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| ARPN Journal of Agricultural and Biological
Science
September 2010
| Vol. 5 No. 5 |
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Title: |
Amino
acids, fatty acids and minerals in Kappaphycus sp. |
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Author (s): |
P.
Rajasulochana, D. Dhamotharan and P. Krishnamoorthy |
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Abstract: |
Amino acid, fatty acid and
minerals of Kappaphycus sp. were determined. Amino
acids were estimated by HPLC method where as fatty acids by
gas chromatography. Total 18 amino acids were found in the
dried species, lysine is the major constituent and followed
by asparagines, histidine, isoleucine, phenylalamine,
tryptophan. In the case of fatty acids, eight components
were identified including two components, namely, palmitic
and cervonic acids are in traces. Alpha linolenic (n-3) and
linoleic acids are found to be the major components.
Macrominerals were identified by using flame atomic
absorption spectrophotometry and found that red algae
contained various macrominerals, namely, Sodium (23.4 mg),
Potasium (12.44 mg), Magnesium (23.56 mg), Phosphorous (19.5
mg) per 1000mg and rich in Calcium (3.565 gm/100 gm). It was
observed that Na/K ratio is below 2.0 which is interesting
to note that Kappaphycus sp. Could be used as a food
supplement. |
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Title: |
Use of
selected plant-derived powders and their combinations to
protect stored cowpea grains against damage
by Callosobruchus maculatus |
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Author (s): |
Nelson N.
Ntonifor, Esther O. Oben and Christina B. Konje |
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Abstract: |
In search for low-cost
plant-based post-harvest insecticide against stored product
insects, dried seed powders of Syzygium aromaticum,
Piper guineense, Ocimum basilicum, Aframomum citratrum
and leaf powders of Cyperus aequalis and
Eucalyptus camaldulensis were tested against
Callosobruchus maculatus in cowpea grains. For
each, 100g of grains were mixed with 1, 2, 3, or 4g of
powder and mortality recorded daily for 5 days. The potency
and persistence of various combinations of potent powders
were also studied. Regardless of concentration, S.
aromaticum or P. guineense powder treated grains
caused 100% and 98.75% adult mortality, respectively, within
5 days after infestation (DAI) compared to 100% 2 DAI for
Actellic® powder, the standard protectant in
Cameroon. Ocimum basilicum or A. citratum
powder were less efficacious compared to S. aromaticum
and P. guineense; each caused significantly lower
grain weight loss after three months of storage. S.
aromaticum powders had longer residual effects by
preventing weevil emergence for
³
8 weeks compared to 6 weeks for P. guineense. Adult
weevils introduced weekly on seeds treated with S.
aromaticum powder were continuously killed for
³
8 weeks after treatment compared to 6 and 4 weeks for P.
guineense and Actellic®, respectively.
Application of 50:50% combinations of S. aromaticum
and C. aequalis powders caused 100% adult mortality
at 5 DAI, earlier than similar mixtures with E.
camaldulensis or P. guineense and C. aequalis
or E. camaldulensis. Equal mixtures of powders of
S. aromaticum and C. aequalis clearly have
potentials for long-term and large-scale protection of
stored grains. |
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Title: |
Studies
on the optimization of cultural conditions for maximum
hydrogen production by selected cyanobacteria |
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Author (s): |
B.
Jeberlin Prabina and K. Kumar |
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Abstract: |
Maximum production of hydrogen
by the cyanobacterial isolates was obtained with 0.3 per
cent CO2, 2 per cent, N2, pH 7.5,
incubated under 3500 lux light intensity with 16:8 h dark:
light cycle at 27°C. Supplementation of photo system II
inhibitor DCMU enhanced the hydrogen production when
incubated with longer light duration.
Supplementation of iron in the growth medium enhanced the
hydrogen production in Anabaena - TE1 and Nostoc
- TE1, whereas supplementation of both nickel and iron
increased the hydrogen efficiency of Fischerella -
TE1. Sulphur stress had a pronounced effect on the
production of hydrogen that it sustained higher production
rate under 8:16 h dark: light cycle and highest production
was recorded in Anabaena - TE1 (26.28 mL g-1
dry wt. L-1). |
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Title: |
Morphology aspects of the fat body and
the haemolymph of males of the predator brontocoris tabidus
(het, pentatomidae): Effect of the phytophagy and age |
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Author (s): |
Walkymário Paulo Lemos, José Eduardo Serrão, José Cola
Zanuncio, Mábio Chrisley Lacerda and Rafael Coelho Ribeiro |
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Abstract: |
Morpho-physiological aspects
of the fat body of the haemolymph of the predator
Brontocoris tabidus (Signoret) (Heteroptera:
Pentatomidae) males fed on Tenebrio molitor L.
(Coleoptera: Tenebrionidae) pupae without plant; T.
molitor pupae plus Eucalyptus cloeziana
plants; T. molitor pupae plus Eucalyptus urophylla
plants; T. molitor pupae plus guava plants (Psidium
guajava) were analyzed. Haemolymph protein content and
fat body morphology were analyzed in samples of B.
tabidus males 15 and 21 days old. The haemolymph protein
content of B. tabidus males was not affected by the
diet or age of this predator. Adult of B. tabidus
males had thophocytes with similar morphological aspects in
all diets and ages analyzed, but they were twice bigger in
those predator fed on T. molitor and plants of E.
urophylla than with the other diets. The histochemical
tests proteins and carbohydrates showed weak reaction of the
fat body of B. tabidus males with all diets and ages.
These results are discussed in relation to the effect of
plant supplementation in predator diets. |
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Title: |
Ecophysiological and genetic characteristics of three
wetland plant species occurring in lake
Victoria
region in Kenya |
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Author (s): |
David M. Musyimi, Godfrey W.
Netondo and Barrack Owuor |
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Abstract: |
This study was carried out to
investigate the ecophysiological and genetic characteristics
of some selected wetland plant species in Lake Victoria
basin, Kenya. Seedlings of Cyperas esculentus L.,
Aframomum angustifolium (Sonn.) and Phragmites
australis (Cav.) Trin. Ex Steudel) were grown outdoors
in pots. Plants were provided with four nutrient dosage
levels of 0 mg [no fertilizer added], 50 mg, 100 mg, 150 mg
fertilizer [N: P: K, 10:26:10] per pot and replicated five
times. Data on Leaf area, number of tillers per pot, Leaf
chlorophyll concentration, Gas exchange parameters and
chlorophyll fluorescence parameters were determined.
Separation of means was carried out to compare nutrient
treatments and species. Increasing nutrient availability
significantly (P ≤ 0.05) influenced most of the
morphological and physiological parameters investigated.
Cyperas esculentus had significantly greater leaf area
compared to A. angustifolium and P. australis.
Number of tillers per pot was significantly increased in
C. esculentus than in all other species, suggesting that
this species was greatly influenced by nutrient availability
than the other species. Phragmites australis had
significantly higher carotenoids compared to the other
species. Cyperas esculentus showed a higher
photosynthetic activity compared to A. angustifolium
and P. australis at increasing nutrient availability.
Stomatal conductance increased with increase in nutrient
availability in all the three species, but interestingly,
P. australis and A. angustifolium had higher
stomatal conductance compared to C. esculentus.
Transpiration rates also increased with increasing nutrient
availability but A. angustifolium and C.
esculentus had significantly higher transpiration rates
compared to P. australis. The study reveals
Cyperas esculentus as a physiologically superior species
compared to Aframomum angustifolium and Phragmites
australis. |
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Title: |
Regulation of cellulase and pectinase activities in cherry
tomato (Lycopersicon esculentum Mill var. cerasiforme) fruit
by use of 1-methylcyclopropene (1-MCP) |
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Author (s): |
Arnold M.
Opiyo |
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Abstract: |
Softening, which accompanies ripening fruits
is also to a large extent, responsible for the damage that
occurs during handling and shipping. The effects of 1-MCP
application at different ripening stages (mature green,
breaker, breaker + 2 days and breaker + 4 days) on cellulase
and pectinase activities of cherry tomato fruit (Lycopersicon
esculentum Mill. var. cerasiforme) were studied.
Fruit were exposed to a 5µl-1 1-MCP concentration
and enzyme activity was determined viscometrically. Both
cellulase and pectinase activities were suppressed by 1-MCP
treatment, especially in MG and BR fruit. 1-MCP delayed
cellulase activity peak by at least 3 days and 6 days in
treated MG and BR fruit respectively compared to their
corresponding controls. In treated
MG fruit, pectinase activity was suppressed and the
initiation delayed by 3 days compared to untreated fruit.
Results indicate that 1-MCP when applied at either MG
or BR stages of ripening is beneficial for at least 10 days. |
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Title: |
Yields
and profitability of a dual–purpose sole cowpea and
cowpea-maize intercrop as influenced by cowpea leaf
harvesting frequency |
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Author (s): |
Mwanarusi
Saidi, Francis M. Itulya, Joseph. N. Aguyoh and Patience. M.
Mshenga |
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Abstract: |
Dual-purpose cowpea production is a common
component of many tropical and sub tropical subsistence
farming systems. Under such systems, cowpea leaves are
harvested for vegetable use at the vegetative stage of the
plants and seeds later at crop maturity. Little information
exists on effects of leaf harvesting frequency on subsequent
yields and economic returns of the many dual-purpose cowpea
based cropping systems. This study investigated the effects
of harvesting cowpea leaves at every 7-days or 14-days
interval on leaf vegetable and grain yields and
profitability of a sole dual-purpose cowpea and a
dual-purpose cowpea-maize intercrop. Harvesting cowpea
leaves at 7-days interval gave higher leaf vegetable yield
with both cropping regimes. Grain yields were higher for
14-days compared to 7-days leaf harvesting frequency. The
highest grain yields were obtained in none leaf harvested
control cowpea. Maize yields in intercrop treatments were
highest when leaves of the companion cowpea were harvested
at 7-days interval and lowest when no leaf harvesting was
done to the companion cowpea. Harvesting cowpea leaves at
7-days interval resulted in higher gross margins with both
cropping regimes. Profitability correlated positively with
leaf vegetable and grain yields. Gross margins were also
higher for intercropping compared to sole cropping in both
seasons. |
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Title: |
Water
requirement, deficit irrigation and crop coefficient of hot
pepper (Capsicum frutescens) using irrigation interval of
four (4) days |
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Author(s): |
J. D.
Owusu-Sekyere, P. Asante and P. Osei-Bonsu |
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Abstract: |
This study was conducted to
determine the seasonal water requirement of pepper, the crop
coefficient under full water requirement as well as the
effect of deficit irrigation on pepper growth and
development under a rain shelter. The treatments imposed
were T1, application of 100% crop water requirement, T2, was
80%, T3 60% and T4 40 % of crop water requirement. It was
determined that pepper requires about 587.48mm of water over
the growth season. The crop coefficient under full water
supply was found to be: 0.47, 0.86, 1.42 and 0.91 for
initial, development, mid-season and the late season stages
respectively. The study also revealed that reduction in 20%
water need of hot pepper has no significant effect on
growth, development and fruiting of the crop. |
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Title: |
Antimicrobial
activity of ethyl acetate extracts from edible Tanzanian Coprinus cinereus (schaeff)
S. Gray s. lat. cultivated on grasses supplemented with cow
dung manure |
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Author (s): |
Theonest Ndyetabura, Sylvester
Leonard Lyantagaye and Anthony Manoni Mshandete |
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Abstract: |
This study is the first broad investigation
of antimicrobial activity of different development stages of
Coprinus cinereus from Tanzania. The indigenous
edible wild C. cinereus mushroom was
successfully grown in tropical conditions on dried grasses
supplemented with different amounts of cow dung manure.
Ethyl acetate crude extracts were prepared from different
developmental stages of the mushroom, and were screened for
antifungal and antibacterial activities using agar
well method. Different extracts from black caps, post
capping stage and black stem exhibited activity against
Escherichia coli, Candida albicans and
Aspergillus
niger
none of the gram positive bacteria was
inhibited to grow. Differences in the substrate composition
presented differences in the bioactivity of the mushroom
extracts with 2: 3 ratio of cow-dung: grasses producing the
highest activity. The results obtained clearly indicated
that Tanzanian C. cinereus extracts contains
bioactive components and are potential sources of
antimicrobial compounds that could be used for development
of new agents for the treatment and prevention of diseases. |
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Title: |
Evaluation of some industrially important enzymes in
filamentous cyanobacteria |
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Author (s): |
Padmapriya V. and Anand N. |
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Abstract: |
Preliminary studies
involving nine filamentous cyanobacterial isolates for the
screening for amylase, protease, beta lactamae and
phosphatase enzymes were carried out. Best growth was
observed in C. membranacea. O. proboscidea showed a
complete absence of amylase activity in the external medium,
extracellular (EC) activity, and P.boryanum showed
the highest amount of EC enzyme activity on the 8th day
amongst non-heterocystous forms. In P. boryanum, the
amylase intracellular (IC) activity was present consistently
throughout the period of study with a gradual increase from
zero day (day of inoculation) up to the 20th day. Amongst
the heterocystous forms, A. variabilis showed the
highest amylase EC and IC activities. All the non-heterocystous
forms showed highest protease EC activity on the 16th day
except O. proboscidea, which registered detectable
protease EC activity only on the 16th and 20th day. The
heterocystous forms, N. paludosum and W. iyengarii
showed a consistent presence of the protease EC activity
throughout the study period. N. paludosum and W.
iyengarii had a sharp increase of protease IC activity
on the 4th day, which incidentally was the highest activity.
Beta-lactamase EC activity observed in L. spiralis
on day 4 was the highest amongst the non-heterocystous
forms. In A. variabilis and C. membranacea,
the beta-lactamase EC activity was the highest on day 4
compared with other heterocystous forms. The EC activity of
acid phosphatase enzyme in the non-heterocystous forms,
P. minnesotensis and P. boryanum, showed a
decrease as the growth increased, reaching negligible levels
on the 20th day. In the heterocystous forms, both
the acid phosphatase EC and IC activities were absent up to
a period of 8 days. In the case of alkaline phosphatase IC
activities, a gradual decrease in the enzyme content from
the first interval is observed in almost all the forms.
W. iyengarii showed higher EC activity compared with
other heterocystous forms but the maximum IC activity was
observed in A. variabilis.
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