Control of Phytophthora capsici and Phytophthora parasitica on pepper (Capsicum annuum L.) with compost teas from different sources, and their effects on plant growth promotion

Abstract

Suppressive effects of different compost teas were evaluated against the phytopathogens P. capsici and P. parasitica, isolated from diseased plants from commercial sweet pepper farms in Almería (Spain), during 2011. Aerated compost tea and non-aerated compost tea were prepared from spent mushroom compost, grape marc compost, crop residues compost and vermicompost. In vitro inhibition of mycelial growth of the two tested pathogens was assessed, and in vivo effects of compost teas on disease severity, caused by P. capsici and P. parasitica were evaluated on pepper plants, in greenhouse experiments. Different morphological parameters were also measured for plants treated with compost teas, to determine growth promotion effects on pepper plants. The compost teas controlled the two tested pathogens in vitro and in vivo. Non-aerated compost teas (NCT) were more beneficial in increasing growth of pepper plants than aerated compost teas. This study demonstrates the clear effect of compost tea on disease suppression and plant growth promotion. These compost extracts may be used as alternatives to inorganic fertilizers/fungicides to enhance plant growth, reduce disease incidence and increase crop yields.