Response of Lowland Rice Plants to Simulated Insect Defoliation in West Africa

Field experiments were conducted to investigate the impact of simulated insect-caused defoliation on irrigated rice. Defoliation levels tested were 0% (control), 25% defoliation at 21 days after transplanting (dat), 25% defoliation at 41 dat, 25% defoliation at 21 and 42 dat, 50% defoliation at 21 dat, 50% defoliation at 42 dat, 75% defoliation at 21 dat, 75% defoliation at 42 dat, 75% defoliation at 21 and 42 dat, 100% defoliation at 21 dat, and 100% defoliation at 21 and 42 dat. Tiller height, total number of tillers, percent panicle-bearing tillers, weight of 100 grains, and grain yields were recorded. The rice plant when defoliated just before tillering or in the tillering stage has the ability to compensate for defoliation damage. No yield losses occurred at 25% defoliation. Defoliation of 100% had a significant effect on the total number of tillers and on grain yield. Yield losses at 100% defoliation over the 3 years of the study averaged 40% in the 21 dat treatment and 55% in the 21 and 42 dat treatment. The implications of the development of cultural practices to manage lowland rice defoliating insects are discussed

Preliminary Evaluation of Storage Behavior of Cola lepidota (K. Schum) Seeds

A preliminary study was conducted to provide information on the behaviour of C. lepidota seeds in storage prior to a proper investigation into different storage temperature regimes, methods and their effect on the viability and subsequent germination of the seed. C. lepidota seeds used in the study were collected from the Swamp Forest Research Station, Onne, Rivers State small plantation. Two storage methods, bare storage and storage in closed container and two temperature regimes, 4º C (refrigeration) and room temperature (30ºC) were applied on the seed. There were a total of eighty-six (86) seeds allocated disproportionately to the treatments in a completely randomized design experimental layout. Data collected were number of decaying seeds and duration of decay (days). Due to non-normality of data after the Shapiro-Wilk test was conducted; the Kruskal-Wallis ANOVA was used for analysis, while Mann-Whitney test was used for pair wise comparison. The results showed that C. lepidota seeds decayed or dried up at an average rate of 1 seed/week when stored bare at room temperature (30ºC); storage in closed container accelerated the rate of seed decay to 6 seeds/week; while refrigeration at 4º C significantly reduced rate of seed decay to 1 seed in 29 weeks. This shows that storage by refrigeration is the best way to keep C. lepidota seeds fresh for a longer duration of time, the worst storage condition is in closed container at room temperature (30ºC), while, storage of the seeds bare at room temperature (30ºC) could only sustain the seeds for a few days. This information will serve as a guide for seed storage and handling when C. lepidota seeds are collected for later propagation or when there is the need to transport the seed a long distance

ENGINEERING AND GEOLOGICAL EVALUATION OF ROCKS FOR CONCRETE PRODUCTION

Engineering and geological properties of rocks from eight different quarries in Ibadan were evaluated to determine their suitability for concrete production. Samples from each quarry sites were subjected to grading, relative density, water absorption, bulk density, amount of materials finer than 75μm, flakiness and elongation Index, Aggregate Impact Value (AIV), Aggregate Crushing Value (ACV), Aggregate Abrasion Value (AAV), 10% fines value and petrographical analysis adopting BS testing methods. The relationship between engineering properties with one another and the petrographical characteristics were described by Pearson correlation coefficient and bar charts. The results of engineering analysis revealed that rocks from all the quarries are generally sound and good because of their possession of necessary characteristics for use in concrete production when compared with British (BS), Indian (IS) and American Society for Testing and Materials (ASTM) standards. Petrographical analyses revealed that samples which have performed better in all the engineering tests possess higher content of quartz mineral and finer texture. Statistically significant correlations were found among the tests performed

Traumatic physical health consequences of intimate partner violence against women: what is the role of community-level factors?

<p>Abstract</p> <p>Background</p> <p>Intimate partner violence (IPV) against women is a serious public health issue with recognizable direct health consequences. This study assessed the association between IPV and traumatic physical health consequences on women in Nigeria, given that communities exert significant influence on the individuals that are embedded within them, with the nature of influence varying between communities.</p> <p>Methods</p> <p>Cross-sectional nationally-representative data of women aged 15 - 49 years in the 2008 Nigeria Demographic and Health Survey was used in this study. Multilevel logistic regression analysis was used to assess the association between IPV and several forms of physical health consequences.</p> <p>Results</p> <p>Bruises were the most common form of traumatic physical health consequences. In the adjusted models, the likelihood of sustaining bruises (OR = 1.91, 95% CI = 1.05 - 3.46), wounds (OR = 2.54, 95% CI = 1.31 - 4.95), and severe burns (OR = 3.20, 95% CI = 1.63 - 6.28) was significantly higher for women exposed to IPV compared to those not exposed to IPV. However, after adjusting for individual- and community-level factors, women with husbands/partners with controlling behavior, those with primary or no education, and those resident in communities with high tolerance for wife beating had a higher likelihood of experiencing IPV, whilst mean community-level education and women 24 years or younger were at lower likelihood of experiencing IPV.</p> <p>Conclusions</p> <p>Evidence from this study shows that exposure to IPV is associated with increased likelihood of traumatic physical consequences for women in Nigeria. Education and justification of wife beating were significant community-level factors associated with traumatic physical consequences, suggesting the importance of increasing women's levels of education and changing community norms that justify controlling behavior and IPV.</p

Arthropod Populations and Rice Yields in Direct-Seeded and Transplanted Lowland Rice in West Africa

Two methods for planting rice in irrigated lowland were evaluated during the wet seasons of 1994 and 1995 to determine their effect on rice arthropod numbers, insect-caused rice plant damage, and rice grain yield. The six treatments tested were: hand transplanting of seedlings at spacings of 14 cm × 14 cm, 20 cm × 20 cm, and 30 cm × 30 cm; and direct-seeding of rice at 60 kg seeds ha–1, 90 kg seeds ha–1, and 120 kg seeds ha–1. The most abundant arthropods in the study were the diopsid flies, Diopsis longicornis Maquart and D. apicalis Dalman; the green leafhoppers Nephotettix spp.; the white leafhoppers Cofana unimaculata (Signoret) and C. spectra (Distant); spiders; dragonflies and damselflies; and stem borers. There was no overall difference between transplanting and direct-seeding, or between plant densities, in regard to sweep net counts of Cofana spp. and spiders. Diopsis longicornis and D. apicalis adult numbers were highest in the 20 cm × 20 cm transplanted plots in 1994, but no significant differences occurred in 1995. Nephotettix spp. adult numbers were highest in the 120 kg seeds ha–1 direct-seeded plots in 1995, but no significant differences occurred in 1994. The percentage of tillers infested with stem borers was highest in the three transplanted and the 120 kg seed ha–1 direct-seeded treatments in 1994 and the three transplanted treatments in 1995. In 1995, the percentage of whiteheads (empty panicles) caused by stem-borer feeding was highest in the direct-seeded treatments, increasing from the low rate of 60 kg seeds ha–1 to the highest rate of 120 kg seeds ha–1. Grain yields were generally similar in the transplanted and direct-seeded plots. Implications of planting methods and plant density as management practices in rice IPM and labor requirements for rice production are discussed

Strepsipteran Parasitism of White Leafhoppers, \u3ci\u3eCofana\u3c/i\u3e spp. (Hemiptera: Cicadellidae) in Lowland Rice in Côte d’Ivoire

Three tests were conducted over a 2-year period in lowland irrigated rice fields on the WARDA Research Station at Bouaké, Côte d’Ivoire, to obtain information on the strepsipteran parasitism of white leafhoppers, Cofana spectra and C. unimaculata. Rice cultivars were sampled with a sweep net to collect leafhoppers for determination of the relative abundance of the two leafhopper species and the effect of rice cultivar and rice crop age on the leafhopper populations and percent strepsipteran parasitism. Dissections of the leafhoppers were made to determine the relative number of the various parasitic stages in the leafhoppers. Cofana unimaculata populations were higher than those of C. spectra while C. spectra parasitism by Halictophagus australensis Perkins (Strepsiptera: Halictophagidae) was higher than that of C. unimaculata. In two tests, there was a relationship between length of rice cultivar duration and C. unimaculata populations with populations being highest on the short duration cultivars. On most cultivars there was no correlation between Cofana populations and percentage parasitism, nor was there a relationship between cultivar growth duration and percent parasitism. The number of the various stages of the parasite was similar in both Cofana species with the male pupal parasitic stage being most common

Arthropod Populations and Rice Yields in Direct-Seeded and Transplanted Lowland Rice in West Africa

Two methods for planting rice in irrigated lowland were evaluated during the wet seasons of 1994 and 1995 to determine their effect on rice arthropod numbers, insect-caused rice plant damage, and rice grain yield. The six treatments tested were: hand transplanting of seedlings at spacings of 14 cm × 14 cm, 20 cm × 20 cm, and 30 cm × 30 cm; and direct-seeding of rice at 60 kg seeds ha–1, 90 kg seeds ha–1, and 120 kg seeds ha–1. The most abundant arthropods in the study were the diopsid flies, Diopsis longicornis Maquart and D. apicalis Dalman; the green leafhoppers Nephotettix spp.; the white leafhoppers Cofana unimaculata (Signoret) and C. spectra (Distant); spiders; dragonflies and damselflies; and stem borers. There was no overall difference between transplanting and direct-seeding, or between plant densities, in regard to sweep net counts of Cofana spp. and spiders. Diopsis longicornis and D. apicalis adult numbers were highest in the 20 cm × 20 cm transplanted plots in 1994, but no significant differences occurred in 1995. Nephotettix spp. adult numbers were highest in the 120 kg seeds ha–1 direct-seeded plots in 1995, but no significant differences occurred in 1994. The percentage of tillers infested with stem borers was highest in the three transplanted and the 120 kg seed ha–1 direct-seeded treatments in 1994 and the three transplanted treatments in 1995. In 1995, the percentage of whiteheads (empty panicles) caused by stem-borer feeding was highest in the direct-seeded treatments, increasing from the low rate of 60 kg seeds ha–1 to the highest rate of 120 kg seeds ha–1. Grain yields were generally similar in the transplanted and direct-seeded plots. Implications of planting methods and plant density as management practices in rice IPM and labor requirements for rice production are discussed

Response of Lowland Rice Plants to Simulated Insect Defoliation in West Africa

Field experiments were conducted to investigate the impact of simulated insect-caused defoliation on irrigated rice. Defoliation levels tested were 0% (control), 25% defoliation at 21 days after transplanting (dat), 25% defoliation at 41 dat, 25% defoliation at 21 and 42 dat, 50% defoliation at 21 dat, 50% defoliation at 42 dat, 75% defoliation at 21 dat, 75% defoliation at 42 dat, 75% defoliation at 21 and 42 dat, 100% defoliation at 21 dat, and 100% defoliation at 21 and 42 dat. Tiller height, total number of tillers, percent panicle-bearing tillers, weight of 100 grains, and grain yields were recorded. The rice plant when defoliated just before tillering or in the tillering stage has the ability to compensate for defoliation damage. No yield losses occurred at 25% defoliation. Defoliation of 100% had a significant effect on the total number of tillers and on grain yield. Yield losses at 100% defoliation over the 3 years of the study averaged 40% in the 21 dat treatment and 55% in the 21 and 42 dat treatment. The implications of the development of cultural practices to manage lowland rice defoliating insects are discussed

Strepsipteran Parasitism of White Leafhoppers, \u3ci\u3eCofana\u3c/i\u3e spp. (Hemiptera: Cicadellidae) in Lowland Rice in Côte d’Ivoire

Three tests were conducted over a 2-year period in lowland irrigated rice fields on the WARDA Research Station at Bouaké, Côte d’Ivoire, to obtain information on the strepsipteran parasitism of white leafhoppers, Cofana spectra and C. unimaculata. Rice cultivars were sampled with a sweep net to collect leafhoppers for determination of the relative abundance of the two leafhopper species and the effect of rice cultivar and rice crop age on the leafhopper populations and percent strepsipteran parasitism. Dissections of the leafhoppers were made to determine the relative number of the various parasitic stages in the leafhoppers. Cofana unimaculata populations were higher than those of C. spectra while C. spectra parasitism by Halictophagus australensis Perkins (Strepsiptera: Halictophagidae) was higher than that of C. unimaculata. In two tests, there was a relationship between length of rice cultivar duration and C. unimaculata populations with populations being highest on the short duration cultivars. On most cultivars there was no correlation between Cofana populations and percentage parasitism, nor was there a relationship between cultivar growth duration and percent parasitism. The number of the various stages of the parasite was similar in both Cofana species with the male pupal parasitic stage being most common