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CASSAVA MOSAIC DISEASE INCIDENCE AND SEVERITY AND WHITEFLY VECTOR DISTRIBUTION IN GABON
Full text linkCassava mosaic disease (CMD) is a major constraint to cassava ( Manihot
esculenta Crantz) production in sub-Saharan Africa. The objective of
this study was to gain insights into the epidemiology of CMD in cassava
production systems in Gabon. An epidemiological survey was conducted
throughout Gabon from October 2020 to May 2021 to evaluate the
epidemiology of cassava mosaic disease (CMD) in cassava farms. A
phytosanitary diagnosis was conducted at each farm, using the
harmonised and unified WAVE protocol to assess the incidence and
severity of CMD and the abundance of its whitefly vector. All data
collected were recorded using WAVE\u2019s mobile application and
uploaded into the WAVE Cube data system. The results showed that CMD
was present in all farms surveyed (n = 227; 100%), but with a variable
incidence rate. At national level, the incidence of CMD was high, with
an average of 64.29%. However, incidence differed among regions with
82.22 and 79.20% for Ogooue-Maritime and Nyanga; respectively, but only
40.42% for Estuaire. Woleu-Ntem had the highest mean severity (3.47)
and Ogooue-Maritime the lowest (2.64). Overall, incidence and severity
differed significantly among regions (P< 0.05). The average
abundance was 2.58 whiteflies per plant (w/p), varying between 1.06
(Nyanga) and 5.25 w/p (Estuaire). The use of infected cuttings was the
main mode of CMD spread (62.67%). These results highlight the need to
identify the viruses responsible for the observed cases of CMD, to
sanitise cultivated plant material, and to implement a CMD control
strategy in Gabon.La maladie de la mosa\uefque du manioc (CMD) est une contrainte
majeure \ue0 la production de manioc (Manihot esculenta Crantz) en
Afrique subsaharienne. L\u2019objectif de cette \ue9tude \ue9tait
de mieux comprendre l\u2019\ue9pid\ue9miologie de la CMD dans les
syst\ue8mes de production de manioc au Gabon. Une enqu\ueate
\ue9pid\ue9miologique a \ue9t\ue9 men\ue9e dans tout le Gabon
d\u2019Octobre 2020 \ue0 Mai 2021 afin de mieux connaitre
l\u2019\ue9pid\ue9miologie de la mosa\uefque du manioc. Un
diagnostic phytosanitaire a \ue9t\ue9 fait dans chaque champ
prospect\ue9. L\u2019incidence, la s\ue9v\ue9rit\ue9 de la
mosa\uefque et l\u2019abondance des mouches blanches vectrices ont
\ue9t\ue9 estim\ue9es en utilisant le protocole harmonis\ue9 et
unifi\ue9 du programme WAVE. Toutes les donn\ue9es de terrain ont
\ue9t\ue9 saisies gr\ue2ce \ue0 l\u2019application mobile de
WAVE puis stock\ue9es dans le gestionnaire de donn\ue9es de WAVE,
le Cube. Les r\ue9sultats de cette \ue9tude ont montr\ue9 que la
mosa\uefque du manioc \ue9tait pr\ue9sente dans toutes les zones
prospect\ue9es (n = 227; 100%), avec une incidence variable. Au
niveau national, l\u2019incidence de la CMD \ue9tait
\ue9lev\ue9e, avec une moyenne de 64,29% pour une
s\ue9v\ue9rit\ue9 moyenne de 3,16. Cette incidence varie entre
les provinces avec respectivement 82,22% et 79,20% pour
l\u2019Ogoou\ue9-Maritime et la Nyanga, mais seulement, 40,42% pour
l\u2019Estuaire. La r\ue9gion du Woleu-Ntem a pr\ue9sent\ue9 la
plus grande s\ue9v\ue9rit\ue9 moyenne (3,47) et
l\u2019Ogoou\ue9-Maritime, la plus faible moyenne (2,64).
L\u2019incidence et la s\ue9v\ue9rit\ue9 ont diff\ue9r\ue9
significativement entre les r\ue9gions (P< 0,05).
L\u2019abondance moyenne des mouches blanches \ue9tait de 2,58
mouches/plante (m/p). Cette abondance a oscill\ue9 entre 1,06 m/p
(Nyanga) et 5,25 m/p (Estuaire). L\u2019utilisation des boutures de
manioc infect\ue9es est le principal mode de propagation de la CMD
(62,67%). Ces r\ue9sultats pr\ue9liminaires mettent en exergue la
n\ue9cessit\ue9 imp\ue9rieuse d\u2019identifier les virus
responsables des cas de CMD observ\ue9s, d\u2019assainir le
mat\ue9riel v\ue9g\ue9tal cultiv\ue9 et de mettre en place une
strat\ue9gie de contr\uf4le de la CMD au Gabon
Comparing durum wheat cultivars by genotype 7 yield 7 trait and genotype 7 trait biplot method
No full textThe specification of the most convenient cultivars based on multiple
trait indices is a new approach in durum wheat ( Triticum durum
Desf.) adaptation and stability studies. This approach helps to define
the best cultivar based on multiple traits and multiple locations
because cultivars are affected by unpredictable climatic conditions.
Some traits (ears per square meter, spike length, number of grains per
spike, spike yield, and leaf chlorophyll content among others) can be
produced for primary breeding purposes because they are influenced by
environmental factors and indirectly affect grain yield and quality.
Therefore, in the present study, the new genotype
7 yield
7
trait (GYT) biplot approach was used to identify the best cultivar
among 10 durum wheat cultivars based on multiple environments (8) and
multiple traits (18). Cultivar ranking was examined by a superiority
index that combined yield and other target traits with the GYT biplot.
The general adaptability of each cultivar in terms of all the traits
indicated differences based on environment means, and significant
differences were found between varieties for the GYT biplot. In the GYT
biplot, yield-trait combinations clearly indicated the most stable
cultivars, whereas in the genotype
7 trait (GT) biplot, the best
cultivars were not defined for all traits. \u2018Sari\ue7anak\u2019
was ranked as the best combination of physio-morphological traits with
grain yield, \u2018Z\ufchre\u2019 was the best for more quality
traits, and \u2018G\ufcneyyildizi\u2019 was the best for both
physio-morphological and quality traits in the GYT biplot. The GYT
biplot combines traits with yield and can help the visual
identification of the best cultivars; it is better than the GT biplot
method
Transcriptome assembly and expression analysis in Colletotrichum gloeosporioides -tolerant Rubus glaucus Benth.
No full textAndean blackberry (Rubus glaucus Benth.) is an important crop of the
Andean region affected by Colletotrichum gloeosporioides. In Colombia,
tolerant plant material has been detected, but it has not been
completely characterized. The objective of this research was oriented
to analyze de novo transcriptome assembly of R. glaucus, and the
comparison of the assembly with different reference genomes to further
complete differential expression analysis of R. glaucus tolerant to C.
gloespoiorides attack. To achieve this, three groups were used:
infected tolerant material, infected susceptible material, and a
susceptible group without inoculation. The RNA-seq sequencing was
achieved through Illumina Hi-seq 2000. De novo assembly (Trinity,
CD-HIT, TopHat) and functional annotation of sequences were carried
out, additionally, mapping with reference genomes belonging to Rosaceae
families was conducted (Bowtie2, TopHat). Subsequently, the
differential expression was quantified (Cuffdiff) and analyzed through
EdgeR. Variant analysis was made using MISA and SAMtools. After editing
and assembly, 43579 consensus sequences were obtained (N50 = 489 bp; GC
= 44.6%), annotation detected 35824 and 35602 sequences in Nt
(partially non-redundant nucleotide sequences) and Nr (non-redundant
protein sequences) databases, respectively. The 85% of Nr sequences was
linked to members of Rosaceae family, mainly strawberry (67.6%). A
total of 3570 simple sequence repeat (SSR) markers and 38791 single
nucleotide polymorphisms (SNP) were found. The transcriptome of
tolerant plants exhibited less SNPs. Finally, differentially expressed
genes were found, including RPM1, MAPKBP1, CKX2. This research
represents a contribution for future understanding of R. glaucus
transcriptome, since there is little information available, and it
would help further tolerance-related analysis
Distribution and molecular characterization of Citrus yellow vein clearing virus in Yunnan Province of China
No full textIn 2009, a new citrus viral disease caused by Citrus yellow vein
clearing virus (CYVCV) was first discovered in Yunnan province of
China. In this study, a survey was conducted in 27 orchards from Yunnan
province from April 2017 to September 2018. In all, 45 of a total of
513 citrus samples were tested positive for CYVCV by reverse
transcription polymerase chain reaction (RT-PCR). Furthermore, the
complete genome sequences of six CYVCV isolates from different hosts
were sequenced. Comparisons of the whole genome sequences of these six
CYVCV isolates as well as 34 isolates previously reported from around
the world revealed the sequence identity ranged from 96.9% to 99.8% at
nucleotide level, indicating that there is a very low level of sequence
heterogeneity among CYVCV isolates of different hosts in Yunnan
province
PREVALENCE OF PLANT-PARASITIC NEMATODES IN RICE FIELDS IN GHANA
Full text linkRice ( Oryza sativa L.) is one of the most cultivated crops worldwide
whose production in sub-Saharan Africa is extensively affected by root
nematodes. The objective of this study was to identify and establish
the distribution of plant-parasitic nematodes (PPNs), in rice growing
fields within different regions of Ghana. Soil and root samples were
taken from rice fields, namely fourteen from Volta Region, eleven from
the Soil and Irrigation Research Centre (SIREC), Kpong (Eastern
Region); and five from Dawhenya (Greater Accra Region). The soil
samples were taken from 0-30 cm depths, together with root samples. A
total of twenty-four nematode genera were identified in soil and root
samples from the three regions. These included: Aphelenchus spp.,
Belonolaimus spp., Ditylenchus spp., Dolichodorus spp.,
Helicotylenchus spp., Hemicriconemoides spp. Hemicycliophora spp.
Heterodera spp., Hirschmaniella spp., Hoplolaimus spp.,
Longidorus spp., Meloidogyne spp., Paralongidorous spp.,
Paratylenchus spp., Pratylenchus spp., Radopholus spp.,
Rhabditida spp., Rotylenchulus spp., Scutellonema spp., Trichodorus
spp., Tylenchornchus spp., Tylenchulus spp., Tylenchus spp. and
Xiphinema spp. In the Volta Region, Tylenchus spp. was the most
abundant (29.01%) in the soil; while Meloidogyne spp. was most the
abundant (36.86%) in the roots. In Dawhenya regions, Meloidogyne spp.
was the most abundant (26.96%) in the soil; while Tylenchus spp. was
the most abundant (25.94%) in the roots. In the Eastern Region,
Meloidogyne spp. was the most abundant (41.7%) in the soil; while
Pratylenchus spp. was the most abundant (36.1%) in the roots. These
nematodes threaten rice production in Ghana, if not managed well in
farmer\u2019s fields.Le riz ( Oryza sativa L.) est l\u2019une des cultures les plus
cultiv\ue9es au monde dont la production en Afrique subsaharienne est
largement affect\ue9e par les n\ue9matodes des racines.
L\u2019objectif de cette \ue9tude \ue9tait d\u2019identifier et
d\u2019\ue9tablir la r\ue9partition des n\ue9matodes
phytoparasites (NPP) dans les rizi\ue8res de diff\ue9rentes
r\ue9gions du Ghana. Des \ue9chantillons de sol et de racines ont
\ue9t\ue9 pr\ue9lev\ue9s dans les rizi\ue8res, \ue0 savoir
quatorze de la r\ue9gion de la Volta, onze du Centre de Recherche sur
les Sols et l\u2019Irrigation (SIREC), Kpong (r\ue9gion de
l\u2019Est)\ua0; et cinq de Dawhenya (r\ue9gion du Grand Accra).
Les \ue9chantillons de sol ont \ue9t\ue9 pr\ue9lev\ue9s
\ue0 des profondeurs de 0 \ue0 30 cm, ainsi que des
\ue9chantillons de racines. Au total, vingt-quatre genres de
n\ue9matodes ont \ue9t\ue9 identifi\ue9s dans des
\ue9chantillons de sol et de racines des trois r\ue9gions. Ceux-ci
comprenaient : Aphelenchus spp., Belonolaimus spp., Ditylenchus
spp., Dolichodorus spp., Helicotylenchus spp., Hemicriconemoides
spp. Hemicycliophora spp. Heterodera spp., Hirschmaniella spp.,
Hoplolaimus spp., Longidorus spp., Meloidogyne spp.,
Paralongidorous spp., Paratylenchus spp., Pratylenchus spp.,
Radopholus spp., Rhabditida spp., T. ., Tylenchornchus spp.,
Tylenchulus spp., Tylenchus spp. et Xiphinema spp. Dans la
r\ue9gion de la Volta, Tylenchus spp. \ue9tait le plus abondant
(29,01 %) dans le sol; tandis que Meloidogyne spp. \ue9tait le plus
abondant (36,86%) dans les racines. Dans les r\ue9gions de Dawhenya,
Meloidogyne spp. \ue9tait le plus abondant (26,96 %) dans le sol;
tandis que Tylenchus spp. \ue9tait le plus abondant (25,94 %) dans
les racines. Dans la r\ue9gion orientale, Meloidogyne spp. \ue9tait
le plus abondant (41,7%) dans le sol; tandis que Pratylenchus spp.
\ue9tait le plus abondant (36,1 %) dans les racines. Ces
n\ue9matodes menacent la production de riz au Ghana, s\u2019ils ne
sont pas bien g\ue9r\ue9s dans les champs des agriculteurs
Fodder yield and nutritive quality of haulm from dual-purpose cowpea cultivars for dry season livestock feeding in Nigeria
Full text linkThe availability of high quality forage, especially during the dry
season remains a major challenge to ruminant livestock production in
Nigeria and many parts of West Africa. This study was conducted to
evaluate forage yield and nutritive quality of haulm from selected dual
purpose cowpea ( Vigna unguiculata L. Walp.) cultivars in the humid
rain forest zone of Nigeria. The forage and pod yields of twenty
cultivars were evaluated at the Teaching and Research Farm of the
Federal University of Technology, Owerri, Imo State, Nigeria.
Subsequently, five dual-purpose cultivars, namely IT04K-334-2,
IT07K-293-3, IT04K-194-3, IT04K-405-5, IT06K-147-2, were selected based
on forage and pod yields from previous trial, for determination of
chemical and fibre compositions. The results revealed significant
(P<0.05) differences in pod and forage yields among the twenty
cowpea cultivars, with yields ranging from 0-1.5 t ha-1 and 0.1-4.5 t
ha-1 for pod and forage, respectively. Cultivars IT07K-293-3,
IT04K-405-5, IT06K-147-2, IT07K-194-3, IT04K-334-2, IT04K-267-8 and
IT04K-339-1 recorded the highest fodder yields of at least 2715 t ha-1,
with crude protein contents ranging from 10.49% in IT07K-194-3 to 13
.57 % in IT04K-405-5. Cultivars IT07K-194-3, IT07K-293-3,
IT07K-220-1-9, IT06K-147-2, IT07K-187-55IT04K-332-1 recorded the
highest pod yields (>700 t ha-1). There were significant (P<0.05)
differences in crude protein, ether extract and non-fibre carbohydrates
(NFC) contents among five cultivars selected from the top ten high
yielding cultivars, based on mean ranking score. These selected
cultivars are recommended as dual-purpose cowpea for the humid forest
zone.La disponibilit\ue9 de fourrage de la haute qualit\ue9, en
particulier pendant la saison s\ue8che, reste un d\ue9fi majeur
pour l\u2019\ue9levage de ruminants au Nigeria et dans de nombreuses
r\ue9gions d\u2019Afrique de l\u2019Ouest. Cette \ue9tude a
\ue9t\ue9 men\ue9e pour \ue9valuer le rendement de fourrage et
la qualit\ue9 nutritive des fanes de cultivars s\ue9lectionn\ue9s
de ni\ue9b\ue9 \ue0 double usage ( Vigna unguiculata L. Walp.)
dans la zone de for\ueat tropicale humide du Nigeria. Les rendements
en fourrage et en gousse de vingt cultivars ont \ue9t\ue9
\ue9valu\ue9s \ue0 la Ferme d\u2019Enseignement et de Recherche
de l\u2019Universit\ue9 F\ue9d\ue9rale de Technologie, Owerri,
\uc9tat d\u2019Imo, Nig\ue9ria. Les cinq cultivars \ue0 double
usage \ue0 savoir IT04K-334-2, IT07K-293-3, IT04K-194-3, IT04K-405-5,
IT06K-147-2 ont \ue9t\ue9 s\ue9lectionn\ue9s sur la base des
rendements en fourrage et en gousse des essais pr\ue9c\ue9dents
pour la d\ue9termination des compositions chimiques et des fibres.
Les r\ue9sultats ont r\ue9v\ue9l\ue9 des diff\ue9rences
significatives (P<0,05) dans les rendements des gousses et du
fourrage parmi les vingt cultivars de ni\ue9b\ue9, avec des
rendements allant de 0-1,5 t ha-1 et 0,1-4,5 t ha-1 pour les gousses et
le fourrage respectivement. Les cultivars IT07K-293-3, IT04K-405-5,
IT06K-147-2, IT07K-194-3, IT04K-334-2, IT04K-267-8 et IT04K-339-1 ont
enregistr\ue9 les rendements fourragers les plus \ue9lev\ue9s
d\u2019au moins 2715 t ha-1 avec des teneurs en prot\ue9ines brutes
allant de 10,49 % en IT07K-194-3 \ue0 13,57 % en IT04K-405-5. Les
cultivars IT07K-194-3, IT07K-293-3, IT07K-220-1-9, IT06K-147-2,
IT07K-187-55IT04K-332-1 ont enregistr\ue9 les rendements en gousses
les plus \ue9lev\ue9s (>700 t ha-1). Il y avait des
diff\ue9rences significatives (P<0,05) dans les teneurs en
prot\ue9ines brutes, en extraits \ue9th\ue9r\ue9s et en
glucides non fibreux (GNF) parmi cinq cultivars s\ue9lectionn\ue9s
parmi les dix premiers cultivars \ue0 haut rendement, sur la base du
score de classement moyen. Ces cultivars s\ue9lectionn\ue9s sont
recommand\ue9s comme ni\ue9b\ue9 \ue0 double usage pour la zone
de for\ueat humide
TEMPORAL AND SPATIAL DYNAMICS OF Bemisia tabaci POPULATIONS AND CASSAVA VIRAL DISEASES ON SELECTED WHITEFLY RESISTANT CASSAVA GENOTYPES IN UGANDA
Full text linkBemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest that
causes widespread damage on cassava ( Manihot esculanta Crantz), a
staple food crop for millions of households in sub-Saharan Africa.
Bemisia tabaci also acts as a vector responsible for spreading plant
viruses that cause two of the most economically damaging diseases in
cassava; namely cassava mosaic disease (CMD) and cassava brown streak
disease (CBSD). The objective of this study was to determine the
population dynamics of B. tabaci on whitefly resistant cassava
genotypes in different agro-ecologies in Uganda. Data were collected
once a month, for six months on adult whitefly populations, cassava
mosaic disease (CMD) and cassava brown streak disease (CBSD) incidence
and symptom severity. The results obtained indicated that cropping
season (2015 and 2016), agro-ecology, cassava age and genotypes
strongly (P 640.001) influenced the population of adult whitefly.
Moderate (47.44% \ub1 0.7821) and high (72.04% \ub1 0.6916) overall
means incidences of CBSD recorded across agro-ecologies on the whitefly
resistant genotypes in 2015 and 2016 trials, respectively, were likely
due to use of cutting-infected planting materials that were not
detected through visual inspection at trial establishment. The analysis
further revealed that the interaction effect of genotype, agro-ecology
and crop age (months after planting: MAP) had a highly significant
influence (P 64 0.001) on whitefly abundance and high significant
effect (P 640.05) on CMD incidence and severity. The CMD and CBSD
incidence as well as symptom severity increased with crop age from 3
months after planting across agro-ecologies. The study demonstrates
that whitefly population dynamics and viral disease incidence are
influenced by cassava genotypes, agro-ecological differences and crop
age (MAP). Information generated could be used to guide the development
of appropriate area-specific control strategies to mitigate the effect
of whitefly and whitefly-transmitted viral diseases in cassava.Bemisia tabaci (Gennadius) (Hemiptera : Aleyrodidae) est un ravageur
qui cause des d\ue9g\ue2ts \ue9tendus sur le manioc ( Manihot
esculanta Crantz), une culture vivri\ue8re de base dans des
millions de m\ue9nages en Afrique subsaharienne. Bemisia tabaci agit
\ue9galement en tant que vecteur responsable de la propagation de
virus v\ue9g\ue9taux qui causent deux des maladies les plus
dommageables sur le plan \ue9conomique du manioc; \ue0 savoir la
maladie de la mosa\uefque du manioc (CMD) et la maladie des stries
brunes du manioc (CBSD). L\u2019objectif de cette \ue9tude
\ue9tait de d\ue9terminer la dynamique des populations de B. tabaci
sur les g\ue9notypes de manioc r\ue9sistants aux aleurodes dans
diff\ue9rentes agro-\ue9cologies en Ouganda. Des donn\ue9es ont
\ue9t\ue9 recueillies une fois par mois pendant six mois sur les
populations d\u2019aleurodes adultes, l\u2019incidence de la maladie
de la mosa\uefque du manioc (CMD) et de la maladie des stries brunes
du manioc (CBSD) et la gravit\ue9 des sympt\uf4mes. Les
r\ue9sultats obtenus ont indiqu\ue9 que la saison de culture (2015
et 2016), l\u2019agro-\ue9cologie, l\u2019\ue2ge et les
g\ue9notypes du manioc ont fortement influenc\ue9 (P 640,001)
la population d\u2019aleurodes adultes. Les incidences moyennes
globales mod\ue9r\ue9es (47,44\ua0% \ub1 0,7821) et
\ue9lev\ue9es (72,04\ua0% \ub1 0,6916) de CBSD
enregistr\ue9es dans les agro-\ue9cologies sur les g\ue9notypes
r\ue9sistants aux aleurodes dans les essais de 2015 et 2016,
respectivement, \ue9taient probablement dues \ue0
l\u2019utilisation de mat\ue9riel de plantation infect\ue9 par des
boutures qui n\u2019ont pas \ue9t\ue9 d\ue9tect\ue9s par
inspection visuelle dans l\u2019\ue9tablissement d\u2019essai.
L\u2019analyse a en outre r\ue9v\ue9l\ue9 que l\u2019effet
d\u2019interaction du g\ue9notype, de l\u2019agro-\ue9cologie et
de l\u2019\ue2ge de la culture (mois apr\ue8s la plantation: MAP)
avait une influence hautement significative (P 640,001) sur
l\u2019abondance des aleurodes et un effet significatif
\ue9lev\ue9 (P 640,05) sur l\u2019incidence et gravit\ue9.
L\u2019incidence de CMD et de CBSD ainsi que la
s\ue9v\ue9rit\ue9 des sympt\uf4mes ont augment\ue9 avec
l\u2019\ue2ge de la culture \ue0 partir de 3 mois apr\ue8s la
plantation dans toutes les agro-\ue9cologies. L\u2019\ue9tude
d\ue9montre que la dynamique des populations d\u2019aleurodes et
l\u2019incidence des maladies virales sont influenc\ue9es par les
g\ue9notypes de manioc, les diff\ue9rences agro-\ue9cologiques et
l\u2019\ue2ge des cultures (MAP). Les informations
g\ue9n\ue9r\ue9es pourraient \ueatre utilis\ue9es pour
orienter l\u2019\ue9laboration de strat\ue9gies de contr\uf4le
appropri\ue9es et sp\ue9cifiques \ue0 la zone pour att\ue9nuer
l\u2019effet des aleurodes et des maladies virales transmises par les
aleurodes sur le manioc
SEED SYSTEM AND SEED QUALITY OF KERSTING\u2019S GROUNDNUT IN BENIN
No full textSwift delivery of quality seeds to farming communities is a fundamental
step in mainstreaming the value chain of orphan crops. The objective of
this study was to characterise seed production and delivery systems of
the orphan Kersting\u2019s groundnut (KG) [ Macrotyloma geocarpum
(Harms) Mar\ue9chal & Baudet] and their influence on seed quality
in Benin. A survey was conducted among 305 farmers from the major KG
growing areas in Benin. A total of 60 seed samples were collected from
different sources (farmer own seed, local markets and agro-dealers) for
quality tests. The results showed that seed sources, acquisition modes
and perceived quality differed significantly (P<0.01) among gender
groups and with farming experience. Majority of farmers (74.93%)
perceived seeds acquired from the local markets and seed stored in
non-hermetic conditions as of poor quality compared to seeds sourced
from their own stock and stored in hermetic conditions. Yet, the seed
quality analysis revealed no differences (P<0.05) among the sources
and storage methods. Less than 20% of the tested samples met the
national quality standards suggesting an important quality constraint
in the current system which may justify the reported low yield and crop
failure.L\u2019acc\ue8s aux semences de qualit\ue9 est une \ue9tape
fondamentale dans l\u2019int\ue9gration de la cha\ueene de valeur
des cultures orphelines. L\u2019objectif de cette \ue9tude
\ue9tait de caract\ue9riser les syst\ue8mes de production et de
distribution de semences de la lentille de terre [Macrotyloma geocarpum
(Harms) Mar\ue9chal & Baudet] au B\ue9nin et leur influence sur
la qualit\ue9 des semences. Une enqu\ueate a \ue9t\ue9
men\ue9e aupr\ue8s de 305 agriculteurs de la principale zone de
production de la lentille de terre au B\ue9nin. Au total, 60
\ue9chantillons de semences ont \ue9t\ue9 collect\ue9s
aupr\ue8s de diff\ue9rentes sources (agriculteurs, march\ue9s
locaux et les vendeurs d\u2019intrants agricole) pour des tests de
qualit\ue9. Les r\ue9sultats ont montr\ue9 que les sources de
semences, les modes d\u2019acquisition et la perception des
r\ue9pondants par rapport \ue0 la qualit\ue9 des semences
diff\ue9raient significativement (P<0,01) avec le genre des
r\ue9pondants et leur l\u2019exp\ue9rience de production. La
majorit\ue9 des r\ue9pondants (74,93%) per\ue7oivent les semences
acquises sur les march\ue9s locaux et les semences stock\ue9es dans
des structures non herm\ue9tiques comme \ue9tant de mauvaise
qualit\ue9 par rapport \ue0 celles provenant de leur propre stock
et stock\ue9es dans des structures herm\ue9tiques. Cependant,
l\u2019analyse de la qualit\ue9 des semences n\u2019a
r\ue9v\ue9l\ue9 aucune diff\ue9rence significative (P<0,05)
entre les sources et les m\ue9thodes de stockage. Moins de 20 % des
\ue9chantillons test\ue9s r\ue9pondaient aux normes de
qualit\ue9 en vigueur au Benin, ce qui sugg\ue8re une contrainte de
qualit\ue9 importante dans le syst\ue8me actuel et pourrait
justifier le faible rendement et l\u2019\ue9chec des r\ue9coltes
enregistr\ue9es
Spatio-temporal Analysis of Urban Growth and Its Effects on Wetlands in Rwanda: The Case of Rwampara Wetland in the City of Kigali
Full text linkThis study aimed at analyzing the spatio-temporal patterns of urban
growth and its effects on Rwampara wetland, located in the City of
Kigali, Rwanda. First, the study was based on the application of remote
sensing technology, where 4 Landsat images (1987, 1999, 2009 &
2018) were classified using maximum likelihood classification
algorithm. This helped in analyzing the Land Use and Land Cover (LULC)
trends in the study area. Secondly, it used the existing LULC data for
the years 1990, 2000, 2010 and 2018 in order to investigate the overall
changes in LULC in Kigali City. Finally, semi-structured interviews
were used to collect data from local people and decision-makers about
their past and future management strategies of Rwampara wetland. In
this regard, 30 local communities (mainly natives from the study area),
15 local government authorities at sector and district levels as well
as 4 senior government authorities in the central administration were
interviewed. The findings revealed that over the past 4 decades, urban
growth in Kigali City has rapidly increased at the expense of resource
degradation in Rwampara wetland. Specifically, there has been an
increase of about 77% of the built-up area over the last 31 years
(1987-2018) which has led to the decrease of the wetland surface area
from 24 ha in 1987 to only 7.7 ha in 2018. The results also revealed
that demographic factors (i.e. a high population growth rate and high
population densities) were mainly responsible for urban growth and
degradation of wetland resources in the area under investigation
Rural Households\u2019 Attitude towards Potential Use of Jatropha for Environmental Restoration in Saki West Local Government Area of Oyo State, Nigeria
Full text linkThe study examined rural households\u2019 attitude towards potential
use of Jatropha for environmental restoration in Saki-West Local
Government Area. A purposive sampling procedure was used in selecting
due to deforestation for charcoal production, while 120 respondents
were sampled with a simple random technique from the study area. The
data were collected through a well-structured questionnaire with
interview section, and were analyzed with frequencies, percentages,
mean scores, and Pearson product moment correlation. There was
correlation between rural households\u2019 awareness on use of
Jatropha and use of Jatropha for environmental restoration (r =
0.399**, p < 0.05). The respondents\u2019 attitude was
significantly related to their behavior in utilization of Jatropha for
environmental restoration (r = - 0.182*, p < 0.05). The study showed
that awareness and attitude of rural households strongly influenced use
of Jatropha for environmental restoration. The implication of this
study is to ensure that the environment becomes free of hazards and
degradation which affect survival of the ecosystem and biodiversity.
Hence, government should join in the advocacy to open continuous
channels of communication on the importance of Jatropha, and to also
motivate the people to having right attitude towards the use of
Jatropha as a measure to restoring the environment