Coffee Science - v.13, n.3, 2018

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10546

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Autor: search.filters.author.Carvalho, Geraldo AndradeTem arquivos: Sim

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    Nitrogen fertilizers and occurrence of Leucoptera coffeella (Guérin-Mèneville & Perrottet) in transplanted coffee seedlings
    (Editora UFLA, 2018-07) Sabino, Paulo Henrique de Siqueira; Reis Júnior, Francisco Ailton dos; Carvalho, Geraldo Andrade; Mantovani, José Ricardo
    The coffee leaf-miner (CLM) Leucoptera coffeella (Lepidoptera: Lyonetiidae) is one of the main pests of coffee plants in Brazil. Its occurrence in the crop is directly related to the physiological state and growth characteristics of coffee plants, in turn related to plant nutrition. The present work, therefore, aimed to evaluate the effect of nitrogen sources on the occurrence of CLM in coffee seedlings. The fertilizers used were ammonium sulfate, urea, and organomineral. The number of leaves mined by CLM and the relative contents of chlorophyll and crude protein in the leaves were recorded. Ammonium sulfate and urea favored higher occurrence of leaves mined and organomineral fertilizer provided the lowest incidence of leaves mined by CLM. The three sources of nitrogen increased the chlorophyll content, but only ammonium sulfate caused an increased percentage of crude protein in the leaves of coffee seedlings. For the improvement of management strategies for L. coffeella it is fundamental to understand favorable conditions, nutritional management it is one of the pest control mechanisms, thus making it possible to control the insect and prevent the population of CLM from reaching an economic damage threshold.
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    Physiological selectivity of insecticides to eggs and larvae of predator chrysoperla externa (Hagen) (Neuroptera: Chrysopidae)
    (Editora UFLA, 2018-07) Soares, Andrea de Fátima Torres; Carvalho, Geraldo Andrade
    Given the importance of green lacewings as agents of biological pest control, the present study aimed to evaluate the toxicity of insecticides used on coffee crops on the eggs and larvae of Chrysoperla externa. The insecticides tested were (g or mL a.i./L) chlorpyrifos (2.25), cartap hydrochloride (1.66), pyriproxyfen (0.33), profenofos/lufenuron (1.33/0.13), fenpropathrin (0.40), triazophos/deltamethrin (0.70/0.02) and zetacypermethrin (0.05). The insecticides, when applied directly on the eggs, caused no adverse effects on the duration of the embryonic period. After the application of triazophos/deltamethrin, pyriproxyfen, profenofos/lufenuron and zetacypermethrin, a reduction in egg viability was induced. The insecticides triazophos/ deltamethrin, chlorpyrifos, and profenofos/lufenuron reduced the survival of newly hatched first instar larvae from treated eggs. The first instar larvae that were treated directly were sensitive to the effects of the products used, with the effect of triazophos and chlorpyrifos/deltamethrin being high. The survival of the second instar larvae was reduced by zetacypermethrin, fenpropathrin, profenofos/lufenuron, and cartap hydrochloride. The products chlorpyrifos and triazophos/deltamethrin also did not allow second instar larvae survival. For treated third instar larvae, chlorpyrifos and triazophos/deltamethrin allowed survival of only 20.0 and 57.5%. Eggs and larvae of C. externa showed sensitiveness to insecticides chlorpyrifos and triazophos, being needed more studies in semi-field and field conditions for the confirmation or not of the toxicity aiming the conservation of this predator specie on the coffee agroecosystem.