ARPN Journal of Agricultural and Biological Science       ISSN 1990-6145
   
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ARPN Journal of Agricultural and Biological Science          September 2010 | Vol. 5 No. 5
 

Title:

Amino acids, fatty acids and minerals in Kappaphycus sp.

Author (s):

P. Rajasulochana, D. Dhamotharan and P. Krishnamoorthy

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

Author (s):

Nelson N. Ntonifor, Esther O. Oben and Christina B. Konje

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

Author (s):

B. Jeberlin Prabina and K. Kumar

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

Author (s):

Walkymário Paulo Lemos, José Eduardo Serrão, José Cola Zanuncio, Mábio Chrisley Lacerda and Rafael Coelho Ribeiro

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

Author (s):

David M. Musyimi, Godfrey W. Netondo and Barrack Owuor

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)
Author (s): Arnold M. Opiyo
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

Author (s):

Mwanarusi Saidi, Francis M. Itulya, Joseph. N. Aguyoh and Patience. M. Mshenga

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

Author(s):

J. D. Owusu-Sekyere, P. Asante and P. Osei-Bonsu

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
Author (s): Theonest Ndyetabura, Sylvester Leonard Lyantagaye and Anthony Manoni Mshandete
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

Author (s):

Padmapriya V. and Anand N.

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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