Biological control of Phytophthora root rot of avocato with microorganisms grown in organic mulches

Brazilian Journal of Microbiology

Jefferson L. Da S. Costa²  John A. Menge¹  Willian L. Casale¹ 

[1] ,Embrapa Arroz e FeijãoSanto Antônio de Goiás GO ,Brasil

关键词: Phytophthora cinnamoni;    Gliocladium virens;    Trichoderma harzianum;    avocado;    Phytophthora cinnamoni;    Gliocladium virens;    Trichoderma harzianum;    abacateiro;   

DOI  :  10.1590/S1517-83822000000400002

来源: SciELO

【 摘 要 】

Organic mulches colonized with microbial biocontrol agents, termed bioenhanced mulches, were tested for their ability to reduce Phytophthora root rot of avocado (Persea americana Mill.). Benomyl-resistant mutants of Gliocladium virens (KA 230-1) and Trichoderma harzianum (KA 159.2) isolated from suppressive soils and selected as efficient antagonists of P. cinnamomi were evaluated for their ability to colonize different mulches under controlled laboratory conditions. Sudangrass and a coarse yardwaste were found to be better substrates than a fine yardwaste, woodwaste or rice hulls for biocontrol agents propagules production. The most suitable conditions for colonization were an optimum temperature of 24°C, a moisture content of 20% for sudangrass and 30% for the coarse yardwaste, and a continuous light exposure during a 15-day incubation period. In the greenhouse, fresh sudangrass and a coarse yardwaste colonized with G. virens and used as a surface mulch proved to be the best combination for reducing the population of P. cinnamomi in 4-liter pots containing artificially-infested soil. Healthy avocado roots made up 31-37% of the roots in the G. virens-mulch combinations compared to 0% healthy in infested controls after two months.

【 授权许可】

CC BY-NC   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License