Compost teas proven as effective biocontrol agent to inhibit plant diseases.

Thanks to Compost Tea Lab for sharing some scientific research regarding how and why compost tea works.

Utilization of compost tea for biochemical response assessment
associated with resistance to phytopathogen causing leaf spot
in Melicope ptelefoli

October 2018
Organic Agriculture
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Malaysia's warm temperatures and wet climate create almost greenhouse like conditions that can be great for growing plants, but also great for culturing plant-disease causing fungi.   Researchers from  Malaysia's University of Technology wanted to  determine what affect compost tea had on the growth of the leaf spot causing Grammothele lineata. The test plant was the Asian herb Melicope ptelefolia which is known for it's edible and medicinal qualities. 

Researchers used two types of teas in the experiment, both were aerated, one of which was supplemented with Molasses.  The researchers then made several concentrations of the tea and dipped leaf leaves into it.  The leaves were then sprayed with a solution that contained the Grammothele spores.  The infected leaves were incubated for a week and then the severity of infection was documented.  The leaves were also tested for the amount of naturally occurring plant defense chemicals present in their tissue.  

What they found was that both teas (with and without molasses) inhibited the growth of the fungal disease by up to 78%.  The highest concentration (40% tea by volume) of molasses brewed tea was the most effective.  The control leaf, which was sprayed with spores only, was completely infected.  Moreover, the leaves that had tea applied to them produced more natural plant defense chemicals (Peroxidase and Polyphenol Oxidase).  The tea boosted the plants own ability to fight off disease.  This is an impressive new discovery in the compost tea realm, as most literature points to compost tea helping reduce infection through competitive exclusion.  This is yet another reason to start using compost tea in your gardens and on your landscape.  Thanks Malaysian scientists for furthering our understanding of why this living fertilizer is such a beneficial substance.