Inoculum Concentration of Armillaria mellea in the Rhizosphere of Intercropped Teak Plantation: the case of the Opro Forest Reserve, Ghana

Teak (Tectona grandis Linn. F.) is the most planted timber tree species in Ghana, with over 73,916 hectares of plantation established at the end of 2008. Many of the teak plantations established in the semi-deciduous forest zones were done using the taungya system with various intercrops. Symptoms of Armillaria (Vahl: Fr.) root-rot of teak have been reported in the taungya plantations, especially in the semi-deciduous forest zones. The study aimed to determine inoculum concentrations of Armillaria mellea in the rhizosphere soil of intercropped teak and compare with sole teak plantation. Mycoflora were isolated from rhizosphere soil of teak intercropped with pepper, okra, maize, yam or cassava at year one to year three sapling stage. Dilution plate technique was used for mycoflora isolation and dilution factor of 10-3 was inoculated on potato dextrose agar amended with chloramphenicol (25mg/l) and incubated at 280C for 14 days after which A. mellea colonies were identified and counted. More A. mellea (Vahl: Fr.) colonies were isolated from rhizosphere soils of intercropped teak plantations than non-intercropped. Differences in A. mellea colonies were more significant amongst intercrops than amongst age of teak plantation at (P ≤ 0.05). There were significantly (P ≤ 0.05) higher numbers of A. mellea colonies in rhizosphere soils of teak intercropped with cassava compared with other intercrops. Number of A. mellea colonies in rhizosphere soils of intercropped teak did not have linear relation with age of teak plantation. Intercropping could promote Armillaria root rot of teak especially with cassava as intercrop

Bioactivities of candlewood, Zanthoxylum Xanthoxyloides (lam.) solvent extracts against two stored-product insect pests

Bioactivities of candlewood, Zanthoxylum xanthoxyloides (Lam.) solvent extracts on control of Sitophilus zeamais Mots.  (Coleoptera: Curculionidae) and Callosobruchus maculatus F. (Coleoptera: Bruchidae) were assessed on maize and cowpea respectively. Of the four solvent extracts investigated, methanol (MeOH) extract gave the highest yield of 75 ± 10.89 %, and caused significant (p<0.001) mortalities in both insects. It also gave hundred percent protections to maize and cowpea against damage by S. zeamais and C. maculatus respectively, while causing complete inhibition of F1 progeny production and egg  development within grains. All solvent extracts studied however, evoked strong to moderate repellent actions against both insect pests, with MeOH  extract being the most bioactive (%R > 95; Fr = 0)

Effect of Cleopatra mandarin rootstock age on bud ‘take’ of Late Valencia sweet orange

Cleopatra mandarin is preferred to rough lemon as rootstock material for budding because of the susceptibility of the latter to major citrus diseases such as gummosis and phytophtora infections. However, Cleopatra mandarin rootstocks have poor bud ‘take’. The experiment was conducted at CSIR-Plant Genetic Resources Research Institute, Bunso to determine the effect of Cleopatra mandarin rootstock age on bud ‘take’ of Late Valencia sweet orange variety. Cleopatra mandarin rootstocks of ages 9 months, 10 months, 11 months and 12 months were budded with Late Valencia sweet orange variety using the chip budding technique in a randomised complete block design. There were 25 budded seedlings for each age group and replicated four times. Results obtained indicated that younger Cleopatra mandarin rootstock favoured bud ‘take’more than older ones. Higher bud ‘take’ was recorded in the 9-month old rootstocks followed by the 10-month old ones. Bud ‘take’, however, decreased with age of the rootstock. Differences in bud ‘take’between younger rootstocks (9 and 10 months old) were insignificant. There were, however, significant differences between bud‘take’ of younger rootstocks and older rootstocks (11 and 12 months old)

Assessment of yield loss due to the millet head miner, Heliocheilus albipunctella (Lepidoptera: Noctuidae) using a damage rating scale and regression analysis in Niger

Linear equations for five pearl millet (Pennisetum glaucum) varieties were established for yield losses due to damage by the noctuid Heliocheilus albipunctella, using a panicle damage rating scale. A very high positive correlation (r0.90; P=0.001) was found between damage rating and percentage yield loss, and also between observed and predicted yield loss. The low percentage absolute deviation (% ad) and deviation ratios (dr) between observed and predicted yield loss demonstrated the reliability of the damage rating scale, and the established yield loss equations. In addition, the damage rating on farmers'' fields by farmers and a team of technicians showed that the method can be used for quick on-farm assessment of yield loss by extension agents and farmers. In four farmers'' fields, the estimated yield loss for the local variety (Sadore local) ranged from 11.7 to 41.9%. Implications of the use of the method for future crop loss assessment in pearl millet are presented and discussed

A matching scheme for aquaculture; a graphing calculator approach

Graphing Calculator Technology possesses a lot of capabilities in solving a variety of scientific and non-scientific problems. Its programming abilities make it very flexible to use. Unfortunately, it has been underutilised. In this paper, we develop an application with the graphing calculator to handle the processes in a Matching Scheme for Assigning Fish Types to Ponds. The application gives an inclusion matrix which is used as the basis of the matching and finally gives summary of the assignment..Journal of Science and Technology (Ghana) Vol. 27 (2) 2007: pp. 99-10

Lowered Serum Triglyceride Levels among Chronic Hepatitis B-Infected Patients in Ghana

Dyslipidemia is a common finding in most studies of liver diseases. Little is however known about the effect of the two pathological stages of chronic hepatitis B (CHB) infection – chronicsymptomatic and asymptomatic – on the distribution of serum lipids in CHB infection. We conducted a study on CHB-infected patients attending specialist care at the Gastro-Intestinal (GI) Clinic at the Komfo Anokye Teaching Hospital (KATH) during a 7-month period. 64 participants were randomly sampled over the period. On the basis of serological and liver enzyme assays, participants were categorised as chronic asymptomatic, chronic symptomatic and healthy individuals. The relationship between the hosts pathological stage of infection were evaluated with the indices of lipid metabolism – LDL, HDL, triglyceride, and total serum cholesterol using ANOVA. The 64 volunteers recruited in the study were found to consist of 18 patients (28.1%) who were chronic symptomatic, 35 patients (54.7%) who were chronic asymptomatic hepatitis B, and 11 (17.2%) were healthy subjects. Significant overall male dominance was observed among all categories of population enrolled (p=0.0063). Serum triglyceride levels decreased more among the CHB-infected population compared to the healthy individuals (p=0.0010) with value lowest among the chronic symptomatic population. Basal serum cholesterol, HDL, and LDL were unaffected by the disease. This work reveals that serum triglyceride is significantly lowered in CHB infection and that the extent of this decrease in host is independent of the pathological stage of the infection.Keywords: chronic hepatitis B, lipid metabolism, triglyceride, chronic symptomati

Differentiation of two Botryosphaeriaceae species isolated from declining mango trees in Ghana

Lasiodiplodia theobromae is the only pathogen reported to cause mango tree decline disease in Ghana. In this study, several Botryosphaeriaceae isolates were obtained from mango tree decline disease symptoms and were identified using both phenotypic and genotypic characteristics and inoculation studies. The methods employed differentiated the isolates into two species, Lasiodiplodia theobromae and Neofussicoccum parvum. L. theobromae sporulated freely on media while N. parvum did not. Also, the species specific primer, Lt347-F/Lt347-R identified only L. theobromae while in the phylogenetic studies, L. theobromae and N. parvum clustered in different clades. L. theobromae caused dieback symptoms on inoculated mango seedlings while N. parvum did not. However, both species caused massive rot symptoms on inoculated fruits. L. theobromae was therefore confirmed as the causal agent of the tree decline disease in Ghana while N. parvum was reported for the first time as a potential pathogen of mango fruits in the country

The Aetiology, Incidence and Severity of Mango Tree Decline Disease in Ghana

Mango tree decline was previously an unknown disease in Ghana. In this study, mango trees from all the major agro-ecological zones of Ghana, where mangoes are grown were surveyed for the disease incidence, severity and aetiology of a similar disease affecting the crop. Farm visits were made to some selected farms within the selected agro-ecological zones and both the local and exotic trees were inspected. The percentage of infected trees were calculated while the severity of the disease was rated on a scale of 0-5, where 0 = no symptoms and 5 = death of trees. Samples of the diseased plant parts were collected and the causal agent was isolated on media and identified. The isolated fungus was tested for its pathogenicity using mango seedlings as test crops. The disease, characterised by profuse gumming, bark cracking and die back, was found to be present in all the agro-ecological zones. The disease incidence was higher on the local variety compared to the exotic varieties. Lasiodiplodia theobromae, isolated from the diseased plant parts, was able to cause the disease on inoculated mango seedlings. The nature of the disease symptoms and its causative agent in Ghana, confirms the disease as the mango tree decline disease

Pathogenicity and fungicide sensitivity of the causal agent of postharvest stem end rot disease of mango in Ghana

ABSTRACTStudies were carried out on the stem end rot disease of mango in Ghana. The incidence and severity of the disease were evaluated on mango fruits collected from major mango growing areas of Ghana. The causal agent was isolated on media and identified. The pathogenicity of the fungus and its cross-infection potential were determined on mango, avocado, papaya and banana fruits. The sensitivity of the pathogen to fungicides was determined by assessing radial mycelial growth on potato dextrose agar (PDA) amended with nine different fungicides (Bendazim, Funguran, Ivory, Topsin, Asuoku master, Kocide, Mirage, Sulphur 80 and Copper oxychloride). Stem end rot disease was prevalent in the major mango growing areas of Ghana. Two pathogens, Lasiodiplodia theobromae and Colletotrichum gloeosporioides were isolated from the disease lesions. However, only the former was able to cause stem end rot disease symptoms on the artificially inoculated fruits, confirming it as the causal agent of the disease. It was also found to be highly susceptible to Bendazim, Ivory, Topsin, Asuoku master and Mirage, whilst it was resistant to Funguran, Kocide, Sulphur 80 and Copper oxychloride.Original sciencitic paper. Received 30 Apr 15; revised 17 Oct 14