scholarly journals Taxonomic and Ecological Significance of Foliar Epidermal Characters in Four Taxa of Mussaenda L. (Rubiaceae) in Nigeria

2019 ◽  
pp. 1-12
Author(s):  
Felix Ifeanyi Nwafor ◽  
Maria O. Nwosu ◽  
Amarachi Z. Nwafor
Keyword(s):  
Block Design ◽  
Weather Conditions ◽  
Environmental Indicators ◽  
West African ◽  
Ecological Significance ◽  
African Species ◽  
Derived Savanna ◽  
Taxonomic Markers ◽  
Epidermal Features ◽  
Clearing Method

Aims: This study investigated leaf epidermal features as taxonomic markers in delimiting two West African species (M. elegans and M. erythrophylla) and two Philippine infraspecific species (M. “Doña Aurora” and M.“Doña Luz”) of Mussaenda L. in Nigeria and their ecological significance. Study Design: The experiment adopted a Completely Block Design (CBD) of four plant taxa from two study locations with 10 replicates each, totaling 80 samples. Place and Duration of Study: The study was carried out in the Department of Plant Science and Biotechnology, University of Nigeria, Nsukka, between June and September, 2010. Methodology: Fresh leaves were collected from the Tropical Rainforest (TRF) and Derived Savanna (DS) vegetations of Nigeria under the same weather conditions. Leaf epidermal strips were prepared by clearing method, stained with Safranin and observed under the light microscope. Results: The stomata are of the paracytic type borne on polygonal to irregularly shaped, wavy epidermal cells. Simple trichomes were also a common feature in all taxa. Mussaenda erythrophylla has significantly (P ˂ 0.05) the least dense stomata (84.51 ± 0.73 mm-2) while M. “Doña Aurora” has the densest stomata (230.98 ± 2.67 mm-2). M. elegans and M. “Doña Aurora” have significantly the highest stomata index (28.48% and 28.98% respectively) while M. “Doña Luz” has the lowest (24.31%). Samples from the TRF have significantly higher density, index and size of stomata in M. elegans and M. “Doña Luz” than those from DS. Quantitative trichome parameters also vary among the taxa. The fewest trichomes were observed in M. elegans (7.90 ± 0.14 and 11.75 ± 0.21) while they are most abundant in M. “Doña Luz” (11.77 ± 0.11 and 18.90 ± 0.51). Ecological conditions affected these variables as trichomes were more abundant in the specimens collected from DS locations. Conclusion: Epidermal features are proven significant tools in taxonomic delimitation and as environmental indicators in predicting climatic changes and environmental pollution.

scholarly journals Some new West African species of Anopheles (sensu lato), with notes on nomenclature

1911 ◽  
Vol 2 (2) ◽  
pp. 141-143 ◽  
Author(s):  
F. W. Edwards
Keyword(s):  
New Species ◽  
Natural History ◽  
West Africa ◽  
West African ◽  
Tropical Medicine ◽  
London School ◽  
African Species ◽  
New West

In describing the following new species from West Africa, some words of explanation are needed as to the generic names used. In the first place, it is necessary to say that the writer follows Messrs. Dyar and Knab in considering that most of the genera into which Meigen's genus Anopheles has recently been split up are not genera in any accepted sense, and should sink under the old name Anopheles. Provisionally, however, Stethomyia, Chagasia, Calvertina and Bironella are considered as distinct; as none of these genera are African, this will not affect the present paper. Lieut.-Col. A. Alcock, of the London School of Tropical Medicine, has kindly allowed me to see the manuscript of a paper on the classification of Anopheles, which he is about to publish in the Annals and Magazine of Natural History, and I have been able to concur entirely with his views; he recognises only five sub-genera of Anopheles, the sub-genus Nyssorhynchus including all those species with flat scales on thorax and abdomen, i.e., the genera Nyssorhynchus, Cellia and Neocellia of Theobald's Monograph.

scholarly journals Carfentrazone Plus Pyroxasulfone Combinations for Weed Control in Peanut (Arachis hypogaea L.)

2021 ◽  
pp. 52-63
Author(s):  
W. James Grichar ◽  
Peter A. Dotray ◽  
Todd Baughman
Keyword(s):  
Weed Control ◽  
Block Design ◽  
Weather Conditions ◽  
South Texas ◽  
High Plains ◽  
Complete Control ◽  
Growing Seasons ◽  
Naturally Occurring ◽  
Arachis Hypogaea L ◽  
Cucumis Melo L

Aims: To determine peanut response and weed control following the use of carfentrazone plus pyroxasulfone (C + P). Study Design:  Randomized complete block design with 3-4 reps depending on location. Place and Duration of Study: Studies were conducted during the 2015 and 2016 growing seasons in south Texas near Yoakum (29.276o N, 97.123o W), the High Plains of Texas near Lamesa (32.769o N, 101.977o W) or Brownfield (33.104o N, 102.161o W), and southwestern Oklahoma near Ft. Cobb (35.091o N, 98.275o W). Methodology: Plots were infested with naturally occurring weed populations. Pendimethalin was applied either preplant incorporated (PPI) or preemergence (PRE). Early postemergence (EPOST) applications varied according to weather conditions and peanut growth at each location. Postemergence (POST) treatments were applied 26 to 58 days after planting. Weed control and peanut stunting were visually estimated on a scale of 0 to 100 (0 indicating no control or plant death and 100 indicating complete control or plant death). Results: Peanut stunting with C + P was only noted at the High Plains and Oklahoma locations in 2015 but not 2016. Urochloa texana (Buckl.) control with C + P (PRE) varied from 75 to 93%. POST applications provided inconsistent control.  Amaranthus palmeri S. Wats. control with C + P (PRE) was at least 78% season-long while POST applications were inconsistent (24 to 100%).  Pendimethalin plus C + P controlled Cucumis melo L. var. Dudaim Naud. at least 80% late-season. Ipomoea hederacea Jacq. control was excellent season-long (> 80%) in 2015 but poor (< 60%) in 2016.  Reduced peanut yields were noted with C + P in Oklahoma in 2015 to excessive season-long injury.    Conclusion: The premix of C + P has potential for use in peanut especially for control of many small-seeded annual broadleaf weeds that continue to plague many peanut growers across the southwest.  For effective broad-spectrum annual weed control season-long, the addition of pendimethalin to PRE applications will be required.

scholarly journals Strip-till technology - a method for uniformity in the emergence and plant growth of winter rapeseed (Brassica napus L.) in different environmental conditions of Northern Poland

2018 ◽  
pp. 194-199 ◽  
Author(s):  
Iwona Jaskulska ◽  
Lech Gałęzewski ◽  
Mariusz Piekarczyk ◽  
Dariusz Jaskulski
Keyword(s):  
Plant Growth ◽  
Environmental Conditions ◽  
Block Design ◽  
Thermal Conditions ◽  
Weather Conditions ◽  
Field Trials ◽  
Initial Growth ◽  
Brassica Napus L ◽  
Initial Development ◽  
Winter Rapeseed

The emergence of plants is especially important for the winter crops that are grown in the challenging environmental conditions of many countries in Central and Eastern Europe. The emergence and initial growth of winter rapeseed were compared in field trials in a randomized block design with three replicates for plants sown in conventional tillage systems (CT) and strip-till (ST), which had different weather conditions and on soil with a non-uniform texture over a period of two years. Sowing in the CT was carried out using Horsch Pronto 4DC (Germany) at a row distance of 0.29 m. The ST operations were performed using a Pro-Til 4T drill manufactured by Mzuri Limited (Great Britain) - row spacing of 0.36 m. In favourable rainfall and thermal conditions, the density of winter rapeseed plants two weeks after sowing was found to be higher if it was sown after the CT than in the ST system. In the year that had a serious shortage of rainfall during the sowing period, a considerably higher density of plants was achieved using the ST system. The uniformity of plant growth using the ST technology in soil with a varied texture, especially in a year with an unfavourable distribution of rainfall, was proven by less variability in the number of leaves in the rosette, in the dry mass of the leaf rosette and in the root neck thickness of the winter rapeseed than in the CT system. The ST system can create good conditions for the initial development and preparation of rapeseed plants for wintering.

Studies in Diurnal Rhythms

1951 ◽  
Vol 28 (2) ◽  
pp. 165-172
Author(s):  
J. L. CLOUDSLEY-THOMPSON
Keyword(s):  
Diurnal Rhythm ◽  
Rhythmic Activity ◽  
Temperature Fluctuations ◽  
West African ◽  
Diurnal Rhythms ◽  
Locomotory Activity ◽  
Depressing Effect ◽  
African Species ◽  
Fluctuating Light ◽  
Effect Of Light

Visual experiments on two small British species of millipedes have demonstrated that the diurnal cycle of rhythmic activity as represented by the number of animals on the surface is primarily a response to light and darkness, but is also correlated with the stimulus of falling temperature in the evening. Aktograph experiments on two large West African species of millipedes have demonstrated an endogenous diurnal rhythm independent of fluctuating light and temperature, and persisting (in Ophistreptus) up to 19 days. Locomotory activity is stimulated both by increases and decreases of temperature; and it is probable that temperature fluctuations are of primary importance in the initiation of diurnal rhythms. The effect of light on activity is slight, but constant temperatures over long periods have, a depressing effect.

Sylvan katydids (Orthoptera: Tettigoniidae: Pseudophyllinae) of the Guinean Forests of West Africa hotspot: an overview and descriptions of new species

Zootaxa ◽  
2008 ◽  
Vol 1712 (1) ◽  
pp. 1
Author(s):  
PIOTR NASKRECKI
Keyword(s):  
New Species ◽  
West Africa ◽  
West African ◽  
The State ◽  
Published Data ◽  
The West ◽  
African Species ◽  
Forest Coverage

The state of knowledge on sylvan katydids (Tettigoniidae, Pseudophyllinae) of Guinean Forests of West Africa hotspot is discussed. Based on published data on their distribution, and the extent of the current forest coverage of the region it is possible that some of the West African species of the Pseudophyllinae may be threatened or even extinct. Five new species are described (Adapantus affluens sp. nov., A. angulatus sp. nov., A. pragerorurm sp. nov., Tomias gerriesmithae sp. nov., and Mormotus alonsae sp. nov.), and 4 species of West African Pseudophyllinae are redescribed.

scholarly journals Direct and Residual Effects of Different Poultry Compost and NPK Fertilizer Applications on Drought-Tolerant Maize Production

2016 ◽  
Vol 9 (4) ◽  
pp. 61
Author(s):  
O. M. O. M. Otitoju ◽  
Moses B. Adewole ◽  
A. A. Olowoake ◽  
A. O. A. O. Ilesanmi
Keyword(s):  
Grain Yield ◽  
Block Design ◽  
Residual Effects ◽  
N Recovery ◽  
Wet Season ◽  
Southwestern Nigeria ◽  
Maize Production ◽  
Drought Tolerant ◽  
Derived Savanna ◽  
Npk Fertilizer

<p>This study investigated the direct and residual effects of different poultry compost and NPK fertilizer applications on the growth components of drought-tolerant maize (<em>Zea mays</em> L.) in a derived savanna agroecology of southwestern Nigeria. The experiment was laid out in a Randomized Complete Block Design (RCBD) with six treatments, each replicated thrice. The treatments which were applied at planting, consisted of 100% cockerel manure (CM), 100% broiler manure (BM), 100% layers manure (LM), 33.3% cockerel manure + 33.3% Broiler manure + 33.3% Layers manure (CBLM) at 4.50 kg plot<sup>-1</sup><sub>,</sub>inorganic NPK 20-20-10 fertilizer at 0.30 kg plot<sup>-1</sup> and zero manure application as control (CT). The apparent efficiency of N recovery (AENR), N and P ear-leaf (NPEL) contents of maize with poultry manures were higher when compared to inorganic NPK fertilizer applications. The highest mean grain yield 1.30 t ha<sup>-1</sup> of maize was obtained with BM treatment that had the highest AENR and NPEL values. This however, was not significantly (p &gt; 0.05) different from the mean grain yield obtained with other treatments during the dry season. Comparable but higher mean grain yield, but also not significantly (p &gt; 0.05) different were obtained during the wet season in all the treatments.</p>

Spar Deck Float-Over Feasibility Study for West Africa Environment Condition

2006 ◽  
Author(s):  
Chunqun Ji ◽  
John Halkyard
Keyword(s):  
West Africa ◽  
Feasibility Study ◽  
Load Transfer ◽  
Weather Conditions ◽  
West African ◽  
Environmental Condition ◽  
Floating Platform ◽  
Sea State ◽  
Long Period ◽  
Environment Condition

Offshore deck installation may be performed by either derrick barges or by the float-over method. Either method involves a variety of technical challenges. The challenges are particularly severe in weather conditions such as West Africa where long period swell dominates the environment. Setting a deck on a floating platform such as a spar presents additional issues compared with operation on fixed platform. This paper provides a spar deck float-over feasibility study for a West Africa environmental condition. The design uses two existing barges in a catamaran configuration. The barges were engaged for both transportation and the float-over procedures. The weather window for spar deck installation and the importance of synchronized motion of spar, barge and deck during the deck load transfer are discussed in the paper. Four-body (two barge, spar and deck) motion simulations were applied. The study shows that the float-over and mating operation is feasible in the specified West African sea state. Rapid spar de-ballasting achieves 20% load transfer to avoid large impact during 0% to 20% load transfer. From the 20% to 85% deck load transfer using conventional ballasting the barges, deck and de-ballasting spar will have synchronized motion.

VARIABILTY OF OIL AND PROTEIN CONTENT IN RAPESEED CULTIVARS AFFECTED BY SEEDING DATE

2017 ◽  
pp. 404 ◽  
Author(s):  
Igor Balalic ◽  
Ana Marjanovic-Jeromela ◽  
Jovan Crnobarac ◽  
Sreten Terzic ◽  
Velimir Radic ◽  
...  
Keyword(s):  
Protein Content ◽  
Oil Content ◽  
Block Design ◽  
Weather Conditions ◽  
Significant Negative Correlation ◽  
First Year ◽  
Seeding Date ◽  
Study Results ◽  
Rapeseed Cultivar ◽  
Cropping Seasons

The aim of this study was to determine the variability of oil and protein content in winter rapeseed cultivars affected by seeding date. Four cultivars (Banaćanka, Slavica, Express, Valeska) were sown at six seeding dates (SD1-21 August, SD2-31 August, SD3-10 September, SD4-21 September, SD5-1 October, SD6-9 October) across two cropping seasons. The trial was arranged as Randomized Complete Block Design (RCBD) with four replications. Analysis of variance (ANOVA) showed that the effect of year, cultivar and seeding date were highly significant for oil and protein content. Increased oil content in the second year (2010/2011) was related to weather conditions which were favorable for rapeseed. However, protein content was significantly higher in the first year (2009/2010). Oil content ranged between 41.19% (Valeska) and 42.69% (Express). Significantly lowest oil content across seeding dates was found in SD6 (40.67%), and highest in SD4 (41.86%) and SD1 (41.61%). Valeska showed significantly highest mean protein content (21.54%). Protein content was highest in SD6 (20.18%). Oil content decreased with delayed seeding. Highly significant negative correlation (r = -0.730) existed between oil and protein content. Seeding date had significant influence on oil and protein content in rapeseed. Cultivar Express and SD4 can be pointed out, based on the achieved oil content, and cultivar Valeska for high protein content. Study results may be helpful in recommending optimal rapeseed seeding date in the region.

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