RootShield^® WP's new, improved formulation using a water soluble carrier, makes it much easier to use than previous formulations of PlantShield^® HC. This root biofungicide contains dormant spores of the effective, and well proven, active ingredient Trichoderma harzianum strain T-22. When mixed with water at the typical application rate of 4 oz/100 gallons, over 100 billion spores are applied to the growing medium in one application. There are many application options that can be utilized to get RootShield WP onto your crop: using an injector with a watering wand, overhead boom irrigation, watering tunnels, Chapin^® tube system, drip tape or emitter systems, ebb and flood, sprayers, etc.

Once RootShield WP (or RootShield® Granules) is applied to the growing medium, the spores germinate within 16 - 24 hours. As the mycelium emerges from the spore it immediately starts coiling around the plant's roots and any plant pathogen propagules present. After 24 hours RootShield cannot be leached from the soil mix. RootShield will grow in a diversity of inorganic and organic growing media from sand, perlite, or clay, to pure peat or bark. RootShield grows tightly on roots in hydroponics systems, including those utilizing the nutrient film technique where there is no medium.

In the growing medium, RootShield can tolerate a wide range of pH (4 - 8) and grow at temperatures from 48^o to 97^o F. What is important to remember is that since RootShield grows on the plant's roots, it is the pH and temperature right around the root system that is most influential. RootShield is drawn to high concentrations of root exudates, seeks out and searches for plant roots and colonizes the root hairs, branching sites, the root surface and callus tissue. It will also colonize the callus which forms on cuttings in propagation. There are two primary modes of action: (1) competitive exclusion, which means RootShield gets to the pathogen-preferred sites first and prevents diseases like Pythium, Fusarium, Rhizoctonia and Thielaviopsis from getting into the roots, and (2) mycoparasitism, whereby RootShield encounters a pathogen mycelial strand, and secretes enzymes, including chitinases and glucanases, that dissolve the invading pathogen's cell walls.

Continuing next month - Part 2: "RootShield Compatibility and Additional Benefits"