Resource Guide for Organic Insect and Disease ... - Cornell University

OMRI LISTED PRODUCTS:
Coniothyrium minitans strain CON/M/91-08
Contans WG Marketed by Encore Technologies, LLC
Manufactured by Prophyta Biologischer Pflanzenschutz GmbH
References to OMRI listed products in this Guide are based on the 2012 edition of the OMRI
Product List. Please consult www.omri.org for changes and updates in the brand name product
listings.
REENTRY INTERVAL (REI) AND PRE-HARVEST INTERVAL (PHI):
The EPA Workers Protection Standard requires a minimum of 4 hours before reentering treated
areas, and has a 0 days pre-harvest interval.
EFFECT ON THE ENVIRONMENT:
Risk to the environment appears to be low. C. minitans is resistant to decomposition by light,
but not resistant to high temperatures (above 104 degrees F). It is insoluble and has been
found to have low toxicity to fish and algae. In the absence of host sclerotia (a food source), its
biocontrol ability is thought to persist at low levels, if at all.
EFFECTS ON HUMAN HEALTH:
Risk to public health appears to be minimal (Table 1).
Table 1. Toxicity of C. minitans through different exposure routes
Acute oral LD50 (rat)
Acute dermal LD50 (rat)
Acute intraperitoneal LD50 (rat)
Acute inhalation toxicity (rat)
Eye irritation (rabbit)
Skin irritation (rabbit)
Relatively non-toxic (>2500mg/kg)
Relatively non-toxic (>2500mg/kg)
Relatively non-toxic (>2000mg/kg)
Relatively non-toxic (>12.74 mg/liter air)
None
None
EFFICACY:
The C. minitans product is variable in its effectiveness, as are many biological products. It
can be effective against both S. sclerotiorum and S. minor (Fig. 1). Factors that cause the
observed variability in field trials are unknown, but may include treatment rate, number of
treatments, soil moisture and temperature at the time of treatment, whether the treatment
was incorporated into the top 2 inches of soil, and whether new sclerotia were brought to the
surface by tillage after treatment. Results appear to be somewhat better against S. sclerotiorum
than S. minor (Fig. 2).
In Figure 1, “good control” means statistically significant reductions in either pest numbers or
damage of 75% or more, compared to an untreated control. “Fair control” includes those with
significant reductions of 50-74%, and any non-significant reductions of over 50%. The “poor
control” group includes any results with less than 50% reduction.
Organic Resource Guide 121