Journal and Journal Articles: Recent submissions

Now showing items 1701-1720 of 5157

    • Field surveys for natural enemies of banana weevil, Cosmopolites sordidus (Germar) in Indonesia with emphasis on searches for egg and larval parasitoids 

      Abera-Kalibata, A.M.; Hasyim, A.; Gold, C.S.; Driesche, R.V. (2002)
      The banana weevil, Cosmopolites sordidus (Germar), is an important pest of highland banana and plantain in Africa. It exists in low densities in its presumed area of origin in Southeast Asia. This suggests the possible existence of effective co-evolved natural enemies that might be useful in a classical biological program against the pest in Africa. Surveys on banana weevil and its natural enemies were under-taken in Indonesia, in 2000 and 2001. Banana weevil incidence was found to be low, 0.6–1.7 ...

    • Responses of maize hybrids developed for drought tolerance to low soil nitrogen 

      Meseka, S.K.; Menkir, A.; Elhassan, A.; Ibrahim, S.S.; Ajala, S.; Kamara, A. (2006)
      High cost of nitrogen fertilizer coupled with frequent occurrence of drought has forced many maize (Zea mays L.) growers in sub-Saharan Africa to either apply fertilizer below optimal dose or no fertilizer to their maize fields. The objectives of this study were to (i) compare the performance of four hybrid groups developed for drought tolerance under low nitrogen and (ii) identify some adaptive secondary traits that contribute to yield improvement. Ninety-six hybrids along with four checks, ...

    • Abundance and life cycle of Zonocerus variegatus (Orthoptera: Pyrgomorphidae) in the humid forest zone of southern Cameroon 

      Messi, J.; Kekeunou, S.; Weise, S. (2006)
      Weekly captures from January 2000 to January 2002 enabled us to study the abundance and life cycle of the variegated grasshopper, Zonocerus variegatus (Orthoptera: Pyrgomorphidae), in the humid forest zone of Southern Cameroon. We found that Z. variegatus was present throughout the year in the forest reserve and the human‐influenced zones of Yaounde and Mbalmayo in two univoltine populations, which had unequal abundance and durations. The separation of the two populations was clearer in the Yaounde ...

    • A USA Africa collaborative strategy for identifying, characterising and developing maize germplasm with resistance to aflatoxin contamination 

      Menkir, A.; Brown, R.L.; Bandyopadhyay, Ranajit; Chen, Z.Y.; Cleveland, T.E. (2006)
      Aflatoxin contamination of maize by Aspergillus flavus poses serious potential economic losses in the US and health hazards to humans, particularly in West Africa. The Southern Regional Research Center of the United States Department of Agriculture, Agricultural Research Service (USDA-ARS-SRRC) and the International Institute of Tropical Agriculture (IITA) initiated a collaborative breeding project to develop maize germplasm with resistance to aflatoxin accumulation. Resistant genotypes from the ...

    • Assessment of reactions of diverse maize inbred lines to Striga hermonthica (Del.) Benth 

      Menkir, A. (2006)
      Striga hermonthica is the most widespread and destructive obligate root parasite infecting maize and other cereals in Africa. Maize inbred lines supporting reduced S. hermonthica emergence can form an important basis for developing Striga‐resistant maize cultivars. Twenty new inbred lines selected for field resistance to S. hermonthica, and five inbred checks with known resitance, tolerance and susceptibility reactions to S. hermonthica were evaluated in pots, greenhouse and field experiments under ...

    • Physicochemical and functional properties of sour starches from different cassava varieties 

      Onitilo, M.O.; Sanni, L.O.; Oyewole, O.B.; Maziya-Dixon, B. (2006)
      This article reports our investigation on the effect of cassava varieties on the physicochemical and functional properties of sour starches. There were significant differences (P < 0.05) in the ash, pH, amylose, amylopectin, starch damage, total titratable acidity (TTA), sugar, and starch content but not moisture contents of various cassava sour starches. There were no significant differences (P > 0.05) in Water Absorption Capacity (WAC), swelling power, and solubility index, while significant ...

    • Physicochemical and functional properties of native starches from CMD cassava varieties 

      Maziya-Dixon, B.; Onitilo, M.; Sanni, L.; Daniel , I. (2006)
      Pre- and postharvest factors such as genetic factors, environmental conditions during the growth of the plant and the method of starch isolation have been found to have a profound effect on the properties of root and tuber starches. The physicochemical, functional and pas ting properties as well as granule morphology of starches from 40 different new cassava varieties (36 cassava mosaic disease-resistant CMD clon es) and currently released cassava varieties in Nigeria (TMS 30572, 4(2) 1425, TME 1 ...

    • A propos de Cordylobia rodhaini Gedoelst et la description d’une nouvelle espèce affine afrotropicale (Diptera, Calliphoridae) 

      Lehrer, A.Z.; Goergen, Georg E. (2006)
      One makes the re-description of the myiasigenes species CordylobiarodhainiGedoelst and the description of a new species found in Togo, Cordylobia ebadianan. sp. One represents the details of their male genitalia and one gives the keys of identification of the four known species of genus.

    • A propos de l'espèce Phumosia vittata (Curran, 1927) de la faune de Nigeria (Diptera, Calliphoridae) 

      Lehrer, A.Z.; Goergen, Georg E. (2006)
      On the species Phumosia vittata (Curran, 1927) of the fauna of Nigeria (Diptera, Calliphoridae). One gives the general description of the species Phumosia vittata (Curran) and one presents, for the first time, the details of its male genitalia.

    • Dead wood and saproxylic beetle assemblages in a semideciduous forest in Southern Benin 

      Lachat, T.; Nagel, P.; Cakpo, Y.; Attignon, S.; Goergen, Georg E.; Sinsin, B.; Peveling, R. (2006)
      Saproxylic (dead wood associated) beetles play an important role in all forest ecosystems and are known to be highly susceptible to forest management and fragmentation. Contrary to temperate forests, there has been very little research on saproxylic beetle assemblages in tropical forests. In Africa, large tracts of natural forest have been converted to tree plantations (mainly exotic species) and cropland, and these land use changes are expected to have a dramatic effect on saproxylic beetle ...

    • Farmers perception on the importance of variegated grasshopper (Zonocerus variegatus (L)) in the agricultural production systems of the humid forest zone of Southern Cameroon 

      Kekeunou, S.; Weise, S.; Messi, J.; Tamo, M. (2006)
      Zonocerus variegatus (Linnaeus, 1758) (Orthoptera: Pyrgomorphidae) is known as an agricultural pest in West and Central Africa. However, its importance in the agricultural production system in Cameroon has not been investigated. The study assesses farmers' perception on the importance of Z. variegatus in the agricultural production systems of the humid forest zone of Southern Cameroon.

    • Performance of old and new maize hybrids at high plant densities in the tropical Guinea Savanna 

      Kamara, A.; Menkir, A.; Kureh, I.; Omoigui, L.; Ekeleme, F. (2006)
      Genetic improvement of maize hybrids for superior stress tolerance has contributed to increased yield by allowing hybrids to be planted at higher plant populations. This study was conducted to evaluate the response of maize hybrids developed in the Nigerian Savanna from different eras to high plant densities. Field research was conducted in 2002 and 2003 at the experiment station of the Institute of Agricultural Research, Samaru in the northern Guinea savanna zone, Zaria, Nigeria. Six hybrids—two ...

    • Cowpea plant architecture in relation to infestation and damage by the legume pod borer, Maruca testulalis Geyer (Lepidoptera: Pyralidae) 1. effect of canopy structure and pod position 

      Oghiakhe, S.; Jackai, L.E.N.; Makanjuola, W.A. (1991)
      The effects of cowpea, Vigna unguiculata (L.) Walp. canopy structure and pod position in relation to infestation and damage by the legume pod borer, Maruca testulalis Geyer were investigated. Defoliated cultivars sustained significantly less infestation and damage (P < 0.05) than those undefoliated. Relative humidity measured under the canopy was lower in defoliated cultivars, while soil and ambient temperatures were higher. Percentage pod damage and larval infestation by M. testulalis in flowers ...

    • Podwall toughness has no effect on cowpea resistance to the legume pod borer 

      Oghiakhe, S.; Jackai, L.E.N.; Makanjuola, W.A. (1992)
      The possibility of the involvement of pod wall toughness in the resistance of cowpea, Vigna unguiculata (L.) Walp., to the legume pod borer, Maruca testulalis was studied. The toughness of non-intact and intact pod wall increased with age, but the rate varied at different growth stages of the pod as well as between cultivars. There was a positive and significant correlation (r = 0.82**) between pod age and pressure required to penetrate pod wall. No significant differences (P > 0.05) were observed ...

    • Biology, status and management of rice insect pest in Nigeria 

      Umeh, E.D.N.; Joshi, R.C.; Ukwungwu, M.N. (1992)
      Rice insect pest management in Nigeria is compartmentalized; literature documenting the status of research on the biology and significance of insect pests and on their management, has therefore been reviewed. A holistic, broadly based, multidisciplinary pest-management research approach is suggested. Because of the immense benefits that integrated pest management (IPM) can provide, it is urged that steps be taken immediately to develop and implement IPM for rice insects in Nigeria.

    • Bud activity of decapitated, nurserygrown plants of triplochiton scleroxylon in Nigeria: effect of light, temperature and humidity 

      Ladipo, D.O.; Leakey, R.R.B.; Grace, J. (1992)
      This study is a continuation of earlier work on apical dominance inTriplochiton scleroxylon K. Schum., aimed at the development of an early clonal selection test for branching habit and yield in tree improvement programmes. Decapitated plants of five to seven clones were treated with either: (i) two photon flux densities (photosynthetically active radiation at full or 10% sunlight, approximately 2000 and 200 μmol quanta m−2s−1 measured at midday on a clear day); (ii) two temperatures (ambient 30°C ...

    • Effects of shelling maize cobs on the oviposition and development Sitophilus zeamais Motschulsky 

      Kossou, D.K.; Bosque-Pérez, N.A.; Mareck, J.H. (1992)
      Oviposition and development of Sitophilus zeamais Motschulsky were studied on shelled maize kernels and unshelled cobs of the variety “Blanc Deux Precoce” from the Republic of Benin. On unshelled cobs adult weevils must feed and oviposit mostly on the kernel's crown, the only part of the kernel fully exposed to the external environment. The resistance of unshelled kernels to the maize weevil, relative to shelled kernels, is shown to depend on three factors: (1) reduced oviposition, as a result of ...

    • Field evaluation of peanut genotypes for resistance to Sclerotinia blight 

      Akem, C.N.; Melouk, H.A.; Smith, O.D. (1992)
      Nineteen peanut genotypes were evaluated for resistance to Sclerotinia blight caused by Sclerotinia minor in small field plots at Stillwater, Oklahoma, USA, in 1986, 1987 and 1988. Entries were arranged in a completely randomized block design in field plots with four replications. Average disease incidence (%) at harvest for the most resistant genotypes TX 804475, Toalson, TX 798731, TX 798683, and TX 798736 was 1.6, 3.9, 6.7, 9.1 and 11.6, respectively; the most susceptible genotypes, Florunner, ...

    • A survey of rice insect pests in Nigeria 

      Alam, M.S. (1992)
      survey of rice insect pests conducted during 1983–87 in Nigeria revealed 70 species of pests, 14 parasitoids and two predators. Both incidence and severity of pests varied considerably across different climatic zones and rice agro‐ecosystems. Thirteen Insects were classified as major pests. They are: stalk‐eyed fly. Diopsis longicornis Macquart; lepidopterous stem borers. Mallarpha separatella Rag., Chllo zacconiusBlesz, Sesamia spp.; African gall midge, Orseolia oryzivoraH&G;armyworm, Spodoptera ...

    • Effect of endophytic Fusarium oxysporum on host preference of Radopholus similis to tissue culture banana plants 

      Athman, S.; Dubois, T.; Coyne, D.; Gold, C.; Labuschagne, N.; Viljoen, A. (2006)
      The burrowing nematode Radopholus similis is one of the major constraints to banana (Musa spp.) production worldwide. Resource-poor farmers can potentially manage R. similis by using naturally occurring banana endophytes, such as nonpathogenic Fusarium oxysporum, that are inoculated into tissue culture banana plantlets. At present, it is unclear at what stage in the R. similis infection process the endophytes are most effective. In this study, the effect of three endophytic F. oxysporum isolates ...