1. Introduction, Distribution and Drivers of Non-native Mangrove Palm Nypa fruticans Van Wurmb (Arecaceae) in Cameroon, Gulf of Guinea

    MOUDINGO, J-Hude1,2*, AJONINA, Gordon2,3, DIBONG, Didier3,4, TOMEDI3, Minette

    1. Département de Biologie des Organismes Végétaux, Faculté des Sciences, Université de Douala, B.P. 24157 Douala, Cameroun.
    2. Cameroon Wildlife Conservation Society P. O. Box. 54 Mouanko, Littoral Region-Cameroon.
    3. Département d’Aquaculture, Institut des Sciences Halieutiques, University of Douala, B.P. 2701 Douala, Cameroun.
    4. Department of Geosciences and Environment, Faculty of Sciences, University of Douala, P. O. Box. 24157 Douala, Cameroon.

    Abstract:

    In this paper, we investigate Nypa fruticans Van Wurmb (Arecaceae), a native plant from the indo-pacific, introduction, dispersal, drivers, invadability and distribution in Cameroon’s mangrove and its shoreline, Atlantic Gulf of Guinea. The study used a combination of observation (qualitative) approach including naïve and scientific. Desk research and interpretative document analysis were the main research methods that guided the finding, selecting, and rigorous examination of Nypa palm invasion process.

    Hence, we found that historically Nypa have been wildly distributed and with re-introduction in the Gulf of Guinea. Today, over 10 Guinea Current Large Marine Ecosystem countries harbours Nypa at varied scale, of which in Nigeria’s all the coastal and marine line (nine states) served as the fundamental niche. We equally hypothesis that the species has been present in Cameroon’s Marine and Coastal line alongside its mangrove ecosystem since First World War period. No single Cameroon mangrove block was Nypa palm free. Hence, the study provided evidences that Nypa dispersed was currently present in many localities and future spread because of climatic factors, paucity in policy and institutional framework, taxa and habitat characteristic, land use and socioeconomic practices. Dispersal mechanism was through barochory, hydrochory and anthropochory likely its invadability upper rate was 175 Nypa palm/ha/year. We suggest further research on biophysical impacts and possible management scenarios of Nypa palm.

    Keywords: Mangrove ecosystem, fundamental niche, Nypa fruticans, invasion, Gulf of Guinea.

    Pages: 1 – 20 | Full PDF Paper

  2. Nutrient Risk Management Using Organic Manures in Radish Production at Rampur, Chitwan, Nepal

    Keshar Bahadur Khatri1, Roshan Babu Ojha2, Keshab Raj Pande1

    1. Department of soil science and agri-engineering, Faculty of Agriculture, Agriculture and Forestry University, Rampur, Chitwan, Nepal.
    2. Soil Science Division, Nepal Agricultural Research Council, Khumaltar, Lalitpur, Nepal.

    Abstract: Nitrate leaching is a problem in medium textured Inceptisols of Chitwan district, Nepal. A field experiment was conducted in sandy loam soil of Agriculture and Forestry University, Rampur, Chitwan, Nepal from October 2016 to January 2017 to evaluate effect of different sources of organic manure in nutrient risk management. The experiment was carried out in a Randomized Complete Block Design with six treatments ( Poultry manure, goat manure, FYM, biogas byproduct, recommended dose of fertilizer and control ) replicated four times. Pyuthane Red variety of radish was used as a test crop. After analysis of primary nutrients of the organic manures, rate of manure was fixed on the basis of nitrogen content. The highest (49.41 Mg/ha) root yield was obtained from poultry manure application which was similar with recommend rate of fertilizer. The highest soil pH (4.722), moister content (15.82), CEC (10.41meq/100g soil) and soil porosity (49.33%) and the lowest bulk density (1.191g/cm3) was obtained from poultry manure application. The highest organic matter content (1.01%) was observed from biogas byproduct application which was similar with FYM and poultry manure application. The highest infiltration rate (0.522 mm/sec) was obtained from FYM whereas the lowest was obtained from control plot. In 30 cm soil depth, the residual NO3-N was highest (0.075%) from goat manure which was similar with poultry manure application where as in 60 cm soil depth highest (0.046%) NO3-N was recorded from RDF which was similar with biogas byproduct and goat manure application whereas lowest (0.46%) was recorded from control which was similar with FYM and poultry manure application. The most of the soil properties were enhanced by application poultry manure and FYM. Furthermore, poultry manure played an important role in increasing nitrate nitrogen availability in upper depth and reduces the potentiality of nitrate nitrogen leaching to the lower depth. In addition, this study indicates the possibility of poultry manure application to enhance the physio-chemical properties of sandy loam soil of Chitwan.

    Keywords: Leaching, Nutrient risk, Organic manure, Radish.

    Pages: 21 – 31 | Full PDF Paper

  3. Effect of Temperature on the Virulence of Entomopathogenic Nematodes

    Manana Lortkipanidze1, Kazim Hwseynov2, Mzia Kokhia1, Oleg Gorgadze1, Madona Kuchava1

    1. Department of entomopathogens, Ilia State University, Institute of Zoology, 3/5 Kakuca Cholokashvili Ave, Tbilisi 0162, Georgia.
    2. Scientific-Research Institute of Plant Protection and Technical Cultures, 91 St. Aziz Aliyev, Ganja, AZ2002, Azerbaijan.

    Abstract:

    Nowadays, the use of entomopathogenic nematodes as a biological control agent is a key component in IPM system. Entomopathogenic nematodes of the genera Steinernema and Heterorhabditis (Nematoda: Rhabditida) are extraordinarily lethal to many important insect pests, yet are safe for plants and animals. They are the only insect-parasitic nematodes possessing an optimal balance of biological control attributes.

    The effect of temperature on the virulence of three species of entomopathogenic nematodes,  Steinernema thesami, Heterorhabditis bacteriophora and Steinernema feltiae was investigated. Last instar of Tenebrio molitor larvae were choosing for experiment. In the laboratory, all three nematode species successfully reproduced inside T. molitor larvae. H. bacteriophora produced the highest number of infective juveniles per larva at 30°C than S. feltiae and S. thesami. S. feltiae caused the highest mortality of larvae at 20°C, whereas S. thesami infected T. molitor larvae at the widest temperature range and killed insects between 8-35°C. Based on the present study, we indicate that entomopathogenic nematodes have well-defined thermal breadths for their development and reproduction.

    Keywords: Entomopathogenic nematodes, Heterorhabditis, Steinernema, Tenebrio molitor, biocontrol.

    Pages: 32 – 38 | Full PDF Paper