Induction of Systemic Resistance by Bacillus cereus Against Tomato Foliar Diseases Under Field Conditions

Abstract

The ability of a rhizobacterium to protect tomato plants against naturally occurring diseases as well as to improve crop yield under field conditions was studied. The rhizobacterium was introduced to the plants through seed microbiolization. Treatments consisted of different frequencies of fungicide (Chlorothalonyl) sprayings (5, 10 or 20 applications) of tomato plants grown from either microbiolized or non-microbiolized seeds over a 90-day evaluation period. Treatment of non-microbiolized seeds without fungicide application was included as a control. The progress of the following three naturally occurring diseases was evaluated in the field and quantified: early blight (Alternaria solani), late blight (Phytophthora infestans), and septoria leaf spot (Septoria lycopersici). All treatments resulted in reduced disease severity when compared with the control treatment. Highest final fruit yields were found after treatment of plants grown from non-microbiolized seeds and sprayed with fungicide 20 times over 90 days, and for treatment of plants from microbiolized seeds that received 10 fungicide spray applications, although all treatments increased yield over that obtained in the control treatment. The results demonstrate that combined rhizobacterial and chemical treatments in the field may permit reducing fungicidal spraying frequency while at the same time increasing crop yields.

PGPR Improves Yield of Strawberry Species under Less-Fertilized Conditions

“…as crop production improvement agents have been studied in many crops. For example, application of B. cereus on seeds of tomato has been reported that the treatment is effective to induce systemic resistance of the plant against several fungal diseases (Silva et al, 2004). This effect was explained as induction of systemic resistance against pathogens by inoculation of Environ.…”

“…Applications of PGPR in growth media or direct application to plant body during cropping are carried out to expect better yield as a result of plant/PGPR interaction. Positive effects of PGPR on commercial products have been reported in many crops such as soybean (Cattelan et al, 1999), maize (Babalola et al, 2003), tomato (Silva et al, 2004) as well as rice (Sen and Chandrasekhar, 2014).…”

Supressão da murcha de fusário em tomateiro por rizobactérias do gênero Bacillus1

“…despontaram como potenciais micro-organismos a serem utilizados no manejo integrado da murcha de fusário em tomateiro. Esse biocontrole poderá ser ampliado pelo desenvolvimento de novas estraté-gias, como a combinação com múltiplos agentes de biocontrole (Souza Júnior et al 2010), rotação com controle químico (Silva et al 2004) e redução da pressão de inóculo inicial ou aumento da supressividade de solos a fitomoléstias, além de influenciar na diminuição de possíveis emergências de raças patogênicas (Chung et al 2008 …”

“…A inoculação desses agentes é uma alternativa viável, principalmente quando empregada em associação com outros métodos de controle, apresentando baixo custo e pouca agressividade ao ecossistema (Silva et al 2004).…”

“…'Viradoro') foram microbiolizadas por embebição, por 24 horas, em suspensão de propágulos de cada rizobactéria (Moura et al 1998, Silva et al 2004), e colocadas para germinar em bandejas de poliestireno contendo substrato Plantmax ® não autoclavado. Aos vinte dias após a semeadura, as mudas foram transplantadas para vasos com capacidade de 1,0 L, contendo solo areno-argiloso previamente autoclavado a 120 ºC, por 40 minutos.…”