|
|
| ARPN Journal of Agricultural and Biological
Science
October 2014 | Vol. 9 No. 10 |
|
Title: |
In vitro
evaluation of some plant extracts against Alternaria
alternata causing leaf spot of Aloe vera |
|
Author (s): |
Roshan
Regmi, Ravi Jha, L .Sobita Simon and Abhilasha A Lal |
|
Abstract: |
Aloe Vera
(L.) Burn f. is a perennial succulent plant grown worldwide
mainly for medicinal and cosmetic uses. During a routine
survey a leaf spot disease of Aloe vera having
infected plants with large necrotic, sunken, circular to
oval, dark brown spots present on both surface of leaves was
observed at SHIATS and neighboring areas. Microscopical
examination revealed the presence of Alternaria
alternata in the infected areas. Pathogen was isolated
and cultured on Potato Dextrose Agar medium. Leaf Extracts
of six plants viz, Jatropa curcas,
Datura strumarium, Azadirachata indica,
Moringa oleifera, Calotropis gigantean and
Morus Alba @ 50 % were evaluated In vitro by food
poison techniques against the fungus. The results revealed
that all plant extracts @ 50 % significantly inhibited the
mycelial growth of pathogen. However leaf extract of J.
curcas demonstrated maximum mycelial growth inhibition
of A. alternata (62.9%) followed by D. strumarium
leaf extract (55.6%) and was significantly superior to
all other tested extracts. A. indica extract (51.9%)
also inhibited its mycelial growth followed by M.
oleifera (46.9%), C. gigantea extract
(23.45%) and M. Alba (13.6%) as compared to control. |
| |
|
|
|
Title: |
Occurrence and abundance of plant
parasitic nematodes in cabbage-based cropping systems in
Kenya |
|
Author (s): |
Mwangi,
J. M., J.W. Waceke and G.M. Kariuki |
|
Abstract: |
A survey was conducted to
determine the incidences of plant parasitic nematodes (PPN)
and factors enhancing population build-up in cabbage (Brassica
oleracea L. var capitata)-based cropping system
in selected agro-ecological zones of Kenya. Samples were
collected from sixty cabbage growing farms in Nyandarua and
Embu Counties. Nematodes assay was conducted for both root
and soil samples. Extraction of PPN from soil and root
sample was done using modified extraction tray method and
modified maceration extraction technique respectively.
Extracted nematodes were enumerated, identified to genus
level and their frequencies of occurrence and abundance
determined. Nematodes belonging to various genera were found
associated with cabbage in six agro-ecological zones. The
study revealed that cabbage is a preferable host to lesion
nematodes (Pratylenchus) with 87% and 58% frequency
of occurrence in soil and roots, respectively. The mean
population of this nematode in soil and root samples was
significantly different from other nematode general.
Meloidogyne was present at low frequency of 42% and 23%
in soil and roots and density 6.36/100cm3 of soil
and 1.1/10g roots. Helicotylenchus was recovered in
significant numbers with 82% frequency of occurrence in
rhizosphere and 27% in roots and a density of 26.28/100cm3
in soils and less than 1 nematode per 10g of roots.
Tylenchorhynchus occurred in 67% of the soil samples
while Paratrichodorus, Trichodorus and
Paratylenchus was present in 78%, 57% and 58% frequency
of occurrence in the cabbage rhizosphere but at a low
population density. Other PPN detected in low frequencies of
occurrence and density include; Tylenchus
Scutellonema, Xiphinema. among others. The study
encourages more research work to establish the economic
importance and the management of the reported nematode
pests. |
| |
|
|
|
Title: |
Virulence of three strains of beauveria
bassiana against the banana weevil |
|
Author (s): |
C.A. Omukoko,
K.N.Maniania, J .M. Wesonga, E.M.
Kahangi and L.S. Wamocho |
|
Abstract: |
The banana weevil, Cosmopolites sordidus Germar, is
the most important insect pest of banana and plantain.
Beauveria bassiana is the most researched and
commercialized fungal biopesticide effective against a
variety of insects. Laboratory studies have revealed a great
potential of this entomopathogen for use against the banana
weevil, Cosmopolites sordidus in banana. Use of traps
for collecting adults or infecting them with biopesticides
will most likely capture only those weevils in the immediate
vicinity of the traps. The indiscriminate use of chemicals
has resulted in the development of resistance in insect
pests, adverse ecological events, affecting beneficial
fauna, and accumulation of residues in the environment.
There is considerable need therefore to develop safe and
cheaper biocontrol alternatives that can be used to
complement existing control methods. The potential of
utilizing the entomopathogen B. bassiana for control
of banana weevil was evaluated by testing the virulence of
three isolates of Beauveria bassiana (ICIPE 273, M353
and M207) at three concentration (108, 3 x108
and 109). From previous pathogenicity tests these
three isolates were the most pathogenic. At higher fungal
concentrations of 3 x108 and 109 adult
mortality for all the three isolates was between 35%-70%.
The highest mortality was achieved using an elevated
concentration of 109, causing
mortalities varying from 50-70% 40 days after exposure
depending on the isolate. ICIPE 273 was the most virulent,
killing 70% of adults followed by M353 (65% mortality) and
M207 (51% mortality). This was far much greater than when a
standard concentration of 108 was used
(mortalities ranged between 28%-50%). Differences in
virulence among the tested isolates were due to their
geographical origins. |
| |
|
|
|
Title: |
Allelopathic interactions
between two barley cultivars (Hordeum Vulgare L) on weed
annual ryegrass (Lolium Multiflorum L) and charlock (Sinapis
Arvensis L) using the equal-compartment-agar-method |
|
Author (s): |
Mohammad Reza Baziar, Farhad Farahvash, Bahram Mirshekari,
and
Varahram Rashidi |
|
Abstract: |
The
use of cultivars with allelopathic potential is one of weed
management techniques. Factorial experiment in a completely
randomized design with two factors including the density and
culture on two barley cultivars namely Valfajer and Reyhaneh
were used in laboratory, Fasa branch, Islamic Azad
University, Fasa 2013. Actors examined included various
densities of barley (0, 8, 16, 24, 32) and culture time
(simultaneous and delayed). Ryegrass and Charlock seedling
growth features were under investigation. The results showed
that increasing barley plant density in both samples,
compared to control, leads to the significant decrease in
the seedling, radical and plumule lengths, wet and dry
seedling weights of both weeds. Compared with plumule
length, the radicle lengths of both weeds were more affected
by a density which shows its high sensitivity. Considering
the culture time of barley revealed that delayed planting
has significant effect on the measured characteristics of
weeds than simultaneous planting. Compared to simultaneous
culture, cut-off interaction of similar densities at both
culture times, showed the noticeable influence of delayed
culture on weeds of ryegrass and charlock growth features,
and also the most effective treatment combination was on the
growth habits of weeds density of 32 and delayed culture of
both barleys. Also, in order to compare the allelopathic
potential of Valfajer and Reyhaneh barleys, using the linear
regression model, the changes in the radicle length and
plumule length of ryegrass and charlock were determined
regarding applied densities. Comparison of model’s
parameters based on the confidence interval revealed the
same reduction of both cultivars on the mentioned features
and there was no noticeable significant difference between
them. |
| |
|
|
|
Title: |
The
response of haricot bean varieties to different rates of
phosphorus at Arba Minch, southern Ethiopia |
|
Author (s): |
Amare Girma, Assaye Demelash and Tuma Ayele |
|
Abstract: |
Field
experiment
was
conducted
during 2013
to determine
the response of common varieties to
phosphorus
fertilizer
application.
The treatment consists of
three common
bean varieties (Hawassa Dume,
Ibbado and Nasir) and
three phosphorus
rates
(0, 20
and
40
kg P2O5
/ha)
laid out in Randomized Complete Block Design with three
replications. Data was collected on plant height (cm),
number of nodule/plant, dry matter, number of pods/plant,
number of seeds/pod, 1000 seed weight (g), seed yield
(kg/ha), harvest index, crude protein content and phosphorus
uptake. The increasing rates of fertilizer showed
substantial improvement in nodule number, seed yield, crude
protein content, fertilizer recovery, agronomic efficiency
and physiological efficiency where the highest values of
these parameters were obtained from fertilizer at the rate
of 20 kg P2O5/ha. Hawasa dume showed
the best performance in most parameters whereas Ibbado gave
the lowest performance in contrary. These results can
indicate the benefit of phosphorus fertilizer application
and variety consideration for yield improvement, nodulation
potential and better nutrient use efficiency of common in
the study area. |
| |
|
|
|
|
|
|
|
Title: |
Effect of
bio-fertilizer and organic manure on growth and nutrients
content of pearl millet |
|
Author (s): |
Abdullahi R, Sheriff, H.H and Buba A |
|
Abstract: |
Field experiment was conducted to study the
effect of bio-fertilizer, Arbuscular mycorrhizal fungi (AMF)
(Glomus mossea) and Azospirillum brasilense
alone or in combination with cow dung (CD) or poultry manure
(PM) on growth of pearl millet. The experiment was laid out
in randomized complete block design with six treatments and
three replications. Treatments were: T1
(Control), T2 (Bio-fertilizer), T3
(Bio-fertilizer + 5 ton ha-1 CD), T4
(Bio-fertilizer + 2.5 ton ha-1 PM), T5
(10 ton ha-1 CD), T6 (5 ton ha-1
PM). Bio-fertilizer and organic manure singly or in
combination enhanced plant growth, % root colonization by AM
fungi, shoot and root dry biomass and nutrients
concentration (N, P and K) compared to control.
Bio-fertilizer + PM recorded highest plant performance
viz; plant height (72.6 cm), number of tillers/plant
(4.1), shoots and root dry biomass (8.8 and 3.9 g) followed
by bio-fertilizer alone and poultry manure. Applying 10 ton-1
of cow dung produced plants with the lowest growth
attributes although not a par with control. N and P
concentrations varied significantly between all treatments.
Bio-fertilizer + PM recorded the highest concentration of N
and P, and values were significantly higher than all the
treatments. There was no definite trend for K concentration
among all treatments. Inoculated and un-inoculated plants
were colonized by AM fungi. Inoculated plants were
significantly colonized compared to un-inoculated plants.
Significant difference in % root colonization was observed
between inoculated plants. Bio- fertilizer + PM recorded the
highest root colonization of 62% followed by bio-fertilizer
alone (56.7%). From the findings of this study, it can be
concluded that application of bio-fertilizer and organic
manure alone or in combination could improve pearl millet
production in low-input agriculture. Results also showed
that bio-fertilizer tended to reduce by half the application
rates of organic manure. Bio-fertilizer in combination with
2.5 ton ha-1 of PM could be recommended for
millet production in the study area. |
| |
|
|
Title: |
Genetic polymorphism and
allelic frequency of GHRH gene locus in Iranian Sarabi breed
of cattle |
|
Author (s): |
Mehdi Amin
Afshar, Mehdi Khosravi and Mohammad Chamani |
|
Abstract: |
Animal
selection based on molecular markers is one of the latest
breeding methods that can improve the correctness
of predictions and of response to selection. The GHRH
(growth hormone-releasing hormone) gene is one of the
candidate genes for selection strategies based on markers.
According to available reports, gene polymorphism is
significantly related to the traits of milk constituents and
milk production. Blood samples were taken from 112 head of
Sarabi breed cattle to study polymorphism in the GHRH gene
locus. The genomic DNA of the blood samples was extracted
and a 297-bp fragment of this gene was amplified using the
polymerase chain reaction. The amplified fragment was cut by
the HaeIII restriction enzyme and electrophoresed on 2%
agarose gel. Results showed that the two alleles GHRHA
and GHRHB with the respective frequencies
of 0.19 and 0.81 in the whole population are in this locus.
Three genotypes GHRHA GHRHA, GHRHA
GHRHB , GHRHB GHRHB)
were identified the calculated genotype frequencies of
which were 0.0357, 0.3037, and 0.6607. The Chi-square test
indicated the Hardy-Weinberg Equilibrium existed in the
population. Results of this research show that the genetic
variety in the Sarabi breed of cattle can help future
selection programs, especially the MAS (marker-assisted
selection) programs. |
| |
|
|
|
|
|
|
|
