Journal and Journal Articles: Recent submissions

Now showing items 1921-1940 of 5157

    • Evaluating the effects of a biopesticide on populations of the variegated grasshopper, Zonocerus variegatus 

      Thomas, M.B.; Langewald, J.; Wood, S.N. (1997)
      A field trial was conducted to investigate the efficacy of an oil formulation of the fungal entomopathogen, Metarhizium flavoviride, for control of the variegated grasshopper, Zonocerus variegatus. The results of the trial showed a significant reduction in grasshopper populations following spray application compared with non-treated controls. 2. Further studies revealed that there was significant movement of insects into and out of the treated plots during the course of the experiment, and that ...

    • Effect of temperature, humidity and inoculation method on susceptibility of Schistocerca gregaria to Metarhizium flavoride 

      Fargues, J.; Ouédraogo, A.; Goettel, M.S.; Lomer, C.J. (1997)
      The effects of temperature on conidial germination and susceptibility of adults of the desert locust, Schistocer cagregaria, to four isolates of Meta rhizium flovoviride were determined. In addition, the eff ects of inoculation method (topical or spray), spore carrie r (oil or wat er) and ambient relative humidity (R H ) on susceptibility of the locust to the most thermotolerant isolate (M f324) were investigated. There were differences among the isolates in the effects of temperature on germination ...

    • Horizontal resistance: core to a research breakthrough to combat Striga in Africa 

      Kim, S.K. (1996)
      The parasltie flowering plants, Striga species, represent the largest biological constraint to cereal and legume crop production in sub-Saharan Africa. Eighty-three percent of Striga worldwide (35 species) occurs in Africa. Among them, Striga hermonthica causes the greatest damage. The IITA's scientists began research on breeding maize for horizontal resistance to Striga in 1982. By 1995 a comprehensive approach to combat Striga on maize had been developed and demonstrated. This included the ...

    • Effects of mulch location on banana weevil, nutrients, soil water, and biomass in banana 

      McIntyre, B.D.; Gold, C.S.; Ssali, H.; Riha, S.J. (2003)
      Major constraints to banana (Musa spp., genome group AAA) production, a dietary staple for over 70 million people in sub-Saharan Africa, are pest infestations, poor nutrition and inadequate water. Although mulch can improve soil water and nutrient status, many farmers believe it also promotes the proliferation of banana weevil (Cosmopolites sordidus), one of the most serious banana pests. In this study, we evaluated the effects of mulch location (mulch to base of banana pseudostem; mulch recessed ...

    • Historical overview of breeding for durable resistance to maize streak virus for tropical Africa 

      Buddenhagen, I.W.; Bosque-Pérez, N.A. (1999)
      Maize streak virus (MSV) was first studied by Storey in Kenya in the 1920s and resistance transferred into East African maize in the 1960's. Yet the majority of farmers of East Africa are still growing streak-susceptible maize. At the International Institute of Tropical Agriculture (IITA) in Nigeria, an effort to incorporate streak resistance as an integral part of a holistic maize improvement program was begun in 1975. By 1979, usable resistance had been found and methods of large scale field ...

    • Root characteristics in cowpea related to drought tolerance in seedlings 

      Matsui, T.; Singh, B.B. (2003)
      Cowpea (Vigna unguiculata) has relatively higher drought tolerance than other legume crops. It is widely grown in semi-arid regions, particularly in West Africa. One objective of the present study was to determine the effects of soil moisture stress on the length, dry matter and distribution of the roots of two cowpea varieties with different drought tolerances. Another objective was to evaluate the pin-board root-box as a method for identifying the role of root characteristics in drought tolerance. ...

    • Effects of photo regime on the timing of male responses to sex pheromones in male Cnaphalocrocis medinalis (Lepidoptera: Crambidae) 

      Kawazu, K.; Adati, T.; Tatsuki, S. (2003)
      We examined the effect of moth age and photoregime on the timing of male response to sex pheromones in male Cnaphalocrocis medinalis. The responsiveness of males varied with age, increasing up to 3-days and then remaining constant to 7-days. In male responses to the pheromone throughout the scotophase under five different photoregimes, it was shown that the time to reach the maximal response level after lights-off was rather constant (ca. 4 h), regardless of the duration of the scotophase in a ...

    • Agronomic performance of maize (Zea mays L.) breeding lines derived from a low nitrogen maize population 

      Kamara, A.Y.; Kling, J.G.; Menkir, A.; Ibikunle, O. (2003)
      Eighteen S1 lines of maize (Zea mays L.) derived from a low nitrogen tolerant pool and two inbred lines were evaluated for agronomic performance under moderate N conditions in the southern Guinea savannah of Nigeria. Generally, the breeding lines differed in yield, growth, vertical rootpulling resistance, N-uptake and N-use efficiency. Breeding lines with high vertical root-pulling resistance took up more N and utilized it more efficiently. They also showed better agronomic performance and recorded ...

    • The influence of drought stress on growth, yield, and yield components of some maize genotypes 

      Kamara, A.Y.; Menkir, A.; Badu-Apraku, B.; Ibikunle, O. (2003)
      The risk of drought is high in the Sudan savannah zone of West and Central Africa because rainfall in this area is unpredictable in quantity and distribution. Thus, improved maize genotypes tolerant to drought could stabilize maize grain yield in this zone, where recurrent drought threatens grain production. Six maize genotypes, two each of hybrids, open-pollinated varieties (OPVs) and landraces, were evaluated for tolerance to terminal water deficit before flowering. Water deficit significantly ...

    • Field evaluation of cowpea cultivars (Vigna unguiculata L Walp.) for resistance to flower thrips (Megalurothrips sjostedti Trybom) (Thysanoptera: Thripidae) 

      Alabi, O.Y.; Odebiyi, J.A.; Jackai, L.E.N. (2003)
      Ten cowpea cultivars were screened for resistance to flower bud thrips, Megalurothrips sjostedti, in replicated field trials. Resistance was evaluated by measuring differences in populations and visual damage on the cultivars. Statistical correlation was employed to assess the degree of association between damage indices and thrips population in the cultivars for each season. In the first season cultivars were conveniently grouped into three, using damage indices and thrips populations size. In ...

    • Management of cogongrass Imperata cylindrica with velvetbean Mucuna pruriens var. utilis and herbicides 

      Udensi, U.E.; Akobundu, I.O.; Ayeni, A.O.; Chikoye, D. (1999)
      Field experiments were conducted in 1992 to 1993 and in 1995 to 1996 in Ibadan, Nigeria, to assess the effect of velvetbean and herbicides on maize (corn) and cogongrass growth and to assess regrowth of the weed 1 yr after treatment. In 1992 and 1995 cover cropping with velvetbean and imazapyr and glyphosate application reduced cogongrass density as much as the handweeded control. The smothering effect of velvetbean was equivalent to that of glyphosate at 1.8 kg/ha but was less than imazapyr even ...

    • Biology and integrated pest management for the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) 

      Gold, C.S.; Pena, J.E.; Karamura, E.B (2001)
      The banana weevil Cosmopolites sordidus (Germar) is the most important insect pest of bananas and plantains (Musa spp.). The larvae bore in the corm, reducing nutrient uptake and weakening the stability of the plant. Attack in newly planted banana stands can lead to crop failure. In established fields, weevil damage can result in reduced bunch weights, mat die-out and shortened stand life. Damage and yield losses tend to increase with time. This paper reviews the research on the taxonomy, distribution, ...

    • Synergistic relationship of bacterial blight and anthracnose disease pathogen in cassava multiple infection 

      Fokunang, C.N.; Dixon, Alfred G.O.; Ikotun, T. (2003)
      A study was conducted at the greenhouse of the international institute of Tropical Agriculture, Ibadan,Nigeria to investigate the synergistic relationship of xanthomonas campestris pv. Manihotics (causal agent of cassava bacteria blight CBB), and colletotrichum gloeosporiodes f.sp manihotics (causal agent of cassava anthracnose disease CAD), in cassava multiple infection. There were statistical differences(p<0.05) in the cassava genotype following sequential inoculation of the pathogens and single ...

    • Plantparasitic nematodes associated with root and tuber crops in Uganda 

      Coyne, D.L.; Talwana, H.; Maslen, N.R. (2003)
      In a nematode survey of eight commonly grown root and tuber crops (cassava, sweet potato, potato, yam, tannia, taro, carrot and turmeric) from 430 fields in Uganda, 69 species of plant-parasitic nematodes representing 28 genera were extracted from soil and roots. About twice as many nematode species were recovered from soil (64) as from roots (36), while 32 species were found only in soil and four species only in roots, usually in mixed populations. Meloidogyne spp. (root-knot nematodes) were the ...

    • Potential of ethyleneproducing pseudomonads in combination with effective N2fixing bradyrhizobial strains as supplements to legume rotation for the control of Striga hermonthica 

      Ahonsi, M.O.; Berner, D.K.; Emechebe, A.M.; Lagoke, S.T.O.; Sanginga, N. (2003)
      Striga hermonthica (Del.) Benth. is an obligate, root-parasitic, flowering plant that limits cereal production in sub-Saharan Africa.Successful control depends on eliminating its seed reserves in soil, thereby preventing parasitism. Striga hermonthica seeds germinate only if adequately conditioned and exogenous stimulant initiates ethylene production within the seed, or if ethylene is directly supplied to the conditioned seed.Since S. hermonthica is an obligate root parasite, stimulating the seeds ...

    • Amelioration de la gestion des sols par lintroduction de legumineuses dans les systemes cerealiers des savannes africaines 

      Carsky, R.J.; Douthwaite, Boru; Manyong, Victor M.; Sanginga, N.; Schulz, S.; Vanlauwe, Bernard; Diels, J.; Keatinge, J.D.H. (2003)
      Lessons for appropriate soil management technology generation for the savannas and their application to the grain legume-cereal rotation system There are many legume-based techno logies capable of regenerating soi l ferti lity but few are being adopted by fa rmers in West Africa . At the Tn ternationa l Institute of Tro pica l Agriculture (TTTA) we found that alley cropping and cover cropping systems are biologica ll y sustainable but have low adoption by farmers in the medium term. Negacive ...

    • Arbuscular mycorrhizal fungi (AMF) respond to rhizobial inoculation and cropping systems in farmers fields in the Guinea savanna 

      Sanginga, N.; Carsky, R.J.; Dashiell, Kenton E. (1999)
      It has been difficult to explain the rotation effect based solely on N availability in maize-soybean cropping systems in the moist savanna zone of sub-Saharan Africa. Although arbuscular mycorrhizal fungi (AMF) can contribute to plant growth by reducing stresses resulting from other nutrient deficiencies (mainly P) and drought, their role in the maize/soybean rotation cropping systems in the Guinea savanna has not yet been determined. Pot and field experiments were conducted for 2 years using 13 ...

    • Longterm assessment of nitrogen and variety technologies on attainable maize yields in Nigeria using CERESmaize 

      Jagtap, S.S.; Abamu, F.J.; Kling, J.G. (1999)
      Maize simulation models are proposed as tools for assessment of response to nitrogen (N) fertilizer and varieties in order to explore potential target zones for improved maize varieties. The CERES-maize model in the Decision Support System for Agrotechnology Transfer version 2.1 was tested using international testing nurseries at Ibadan, Mokwa, and Kaduna situated, respectively, in the derived savanna, southern guinea savanna, and northern guinea savanna zones in Nigeria during 1992–95. Historical ...

    • A simple screening method for drought tolerance in cowpea 

      Singh, B.B.; Mai-Kodomi, Y.; Terao, T. (1999)
      A simple screening method was developed that accurately discriminates between drought and susceptible cowpea(Vigna unguiculata(L) walp). Wooden boxes (130 cm length. 65cm width. 15cm depth) made of 2.5cm thick planks were lined with polythene sheets, filled with a 12cm layer of soil and sand mixture(1.1) and kept on the table top in a screenhouse. Test materials were planted in the boxes with 10cm between rows and 5cm between plants within the row and watered daily until the partial emergence of ...

    • Inheritance of resistance to Stenocarpella macrospora (Earle) ear rot of maize in the midaltitude zone of Nigeria 

      Olatinwo, R.; Cardwell, K.; Menkir, A.; Deadman, M.L.; Julian, A. (1999)
      Inheritance of resistance to Stenocarpella macrospora (Earle) Sutton (syn. Diplodia macrospora Earle) ear rot of maize was studied among selected maize populations in the mid-altitude (1280 m) agro-ecological zone of Nigeria. Diallel analysis among the populations showed significant values for general combining ability (GCA) and specific combining ability (SCA) effects at 5% and 1% levels respectively. Variance components of GCA and SCA on Stenocarpella ear rot were 0.019 and 0.627 respectively, ...