Técnica de medição de área foliarconsumida por insetos através de digitalizador de imagens
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Data
1998-05-01
Autores
Wilcken, Carlos Frederico [UNESP]
Moraes, R. C. B. de
Haddad, M. de L.
Parra, J. R. P.
Título da Revista
ISSN da Revista
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Editor
Universidade de São Paulo (USP), Escola Superior de Agricultura Luiz de Queiroz (ESALQ)
Resumo
Este trabalho teve por objetivo verificar a viabilidade do uso de digitalizador de imagens manual, acoplado a um microcomputador, para a avaliação do consumo de folhas de soja, por lagartas de 5o instar de Anticarsia gemmatalis Hübner (Lep.: Noctuidae), em comparação com o método de pesagem e do planímetro, baseando-se na eficiência dos métodos e no tempo gasto para a avaliação. Os testes foram realizados utilizando-se folhas de soja `IAC 8' e lagartas criadas em dieta artificial. Foram realizados 2 tipos de teste: 1o) oferecimento de folíolos inteiros de soja às lagartas e, 2o) oferecimento de disco de folhas de área conhecida. No 1o teste comparou-se o método de pesagem com o digitalizador de imagens (scanner); no 2o experimento foram comparados o método do planímetro com o digitalizador de imagens que emprega o programa PCXAREA. Os resultados obtidos demonstraram que não existem diferenças nas medições de folíolos e discos de soja consumidos por A. gemmatalis quando comparados os métodos tradicionais (planímetro e pesagem) e o de digitalização de imagens. A medição com o digitalizador reduziu o tempo de avaliação em 88,5% e 87%, em relação ao planímetro e método de pesagem, respectivamente, sendo plenamente viável a sua utilização.
The viability of the use of an image analyzer (scanner), was compared with the use of leaf weight and planimeter techniques, to measure leaf area consumption by insects. The tests were conducted with 5th instar Anticarsia gemmatalis Hübner (Lep.: Noctuidae) larvae reared on artificial diet. Soybean leaves (cultivar IAC - 8) were offered to velvetbean caterpilars held in Petri dishes. Two experiments were conducted in a completely randomized design: (1) with whole soybean leaves, and (2) with leaf disks. The image analyzer use was compared with the leaf weight method in the first experiment and with the planimeter. The image data was analyzed with PCXAREA software. There were no significant differences between the image analyzer and the standard techniques. The evaluation time with image analyzer reduced by 88.5 and 87% the time consumed with planimeter and leaf weight methods, respectively. Based on the results, it is concluded that the use of a scanner is viable for measuring leaf area consumption by insects.
The viability of the use of an image analyzer (scanner), was compared with the use of leaf weight and planimeter techniques, to measure leaf area consumption by insects. The tests were conducted with 5th instar Anticarsia gemmatalis Hübner (Lep.: Noctuidae) larvae reared on artificial diet. Soybean leaves (cultivar IAC - 8) were offered to velvetbean caterpilars held in Petri dishes. Two experiments were conducted in a completely randomized design: (1) with whole soybean leaves, and (2) with leaf disks. The image analyzer use was compared with the leaf weight method in the first experiment and with the planimeter. The image data was analyzed with PCXAREA software. There were no significant differences between the image analyzer and the standard techniques. The evaluation time with image analyzer reduced by 88.5 and 87% the time consumed with planimeter and leaf weight methods, respectively. Based on the results, it is concluded that the use of a scanner is viable for measuring leaf area consumption by insects.
Descrição
Palavras-chave
Insecta, medição de área foliar consumida, lagarta da soja, digitalizador de imagens, Insecta, leaf area consumed measurement, velvetbean caterpillar, scanner
Como citar
Scientia Agricola. São Paulo - Escola Superior de Agricultura Luiz de Queiroz, v. 55, n. 2, p. 218-221, 1998.