Resistência de soja a Nezara viridula e Piezodorus guildinii em condições de campo

• Published in: Bragantia 1979, Vol.38 (1), p.181-188
• Main Authors: Miranda, M. A. C. de, Rossetto, C. J., Rossetto, D., Braga, N. R., Mascarenhas, H. A. A., Teixeira, J. P. F., Massariol, E A.
• Format: Article
• Language: English
• ISSN: 0006-8705; 0006-8705
• DOI: 10.1590/S0006-87051979000100019

Os cultivares de soja 'paraná', 'viçoja' e 'santa-rosa', a linhagem IAC 73-223 e as introduções PI 171451 e PI 229358 foram testados em condições de campo para avaliar a resistência a percevejos. Ocorreram nesse campo experimental apenas as espécies de percevejos pentatomídios Nezara viridula L. e Piezodorus guildinii Westw. em iguais proporções. A linhagem IAC 73-228 teve a menor porcentagem de grãos danificados (48,1%) na metade superior da planta e as introduções PI 171451 (71,1%) e PI 229358 (79,1%) apresentaram porcentagem intermediária de grãos danificados. O cultivar 'paraná' foi o mais danificado, com 96,87%. Houve correlação significativa entre porcentagem de dano e porcentagem de plantas com retenção foliar (hastes verdes) por ocasião da colheita. Houve correlação positiva entre tamanho dos grãos e dano dos percevejos. O dano foi maior na parte superior das plantas que na inferior. The soybean cultivars Paraná. Viçoja and Santa Rosa, the line IAC 73-228 and the introductions PI 171451 and PI 229358,e were tsted in Campinas, State of São Paulo, Brazil, in relation to the stink bugs Nezara viridula L. and Piezodorus guildinii Westw. The line IAC 73-228 had the least percentage of damaged seed (48,l%) in the superior half of the plant, whereas Paraná had the highest (96,8%). The introductions PI-171451 (71,1%) and PI 229358 (79,1%) had intermediate degrees of damaged seeds. This difference in damaged seeds could be due to actual resistance to the stink bugs, to resistance to Nematospora coryli transmitted by these insects or due to host evasion. It has been observed by DAUGHERTY et al. (1964) and LINK & COSTA (1974), that varieties with shorter period from flowering to harvest are less damaged by stink bugs and this would be a case of pseudo resistance called host evasion according to PAINTER (1951). There was a high positive correlation between percentage of seeds damaged and green stems at harvest. This feature could be used for field selection against these insects. There was positive significant correlation between damage and seed size. The seed size may be linked in some way to susceptibility to stink bugs. The damage was higher in the superior half of the plants than in the inferior.