Patrick E. Lipps, Anne E. Dorrance and Landon H. Rhodes
Professor, Assistant and Associate Professor
Department of Plant Pathology
The Ohio State University
Seed treatment fungicides are useful tools to manage seed- and soilborne pathogens. Seed treatments are highly recommended in Ohio on seeds of alfalfa, corn, soybeans, and small grains. However, a specific fungicide will not control all of the pathogens that may be present. It is important that agronomic crop producers know what the pathogens are in specific fields in order to choose the best fungicide or combination of fungicides for that field. In addition, the correct choice of fungicide will also limit losses due to seed-borne pathogens. The same rule applies in that specific fungicides will not effectively control all seed-borne pathogens. Refer to Extension Bulletin 639 Seed Treatment for Agronomic Crops for more detailed information concerning seed and seedling diseases affecting field crops in Ohio.
The following tables list the effectiveness or efficacy of fungicide seed treatments for alfalfa, corn, soybeans and small grains. These tables are based on field trials where these fungicides have been evaluated under very high disease conditions. The listed products may be applied in various combinations within limits of the label. Using combinations of fungicides will broaden the effectiveness against several different diseases.
Table 1. Relative efficacy of seed treatments for control of certain diseases of ALFALFA in Ohio.
| Trade name | Active Ingredient | Phytophthora |
| Allegiance | Metalaxyl | E |
| Apron XL | Mefenoxam | E |
| Captan | Captan | N |
| Thiram | Thiram | N |
Table 2. Relative efficacy of seed treatments for control of certain diseases of CORN in Ohio.
| Trade name | Active Ingredient |
Soil-borne | Seed borne | ||
| Fusarium | Rhizoctonia | Pythium damping off |
Fusarium | ||
| Allegiance | Metalaxyl | N | N | E | N |
| Apron XL | Mefenoxam | N | N | E | N |
| Captan | Captan | G | P | F | G |
| Maxim | Fludioxonil | G | G | N | G |
Table 3. Relative efficacy of fungicide seed treatments for control of certain diseases of SOYBEANS in Ohio.
| Trade name | Active Ingredient |
Phomopsis seed rot |
Phytophthora damping off |
Pythium damping off |
Rhizoctonia seedling blight |
Fusarium seedling blight |
| Agrosol FL | Captan, TBZ | G | N | P | F | F |
| Agrosol T | Thiram, TBZ | G | N | N | F | F |
| Allegiance | Metalaxyl | N | E | E | N | N |
| Apron XL | Mefenoxam | N | E | E | N | N |
| Captan | Captan | G | N | P | P | F |
| Captan T | Captan, TBZ | G | N | P | F | F |
| Maxim | Fludioxonil | G | N | N | G | ND |
| Rival | Captan, PCNB, TBZ |
G | N | P | G | F |
| Thiram | Thiram | G | N | P | F | P |
Table 4. Relative efficacy of fungicide seed treatments for management of certain diseases of WHEAT and BARLEY in Ohio.a
| Trade name |
Active Ingedient |
Seedborne | Soil- borne |
Early Season | |||||
| Loose smut |
Common bunt |
Stagonospora nodorum |
Fusarium Head scab |
Pythium | Powdery mildew |
Leaf rust |
Stagonospora blotch |
||
| Agrosol T | Thiram, TBZ | N | G | F | G | F | N | N | P |
| Allegiance | Metalaxyl | N | N | N | N | E | N | N | N |
| Apron XL | Mefenoxam | N | N | N | N | E | N | N | N |
| Dividend XL |
Difenoconazol + Mefanoxam |
E | E | E | G | E | F | G | G |
| LSP Flowable Fungicide |
TBZ | N | G | P | G | N | N | N | N |
| Maxim 4FS | Fludioxonil | N | N | N | G | N | N | N | N |
| Raxil- Thiram |
Tebuconazole, Thiram |
E | E | E | G | F | F | G | F |
| Raxil MD | Tebuconazole, Metalaxyl |
E | E | E | G | E | F | G | G |
| Raxil XT | Tebuconazole, Metalaxyl |
E | E | E | G | E | F | G | G |
| RTU- Vitavax- Thiram |
Carboxin, Thiram |
G | G | F | G | F | N | N | F |
| Vitavax- 200 |
Carboxin, Thiram |
G | G | F | G | F | N | N | F |
aEfficacy based on labeled rates of active ingredient for each product.
bEfficacy rating scale: E=Excellent, G=good, F=fair, P=poor and N=no activity.