Our Insights | Crop Protection
August 01, 2019

Impact of Fungicide, Nutrient and Biological Compounds on the Incidence and Severity of Anthracnose

September 2019

 

Historically, GRIGG nutritional integrated pest management (NIPM) programs have provided excellent results as part of an anthracnose management program. Specifically, key components to the program(s) include foliar nitrogen (N), potassium phosphite (K2PO3-), and low label rates of contact fungicide (either chlorothalonil or fludioxonil). In this trial we included many of the best performing treatments historically and also included BRANDT’s Manni-Plex technology – combined with a different potassium phosphite source – NutriGro Magnum. We also included some experimental treatments. Our objective was to compile additional efficacy data for GRIGG and BRANDT NIPM programs and test some experimental formulations.

 

GRIGG and BRANDT nutritional IPM programs significantly reduced anthracnose disease. Headway® fungicide provided the best disease control throughout the course of this study. Numerically, the BRANDT anthracnose program performed better than the GRIGG program in terms of reducing disease severity. Importantly, significantly better turf quality was evident for both NIPM programs compared to fungicide alone and the untreated control due to the highly efficient Proven Foliar® and Manni-Plex technology nutrient inputs.

 

 

General Information

Study Director Gordon Kauffman III, Ph.D. – BRANDT
Investigator Brian McDonald and Alec Kowalewski – Oregon State University
BRANDT Rep Michael Steve
Location Oregon State Turfgrass Research Center, Corvalis OR
Crop/Variety Annual bluegrass (Poa annua L.)
Weather Mod warmth, abiotic stress During Application: Variable
Pest Pressure Anthracnose (Colletotrichum cereale)

 

 

Trial Details

General Fertility Lean to encourage disease ~2 lbs. N/M/YR
Soil Type Sand loam – Modified with sand.
Plot Size 3x5
Replications 3 - Random Complete Block
Crop Stage at Application Perennial Grass Cover

Site type

Field Grown
Application Dates Every 14 days; Jun 1 –Aug 31 2018
Spray Volume Carrier 88 GAL H2O/A
Application Method CO2 powered backpack sprayer
Nozzle and Pressure Flat fan nozzles at 40 p.s.i.

Treatments:
1. Headway® (3 fl. oz./M)
2. GRIGG Gary’s Green Ultra (12 fl. oz./M) + PK Plus (6 fl. oz./M) + Daconil Ultrex® (1.8 oz./M)
3. BRANDT Manni-Plex Grow (12 fl. oz./M) + Nutri-Gro Magnum (2 fl. oz./M) + Daconil Ultrex (1.8 oz./M)
4. Daconil Ultrex® (1.8 oz./M)
5. Untreated Control

 

Results

  • All nutritional integrated pest management programs reduced anthracnose disease and provided acceptable control (Figure 1).
  • Moderate pest pressure occurred; therefore ≤ 5% was considered commercially acceptable control.
  • The BRANDT NIPM program provided statistically similar control to Headway fungicide throughout the entire trial (Figure 1).
  • EXP treatments and Daconil fungicide alone did not provide acceptable disease control (Figure 1).
  • GRIGG and BRANDT NIPM programs produced consistently and significantly better turfgrass quality as measured by NDVI (Figure 2).

 

Figure 1. Impact of foliar fertilizers (including phosphite) applied with low label fungicides on anthracnose incidence and severity. Treatment means located at or below the dotted red line indicates commercially acceptable control (5%).

Figure 2. Impact of foliar fertilizers (including phosphite) applied with low label fungicides on overall turfgrass quality as measured by NDVI after moderate anthracnose infestation. * - Error bars indicate least significant differences (P=0.05)

Recommendations

  • Use BRANDT Manni-Plex technology nutrient source(s) and NutriGrow Magnum fertilizer programs in combination with low label chlorothalonil rates to improve turfgrass performance under stress and subsequent anthracnose pressure.
  • Use GRIGG Proven Foliar® nutrient formulations in combination with PK Plus and low label chlorothalonil rates to improve turfgrass performance under stress and subsequent anthracnose pressure.
  • To ensure optimum performance, quality, color and playability combine contact fungicide with efficient and complete/balanced BRANDT or GRIGG formulations.
  • Apply these programs preventatively and sequentially prior to the onset of environmental stress and before conditions are conducive to disease pressure.

 

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