study was conducted in eight
communities located in two municipalities of Ghana, during 2015-2017.
Parameters evaluated included Yam Mosaic Virus incidence and severity,
incidence and severity of nematode cracks and galling on yam tubers,
plant establishment and yield of yam. It was observed that Yam Mosaic
Virus (YMV) disease incidence decreased from 38% in 2016 to 31% in 2017
in PS plots as a result of using virus-free planting materials.
However, in FP plots, it increased from 67% in 2016 to 72% in 2017.
Neem leaf powder amendment resulted in significantly (P< 0.05) low
tuber galling (7%) compared with 40% in unamended plots. Similarly, PS
plots yielded 7.7 t ha-1 compared to 5.9 t ha-1 in FP fields. In
conclusion, Positive selection out-yielded FP by 30.5%; while PS-neem
leaf powder interaction resulted in 38.5% over and above FP without
neem amendment.Le recyclage des semences d\u2019igname ( Dioscorea spp.)
contamin\ue9es par des maladies et des parasites a entra\ueen\ue9
une r\ue9duction drastique du rendement de la production
d\u2019igname. L\u2019objectif de cette \ue9tude \ue9tait de
d\ue9terminer l\u2019effet de la s\ue9lection positive sur la
qualit\ue9 des semences d\u2019igname conserv\ue9es par les
agriculteurs et \ue9galement d\u2019\ue9valuer l\u2019effet de la
poudre de feuilles de neem dans la gestion des dommages caus\ue9s par
les n\ue9matodes parasites des plantes. Deux syst\ue8mes agricoles
\ue0 savoir; S\ue9lection positive (PS) et pratique paysanne (PF)
et deux r\ue9gimes d\u2019amendement du sol; De la poudre de feuille
de neem \ue0 20 g du stand-1 (NA20) et aucun amendement de neem (NA0)
ont \ue9t\ue9 test\ue9s sur une vari\ue9t\ue9 d\u2019igname
(Dente). Une \ue9tude factorielle de 2 x 2 x 1, mont\ue9e sur une
dispositif en\ua0blocs al\ue9atoires complets dans un arrangement
en parcelles divis\ue9es, a \ue9t\ue9 men\ue9e en quatre
r\ue9p\ue9titions. S\ue9lection positive occup\ue9e parcelles
principales; tandis que la pratique paysanne occupait des
sous-parcelles. L\u2019\ue9tude a \ue9t\ue9 men\ue9e dans huit
communaut\ue9s situ\ue9es dans deux municipalit\ue9s du Ghana en
2015-2017. Les param\ue8tres \ue9valu\ue9s comprenaient
l\u2019incidence et la gravit\ue9 du virus de la mosa\uefque de
l\u2019igname, l\u2019incidence et la gravit\ue9 des fissures de
n\ue9matode et le grippage des tubercules de l\u2019igname,
l\u2019\ue9tablissement de la plante et le rendement de
l\u2019igname. Il a \ue9t\ue9 observ\ue9 que l\u2019incidence
de la maladie caus\ue9e par le virus de la mosa\uefque \ue0
l\u2019igname (YMV) avait diminu\ue9 de 38% en 2016 \ue0 31% en
2017 dans les parcelles PS gr\ue2ce \ue0 l\u2019utilisation de
mat\ue9riel de plantation d\ue9pourvu de virus. Cependant, dans les
parcelles de PF, il est pass\ue9 de 67% en 2016 \ue0 72% en 2017.
L\u2019amendement de poudre de feuille de Neem a entra\ueen\ue9
une r\ue9duction significative du galles des tubercules (P <0,05)
(7%) par rapport \ue0 40% dans les parcelles non modifi\ue9es. De
m\ueame, les parcelles de PS ont produit 7,7 t ha-1, contre 5,9 t
ha-1 dans les champs de PF. En conclusion, la s\ue9lection positive a
eu un rendement sup\ue9rieur de 30,5% \ue0 celui de la PF; tandis
que l\u2019interaction de la poudre de feuille PS-neem a eu pour
r\ue9sultat 38,5% de plus que FP sans amendement de nee
Promoting best business practices among smallholder farmers in Ghana: the case of MiDA training for FBOs in Hohoe District in the Volta Region
This study was carried out to assess the adoption of best business practices among farmers in the Hohoe district of the Volta Region. A random sampling technique was used for selecting the respondents for the study. The total sample size of 191 respondents was randomly selected from four Farmer Based Organizations (FBOs). Data was collected through a structured interview schedule and analyzed with descriptive statistics. The study showed that majority (57.1%) of respondents were males and farmers up to 45 years constituted (60.2%) of the sample size. The study also revealed that the mean bags per acre of maize for all FBOs produced by the respondents increased from 1.3 before the training to 10.0 after the training. The farmers therefore, increased yields by as much as 87% over and above what they realized before the start of the training. The respondents further increased their access to produce markets with linkages to institutional markets. The factors influencing increased yields and respondents' greater access to produce markets were also identified to be low. Non-adoption of improved agricultural technologies and best business practices accounted for the low productivity at the start of the training. To encourage smallholder farmers to benefit from 'agriculture as business', there is the need to equip them with the capacity to keep accurate records and patronize improved agro inputs to strengthen their businesses, improve their technical skills to enhance efficiency in their routine operations, assist them to maximise sales by facilitating their access to markets and providing them with infrastructural support.Keywords: Best business practices, Farmer based organizations, improved agricultural technologies, maize, MiD
Wolbachia infection in Cotesia sesamiae (Hymenoptera: Braconidae) causes cytoplasmic incompatibility : implications for biological control
Cotesia sesamiae (Hymenoptera: Braconidae) is an indigenous, gregarious, larval endoparasitoid that attacks mid- to late-instar of the stem borer larvae. Although the parasitoid is distributed widely throughout Africa, not all local populations appear to be equally effective in controlling stem borers. Consequently, there is an interest in releasing the more effective strains in areas that already have very low populations of C. sesamiae. Some C. sesamiae populations are infected with bacterial symbionts in the genus Wolbachia, which may induce cytoplasmic incompatibility. Using an antibiotic treatment, we have established that the Wolbachia infection causes cytoplasmic incompatibility of the female mortality type in C. sesamiae. Using a simple recurrent equation model, we showed that mixing infected and uninfected populations that exhibit cytoplasmic incompatibility causes a transient, but possibly long, reduction in population growth rate. Knowledge of the infection status of native populations and populations that would be introduced could be used to avoid the incompatibility problems, by adjusting the population that will be introduced to the infection status of the native population
Examining the Relationship Among Socio-Demographic, Institutional Factors and Adoption of Best Tomato Production Practices in Southern Ghana
Tomato, an important staple in many Ghanaian homes, provides livelihood for many farming households. Despite its importance, farmers within major growing tomato districts are either unaware or have not adopted productivity enhancing tomato production practices. This paper examined the relationship between socioeconomic and institutional factors and the adoption of pre-emergence, post-emergence and filed management practices in the Ada West and Central Tongu districts. The study employed descriptive and inferential statistics such as frequencies, percentages, means, and chi-square test to describe the respondents and test of independence between farmer characteristics and adoption. The results revealed that the adoption rates of preemergence, post-emergence and field management practices were 48%, 50% and 64%, respectively. Factors such as farm size, education, farming experience, land tenure arrangements, access to extension services, access to credit and point of sale were found to be significantly associated with adoption of these practices. The main constraints to double season production were reported as unavailability of water and fluctuations in market demand. It is recommended that extension officers and researchers focus their dissemination messages on improved tomato production practices through appropriate channels and build farmers' capacity on the improved practices for enhanced food security and incomes of smallholder tomato farmers in Ghana