Bragantia (2005) 64, 423-433

André Luiz Lourenção, Nelson Raimundo Braga, Manoel Albino Coelho de Miranda, Paulo César Reco, Cristina Gomes Quevedo Fugi and José Carlos Vila Nova Alves Pereira (2005)
Avaliação de danos de insetos e de severidade de oídio em genótipos de soja
[Evaluation of insect damage and powdery mildew severity in soybean genotypes]
Bragantia 64 (3), 423-433
Abstract: Performance of 24 soybean lines from the breeding program of Instituto Agronômico (IAC) was evaluated under field conditions, as to attack of insects and incidence of powdery mildew. Three experiments, one for each maturity group (early-110, intermediate-120, and late-135 days), were carried out at the Experimental Station of Assis (2001/2002 and 2002/2003 growing seasons) and Experimental Station of Ribeirão Preto (2001/2002), both located in the State of São Paulo, Brazil. For all experiments, with ten treatments and six replicates, in randomized block design was adopted. Defoliation damage caused by Anticarsia gemmatalis Hübn. caterpillars was estimated visually, by the percentage of eaten leaf area (PAFC). Stink bugs [Piezodorus guildiniii (West.) and Euschistus heros (F.)] damage was evaluated by two criteria: percentage of foliar retention (PRF) and yield. The severity of powdery mildew (Microsphaera diffusa Cke. Pk.) was evaluated using a scale from 1 (no symptom) to 5 (more than 50% of leaves with symptoms). Considering the results of both locations, among the early maturity genotypes (110 days), the line IAC 98-4307 could be distinguished for the higher grain yield and low PRF under stink bug infestations. Regarding the genotypes of 120-day maturity group, the line IAC 98-2814 does not show foliar retention and presents higher grain yield, proving to be resistant to stink bugs; however this line is the most defoliated by caterpillars and presents more intense powdery mildew symptoms. Among the genotypes of 135-day maturity group, higher grain yield was observed in IAC 98-2856 under high or low stink bugs infestations, indicating tolerance to these insects, although it shows foliar retention under low stink bug infestation.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): André Luiz Lourencao

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Anticarsia gemmatalis	Soybean (Glycine max)	Brazil (south)
	Euschistus heros	Soybean (Glycine max)	Brazil (south)
	Piezodorus guildinii	Soybean (Glycine max)	Brazil (south)
	Erysiphe diffusa	Soybean (Glycine max)	Brazil (south)