Objective
This two-year trial aimed to assess the suppression effects of Promax® and 2 types of beneficial nematode treatments (S. feltiae and S. riobrave) versus a control on plant-parasitic nematodes (Stunt, Lance, Ring, and Spiral) for English Boxwood (Buxus sempervirens L. var. suffruticosa) ornamental plants.
Materials & Methods
Each experimental unit consisted of 2 English Boxwood plants with a Wheeling silt loam soil type (20% sand, 64% silt, 16% clay). Each experimental unit (16 total boxes) was separated from the next by at least 1 untreated boxwood plant. Soil samples (15–20 cores) from the boxwood plants were recorded before the treatment and at 7 and 30 days after one treatment was given. Treatments with S. feltiae and S. riobrave were accomplished by applying infective juveniles at a rate of 1.0 billion per acre (2.5 billion per hectare). Promax® was applied at a rate of 1 gallon per acre (10 liters per hectare).
Nematode species were identified and counted after each soil sample was taken. Species identified for this study were as follows: Stunt (Tylenchorhynshus sp.), Lance (Hoplolaimus sp.), Ring (Mesocriconema sp.), and Spiral (Rotylenchus buxophilus). The following year, the experiment was repeated with a second round of treatments and calculations of the nematode population percentages.
Figure 1. Year 1 Percentage Change in Nematode Counts for English
Boxwood Plants, 30 Days After Treatment, Control and 3
Treatment Types for 4 Nematode Types
Results
Figure 2. Year 2 Percentage Change in Nematode Counts for English
Boxwood Plants, 30 Days After Treatment, Control and 3
Treatment Types for 4 Nematode Types
Conclusions
The results reported in this trial demonstrate that application of 1 treatment of the nematicide Promax® reduced population percentages of the 4 plant-parasitic nematodes studied at both 7 days and 30 days post-treatment in years 1 and 2, with Promax® being more effective than the other 2 treatments studied for both time periods. This is an indication that Promax® suppresses nematodes by killing them on contact. Repeated applications may be required to achieve suppression for periods longer than 30 days.
Product Description
Promax® is an organic, OMRI-listed, EPA-exempt broadspectrum soil fungicide and nematicide. It is a protective and curative pesticide recommended for control of plant parasitic nematodes and soil-borne diseases. The mode of action is as a contact killer. There is no restricted use. Additionally, Promax® enhances root growth and, as a result, reduces susceptibility to secondary root infection.
For best results, 7–10 days after the final Promax® treatment is completed, Huma® recommends applying Zap® at 1 gal/acre (10 liters/hectare) for the stimulation of beneficial soil biology.
