Lexington, Kentucky 40546
      
Nursery Update - A University of Kentucky Cooperative Extension Service update for the Kentucky Nursery Industry
  
By Amy Fulcher, Extension Associate - Nursery Crops
  
University of Kentucky Department of Horticulture
  
Update #19
  
February 13, 2004
  

Disease:
Avoid diseases during cold storage by cleaning storage areas with a bleach solution prior to arrival of plants. Spray with a fungicide (Cleary's 3336) to prevent damage while in storage. Consider using footbaths at the entrance with a product such as Green-Shield®. Routinely inspect plants. Keep the temperature at 34-38F at 85-100% relative humidity. For more information see the 2004 IPM Calendar for Deciduous Tree Production.
Insect:
Periodical cicada
Brood X of the 17 year periodical cicada will be emerging this spring (April - June) across much of Kentucky. In the Purchase Area only Hickman County won't spared. Muhlenberg, Todd, Logan, and Simpson counties are predicted to be spared while the other counties likely to escape periodical cicadas are scattered across more central and eastern portions of the state. Emergence is foreshadowed by a crayfish-type mud chimney on water soaked ground used to help the cicadas shed their outer shell.

Periodical cicadas mainly cause damage to nursery crops when eggs are laid. This spring, a week or so after emergence, females will be ready to lay eggs. Chlorpyrifos Pro 4 and Dursban TNP are labeled for use in nurseries and for cicada control. Both are restricted use pesticides. Carbaryl 4L as well as several synthetic pyrethroids are also labeled for use in nurseries against periodical cicada. During low-level outbreaks applications may be needed 2 times a week. During heavy outbreaks even daily applications may not prevent damage. Continued flight from surrounding areas keeps reinfestation pressure high for several weeks. The best control is acheived when the spray droplets contact the insect. For a map and more detailed information see the link listed below.

Source: UK Pub. ENT-52 Periodical Cicadas in Kentucky

 
Cultural:

Not Just Chlorosis
In the past we have experienced chlorosis in field produced red maples, in particular, Red Sunset®. A recent article in Digger magazine reported the results of OSU's research into the cause. Researchers found that manganese deficiency was to blame and revealed that poor appearance was the least of the outcomes. By the time manganese deficiency is visible as chlorosis, shoot and root growth have already been compromised.

 

The author of the study recommends the following steps to prevent manganese deficiencies:
1. Conduct soil tests to determine the soil pH and plant red maples in the field with the appropriate pH.
2. Do not lime the soil! If soil test reveals Ca and or Mg deficiencies, use gypsum or Epsom salt.
3. Using soil tests, be sure Mn levels are sufficient for plant growth. Foliar sprays only temporarily help those plant parts contacted by the spray.
4. Apply elemental sulfur to adjust sulfate to optimal levels.

Maximum and minimum ranges for Red Sunset® were established during this study. Foliar manganese levels should be between 70-285 ppm. Soil pH should be between 5.0-5.8 and soil manganese levels be 20-40 ppm.

Source: Chlorosis in Field Grown Maples Digger December 2003.
 
Foliar Analysis
Waters Agricultural Laboratories, Inc. in Owensboro offers foliar analysis for woody crops. They can give results and fertilizer recommendations specific to Autumn Blaze®, 'Columnare', var. drummondii, October Glory®, Red Sunset®, Upright, and red maple species as well as other species. Fertilizer recommendations are based on data from the University of Georgia, and J.B. Jones, coauthor of the Plant Analysis Handbook II. Dr. Jones also serves in a reference role with Waters. Waters advertises a 1-2 day turn around and can email, fax, or mail results and recommendations for no extra charge. For $12 N, P, K, Mg, Ca, S, B, Zn, Mn, Fe, and Cu can be analyzed. Any of the above individual elements and Sodium, Aluminum, and Molybdenum are $3.50 per element. Waters can customize an anaylsis package tailored to a specific nursery's needs.

Penn State Agricultural Analytical Services Lab also offers foliar analysis for nursery crops. For $18 the same 11 elements can be analyzed. There is anticipated a 3-4 day turn around time. Results are based on Plant Anaylsis Handbook II or PSU faculty guidelines. Results do not include fertilizer recommendations but do include contact information for Dr. Jim Sellmer, PSU Horticulture Professor. Recommended ranges are listed on the lab webpage for several maple species (not red maple) and many other species. Results and recommendations cannot be emailed; they can be faxed for $0.50 per page.

The Plant Anaylsis Handbook II is available from the publisher, MicroMacro Publishing (706) 613-7813. Waters Ag. Lab. 270-685-4039, PSU Ag. Analytical Services 814-863-0841

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Note: Trade names are used to simplify the information presented. No endorsement by the Kentucky Cooperative Extension Service is intended, nor is criticism implied of similar products that are not named. Always read product label before use.