Ask the experts

When choosing a biological fungicide, nursery or greenhouse growers must decide what type of formulation would work best for their particular situation. Often, the choice comes down to whether to use granules or wettable powder.

 

Granules are small pellets that can be blended into your soil mix at the time of planting. Wettable powder can be applied through a soil drench, in-furrow spray or tank mix. Both can be used with other fungicides, liquid fertilizers, herbicides, insecticides or other biological control products.

 

Chris Hayes, Southeast Technical Sales Manager for BioWorks, said that both types of formulation work equally well when applied to the ground for root protection. The choice really comes down to how your growing operation works and what types of plants you produce.

 

“Some people buy their growing media from a commercial source like Sun Gro or Fafard,” he said. “Some growers have their own mixing equipment, put their own peat and micro nutrient mix to make their own growing media in-house. If they have a hopper available, they can apply the granules in their own hopper system, soil mixing or media growing system. Or the big mix companies or even regional ones will incorporate it for you.”

 

For other growers, wettable powder makes more sense. If you produce a variety of different plants, including some, like marigolds, that never have root rot issues, using granules might be overkill. Those growers would rather use wettable powder to treat their more problematic plants.

 

Wettable powder can be applied through the following systems: 1) pressurized drench (flood) or drip (trickle), 2) furrow, 3) microirrigation such as spaghetti-tube or individual tube irrigation, 4) hand-held calibrated irrigation equipment such as the hand-held wand with injector, and 5) ebb and flow.

 

 “The wettable powder option lets you target the plants you want to protect,” Hayes said. “So instead of treating everything, including some plants that never have root rot issues, they choose to treat only those that have the potential for root rot issues.”