• Each gardener will designate at least one planting of rose bushes to the study.
• The base of each rose bush should be mulched with a 2 to 3 inch layer of peat moss, shredded bark, straw, or similar material to discourage weeds and retain moisture in the soil. Be sure that your source of mulch is free of weed seeds.
• After new growth is about 6 inches long, apply a complete fertilizer (5-10-5, 4-8-4 or similar analysis) at the rate of 1 heaping teaspoon per plant. Spread the fertilizer on the soil around each plant, scratch it into the soil surface, and water thoroughly.
• Throughout the entire growing season spent blooms should be removed (dead headed) to encourage further bloom production and overall better aesthetic appearance of the plant. Spent blooms are those blooms whose petals readily fall off when lightly brushed or blown by the wind. Remove spent blossoms by cutting the stem beneath the blossom a ¼’’ above the second leaf set along the stem. (Dead head link).
• Roses should receive the equivalent of 1 inch of water every 7 to 10 days throughout the growing season.
• If your roses have a history of blackspot, fungicide spray programs need to be started as soon as new leaves appear in the spring. Apply one of the following chemicals following label instructions; chlorothalonil (Daconil 2787), myclobutanil (Immunox), propiconazole (Banner Maxx) or thiophanate-methyl (Cleary's 3336, Domain, Fungo-Flo). Avoid wetting the leaves when watering and locate plants where there is good air circulation to prevent fungal disease.
  

Time Line:

Control Tactics:

• Each research participant will be randomly assigned to one or more of the five possible control tactics. Individuals will test one tactic on a given plant for the entire season. Those wish to apply more than one tactic may request to do so on the pre-survey, only one tactic should be implemented on a particular plant.

  Possible tactics:

  1. Weekly Carbaryl Spray.

  • Carbaryl foliar spray (Bayer product, Sevin Liquid) will be applied when the first Japanese beetle is seen on designated Rose bushes. Applications will continue on a weekly basis until the end of beetle flight at the end of August. The product should be applied as directed on the label (usually at a rate of 3 Tbsp per gallon) and each bush should be covered with the product until “run off”.

  2. Weekly Azadirachtin Spray.

  • Azadirachtin Foliar spray (PBI Gordon product, Azatrol 1.2% @ 120 ppm foliar) needs to be applied when the first Japanese beetle is seen on designated Rose bushes. Applications will continue on a weekly basis until the end of beetle flight at the end of August. The product should be applied at a rate of 3 Tbsp per gallon and each bush should be covered with the product until “run off”.

  3. Hand Removal of Beetles and Blooms.

  • Blooms damaged by beetles and the beetles themselves will be removed three times a week (Monday, Wednesday and Friday). Blooms are considered to be damaged when 25% of a single bloom has been damaged and should be removed by cutting the bloom off 1/4” above the second leaf set. Please note that damage blooms are removed before they would normally be removed in the deadheading procedure.
  • Beetles should be removed and destroyed by placing them in a cup of soapy water until dead.

  4. Soil applied Imidacloprid plus Hand Removal of Beetles and Blooms.

  • Imidacloprid (Bayer product, Merit 2.5G) applied on May 29th 2004 (if scheduling conflict, product must be applied within 3 days of the 29th). Application should be made with a hand aerator or trowel to scratch up the soil surface around the base of the rose bush, spread ½ a cup of product evenly over churned soil and water into the soil with two liters of water.
  • In conjunction to chemical application blooms damaged by beetles and the beetles themselves will be removed three times a week (Monday, Wednesday and Friday). Blooms are considered to be damaged when 25% of a single bloom has been damaged and should be removed by cutting the bloom off 1/4” above the second leaf set (Deadhead link).
  • Beetles should be removed and destroyed by placing them in a cup of soapy water until dead.

  5. Soil applied Imidacloprid.

  • Imidacloprid (Bayer product, Merit 2.5G) applied on May 29th 2004 (if scheduling conflict, product must be applied within 3 days after the 29th). Application should be made with a hand aerator or trowel to scratch up the soil surface around the base of the rose bush, spread ½ a cup of product evenly over churned soil and water into the soil with two liters of water.

Information to be collected:

• Complete Pre-survey before beginning research. Assess management practices used on roses during the 2003 growing season. (Pre-survey link in rtf format)
• Complete Implementation Survey at the end of the 2004 growing season. Assess the gardeners’ perspective on the tactic that they evaluated. (Implementation Survey link in rtf format)
• Send completed surveys via the web to jvitullo@purdue.edu or US Mail to the following address:

  Justin Vitullo
  901 W State St
  West Lafayette, IN 47907-2089