Bipolaris euphorbiae as a Biological Control Agent for Wild Poinsettia (Euphorbia heterophylla): Host-Specificity and Variability in Pathogen and Host Populations

Abstract

Bipolaris euphorbiae (anamorphic Ascomycota: Pleosporaceae) has been studied since the early 1980s as a potential biocontrol agent of wild poinsettia (Euphorbia heterophylla), a noxious invader of soybean fields in Brazil. A new isolate (KLN05) was arbitrarily selected after the aggressiveness of six isolates of the fungus obtained from different sites was evaluated on wild poinsettias grown from seeds obtained from six different geographic origins in Brazil: Vic¸osa-state of Minas Gerais; Itabuna-state of Bahia; Nitero´i-state of Rio de Janeiro; Nova Laranjeira, Londrina and Foz do Iguac¸u´-state of Parana´. Bipolaris euphorbiae grew between 10 and 30°C, with the optimum for colony growth at 25°C. The best temperature range for conidial germination was between 20 and 30°C. Conidial germination was not inhibited by mixing conidia with imazethapyr (106 g of active ingredient [a.

Dealing with weedy problems in agriculture: the role of three agricultural land use management practices in the forest‐savanna ecological zone of Ghana

“…Slaats et al (1998) report the significant effect of weeds on maize crop yields in Côte d’Ivoire, while Roder et al (1997) indicate the effects of weeds on rice yields in Laos. Nechet et al submit that ‘the most important limiting factor for soybean production [in Brazil] is competition from weeds’ (2006, 259). In more specific terms, Silwana and Lucas (2002) show that effective weed management enhances the yield of maize by 30–35 per cent in South Africa, and Gupta (1993) suggests that weeds reduce the yields of maize and rice in India by 18–85 per cent and 30–35 per cent, respectively.…”

Métodos de controle de plantas daninhas em sistemas orgânicos: breve revisão

“…Ressalta-se que algumas espécies de fungos possuem alta especificidade para determinadas plantas daninhas, o que representa grande seletividade de controle, todavia, a eficiência tende a ser maximizada em áreas com infestações monoespecíficas. Neste sentido, foi demonstrada alta especificidade do fungo Bipolaris euphorbiae (concentração de 1×10 7 esporos ml -1 ) em plantas de leiteiro (Euphorbia heterophylla), o qual induz sintomas (manchas necróticas nas folhas e caules) sete dias após a inoculação, sendo que, os autores observaram taxa de mortalidade de 80% em plantas inoculadas (Nechet et al, 2006).…”

Sustainable Horticultural Systems

“…used as mycoherbicides have controlled E. heterophylla effectively in experiments (Parsons and Cuthbertson 2001). Bipolaris euphorbiae (anamorphic Ascomycota: Pleosporaceae) has been studied since the early 1980s as a potential biocontrol agent for E. heterophylla, which invades soybean fields in Brazil (Nechet et al 2006). …”