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Determination and Remediation of Selected Polycyclic Aromatic Hydrocarbons in Petroleum Contaminated Water
No full textDetermination and remediation of pollutants such as polycyclic aromatic
hydrocarbons (PAHs) have not being fully regulated in Nigeria; hence
contamination of surface water by such pollutant is a major concern.
This study was designed to determine the level of selected PAHs in
petroleum contaminated water using spectroscopic techniques and the
efficacy of activated carbons made from Bambusa vulgaris and
Oxytenanthera vabyssinaca. Bambusa vulgaris and Oxytenanthera
abyssinaca were carbonized at 350OC and activated with Phosphoric acid
(CBV350OC H3PO4) and Potassium chloride (COA 350OC KCl) as dehydrating
agent respectively. The adsorbents were then used to remediate PAHs in
petroleum contaminated water. Liquid-Liquid extraction procedures were
used for extracting selected PAHs from sampled solutions. The batch
experiment was performed to study the adsorption capacity of adsorbents
at 5hrs contact time. Analysis of PAHs concentration for each sampling
day was determined by GC-MS. Total PAHs in simulated wastewater did not
show a clear trend, contrary to the expectation that there should be a
progressive increase with time due to photolysis or photodecomposition
of compounds or PAHs. COA 350OC KCl showed a range of 6.2-19.3% removal
efficiency of each selected PAH with a total percentage efficiency of
27.7-70.8 for all days. For CBV350OC H3PO4 removal efficiency ranged
from 10.26-19.30% for each selected PAH and a total efficiency of
50.8-100% for all selected PAHs for the 4 days intervals. The
experimental result showed that adsorbent made from Bambusa vulgaris
and Oxytenanthera abyssinaca and activated with H3PO4 and KCl as
dehydrating agent respectively can efficiently adsorb the selected PAHs
in contaminated water. The study also revealed that PAHs in
contaminated water increases with time due to photodecomposition, thus
necessitating their treatment on time
Biodegradation Potentials of Waste Engine Oil by Three Bacterial Isolates
No full textEnvironmental contamination by waste engine oil in cities all over the
world constitute serious public health concern because its effects are
unwholesome and unquantifiable. This study was carried out to
biodegrade waste engine oil using bacterial isolates. Three bacteria
were isolated from soil samples that have been contaminated with waste
engine oil for over seven years in automechanic workshops at Ebelle.
They were analysed using standard methods. The bacterial count was 89.4
\ub1 0.02cfu/g while the control was 3.6 \ub1 0.14cfu/g. The
bacterial diversity identified in descending order were Bacillus sp.
(25.41%), Pseudomonas sp. (22.13%), Corynebacterium sp. (18.44%),
Acetobacter sp. (18.03%) and Aeromonas sp. (15.98%). The
biodegradation efficiencies of three bacterial isolates; Bacillus,
Pseudomonas and Corynebacterium species were observed taking records of
change in physicochemical parameters (pH, electrical conductivity and
total hydrocarbon content) for 40 days at 10 days interval with waste
engine oil sample at concentrations of 10%, 20%, 30% and 40%.
Corynebacterium sp. gave the highest percentage reduction in pH values
of 52.92% at 10% contamination level while Pseudomonas sp. gave the
highest percentage reduction of 53.04%, 52.99% and 53.01% at 20%, 30%
and 40% crude oil contamination levels respectively. The pH values of
the control was almost the same all through the period of incubation.
Bacillus sp. gave the highest percentage increase in electrical
conductivity value of 74.17%, 69.93% and 69.91% at 10%, 20% and 40%
contamination level respectively while Pseudomonas sp. gave the highest
increase of 70.45% at 30% contamination level. Also, the values at day
0 and the control were not so different from each other.
Corynebacterium sp. gave the highest percentage reduction in total
hydrocarbon content of 95.49%, 95.48%, 96.50% and 96.50% at 10%, 20%,
30% and 40% contamination level respectively. The result revealed a
reduction in pH and total hydrocarbon content while there was an
increase in electrical conductivity values. This indicated that
biodegradation occurred. This study revealed that the bacterial
isolates particularly Corynebacterium sp. possess the ability to
biodegrade waste engine oil thereby guaranteeing environmental quality
and sustained public health for all and sundry
Effets de la fumure minerale et des predateurs sur le niveau d\u2019infestation du cotonnier par le puceron (Homoptera\ua0: Aphididae) au Togo
No full textIn order to contribute to the development of an integrated management
strategy for cotton aphids ( Aphis gossypii ), tests of the effects of
mineral manure and predators on the variation of its population levels
were studied. Data collection was carried out in a three-day follow-up
on cotton plants ( Gossypium hirsutum L.) grown in experimental plots
at the Station d\u2019Exp\ue9rimentation Agronomique de
l\u2019Universit\ue9 de Lom\ue9 in Togo. The results from
population fluctuation of Aphis gossypii revealed two peaks of swarming
during the cotton plant cycle. The first peak of the small outbreak
period on the 46th day after sowing (DAS) was less important
numerically. The second peak of the great outbreak period on the 86th
DAS was numerically larger and caused considerable damage to cotton
plants. Infestations and levels of population variation during the
cotton growing cycle were highly dependent on the dose of applied
mineral fertilisers. The presence and development of predators
positively correlated with the level of plant infestation by the
aphids, without having a noticeable regulatory effect on their
population.Dans la perspective de contribuer \ue0 l\u2019\ue9laboration
d\u2019une strat\ue9gie de gestion int\ue9gr\ue9e du puceron de
cotonnier Aphis gossypii , les tests de l\u2019effet de la fumure
min\ue9rale et des pr\ue9dateurs sur la variation des niveaux de
population de ce dernier ont \ue9t\ue9 \ue9tudi\ue9s. La
collecte des donn\ue9es a \ue9t\ue9 r\ue9alis\ue9e par un
suivi \ue0 chaque trois jour sur plants de cotonnier ( Gossypium
hirsutum L.) install\ue9 en parcelles exp\ue9rimentales \ue0 la
Station d\u2019 Exp\ue9rimentation Agronomique de
l\u2019Universit\ue9 de Lom\ue9. Les r\ue9sultats de la
fluctuation de population d\u2019Aphis gossypii ont
r\ue9v\ue9l\ue9 deux pics de pullulation durant le cycle du
cotonnier. Le premier pic de la petite p\ue9riode de pullulation au
46\ue8me jour apr\ue8s semis (jas) est moins important
num\ue9riquement. Le second pic de la grande p\ue9riode de
pullulation au 86\ue8me jas est num\ue9riquement plus important et
cause des d\ue9g\ue2ts consid\ue9rables aux cotonniers. Les
infestations et les niveaux de variation de populations au cours du
cycle de la culture cotonni\ue8re sont tr\ue8s d\ue9pendants de
la dose de fumure min\ue9rale appliqu\ue9e La pr\ue9sence et le
d\ue9veloppement des pr\ue9dateurs ont corr\ue9l\ue9
positivement avec le niveau d\u2019infestation des plants par le
puceron sans avoir un effet r\ue9gulateur remarquable de la
population de ce dernier
Differential and comparative screening of cowpea varieties to Striga gesnerioides (Willd.) Vatke for race specific identification in Burkina Faso
Get PDFSignificant efforts have been made to develop cowpea ( Vigna
unguiculata (L.) Walp.) varieties resistant to Striga gesnerioides in
Burkina Faso. Despite these efforts, the resistant genotypes developed
still express differential responses to Striga gesnerioides in
different zones of the country. This suggests existence of
intraspecific variability within the parasite. The objective of this
study was to assess the intraspecific variability of cowpea genotypes
to Striga gesnerioides infection in Burkina Faso. Ten cowpea varieties
were screened over two consecutive years, under artificial infestation
with 30 ecotypes of Striga seeds at Kamboins\ue9 research station, in
a screenhouse in Burkina Faso. Cowpea varieties used included Moussa
local, Komsar\ue9 and KVx404-8-1, which are susceptible to all Striga
ecotypes; and varieties B301, IT93K-693-2 and IT82D-849, which are free
from all Striga ecotypes infestation. Cowpea varieties Tiligr\ue9,
524B, local Gorom and Niizw\ue8 had specific reactions depending on
the ecotypes. The study highlights the existence of varietal
specificities according to the geographical origin of Striga
gesnerioides seeds. The structuring of the intraspecific diversity
showed five biotypes, of which three were clearly identified as SG1,
SG5 and SG Kp races; and two biotypes could not be identified. Although
this study did not allow for a clear determination of the racial
affiliation of the two new biotypes, it offers the possibility of
developing new strategies to control Striga by focusing on the
selection of resistant varieties based on regional specificities of
Striga races in each agricultural zone.Des efforts importants ont \ue9t\ue9 consentis pour d\ue9velopper
des vari\ue9t\ue9s de ni\ue9b\ue9 r\ue9sistantes au Striga
gesnerioides . Malgr\ue9 ces efforts, les g\ue9notypes
r\ue9sistants d\ue9velopp\ue9s expriment des r\ue9ponses
diff\ue9rentielles au Striga gesnerioides dans diff\ue9rentes zones
du pays. Cela sugg\ue8re l\u2019existence d\u2019une
variabilit\ue9 intrasp\ue9cifique au sein du parasite.
D\u2019o\uf9 la n\ue9cessit\ue9 d\u2019\ue9valuer la
variabilit\ue9 intrasp\ue9cifique de Striga gesnerioides. Dix
vari\ue9t\ue9s de ni\ue9b\ue9 ont \ue9t\ue9 cribl\ue9es
sur deux ann\ue9es successives sous infestation artificielle avec 30
\ue9cotypes de Striga \ue0 la station de recherche de
Kamboins\ue9. Des pots en plastique ont \ue9t\ue9 utilis\ue9s
comme parcelles exp\ue9rimentales dispos\ue9es en blocs de Fisher
avec trois r\ue9p\ue9titions. Les vari\ue9t\ue9s Moussa Local,
Komsar\ue9 et KVx404-8-1 ont \ue9t\ue9 sensibles \ue0 tous les
\ue9cotypes tandis que les vari\ue9t\ue9s B301, IT93K-693-2 et
IT82D-849 ont \ue9t\ue9 exemptes de toute infestation. Les
vari\ue9t\ue9s Tiligr\ue9, 524B, Gorom local et Niizw\ue8 ont
eu des r\ue9actions sp\ue9cifiques en fonction des \ue9cotypes.
L\u2019\ue9tude a mis en \ue9vidence l\u2019existence de
sp\ue9cificit\ue9s vari\ue9tales selon les \ue9cotypes. La
structuration de la diversit\ue9 intrasp\ue9cifique a montr\ue9
cinq biotypes dont trois ont \ue9t\ue9 clairement identifi\ue9s
comme les races SG1, SG5 et SG Kp et deux n\u2019ont pas pu \ueatre
identifi\ue9s. Bien que cette \ue9tude n\u2019ait pas permis de
d\ue9terminer l\u2019appartenance raciale des deux nouveaux
biotypes, elle offre n\ue9anmoins la possibilit\ue9 de
d\ue9velopper de nouvelles strat\ue9gies de lutte contre Striga
gesnerioides en se concentrant sur la s\ue9lection de
vari\ue9t\ue9s r\ue9sistantes en fonction des
sp\ue9cificit\ue9s r\ue9gionales des races de Striga dans chaque
zone agricole
Leveraging early dry season planting of ginger under irrigation to enhance production from bacterial wilt infected seed rhizome
Get PDFGinger ( Zingiber officinale Rosc.), one of the important export
crops grown in Ethiopia for its underground aromatic rhizome, is
threatened by the destructive Ginger Bacterial Wilt (GBW) disease. The
objective of this study was to evaluate the effect of moisture sources,
plant spacing, and nitrogen fertiliser, on rhizome yield and yield
attributes of latently infected ginger seed rhizomes. Treatments
included two levels of moisture sources (irrigation and rainfall), two
levels of plant spacing (40 cm x 15 cm and 40 cm x 30 cm), and three
rates of nitrogen fertiliser, i.e., 0, 46 and 92 kg N ha1 applied in
the form of urea. Analysis of variance showed significant (P<0.01)
variations between moisture sources and planting space for fresh
rhizome yield, but not for N levels. Moisture sources also
significantly (P<0.01) affected stand count at harvest, and other
yield attributes, viz., number of buds per rhizome per hill, number of
rhizomes per plant, rhizome size and rhizome and propagule weight.
Planting infected ginger rhizomes early in dry season, with irrigation,
led to production of healthy and large rhizomes weighing up to 662 g.
Narrow plant spacing showed better yield performance and yield
attributes, as opposed to wide spacing; though wide plant spacing was
more preferred for management of Ginger Bacterial Wilt during humid and
warm weather conditions. This experiment clearly demonstrated that
planting ginger rhizomes, which are latently infected with Ralistonia
solanacearum early in dry season, using irrigation could be the best
option to propagate disease free rhizomes since dry condition
successfully restrains bacterial development, disintegrating the
pathosystem. i.e., avoiding high humidity, which is one of the ideal
conditions for bacterial growth. Early planting in dry season, using
irrigation is a cost effective and easily applicable practice to
control Ginger Bacterial Wilt disease.Le gingembre ( Zingiber officinale Rosc.), est l\u2019une des
principales cultures d\u2019exportation cultiv\ue9es en
\uc9thiopie pour son rhizome aromatique souterrain, et il est
menac\ue9 par la maladie destructrice de la fl\ue9trissure
bact\ue9rienne du gingembre (GBW). L\u2019objectif de cette
\ue9tude \ue9tait d\u2019\ue9valuer l\u2019effet des sources
d\u2019humidit\ue9, des espaces de plantation et des engrais
azot\ue9s sur le rendement des rhizomes et les attributs de rendement
des rhizomes de graines de gingembre infect\ue9s de fa\ue7on
latente. Les traitements comprenaient deux niveaux de sources
d\u2019humidit\ue9 (irrigation et pluviom\ue9trie), deux niveaux
d\u2019espaces de plantation (40 cm x 15 cm et 40 cm x 30 cm) et trois
taux d\u2019engrais azot\ue9, soit 0, 46 et 92 kg N ha-1
appliqu\ue9 sous forme d\u2019ur\ue9e. L\u2019analyse de la
variance a montr\ue9 des variations significatives (P<0,01) entre
les sources d\u2019humidit\ue9 et l\u2019espace de plantation pour
le rendement des rhizomes frais, mais pas pour les niveaux
d\u2019azote. Les sources d\u2019humidit\ue9 ont \ue9galement
affect\ue9 de mani\ue8re significative (P<0,01) le nombre de
peuplements \ue0 la r\ue9colte et d\u2019autres attributs de
rendement, \ue0 savoir le nombre de bourgeons par rhizome par
colline, le nombre de rhizomes par plante, la taille des rhizomes et le
rhizome et le poids des propagules. La plantation de rhizomes de
gingembre infect\ue9s au d\ue9but de la saison s\ue8che, avec
irrigation, a conduit \ue0 la production de rhizomes sains et de
grande taille pesant jusqu\u2019\ue0 662 g. Un espacement
\ue9troit des plantes a montr\ue9 une meilleure performance de
rendement et des attributs de rendement, par opposition \ue0 un
espacement large; bien qu\u2019un espacement large entre les plantes
soit pr\ue9f\ue9rable pour la gestion de la fl\ue9trissure
bact\ue9rienne du gingembre dans des conditions
m\ue9t\ue9orologiques humides et chaudes. Cette exp\ue9rience a
clairement d\ue9montr\ue9 que la plantation de rhizomes de
gingembre qui sont infect\ue9s de mani\ue8re latente par Ralistonia
solanacearum au d\ue9but de la saison s\ue8che en utilisant
l\u2019irrigation pourrait \ueatre la meilleure option pour propager
des rhizomes indemnes de maladie, car la s\ue9cheresse freine avec
succ\ue8s le d\ue9veloppement bact\ue9rien,
d\ue9sint\ue9grant le pathosyst\ue8me. c\u2019est-\ue0-dire
\ue9viter une humidit\ue9 \ue9lev\ue9e, qui est l\u2019une des
conditions id\ue9ales pour la croissance bact\ue9rienne. La
plantation pr\ue9coce en saison s\ue8che en utilisant
l\u2019irrigation est une pratique rentable et facilement applicable
pour lutter contre la fl\ue9trissure bact\ue9rienne du gingembre
Occurrence of rice yellow mottle virus resistance breaking isolates in lowland catchment zones of Uganda
Get PDFRice ( Oryza spp; 2n=24.) production in Uganda and Africa in general,
is seriously threatened by the Rice yellow mottle virus disease
(RYMVD), a disease caused by Rice yellow mottle virus (RYMV) within the
genus Sobemovirus; family Sobemoviridae. This study investigated the
existence and distribution of resistance-breaking RYMV pathotype in the
three major lowland rice catchment areas in Uganda. Four known rice
accessions resistant to Rice yellow mottle virus (RYMV) namely;
Gigante, Tog5672, Tog5674 and Tog5681, carrying resistant
allele\u2019s rymv1-2, rymv1-4 & RYMV3, rymv1-5 and rymv1-3,
respectively, were tested for their response to different RYMV
isolates. The isolates were collected from three major lowland rice
catchment areas of Doho, Kibimba, and Olweny in Uganda. Out of 100 leaf
samples collected from the field and assayed for RYMV and confirmed to
be positive using RT-PCR, 83 isolates induced symptoms on IR64- the
RYMV susceptible line. Seventy-seven (92.8%) isolates were able to
overcome resistance in at least one of the four differential rice
accessions, as confirmed by the presence of RYMV symptoms; while 6
(7.2%) isolates were asymptomatic. Variation in time (days) for symptom
development post-inoculation (dpi) and AUDPC were observed. Symptoms
appeared within 5-7 days on IR64; while it took on average 11, 18, 36,
and 18 days to appear on Gigante, Tog5672, Tog5674 and Tog5681,
respectively. The highest AUDPC was observed on IR64 (254.7); while the
lowest was observed on Tog5681 (74.1). Two major patho-groups were
observed; those that broke down resistance in Gigante only (25.3%) and
Gigante & Tog5672 (33.7%). Five isolates from Doho (Budaka &
Bugiri districts) and Kibimba (Butaleja district) catchment areas broke
down RYMV resistance in three accessions i.e. (Tog5681, Gigante &
Tog5672) and (Tog5674, Gigante & Tog5672), respectively. Resistance
breaking isolates were confirmed in all \ua0the three sampled
catchment zones, however, Doho and Kibimba had some unique isolates
that broke down resistance in accessions carrying resistance allele
rymv 1-3 and rymv1-5 in addition to rymv1-2. Results from this study
showed that RYMV isolates in Uganda can break down resistance conferred
by the\ua0rymv1-2 resistance gene allele. However, accessions Tog5681
and Tog5674 seem to hold stable RYMV resistance and, thus are
recommended for RYMV breeding.La production de riz ( Oryza spp ; 2n=24.) en Ouganda et en Afrique
en g\ue9n\ue9ral, est s\ue9rieusement menac\ue9e par la maladie
du virus de la marbrure jaune du riz (RYMVD), une maladie caus\ue9e
par le virus de la marbrure jaune du riz (RYMV) du genre Sobemovirus ;
famille des Sobemoviridae. Cette \ue9tude a examin\ue9
l\u2019existence et la distribution du pathotype RYMV qui brise la
r\ue9sistance dans les trois principaux bassins versants de riz de
plaine en Ouganda. Les quatre accessions de riz connues
r\ue9sistantes au \ua0virus\ua0de la panachure\ua0jaune du
riz\ua0(RYMV, Rice yellow mottle\ua0virus) \ue0 savoir; Gigante,
Tog5672, Tog5674 et Tog5681, portant respectivement les all\ue8les
r\ue9sistants rymv1-2, rymv1-4 & rymv3, rymv1-5 et rymv1-3, ont
\ue9t\ue9 test\ue9s pour leur r\ue9ponse \ue0 diff\ue9rents
isolats de RYMV. Les isolats ont \ue9t\ue9 collect\ue9s dans les
trois principaux bassins versants du riz de plaine de Doho, Kibimba et
Olweny en Ouganda. Sur les 100 \ue9chantillons des feuilles
pr\ue9lev\ue9s sur le terrain et test\ue9s pour le RYMV et
confirm\ue9s positifs par RT-PCR, 83 isolats ont induit des
sympt\uf4mes sur IR64, la lign\ue9e sensible au RYMV. Les
soixante-dix-sept (92,8 %) isolats ont r\ue9ussi \ue0 surmonter la
r\ue9sistance dans au moins une des quatre accessions du riz
diff\ue9rentielles, comme le confirme la pr\ue9sence des
sympt\uf4mes du RYMV\ua0; tandis que 6 (7,2 %) isolats \ue9taient
asymptomatiques. Une variation dans le temps (jours) pour le
d\ue9veloppement des sympt\uf4mes apr\ue8s l\u2019inoculation
(dpi, development post-inoculation) et l\u2019AUDPC a \ue9t\ue9
observ\ue9e. Les sympt\uf4mes sont apparus dans les 5 \ue0 7
jours sur IR64\ua0; alors qu\u2019il a fallu en moyenne 11, 18, 36
et 18 jours pour appara\ueetre sur Gigante, Tog5672, Tog5674 et
Tog5681, respectivement. L\u2019AUDPC le plus \ue9lev\ue9 a
\ue9t\ue9 observ\ue9 sur IR64 (254,7); tandis que l\u2019AUDPC
le plus bas a \ue9t\ue9 observ\ue9 sur Tog5681 (74,1). Deux
patho-groupes principaux ont \ue9t\ue9 observ\ue9s; ceux qui ont
bris\ue9 la r\ue9sistance dans les Gigante uniquement (25,3%) et
Gigante & Tog5672 (33,7%). Les cinq isolats des bassins versants de
Doho (districts de Budaka et Bugiri) et de Kibimba (district de
Butaleja) ont bris\ue9 la r\ue9sistance au RYMV dans trois
accessions, \ue0 savoir (Tog5681, Gigante et Tog5672) et (Tog5674,
Gigante et Tog5672), respectivement. Des isolats brisant la
r\ue9sistance ont \ue9t\ue9 confirm\ue9s dans les trois zones
de captage \ue9chantillonn\ue9es, cependant, Doho et Kibimba
avaient des isolats uniques qui brisaient la r\ue9sistance dans des
accessions portant les all\ue8les de r\ue9sistance rymv1-3 et
rymv1-5 en plus de rymv1-2. Les r\ue9sultats de cette \ue9tude ont
montr\ue9 que les isolats de RYMV en Ouganda peuvent briser la
r\ue9sistance conf\ue9r\ue9e par l\u2019all\ue8le du g\ue8ne
de r\ue9sistance rymv1-2. Cependant, les accessions Tog5681 et
Tog5674 semblent d\ue9tenir une r\ue9sistance stable au RYMV et
sont donc recommand\ue9es pour la s\ue9lection du RYMV
The relation between natural vegetation and climatic availability in Rio Grande do Sul state, Brazil
No full textO clima do estado do Rio Grande do Sul (RS) \ue9 temperado
\ufamido, condi\ue7\uf5es de vegeta\ue7\ue3o natural do tipo
floresta temperada ou decidual, entretanto, em aproximadamente 46,3% de
sua \ue1rea, a vegeta\ue7\ue3o \ue9 campestre. Assim, neste
estudo, procurou-se colaborar no sentido de melhor entender as
rela\ue7\uf5es entre as condi\ue7\uf5es clim\ue1ticas e a
vegeta\ue7\ue3o natural do estado do RS. Para isso, relacionou-se a
vegeta\ue7\ue3o natural do estado do RS com as disponibilidades
clim\ue1ticas. Foram utilizados doze modelos fitoclim\ue1ticos e
tr\ueas classifica\ue7\uf5es clim\ue1ticas. Para o c\ue1lculo
dos modelos e o enquadramento nas classifica\ue7\uf5es
clim\ue1ticas, foram utilizadas as m\ue9dias dos totais mensais e
anuais da precipita\ue7\ue3o pluviom\ue9trica e
evapotranspira\ue7\ue3o potencial, as m\ue9dias, m\ue9dias das
m\ue1ximas e m\ue9dias das m\uednimas mensais e anuais das
temperaturas do ar e as m\ue9dias mensais e anuais das
defici\ueancias e excessos h\ueddricos do solo de 41
esta\ue7\uf5es meteorol\uf3gicas, per\uedodo 1931-1960 e,
ainda, as m\ue9dias mensais da radia\ue7\ue3o solar global de 25
esta\ue7\uf5es meteorol\uf3gicas, per\uedodo 1957-1984. Pelos
resultados obtidos para todas as esta\ue7\uf5es meteorol\uf3gicas
utilizadas, as disponibilidades clim\ue1ticas do estado s\ue3o
caracter\uedsticas de forma\ue7\ue3o vegetal natural do tipo
floresta. Dessa forma, tendo em vista que em torno de 46,3% da
vegeta\ue7\ue3o natural do estado \ue9 do tipo campestre,
conclui-se que outros fatores, al\ue9m do clima, interferem e/ou
interferiram na forma\ue7\ue3o da vegeta\ue7\ue3o do Rio Grande
do Sul.The climate of the state of Rio Grande do Sul (RS) is humid temperate,
conditions of natural vegetation of the kind called temperate or
deciduous forest. However, in approximately 46.6% of its area the
vegetation is country. Thus, in this study, we tried to corroborate in
order to better understand the relationships between climatic
conditions and the natural vegetation of RS state. To do so, the
natural vegetation of RS was related to the climatic availability.
Twelve phytoclimatic models and three climatic classifications were
used. For the calculation of the models and the classification in the
climatic classifications, the averages of the monthly and annual totals
of the rainfall and potential evapotranspiration were used, the means,
average of the maximum and average of the monthly and annual minimum of
the air temperatures and the monthly averages and of the soil water
deficiencies and excesses of 41 meteorological stations, period
1931-1960, and also the monthly averages of the global solar radiation
of 25 meteorological stations, period 1957-1984. From the results
obtained for all the meteorological stations used, the climatic
availabilities of the state are characteristics of natural vegetation
formation of the forest type. Thus, considering that about 46.3% of the
state\u92s natural vegetation is of the country type, it is concluded
that other factors, in addition to the climate, interfere and/or have
interfered in the formation of vegetation in Rio Grande do Sul state
Management of Lasiodiplodia theobromae , the causal agent of mango tree decline disease in Ghana
Get PDFMango ( Mangifera indica L.), is one of the economically most
important crops in Ghana. It is recognised for its popularity in
contributing to food and nutritional security. Despite its economic
importance, mango tree decline disease, caused by Lasiodiplodia
theobromae, poses a serious threat to the mango industry in the
country. The objective of this study was to evaluate fungicides (i.e.,
carbendazim, zamir, mancozeb, funguran and sulphur 80) and bio
pesticides ( Chromolaena odorata , Azadirachta indica and Carica
papaya ) against L. theobromae. The results showed that all the tested
fungicides, except for sulphur 80, inhibited mycelial radial growth of
L. theobromae, with carbendazim and funguran improving the vegetative
growth of the shoots and leaves in the field. Mango trees treated with
carbendazim, after the third spray, had no disease symptoms. However,
application of urea fertiliser and carbendazim (50 g 15 L-1 water), at
a two-week spraying interval in the field, reduced the severity of L.
theobromae. Application of biopesticides (plant extracts) showed that
C. odorata had the highest efficacy, followed by A. indica and then C.
papaya. Although further studies on plant extracts in the field are
required, our findings provide important information for the
development of integrated management strategies for the pathogen, and
the disease it transmits.La mangue ( Mangifera indica L.) est l\u2019une des cultures les
plus importantes \ue9conomiquement au Ghana. Il est reconnu pour sa
popularit\ue9 en contribuant \ue0 la s\ue9curit\ue9 alimentaire
et nutritionnelle. Malgr\ue9 son importance \ue9conomique, la
maladie du d\ue9clin du manguier, caus\ue9e par Lasiodiplodia
theobromae , constitue une menace s\ue9rieuse pour l\u2019industrie
de la mangue dans le pays. L\u2019objectif de cette \ue9tude
\ue9tait d\u2019\ue9valuer les fongicides (c\u2019est-\ue0-dire
le carbendazime, le zamir, le mancoz\ue8be, le fonguran et le soufre
80) et les pesticides biologiques ( Chromolaena odorata , Azadirachta
indica et Carica papaya ) contre L. theobromae. Les r\ue9sultats
ont montr\ue9 que tous les fongicides test\ue9s, \ue0
l\u2019exception du soufre 80, inhibaient la croissance radiale
myc\ue9lienne de L. theobromae, le carbendazime et le fonguran
am\ue9liorant la croissance v\ue9g\ue9tative des pousses et des
feuilles au champ. Les manguiers trait\ue9s au carbendazime
apr\ue8s la troisi\ue8me pulv\ue9risation ne pr\ue9sentaient
aucun sympt\uf4me de maladie. Cependant, l\u2019application
d\u2019engrais \ue0 base d\u2019ur\ue9e et de carbendazime (50 g
15 L-1 d\u2019eau) \ue0 un intervalle de pulv\ue9risation de deux
semaines dans le champ a r\ue9duit la gravit\ue9 de L. theobromae.
L\u2019application de biopesticides (extraits de plantes) a
montr\ue9 que C. odorata avait la plus grande efficacit\ue9, suivie
par A. indica et ensuite C. papaya. Bien que des \ue9tudes
suppl\ue9mentaires sur les extraits de plantes sur le terrain soient
n\ue9cessaires, nos r\ue9sultats fournissent des informations
importantes pour le d\ue9veloppement de strat\ue9gies de gestion
int\ue9gr\ue9e du pathog\ue8ne et de la maladie qu\u2019il
transmet
Farmers\u2019 preference for onion varieties and implications of knowledge of Iris yellow spot disease in Kenya
No full textThrip transmitted Iris yellow spot disease (IYSD) is an economically
important viral disease, affecting bulb onions worldwide. Recommended
IYSD resistant varieties are not commonly grown in countries like
Kenya, yet inappropriate disease control measures are applied upon
disease occurrence in the fields. This is presumably due to lack of
knowledge on the disease and/or recommended varieties do not match
farmers\u2019 preferred traits. The objective of this study was to
assess farmers\u2019 knowledge of IYSD and their criteria for
selecting onion varieties for/against IYSD in Kenya. A study was
conducted with 360 respondents across three onion growing
agro-ecological zones (AEZ) in Kenya, during 2019-2020. Farmers\u2019
fields were assessed for IYSD incidence and severity. All farmers
acknowledged the existence of IYSD based on diseased plants in the
field. However, majority of the farmers (95.6%) were not aware of the
cause of the disease. Onion thrips and IYSD susceptible red onion
varieties were the most preferred (77.9%) by farmers. Preference for
these varieties was based on their high yielding capacity, early
maturity, strong pungency, marketability and long shelf life. Most
farmers (59.8%) relied on fungicides to control IYSD, though
ineffectively. Lack of appropriate management strategies for IYSD was
due to lack of knowledge on the disease diagnosis, epidemiology as well
as cultivation of IYSD susceptible red varieties.La maladie des taches jaunes de l\u2019iris (IYSD) transmise par le
thrip est une maladie virale \ue9conomiquement affectant les oignons
\ue0 bulbe dans le monde entier. Les vari\ue9t\ue9s
r\ue9sistantes qui sont recommand\ue9es \ue0 l\u2019IYSD ne sont
pas couramment cultiv\ue9es dans des pays comme le Kenya, mais des
mesures de lutte contre la maladie inappropri\ue9es sont
appliqu\ue9es en cas d\u2019apparition de la maladie dans les
champs. Cela est probablement d\ufb au manque de connaissances sur la
maladie et / ou les vari\ue9t\ue9s recommand\ue9es ne
correspondent pas aux caract\ue9ristiques pr\ue9f\ue9r\ue9es
des agriculteurs. L\u2019objectif de cette \ue9tude \ue9tait
d\u2019\ue9valuer les connaissances des agriculteurs sur
l\u2019IYSD et leurs crit\ue8res de s\ue9lection des
vari\ue9t\ue9s d\u2019oignon pour / contre l\u2019IYSD au Kenya.
Des entretiens structur\ue9s ont \ue9t\ue9 men\ue9s avec 360
personnes interrog\ue9es dans trois zones agro\ue9cologiques (AEZ)
de culture d\u2019oignon au Kenya, au cours de la p\ue9riode
2019-2020. Les agriculteurs ont \ue9t\ue9 s\ue9lectionn\ue9s au
hasard et leurs champs ont \ue9t\ue9 \ue9valu\ue9s pour
l\u2019incidence et la gravit\ue9 de l\u2019IYSD. Tous les
agriculteurs enqu\ueat\ue9s ont reconnu l\u2019existence de
l\u2019IYSD sur la base des plantes malades qui leur ont \ue9t\ue9
montr\ue9es sur le terrain. Cependant, la majorit\ue9 des
agriculteurs (95,6%) ne connaissaient pas la cause de la maladie. Les
thrips de l\u2019oignon et les vari\ue9t\ue9s d\u2019oignon rouge
sensibles \ue0 l\u2019IYSD \ue9taient les plus
appr\ue9ci\ue9es (77,9%) par les agriculteurs. La
pr\ue9f\ue9rence pour ces vari\ue9t\ue9s \ue9tait bas\ue9e
sur leur capacit\ue9 de rendement \ue9lev\ue9e, leur
maturit\ue9 pr\ue9coce, leur fort piquant, leur aptitude \ue0 la
commercialisation et leur longue dur\ue9e de conservation. La plupart
des agriculteurs (59,8%) se sont appuy\ue9s sur des fongicides pour
lutter contre l\u2019IYSD, bien que de mani\ue8re inefficace. Le
manque de strat\ue9gies de gestion appropri\ue9es pour l\u2019IYSD
\ue9tait d\ufb au manque de connaissances sur le diagnostic de la
maladie, l\u2019\ue9pid\ue9miologie ainsi que la culture de
vari\ue9t\ue9s rouges sensibles \ue0 l\u2019IYSD
Changes in endogenous levels of IAA and PAA in rice seed during development, prediction of auxin signaling proteins and docking for its binding efficiency with auxin molecules
Get PDFIndole-3-acetic acid (IAA) and phenyl acetic acid (PAA) are two major
physiologically active auxins, found in higher plants. The objective of
this study was to evaluate changes in the endogenous levels of IAA and
PAA in rice ( Oryza sativa ) seed and predict probable transporter and
efflux (signaling) proteins for docking with auxins from the available
rice genome data. IAA and PAA were estimated during rice seed
development using sensitive and specific antibodies against each
hormone. The levels of IAA and PAA were higher when sink size
development was at its peak, suggesting an important role played by the
auxin in sink size development of rice seed. Furthermore, auxin binding
transporters proteins of rice were confirmed for docking purpose and
compared with Arabidopsis and maize proteins. In this context, PAA
docked with known IAA proteins; although, docking score of IAA was
higher than that of PAA in rice seed. Twelve genes of the auxin efflux
carrier (PIN family) of rice were also analysed for phylogeny
relatedness with Arabidopsis and maize, to further understanding auxin
concentrations and efflux within rice seeds. The predicted PIN proteins
for IAA efflux of rice showed docking affinities with PAA, revealed its
role in maintaining physiological concentrations of auxins in rice
seeds.L\u2019acide indole-3-ac\ue9tique (IAA, Indole-3-acetic acid) et
l\u2019acide ph\ue9nylac\ue9tique (PAA, phenyl acetic acid) sont
deux auxines physiologiquement actives majeures, trouv\ue9es dans les
plantes sup\ue9rieures. L\u2019objectif de cette \ue9tude
\ue9tait d\u2019\ue9valuer les changements dans les niveaux
endog\ue8nes d\u2019IAA et de PAA dans les graines de riz (Oryza
sativa) et de pr\ue9dire les prot\ue9ines de transport et
d\u2019efflux (signalisation) probables pour l\u2019amarrage aux
auxines \ue0 partir des donn\ue9es disponibles sur le g\ue9nome
du riz. L\u2019IAA et le PAA ont \ue9t\ue9 estim\ue9s au cours
du d\ue9veloppement des semences de riz en utilisant des anticorps
sensibles et sp\ue9cifiques contre chaque hormone. Les niveaux
d\u2019IAA et de PAA \ue9taient plus \ue9lev\ue9s lorsque le
d\ue9veloppement de la taille du puits \ue9tait \ue0 son maximum,
sugg\ue9rant un r\uf4le important jou\ue9 par l\u2019auxine dans
le d\ue9veloppement de la taille du puits des graines de riz. De
plus, les prot\ue9ines transporteuses de liaison aux auxines du riz
ont \ue9t\ue9 confirm\ue9es \ue0 des fins d\u2019amarrage et
compar\ue9es aux prot\ue9ines d\u2019Arabidopsis et de ma\uefs.
Dans ce contexte, le PAA s\u2019est amarr\ue9 \ue0 des
prot\ue9ines IAA connues ; cependant, le but d\u2019amarrage de
l\u2019IAA \ue9tait plus \ue9lev\ue9 que celui du PAA dans les
semences de riz. Douze g\ue8nes du transporteur d\u2019efflux
d\u2019auxine (famille PIN) du riz ont \ue9galement \ue9t\ue9
analys\ue9s pour la phylog\ue9nie avec Arabidopsis et le ma\uefs,
afin de mieux comprendre les concentrations d\u2019auxine et
l\u2019efflux dans les graines de riz. Les prot\ue9ines PIN
pr\ue9dites pour l\u2019efflux d\u2019IAA du riz ont montr\ue9
des affinit\ue9s d\u2019amarrage avec le PAA, ont
r\ue9v\ue9l\ue9 son r\uf4le dans le maintien des concentrations
physiologiques d\u2019auxines dans les graines de riz