Showing papers by "Rivers State University of Science and Technology published in 1993"

Remediation of oil polluted soils: 1. effect of organic and inorganic nutrient supplements on the performance of maize ( Zea may L)

Abstract: Percentage germination, plant height, leaf area, relative dry matter yield, plant nutrient concentration, soil chemical characteristics and source/sink relationship were assessed for maize (Zea mays L TZ-SR-Y) planted in a soil polluted with 3% (v/w) crude oil or 0% (untreated soil), after remediation of soil with different organic (Poultry manure, peptone water, sawdust and yeast extract) and inorganic (NPK, KNO3, NH4H2PO4 and (NH4)2SO4) nutrient supplements applied 7 days after oil treatment. Germination of maize in oil polluted soil was not significantly affected by nutrient supplementation (P=0.05). Maize performance in terms of other studied parameters was highest in the oil polluted soil supplemented with poultry manure, and least in oil polluted soil supplemented with sawdust. Oil treatment correlated significantly with organic C, N, Na, Mg and ferrous in the soil (P=0.05) and with nutrient composition in maize plant tissues (P=0.05). For nutrient uptake, significant correlation was only established between soil N and plant N. Population of petroleum hydrocarbon tolerant microbes increased initially but decreased with time. There is every indication that nutrient supplementation of oil polluted soil especially with organic nutrient sources is beneficial for maize growth, because the C/N ratio is narrowed while the rate of biodegradation of oil and soil recovery is also enhanced. Poultry manure is recommended, however sawdust is not recommended since it tends to impose adverse effect by widening the C/N ratio in soil.

Physicochemical properties and cooking quality of four new cultivars of Nigerian cowpea (Vigna unguiculata L Walp)

Abstract: Four new cowpea cultivars (IT81D-699, IT82E-18, IT84S-2246-4 and TVx 3236) were evaluated for their physicochemical properties and cooking quality. The four cultivars fell into two categories (rough and smooth) according to testa texture, and varied in seed dimensions and weights with IT81D-699 and IT84S-2246-4 having smaller seed volume than IT82E-18 and TVx 3236. Leached solids, swelling capacity and seed coat percentage were within a range of 0·33–0·94 g per 100g, 77·0–123·5 g per 100 g and 5·6–15·7% w/w of dry beans respectively. The total polyphenol content of the brown or cream-coloured beans were similar (1·53–1·96 mg g−1) but higher than the amount (1·03 mg g−1) found in the white bean. Cooking time varied between 29 and 37 min and was reduced by about 21% following a presoaking treatment in water for 12 h at room temperature (28 °C). Cooking time was significantly positively correlated (P < 0·05) with seed weight (r = 0·82) and seed volume (r = 0·75). Water absorption was not related to cooking time, and was much lower for the cultivar with larger seeds. No significant difference in hardness was found between unsoaked beans cooked for 30 min and soaked beans cooked for 10 min, suggesting that cookability for all cultivars was improved through soaking.

Effect of stocking density on growth and survival of Oreochromis niloticus (L.) fry in the hatchery

Abstract: . The effect of stocking density on growth and survival of Oreochromis niloticus (L.) fry was evaluated. O. niloticus fry (average weight, 10·56 ± 0·28mg and average length. 9·09 ± 0·05nim) were stocked in 2–1 tanks at 2, 5, 10, 15 and 20 fry/1 and reared for 33 days post fertilization, at 30°C (±1°C). Mean lengths, mean weights, and specific growth rates were found to be significantly lower (P < 0·05) at the higher stocking densities. The coefficient of variation for the five stocking densities was significantly (P < 0·05) different. Condition factors, however, were not significantly (P < 0·05) different and survival was high at all density treatments. These data suggest that the culture of O. niloticus is feasible at the density groups tested but 5–10fry/I is recommended for fry culture in the hatchery, if a more uniform size is desired.

Biology of Cathartus quadricollis Guerin-Meneville (Coleoptera: Silvanidae) on some selected food media

Abstract: The life cycle of Cathartus quadricollis (Guerin-Meneville) was studied under ambient laboratory condition on maize, sorghum, wheat, cowpea and melon. Egg hatchability was found to be 95.5% with an incubation period of 3–7 days. Five larval instars were recorded based on head-capsule width measurements. The growth ratio of the head-capsule width ranged from 1.05–1.20 with a grand mean of 1.12. This range falls within the acceptable range in Dyar’s rule. The mean growth rate of C. quadricollis after 2 weeks of rearing on maize, sorghum, melon, wheat and cowpea, ranged from 22.4 to 1.6. While the mean developmental periods of C. quadricollis on the selected food media ranged from 18.80 days on cut maize to 30.70 days on cut cowpea.

Spatial Variability in Soil Chemical Properties under Dactyladenia barteri, Alchornea cordifolia, Senna siamea and Gmelina arborea Hedgerows on an Acid Ultisol

Abstract: Spatial nutrient distribution was studied under a three-and-a-half-year-old fallow of Dactyladenia barteri, Alchornea cordifolia, Senna siamea and Gmelina arborea hedgerows grown on an acid Ultisol in southeastern Nigeria. The objectives were to evaluate the nutrient cycling capacity and suitability of the hedgerow species for alley cropping. No consistent patterns were observed in the lateral distribution of soil pH, total nitrogen, organic carbon, available phosphorus, exchangeable cations (potassium, calcium, magnesium and sodium), total acidity and effective cation exchange capacity in the 4 m wide alleys formed between the hedgerow species. Senna siamea and Gmelina arborea tended to increase soil organic carbon, calcium, magnesium and effective cation exchange capacity, particularly in the top 50 cm, compared with Alchornea cordifolia and Dactyladenia barteri, and can therefore be recommended for soil fertility regeneration on acid Ultisols during periods of fallow. However, they appear to be less suitable for alley cropping than Dactyladenia barteri because they are shallow rooting.Propiedades quimicas delo suelo bajo cuatro especies de seto vivo

Aspects of the biology of Lasioderma serricorne (F.) on selected food media under tropical conditions

Abstract: The length of the reproduction cycle of Lasioderma serricorne (F) under ambient laboratory conditions (temperature range 280–32°C and 725–805% rh)was shown to depend on the identity and state of division of various cereal grains, cowpeas, groundnuts and dried root crops Cut dried yams allowed the shortest cycle andwholericethelongestThe rate of population increase by L serricorne was also assessed and this was maximal when cut wheat and minimal when whole rice was provided Fecundity was highest with sorghum and lowest with rice as food source Females of the species lived longer than males