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Browsing by Author "Soares, Ana Cristina Fermino"

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  • Control of the banana burrowing nematode using sisal extract
    Publication . Jesus, Fábio N.; Damasceno, Josilda C.A.; Barbosa, Dimmy H.S.G.; Malheiro, Ricardo; Pereira, J.A.; Soares, Ana Cristina Fermino
    The nematode Radopholus similis is a major pest in banana plantations worldwide. This nematode is actually controlled using synthetic, toxic nematicides. Alternative control methods are therefore needed. For instance the liquid byproduct of fiber extraction from sisal (Agave sisalana) may be used as a nematicide. Here we tested the nematicidal activity of the sisal residue, fresh or fermented, on R. similis in banana plants. We measured immobility and mortality effects by nematode immersion in an aqueous solution of sisal residue for 24 and 48 h. Nematode control was also evaluated in the Grand Naine banana plants under greenhouse conditions using soil amendments of residues. We measured plant growth, pseudostem diameter, the number of leaves, and the dry weight of the aerial parts, corm and roots, aswell as factors related to nematode control such as the level of damage, the population of R. similis in roots and soil, and nematode reproduction factors. Our results show that the sisal residue efficiently controlled R. similis in vitro, displaying mortality rates of 99.2 % for the fresh residue. The damage caused by R. similis on plants was similar for the treatment with the sisal residue at a concentration of 25 % and with the nematicide. This is the first report on the nematicidal effect of the sisal liquid residue on the banana burrowing nematode. This byproduct presents the potential for the development of new alternatives for nematode control, with a low-cost and lowenvironmental risk plant nematicide.
    2015Journal article Restricted access Show more
  • Homeopathic drugs to control red rot disease in sisal plants
    Publication . Gama, Erasto V.S.; Silva, Franceli; Santos, Ivanete; Malheiro, Ricardo; Soares, Ana Cristina Fermino; Pereira, J.A.; Armond, Cintia
    Sisal—Agave sisalana Perrine ex. Engelm—is a key economical and social crop in the semi-arid region of Brazil, especially in the Bahia state. Sisal is severely affected by Aspergillus niger Thieg, the causal agent of sisal red rot. Currently, existing control strategies are fruitless. Here, we tested different homeopathic drugs Carbo vegetabilis, Ferrum metallicum, Natrum muriaticum, phosphorus and sulphur at centesimal Hahnemannian (CH) dynamizations, of 3CH, 5CH, 7CH, 9CH and 12CH, on Aspergillus niger. We measured in vitro growth inhibition, sporulation and germination of Aspergillus niger during 12 days. We assessed in planta Aspergillus niger incidence and disease severity. Our results show that homeopathic drugs inhibited Aspergillus niger growth in vitro, in a dynamization-dependent way. Natrum muriaticum 5CH revealed the higher inhibition of 66 %, whereas sulphur 5CH yielded the lowest inhibition of 6.4 %. Spore production was stimulated using all homeopathic drugs at all dynamization levels, whereas spore germination was reduced. In planta assays revealed different results from in vitro assays, corroborating that in planta and in vitro effectiveness is different according to the homeopathic drugs applied. Here, disease incidence was not reduced significantly, but disease severity was lower in treated plants, of 27.8 % using Ferrum metallicum 9CH than in control trials, of 73.6 %. Overall, our findings suggest that homeopathic drugs could be a good strategy to control Aspergillus niger incidence in sisal plants.
    2015Journal article Open access Show more