Sprayed Daylilies & Roses with Fungicide Mix


6/27/2020 – The concept to mix a contact and a systemic fungicide seems smart. Found a recommendation that sounded well conceived–at the end of this post–and this spray and the followup plan below is based on that advice.

Mixed 5 gallons in the 2-gallon sprayer of the following and sprayed top and bottom of leaves of all daylilies and roses:

  • Propiconazole 14.3 – 0.5 tsp per one gallon of water.
  • Daconil – chlorothalonil – 2.5 Tbsp per 4 gallons of water

Planned Followup based on guidance below:

  1. In 7-14 days (depending on the rain) Spray: Propiconazole 14.3 – 0.5 tsp per one gallon of water plus Mancozeb. This repeats the systemic for the advantage she cites in the last paragraph but rotates the contact.
  2. In 14-28 days (depending on the rain) after the second spray apply the following to rotate the systemic and contact:
    1. for the systemic either:
      1. Spectracide Immunox Multi-Purpose 16-fl oz Concentrate Garden Fungicide. Primary Active Ingredient: Myclobutanil, OR
      2. BAYER ADVANCED Disease Control 32-oz Concentrate Garden Fungicide. Primary Active Ingredient: Tebuconazonle
    2. Daconil for the contact component.

Plan to follow guidance below for the rest of this year

From http://oldsite.daylilies.org/RustReportFromPatHenleyFall08DJ.pdf

Many plant pathologists recommend adding a contact fungicide to each application of a systemic to assist in killing spores. Although alternating two different contact fungicides seems to be common practice among daylily nurseries, you could add the same one each time if it can be mixed with the other products you are using. An example of an intensive rotation program using the above products:

  1. First application: Group 3 DMI (such as Bayleton or Banner Maxx) + mancozeb
  2. Wait 14-28 days (if less than 14 days, repeat this combination once – see below)
  3. Second application: Group 11 strobilurin (Compass, Heritage, or Insignia) + chlorothalonil
  4. Wait 14-28 days (if less than 14 days, repeat this combination once – see below)
  5. Repeat the cycle

The “waits” given reflect the long residual activity of these systemic fungicides. The labels might permit using them as often as every seven days, but if you find it necessary to use any of these systemics at intervals of less than 14 days, use the same one twice before switching. The reason being the residual activity of these systemics can extend beyond two weeks. By repeating the same fungicide at close intervals the two applications reinforce each other, building and maintaining an effective level of that fungicide for a longer period. Then, while you make the next two applications using different fungicides, the longer reprieve allows the first combination to dissipate from the plant before it is applied again. This meets the goal of rotation. When rust threat is highest and when daylilies are actively growing, use the highest rate (amount) of the fungicide per application that the product’s manufacturer

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