Marrone Bio - Stargus 2.5 gal

What Is Actually in Stargus Biofungicide

The active is a bacterium, not a chemistry. Read the label and it says 96.4 percent Bacillus amyloliquefaciens strain F727 cells and spent fermentation media, with 3.6 percent other ingredients. That is an unusually high number because the product essentially is the fermentation. The bacterium colonises plant tissue and competes with pathogens for the space and the food. It also provokes the plant into switching on its own defences. Because nothing synthetic is being deposited, the label carries a zero-day pre-harvest interval and a four-hour re-entry interval. It is MRL-exempt and OMRI Listed for organic production. The signal word is caution and the protective equipment required is minimal. Foliar, chemigation, soil treatment and backpack sprayer are all on the label. Greenhouse use is approved with its own rates.

Rates and Timing Against Downy Mildew

ProFarm publish two to four quarts an acre for grey mould, white mould and downy mildew, and three to four quarts an acre for fusarium. Sprayed by volume rather than by area the label runs one to four quarts in a hundred gallons of water. Timing is the thing that decides whether a biological works at all. These products are preventative and they need to be on the leaf before the spore lands, not after the lesion appears. Start early, keep the interval tight, and treat it as a programme rather than a rescue. Living products also have living limits. Tank water that is chlorinated or badly pH-adjusted will kill the culture before it reaches the plant. Check the expiry and store it out of heat, because the shelf life belongs to the bacteria and not to the bottle. The honest limit is that a curative spray on an established infection is the wrong job for this.

Key Features

• Active ingredient: Bacillus amyloliquefaciens strain F727, listed at 96.4 percent
• Mode of action: Colonises tissue, competes with pathogens, provokes plant defences
• Pre-harvest interval: Zero days, so it can go on the day of harvest
• Re-entry interval: Four hours before anyone goes back in
• Residue: MRL-exempt, and OMRI Listed for organic production
• Application: Foliar by air or ground, chemigation, soil treatment, backpack sprayer
• Foliar rate: Two to four quarts an acre on most labelled diseases
• Greenhouse: Approved, with its own rates on the label
• Container: Supplied in a 2.5 gallon jug

Technical Specifications