NOTES: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 26 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.
The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details.
Crown Rot (Fusarium species)
Vigorously growing plants are less susceptible to crown rot. Buy top quality crowns. Use new land or land where asparagus has not been grown for 10 years. Use tolerant varieties.
Rust (Puccinia asparagi)
Rust disease attacks fern foliage and can spread rapidly affecting production in subsequent years. Fern residues should be removed and destroyed prior to spear emergence in the spring. Control volunteer asparagus plants that might be infected. Resistant cultivars are not available. Apply fungicides after spear harvest is complete.
- Bacillus amyloliquefaciens strain D747 (DoubleNickel 55OG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group BM02. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.
- chlorothalonil (Bravo Weather Stik): 2.0 to 4.0 pt/A; PHI 190d, REI 12h, Group M05. Do not apply within 190 days of the harvest of spears in the following season.
- copper (Badge SC): 1.0 to 2.5 pt./A; PHI 0d, REI 48h, Group M01. For suppression. Tank mix with other products registered for rust control. Addition of sticker/spreader recommended.
- laminarim (Vacciplant): 14.0 to 22.0 fl oz/A; PHI od, REI 4h, Group P04. See label for application methods and restrictions.
- mancozeb (Dithane F45): 2.0 qt/A; PHI 180d, REI 24h, Group M03. Begin applications after spears have been harvested.
- mancozeb plus azoxystrobin (Dexter Max): 2.0 to 2.2 lb./A; PHI 180d, REI 24h, Group M03 &11. Begin applications after spears have been harvested. Alternate with fungicides outside of Group 11.
- myclobutanil (Rally 40 WSP): 5.0 oz/A; PHI 180d, REI 24h, Group 3. Begin applications after spears have been harvested. Observe a 30-day plant-back interval between the last application and planting new crops at the treatment site.
- sulfur (Microthiol DisperssOG): 10.0 to 30.0 lb/A; PHI 0d, REI 24h, Group M02. Apply to ferns after cutting.
- tebuconazole (Monsoon): 4.0 to 6.0 fl. oz./ A; PHI 180d, REI 12h, Group 3. Begin applications after spears have been harvested. Do not make more than 3 foliar applications per year.
- thyme oil (Guarda): See label for rate; PHI 0h, REI 0h, Group NC. See label for application methods and rates. Ensure thorough coverage to the point of runoff ( 15-25 gallons per acre.)