C. Minitans is a naturally occurring parasitic fungus that feeds on Sclerotinia sclerotiorum, which infects many broadleaf crops. Contans WG is a commercially produced biofungicide that can be used in an integrated approach to manage economically prohibiting crop diseases such as Sclerotinia in Canola and White Mold in Dry Beans. Evaluate efficacy of Serenade and applications of Contans in conjunction with Serenade.
Examine efficacy of Contans WG for the control of Sclerotinia diseases in susceptible crops, including sclerotinia in canola and white mold in beans.
Over three years, 28 Contans applications were made on ten field sites in southern Alberta, in addition to the Farming Smarter demo site. These applications included rates of 2 and/or 4 kg/ha, and various foliar fungicides were also applied in combination with these treatments. Incorporation methods included various types of tillage, irrigation, and natural precipitation. Serenade was applied to 12 fields, six of which were also treated with Contans.
Small mesh bags, called depots, containing sclerotia (bodies producing infectious sclerotinia spores) were buried in each treatment following each Contans application and then taken out and examined in the lab to estimate the rate at which the sclerotia were degraded by the Contans application.
Positive results were seen from both Contans and Serenade applications in a variety of fields. Reductions in disease ratings were not as useful in predicting yields as anticipated, but yields increased to varying degrees in almost all cases where application of these biofungicides was compared with an untreated check. Even more positive results are expected from the fields in which Contans was applied, as this product has a longer-term effect on the Sclerotinia pathogen.
In the entire duration of the trial, two applications of Lance at Co-operator 5’s bean field in 2009 was the most effective treatment, with disease incidence reduced from 88 to 28%, severity from 1.9 to 0.65 and yield increased 67% from 2315 to 3439 kg/ha compared to the untreated check. The best result received from a Serenade treatment was in Co-operator 9’s field in 2009, with a yield increase of 214 lb/ac (14.9%) over the check. In many cases, one or two applications of Lance was as effective as or more effective than treatment with either of the trial biofungicides, but there were cases were efficacy was similar.
Economics and perception of cost plays a large part in decisions, as does convenience and timing of application. Several producers stated that they liked Contans, but were unsure that its cost was justified by the increase in yield or decrease in disease severity.
It is important to note that, in most cases, higher disease ratings for treatments did not necessarily translate to lower yields. This can be attributed to two factors, or a combination of both. The first is the nature of the white mold disease, since it develops in the healthiest areas of the crop due to increased humidity in a denser canopy. This may reduce yield, but often not reducing it below comparable yields in less dense areas of the crop, where disease incidence and/or severity are often lower. Second is the variability of disease based on previous years’ infestations and variability of soils. These factors can make it difficult to interpret disease ratings and draw conclusions about the efficacy of the products.
Contans final report
Biofungicide shows promise despite low mould year Western Producer Producer Sept 2011
Contans cleans up sclerotinia Grainews Feb 2011