Effect of mycorrhiza and pruning regimes on seasonality of hedgerow tree mulch contribution to alley-cropped cassava in Ibadan, Nigeria

Field experiments were carried out on an alley-cropping farm in Ajibode village, near Ibadan where cassava alley-cropped with three hedgerow trees (Leucaena leucocephala, Gliricidia sepium and Senna(Syn Cassia) siamea), and sole planted cassava (all in three replicates) were arranged with arbuscular mycorrhizal fungi (AMF) inoculation (with Glomus deserticolum) in a completely randomized blockdesign. Each plot was split after the first year into two and hedgerows within subjected to 2 and 3- month pruning regimes. Wet and dry season mulch contribution by pruning to alley-cropped cassava, as well as cassava yield characteristics in both alley-cropped and sole plots as affected by AMFinoculation and pruning regimes were monitored over two consecutive planting periods. During the first pruning year, AMF inoculation promoted dry season pruning production which was masked in Leucaena at 3 months by biomass diversion into flowering and in Gliricidia with both flowering and mite infestation. No definite patterns were observed in the second pruning year due to development of indigenous AMF symbiosis in all plots. Total yield of cassava increased with inoculation in all plots butdry season leaf area values and tuber yield indices were relatively higher in cassava alley-cropped with Senna and sole cassava than in others. The low total yield of sole cassava makes cassava alley cropped with Senna (inoculated or uninoculated) the best option for maintaining steady tuber yield with time in a continuing alley-cropping syste

Heavy metal contamination of amaranthus grown along major highways in Lagos, Nigeria

Consumption of food contaminated with heavy metals is a major source of health problems for man and animals. Vegetable cropping along major highways with heavy vehicular movement has been a serious concern to food safety experts in large cities. A study was, therefore, carried out in two major highways in Lagos, Nigeria to determine the extent of lead (Pb) and cadmium (Cd) contamination in vegetable tissues. Samples of soil and plant (Amaranthus viridis) were collected from three sites; two of which were located on major highways, and another in a rural area which served as the reference site. These samples were collected at distances of 5, 10, 15 and 20 m from the roadside and analysed for Pb and Cd. Levels of Pb and Cd in soil were found to be 47 to 151 mg kg-1 and 0.30 to 1.33 mg kg-1 (dry weight) respectively. Concentrations in leaves ranged from 68 to 152 mg kg-1 and 0.5 to 4.9 mg kg-1 (dry weight) for Pb and Cd, respectively. The pattern of these heavy metals deposition, as reflected by the plant concentration factor (PCF) values, showed decrease in concentration with increase in distance fromthe road. Heavy metal concentrations in Amaranthus cultivated on soils characterized by heavy traffic were significantly higher (P . 0.05) than those cultivated on the reference soil. These findings in general indicated that while the levels of metals in soil were within the critical limits proposed by Kabata-Pendias and Pendias (1984),the range within the plant leaves were above the normal limit for plants  suggesting that amaranthus has away of concentrating metals in their tissues and or that aerial deposition may be a major source of contamination

A survey of the microflora of Hibiscus sabdariffa (Roselle) and the resulting “Zobo” juice

The dried calyx of Hibiscus sabdariffa (Roselle) is locally processed into a non alcoholic drink known as ‘Zobo’ in Nigeria. This popular drink is quite cheap compared to other bottled soft drinks but its acceptability is still limited because of its very short shelf life (24 h at room temperature). The composition and numbers of the microflora of the dried calyx of the Roselle plant and its resulting juice (Zobo) were examined using standard microbiological methods. The dried calyx obtained from a retail market was processed into juice that was compared with commercially sold (retail) juice. The microorganisms isolated from the dried calyx and the juices included the fungi, Aspergillus niger, Aspergillus flavus, Rhizopus oligosporus, Penicillium citrinum, Mucor spp., Saccharomyces cerevisiae, and Candida krusei, while Bacillus subtilis, Pseudomonas spp., Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Proteus mirabilis, Serratia spp., Lactobacillus brevis and Lactobacillus fermentum represented the bacterial isolates. Viable counts ranged from 0.4 x 104 to 3.2 x 104 cfu/ml. Aerobic and anaerobic bacterial counts were higher in the retail juice (1.1 to 2.2 x104 cfu/ml) than in the laboratory-prepared juice (0.8 to 1.4 x104 cfu/ml) while the dried calyx had the highest fungal counts of 3.2 x 104 cfu/ml. pH of the juices ranged between 2.67 and 2.77 while total titratable acidity values were between 0.02 and 0.08.Keywords: Dried calyx, microflora, viable counts, Zobo juic

Field response of groundnut (Arachis hypogea L.) cultivars to mycorrhizal inoculation and phosphorus fertilizer in the transitional agro-ecological zone of South West Nigeria

A field experiment was conducted in Abeokuta, South Western Nigeria, to evaluate the growth and yield response of three groundnut cultivars to inoculation with mycorrhizal fungus (Glomus mosseae) and phosphorus (P) fertilization in 2003 and 2004 planting seasons. The design was split-split plot in randomized complete block design (RCBD) in a 3x2x2 factorial combination of groundnut cultivars (RMP91, RRB and RMP12), phosphorus (54kgha-1 and 0Kgha-1) and mycorrhizal inoculation (inoculated and uninoculated). Observations were made on canopy spread, leaf area, dry matter yield and grain yield. Mycorrhizal root infections, leaf P uptake and available P in the rhizosphere were also determined. Result shows that inoculation of groundnut cultivars with G. mosseae significantly enhanced grain yield in the 2003 planting season (54 % in RMP91 to 66% in RMP12) whereas the enhancement was lower and only significant in RRB (21%) in the 2004 planting season. Phosphorus fertilization enhanced grain yield by a range of 22% (RMP91) and 40% (RMP12) in the 2003 planting season while it was a range of between 20% (RMP91) and 16% (RRP) in the 2004 planting season. Mycorrhizal root infection was as high as 64.1% relative to control (10.6%) in 2003 season. Inoculation with G. mosseae increased leaf P uptake by 30% within the two planting seasons. Phosphorus application increased the level of P in the leaf (average 32%}in the two years and rhizosphere soil P (average 1400%) only in the 2004 planting season. Percentage root colonisation ranged between 60 and 67% in all the inoculated plots in the two years. There was a marked increase in the root infection rate in the uninoculated plots (averaged 180%) in the 2004 planting season. In the 2004 planting season, available rhizosphere soil P averaged 2.06 mg/kg in the inoculated plots when compared to 2.6mg/kg in P fertilized and 2.69mg/kg in the P+M plots. All the treatments increased canopy spread (average 25%), leaf area (average 14%) and root dry weight (17%) over the control in the 2003 planting season, while in 2004 planting season, increase was recorded in canopy spread (average 22%), leaf area (average 40%) and shoot dry weight (average 35%) over the control. Inoculation of groundnut cultivars with the mycorrhizal fungus improved their performance in the field and compared favorably with the groundnuts fertilized with 54kg ha-1 of SSP fertilizer. Keywords: Groundnut cultivars; Arbuscular mycorrhizal inoculation; Leaf phosphorus uptake; grain yield; transitional agro-ecological zone Moor Journal of Agricultural Research Vol. 6 (1&2) 2005 pp. 60-6

Influence of mycorrhizal inoculation on alley cropped farms in a humid tropical environment

The use of Arbuscular mycorrhizal (AM) fungi under farmers' conditions was tried at Ajibode Village, a humid tropical environment on maize/cassava intercropped farms in an alley cropping system. Four species of AM fungi (Glomus clarum, Glomus mosseae Glomus etunicatum and Acaulospora dilatata) were used in paired treatment experimental design. Cassava and maize yields on the inoculated plots were higher than the control. It was also found that G. etunicatum was more efficient for cassava while G. mosesae was more efficient for maize. The study concluded that AM fungi inoculation can be easily adopted by farmers in the humid tropics as a low external input sustainable agricultural technology. Key words: Abuscular Mycorrhiza; Fungi; Glomus clarum; Glomus mosseae; Glomus etunicatum; Acaulospora dilatata Moor Journal of Agricultural Research Vol.4(2) 2003: 246-25