University of Kentucky HortMemo

HortMemo - A University of Kentucky Cooperative Extension Service Newsletter for the Kentucky Nursery/Landscape Industry
Current 2017 HortMemo below

by Winston C. Dunwell, Professor - Nursery Crops Development Center

UK Department of Horticulture

To subscribe send an e-mail to cforsyth@uky.edu or call Christi, 270.365.7541 x 221.

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April 11, 2017



Zenaida is monitoring and scouting for ambrosia beetles again in west Kentucky and will keep you up on results through Kentucky Pest News https://kentuckypestnews.wordpress.com/, the Nursery Listserve http://nursery-crop-extension.ca.uky.edu/listserv and here in HortMemo.  The week of April 3rd marked the first large number of Granulate Ambrosia beetles in the traps in Calloway, Graves, Caldwell and Todd Counties of west Kentucky.

Nicole Ward Gauthier sent out the following information for Orchardists but much of it applies to crabapples, hawthorn and serviceberry.

Fire Blight Alert and Risk Map Overview
By: Nicole Ward Gauthier, Extension Specialist 

Apple trees are blooming throughout the commonwealth. Infection by the fire blight bacterium occurs during bloom, thus, protectant antibiotics should be applied when risk is high. 

Risk for infection can be assessed using the Fire Blight Disease Prediction Model. Growers can assess local risk by selecting their county and orchard history. This model incorporates the previous 4 days of weather data plus adds a 7-day forecast for estimating leaf wetness and temperature (thereby estimating risk for bacterial growth and infection). There are 66 Mesonet weather stations throughout Kentucky, thus, weather information for the model is based on data from the closest weather station. For a mobile (phone or tablet) friendly version of this site, visit http://weather.uky.edu/dim.html.

Remember that apple and pear trees must be in bloom for predictions to be accurate. The map overview presented here indicates fire blight risk as of April 10, 2017 (Figure 1).  According to the current assessment, risk is low to marginal across the state due to low humidity during the past several days.  A rain event, however, can increase that risk.  Growers are encouraged to check the model regularly for the most accurate analyses and county-specific forecasts.

Information regarding prevention and management of fire blight can be found in:
Commercial Fruit Pest Management Guide (ID-232)
Backyard Apple Disease Management Using Cultural Practices (PPFS-FR-T-21)
Fire blight (PPFS-FR-T-12)
Fire blight of Apple (Video)

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February 3, 2017



Dr. Chris Ranger, Research Entomologist Horticultural Insects Research Lab, USDA-Agricultural Research Service, Wooster, OH will be giving a seminar on Ambrosia Beetles damaging nursery and orchard trees in west Kentucky. The seminar will be at the UKREC, 1205 Hopkinsville Street, Princeton, KY 42445 on February 15, 2017 at 8:30 AM CST.  http://www2.ca.uky.edu/HLA/Dunwell/RangerAmbrosiaSeminarUKRECHort.pdf


Dr. Zenaida Viloria, Extension Associate for Nursery Crops, with UKREC Horticulture! has published a timely article on How To Build a Trap for Ambrosia Beetles in the January 2017 Nursery Listserve. https://NCER.ca.uky.edu/listserv for the article go to:
http://j.tinyurl.com/zxp7hwk  zenaida.viloria@uky.edu


From Kentucky Pest News. This might be useful to those growing crabapples (Malus), serviceberry (Amelanchier), and pears (Pyrus). The Extension publication, An IPM Scouting Guide for Common Problems of Apple in Kentucky, was first introduced in 2014 as an online/paper version. In order to improve access to this important scouting guide, a mobile website has been developed. The Apple Scout Website (http://applescout.ca.uky.edu) is now available for grower, agent, and homeowner use. The website can be easily accessed from any phone, tablet, iPad, or computer.

The Organic Association of Kentucky will hold its sixth annual conference focusing on organic farming and living, March 3-4, 2017 at Paroquet Springs Conference Center, Shepherdsville, KY. The keynote speaker is American novelist, poet, environmental activist, cultural critic, farmer, and Kentucky native Wendell Berry. Kentucky farmer and researcher Dr. Greg Halich will talk about the key to profitability with grass-fed beef. Diversified farmer John Bell of Elmwood Stock Farm will present his 8-year rotation plan on adding fertility and creating an extra revenue stream with livestock. For more information go to http://www.oak-ky.org/2017-conference there is a significant discount for those that register before February 10, 2017.


The Kentucky Nursery and Landscape Association inducted me into the KNLA Hall of Fame.  What an honor to be included with the best-of-the-best leaders in Kentucky’s nursery/landscape industry and the KNLA. Thank you to all who supported me over the years. http://www2.ca.uky.edu/HLA/Dunwell/DunwellKNLAHallofFame.pdf

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January 17, 2017


The Kentucky Nursery and Landscape Spring Training & Showplace – 2017 conference/educational programs and trade show is January 25-26, 2017 at the Ramada Plaza Louisville Hotel and Conference Center, 9700 Bluegrass Parkway Louisville KY 40299. One can register and view the program online at http://knla.org/event/knlas-spring-training-showplace or be a walk-in the day of.  See you there!


Richard “Dick” Ammon passed away at age 87, January 1st, 2017.  He was a leader in the nursery/landscape industry from the moment he established Ammon Nursery.  Past-President of the KNLA (1969) and a founding member of the committee that established the Kentucky Certified Nurseryman program. His contributions to the industry have been significant. Dick served, as President of Southern Nursery Association (SNA - 1974), was a founding director of the Sidney B. Meadows Scholarship Endowment Fund (1989), and served as President of the fund. For a brief obituary (brief in that so many of us have wonderful memories of Dick) see http://www.sna.org/page-975977/4519224


newTerrain, a Ball Publishing newsletter, on “Functional Plants, Functional Landscapes” has contained some interesting information. You can see the most current edition at http://www.ballpublishing.com/NewTerrain/CurrentNewsletter.aspx and subscribe by clicking on the subscribe button or by going to:


From Kentucky Pest News: Two dicamba formulations, XtendiMaxTM (Monsanto) and EngeniaTM (BASF), received federal EPA approval in December for use with RoundupReady2Xtend soybean.  In addition to federal registration, a pesticide must also be registered and approved within a state before it can be sold.  The XtendiMaxTM product received state approval in early January for applications in Kentucky.  The EngeniaTM product is still pending state approval, but it is anticipated in the near future.  These products can be applied before or immediately after planting Roundup Ready 2 Xtend Soybeans or as an in-crop application from emergence (cracking) up to and including the beginning bloom (R1 growth stage of soybeans).  Because of the potential for injury of off-target plants there are rules for application in supplemental labels. In Kentucky, applicators will need to be extra cautious about making an application where sensitive crops such as tobacco, grapes, landscape plants, fruit trees, vegetables, greenhouses or home gardens are growing nearby. https://kentuckypestnews.wordpress.com/2017/01/10/new-dicamba-products-receive-approval-for-use-on-rr2xtend-soybean
To subscribe or read Kentucky Pest News go to http://plantpathology.ca.uky.edu/extension/kpn

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