Optimizing Nitrogen Fertilization for Production of White and Orange-Fleshed Sweet Potato in Southeast Nigeria

ABSTRACT

Two field experiments were used in 2005–2006 to study the effects of nitrogen (N) on light interception, weed biomass, and yield of white and orange-fleshed sweet potato varieties in southeastern Nigeria. Treatments comprised four N levels (0, 40, 80, 120 kg N ha^?1) and four varieties of sweet potato (White-fleshed TIS 87/0087 and TIS 8164, orange-fleshed Ex-Igbariam and CIP Tanzania), arranged in randomized complete block design with three replications. Nitrogen application up to 120 kg N ha^?1 increased light interception, leaf area index and shoot dry matter. Regardless of rate, N application reduced weed growth at 12 weeks after planting. On average, the storage root yield increased with N application up to 80 kg N ha^?1 when the background soil N was 0.056% in 2005, but not beyond the rate of 40 kg N ha^?1 when the background N was 0.104% in 2006. The white-fleshed TIS 87/0087 followed by orange-fleshed Ex-Igbariam out-yielded other varieties and intercepted over 70% of the incident radiation.     

Anthelmintic activity of pyrantel tartrate against Ascaridia galli in fowls.

At a dose of 15 mg/kg body weight, pyrantel tartrate was 18-51, 99-63, 100 and 100 per cent effective in chickens treated at 10, 20, 30 and 40 days respectively after infection with Ascaridia galli. Similarly, 25 mg/kg was 14-44, 100, 100 and 99-63 per cent effective.     

Vitamin A status of pregnant women in Calabar metropolis, Nigeria

The vitamin A status of 101 pregnant women attending clinic at the University of Calabar Teaching Hospital (UCTH), Calabar, Nigeria was assessed based on 24 h dietary recall, serum retinol concentration, history of night blindness, physical appearance and clinical eye signs. The study revealed that the mean dietary vitamin A intake of the respondents (2645.31 +/- 188.91 microg RE) and their mean serum retinol concentration (31.18 +/- 2.94 microg dL(-1)) were significantly (p < 0.05) higher than the FAO/WHO recommended intake and cutoff level for VAD. No case of night blindness, physical signs and symptoms, or clinical eye signs attributable to VAD was observed. There was a significant (p < 0.01) correlation between the amount of 24 h vitamin A intake of the women and their serum retinol concentration (r = 0.31). Also, women who had above 50% of their vitamin A intake from provitamin A sources had a significantly (p < 0.05) lower serum retinol concentration (23.10 +/- 21.12 microg dL(-1)) than those who had above 50% intake from preformed sources (49.54 +/- 42.63 microg dL(-1)) and those with about equal intake from both sources (55.75 +/- 30.80 microg dL(-1)). There was a significant (p < 0.05) and steady decline in serum retinol concentration in the women from the first trimester (37.79 +/- 6.65 microg dL(-1)), through the second trimester (35.12 +/- 4.72 microg dL(-1)), to the third trimester (21.54 +/- 1.46 microg dL(-1)) of pregnancy.     

Influence of different treatments on the variation of grain size trait in winter wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) varieties

Genetical and biometrical analyses were carried out to investigate the variation of grain sizes in three winter varieties (namely Batko, Diya and Krasnodarskaya 99) under the influence of the growth regulator, Furolan and mineral fertilizer. The 1000–grain weight trait was equally analyzed. The difference in germination energy of large seeds between extreme variants amounted 6.0% (LSD₀₅-var. = 2.85). There were significant differences in germination energy of seeds. Extreme variants differed significantly among themselves in laboratory germinating power of seeds. The difference between them was 4.0% (LSD₀₅-var. = 1.84). The variant treated with growth regulator, Furolan did not differ significantly from control. Mineral fertilizers in Bat’ko variety increased laboratory germinating power of seeds; its increase in comparison with control was 2.0% (LSD₀₅-var. = 1.84). The difference between experimental variants in 1000–grain weight of small grains was 0.6 g (LSD₀₅-fact. C = 0.13) which showed that Furolan significantly increased 1000–grain weight of most of the winter wheat varieties studied.     

Influence of furolan-treated seeds on sowing characteristics of winter wheat cultivars

The study was carried out at the All-Russian Rice Research Institute, Belozerny, Krasnodar, Russia in 2009. The seeds of three varieties of winter wheat namely; Bat’ko, Deya and Krasnodarskaya 99 were grown in different concentrations of growth regulators namely; Furolan, (2-furyl-2)-1,3-dioxolane, gibberellins (plant hormone) and water as control. The influence of the growth regulators on seed germination energy and germinating power were determined. The effect of the regulators was higher in all the experimental variants than in the control. However, this increase was insignificant (LSD_0.05 = 6.88). Application of Furolan in concentration of 0.001 and 0.0001% in Deya’s variety decreased germination energy in comparison with that of concentration 0.01%. Weak concentration virtually did not stimulate germination energy of seeds. The different varieties investigated in this study showed very positive response to growth regulators at different stages of ontogenesis of the plants. The effect of the factor B (growth regulators) on the formation of sprout length was 11.7%. Interaction of factors A and B was very small; its effect was only 0.6%.     

Studies of infection withxanthomonas campestris pv.vesicatoria,causal agent of bacterial scab of pepper in Israel

Xanthomonas campestris pv. vesicatoria, the causal agent of bacterial scab of pepper, was isolated in several regions in Israel. When artificial inoculation was practiced, pathogen growth was enhanced by high temperatures (30-36°C), and an inoculum concentration of 10^p6 colony-forming units (CFU) per ml was optimal for symptoms to develop on plants. Pre-inoculation treatments such as wounding the leaves by rubbing them with carborundum powder or spraying them with diluted wax solvents, markedly increased disease severity, but were not essential. Pre-inoculation conditioning at two different relative humidity levels (R.H. = 100% or R.H. < 40%) did not affect disease severity. Young leaves were more severely affected following infection than older leaves. Disease severity was similar with several isolates ofX. campestris pv. vesicatoria.     

Yield response of spring wheat cultivars (Triticum aestivum and T. turgidum) to inoculation with Azospirillum brasilense under field conditions

Summary Eight commercial Israeli spring wheat cultivars (six Triticum aestivum and two T. turgidum) grown with 40 and 120 kg N/ha were tested for responses to inoculation with Azospirillum brasilense. At the low level of N fertilization (40 kg/ha), five cultivars showed significant increases in plant dry weight measured at the milky ripe stage; however, by maturation only the cultivar Miriam showed a significant increase in grain yield. Two cultivars, which had shown a positive inoculation effect at the earlier stages, had a significant decrease in grain yield. No significant effect of inoculation was found at the high N level. To confirm those results, four wheat (T. aestivum) cultivars were tested separately over 4 years in 4 different locations under varying N levels. Only Miriam showed a consistently positive effect of Azospirillum inoculation on grain yield. Inoculation increased the number of roots per plant on Miriam compared with uninoculated plants. This effect was found at all N levels. Nutrient (N, P and K) accumulation and number of fertile tillers per unit area were also enhanced by Azospirillum, but these parameters were greatly affected by the level of applied N. It is suggested that the positive response of the spring wheat cultivar Miriam to Azospirillum inoculation is due to its capacity to escape water stresses at the end of the growth season.