World Journal of Agricultural Research

Potato (Solanum tuberosum L.) is the fourth major crop of the world after rice, wheat and maize. In Ethiopia, the yield per unit area of potato is very low compared to those of other countries. There are many factors that reduce the yield of the crop among which the diseases like late blight (Phytophthora infestans) and bacterial wilt (Ralstonia (Pseudomonas) solanacearum) which play an important role. Management of these diseases is therefore very essential. In Ethiopia, however, much research has not been done for the management of bacterial wilt disease except identification of bacteria and screening of biological control agents and use of resistant varieties. Late blight of potato can be managed using the following management (control) strategies: use of biological control agents, use of resistant varieties, intercropping, use of certified disease-free seed, use of selective fungicides and cultural practices such as destruction of cull piles by freezing or deep burying, destruction of volunteer potato plants in nearby fields throughout the season, destruction (desiccate, disc or flail and desiccate) of infected plants to avoid spread, reduction of periods of leaf wetness and high humidity within the crop canopy by appropriately timing irrigation, application of a recommended fungicide spray program (the program should start prior to the arrival of the pathogen) and desiccation of vines prior to harvest.

World Journal of Agricultural Research. 2015, 3(1), 34-42. DOI: 10.12691/wjar-3-1-8
Pub. Date: March 05, 2015

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Comparative Pharmacognostic Study of Different Parts of Withania somnifera and its Substitute Ruellia tuberosa

by Luxmini. K.P.A.M.K, Dharmadasa. R.M, Samarasinghe and K. Muthukumarana. P.R.M

Original Research

Withania somnifera (L.) Dunal. (Solanaceae) is a therapeutically important medicinal plant widely used in Ayurveda and traditional systems of medicine in all over the world. Since this valuable plant is not commercially cultivated in Sri Lanka, traditional practitioners use Ruellia tuberosa L. (Acanthaceae) as a substitute for Withania somnifera. However, use of R. tuberosa as a substitute without scientifically proven data on important quality standards might adversely affect on the therapeutic properties of herbal drugs. Present study investigates the important pharmacognostic aspects of W. somnifera and R. tuberosa. Comparative quality parameters on morphological, anatomical, powder microscopical, phytochemical, physicochemical and brine shrimp toxicity of different parts of (leaf, bark and roots) W. somnifera and R. tuberosa by using established protocols. Results demonstrated that all major phytochemical groups tested were present in leaves, bark and roots of both plants. Physicochemical analysis exhibited the higher total ash, water soluble ash and acid insoluble ash in all parts of R. tuberosa. However, TLC profiles exhibited the higher number of spots in all 3 parts for W. somnifera over R. tuberosa. Potent of brine shrimp toxicity was increased as leaf>bark>roots for R. tuberosa and bark>root>leaf for Withania somnifera. Therefore, W. somnifer acould be differentiated from R. tuberosaby comparing polymorphic macroscopic, microscopic, phytochemical, physicochemical characters either singularly or as a whole. The presence of certain similarities in major phytochemical groups, and in brine shrimp toxicity of W. somnifera and R. tuberosa partially justifies the use of R. tuberosa as a substitute for W. somnifera in traditional systems of medicine in Sri Lanka which needs to be confirmed after further clinical trials.

World Journal of Agricultural Research. 2015, 3(1), 28-33. DOI: 10.12691/wjar-3-1-7
Pub. Date: March 05, 2015

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Sarcoptic Mange Infestation in West Africa Dwarf Goat Herd in Ibadan, South West Nigeria

by Falohun Olufarati Oludunsin, Sadiq Nurudeen Ayinde, Onyiche Emmanuel ThankGod, Obebe Oluwasola Olaiya and Oke Philip Oladele

Case Report

An adult, Female West Africa Dwarf goat, the only surviving from a local goat herd comprising 31 goats, all reported to be dead was presented to the Small ruminant ward of Veterinary Teaching Hospital, University of Ibadan, Ibadan, South West Nigeria. Clinical examination revealed generalized wrinkling and thickening of the skin with heavy crust formation on the abdomen, forehead, ear, the limbs, inter-digital spaces, mammary gland and inner thigh. Skin biopsy, skin scrapings, whole blood and serum samples were collected respectively for histopathology, ectoparasite identification, hematology and biochemistry. Histomorphometric studies were also conducted for tunnel measurement. Parasite sections, tunnels, orthokeratosis, exocytosis, folliculitis, scarring, hyperkeratosis, sero-cellular exudate, pustule and acanthosis were observed with histological studies while several Sarcoptes scabie var caprae which have oval to round, dorsally convex tortoise-like body that is covered with spines and triangular scales with only the first two pairs of legs protruding beyond the body margin in both sexes were identified. There was severe anemia with very low PCV and erythrocyte count, leucocytosis, eosinophilia, hypoproteinemia, hypoalbuminemia and hypoglobulinaemia. Reduction in epidermal tunnel diameter ranges from 200 µm to 170 µm while tunnel height ranges from 220 µm to 180 µm. The goat died 15 days after presentation due to the fact that the goat was in the severe, advanced chronic stage of the disease which often terminate in mortality. It is very paramount to note that early diagnosis and treatment of Sarcoptic mange in goat should be made by a Veterinarian as a therapeutic efficacy of a combination of amitraz and ivermectin will provide an excellent result of complete recovery from generalized infestation of mange mite.

World Journal of Agricultural Research. 2015, 3(1), 24-27. DOI: 10.12691/wjar-3-1-6
Pub. Date: February 16, 2015

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Determination of Sprout Control Treatment Using Seven Key Yam (Dioscorea spp.) Varieties of Farmers in Ghana

by C. Tortoe, S. Dowuona and N. T. Dziedzoave

Original Research

Yams (Dioscorea spp.) are an important economic crop in Ghana. The formation of buds and subsequent sprouting of yam tubers influences postharvest losses. Efforts to prolong dormancy and inhibit bud and sprouting are therefore laudable. Seven key yam varieties of farmers identified as Pona, Lariboko, Dente, Mutwumudoo, Serwah, Matches and Akaba in Ghana were subjected to plant extracts from cocoa pod (Theobroma cacao) potash, neem (Azachirata indica) seeds, neem (Azachirata indica) leaves, sweetpotato (Ipomoea batatas) leaves to inhibit bud and sprout formation. The potash extracts suppressed bud formation in Mutwumudoo, Akaba and Matches compared to Lariboko and Serwah yam varieties. In a descending order of Lariboko, Matches, Mutwumudoo, Serwah, Pona, Dente and Akaba, neem seed extracts was able to suppress bud formation and subsequent sprouting. In neem leaves treatment, suppression of bud formation was highest in Lariboko, Dente, Mutwumudoo, Akaba, Matches, Serwah and Pona in a descending order. Sweetpotato leaves suppression of bud formation was highest in Serwah, Akaba, Mutwumudoo, Dente, Matches, Lariboko and Pona as the least. The control treatment showed higher number of buds formed in all the yam varieties in a descending order of Akaba, Serwah Mutwumudoo, Lariboko, Dente, Pona and Matches as compared to all the other treatments. The four plant extracts effect on bud formation and subsequent sprouting on the seven varieties of yam was comparable (p = 0.05). The control, sweetpotato and neem leaves plant extract performed poorly as compared to the potash and neem seed extracts. Interestingly, potash was the best bet plant extract in reducing bud formation and sprouting (0.26) while sweetpotato leaves was the least (0.42) and corresponding yam varieties was Mutwumudoo followed by Matches and Akaba.

World Journal of Agricultural Research. 2015, 3(1), 20-23. DOI: 10.12691/wjar-3-1-5
Pub. Date: February 01, 2015

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Estimating Aboveground Biomass of Oil Palm Trees by Using the Destructive Method

by Putri Ida Sunaryathy, Suhasman, Kasturi Devi Kanniah and Kian Pang Tan

Original Research

Palm oil is one of the important commodities in Indonesia. Estimating the aboveground biomass of oil palms is one of the most important oil palm carbon studies. The objective of this study was to estimate the aboveground biomass of oil palm trees at plot scale for three age classes namely, class 1 (1 to 3 years), class 2 (4 to 10 years) and class 3 (11 to 20 years) in South Sulawesi, Indonesia using destructive method. The AGB for each age class: class 1, class 2, and class 3 they are 5.84 kg tree^-1, 173.17 kg tree^-1, 823.50 kg tree^-1 respectively.

World Journal of Agricultural Research. 2015, 3(1), 17-19. DOI: 10.12691/wjar-3-1-4
Pub. Date: January 29, 2015

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Isolation, Screening and Characterization of Effective Microbes with Potential for Biological Control of Fusarium wilt of Rock Melon

by Salha Elmahdi, Jugah Kadir, Mahmud Tengku Muda Mohamed, Ganesan Vadamalai and Shamima Akter

Original Research

Effective microbes are a group of microorganisms that can be found in the rhizosphere, in association with plant roots which can suppress soil-borne plant pathogens directly or indirectly. A large number of bacteria including species of Alcaligenes, Arthrobacter, Bacillus, Pseudomonas, Rhizobium and Serratia have been reported to suppress the soil borne plant pathogens. In this study, Fusarium wilt symptomless Rock melon rhizospheric soil samples were collected from three locations (Malaysia). A total of seventy two effective bacteria were isolated by the dilution method. These isolates were firstly dually cultured in vitro on PDA medium with F. oxysporum f.s. melonis, the causal agent of Fusarium wilt of Rock melon. Isolates with inhibitory characteristics against the test fungus were selected for further screening by means of extracellular metabolite test. Seven isolates which showed >60% inhibition of the fungal growth was further identified on the basis of colony morphology, biochemical tests and Biolog® System. These isolates were identified as Pseudomonas sp., Bacillus sp., Serratia sp., only one isolate could not be identified. MKB04 and MKB10 gave the best suppression of Fom mycelial growth. Further molecular identification of these two isolates identified them as Bacillus amyloliquefaciens, and Alcaligenes faecalis respectively. Effective microbes are environmental friendly and in vitro antagonistic activities they manifested against F. oxysporium f. s. melonis in this study suggest that they can be used as an effective biological control agent.

World Journal of Agricultural Research. 2015, 3(1), 11-16. DOI: 10.12691/wjar-3-1-3
Pub. Date: January 27, 2015

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Screening of Kenyan Bread Wheat Varieties for Resistance to the Emerging Strains of Stem rust Fungi (Puccinia graminis f. sp. tritici) Race Ug99

by Kimani N. C, Onguso J. and Njau P.

Original Research

Stem rust disease of wheat caused by Puccinia graminis f. sp. tritici is of major concern because of its devastating effects on wheat. It can cause yield loss of up to 100% in susceptible varieties. East Africa has been designated as a “hot spot” of the stem rust pathogen as evidenced by the emergence of a new race of stem rust designated as TTKSK or better known as Ug99 and several of its variants. This pathogen therefore poses a threat to wheat production and hence to food security in Kenya. The frequent use of fungicides to control the disease also poses a potential adverse effect on the environment. The objective of this study was to screen a core collection of Kenyan bread wheat varieties to determine those with natural resistance to stem rust disease hence reduce the risk posed to food security and the environment. Twenty Kenyan commercial bread wheat varieties were screened for stem rust resistance under artificial disease epidemic simulation in the International Stem Rust Screening Field at Kenya Agricultural and Livestock Research Organisation, Food Crops Research Centre-Njoro, Kenya. The disease notes were taken using the Modified Cobb’s Scale and the Area Under Disease Progress Curve (AUDPC) values computed. Thirteen random samples of stem rust fungi were collected from the trial plot and analyzed using Ug99 race group-specific Single Nucleotide Polymorphism (SNP) markers. The varieties fell in three disease categories of resistant, intermediate and susceptible, with the most susceptible being Pasa and Kenya Swara being the most resistant. The mean AUDPC computed showed that there was variation in the AUDPC values among the varieties with the variety K.Swara having the lowest AUDPC value of 78.33 and variety Pasa having the highest value of 478.67. Analysis of Variance (ANOVA) showed that both AUDPC and disease scores had significant variation (P<0.0001) among the varieties. From the analysis of stem rust fungi samples two genotypes of stem rust race TTKSK (AF-001ad and AF-001aa) were detected indicating mutations within the same race variant. In conclusion there are Ug99 resistant Kenyan bread wheat varieties which hold a promise for food security. There is also evidence of further mutation within the TTKSK race variant and hence a possible increased virulence on the wheat genotypes.

World Journal of Agricultural Research. 2015, 3(1), 5-10. DOI: 10.12691/wjar-3-1-2
Pub. Date: January 19, 2015

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Screening of Two Ocimum tenuiflorum L. (Lamiaceae) Morphotypes for their Morphological Characters, Essential Oil Composition and Fruit Fly Attractant Ability

by R.M. Dharmadasa, D.A.S. Siriwardhane, K. Samarasinghe, S.H.C.S. Rangana, L. Nugaliyadda, Indika Gunawardane and A.M.L. Aththanayake

Review Article

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is the destructive pest of over 300 cultivated and wild fruits all over the world. Present study describes the morphology, essential oil content and composition and bioassay on fruit fly attractant ability of essential oil of two Ocimum tenuiflorum morphotypes (MT₁ purple and MT₂ purple-green) grown in Sri Lanka. Four months old, O. tenuiflorum aerial parts were hydro-distilled for 4 h. GC-MS analysis of essential oils and bio-assay for B. dorsalis attractant ability was performed using previously established methodologies. The yield of the essential oils of O. tenuiflorum MT₁ and MT₂ were 1.51±0.02% and 1.45±0.01% (v/w), respectively. Eighteen compounds were identified, which encountered over 97% of the oil constituents. The main constituents found in the oil of MT₁ were methyl eugenol (72.50±1.03%) followed by β-caryophyllene (17.53±2.0%), germacrene D (1.55±0.10%), β-elemene (2.46±0.17%), while methyl eugenol (64.23±2.43%), β-caryophyllene (13.29±2.18%), β-elemene (6.94±1.41%), germacrene D (2.47±0.96%), were from extracted from MT₂. Bioassays conducted on essential oils of MT₁, MT₂ and purified Methyl Eugenol demonstrated that the B. dorsalis attractant ability of essential oil MT1 (106±8.1), MT2 104±2 and commercial Methyl Eugenol (111±8.5) was not significantly different during the first week of the experiment. Results of our study open an avenue for use of essential oil of Ocimum tenuiflorum as potential natural para pheromone source for fruit fly control and monitoring in fruit industry in Sri Lanka.

World Journal of Agricultural Research. 2015, 3(1), 1-4. DOI: 10.12691/wjar-3-1-1
Pub. Date: January 12, 2015

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