IPM in action

In part one of this two-part series, the author covers how nursery growers are using IPM to improve their bottom line. Part II will discuss how intelligent sprayers can be an important part of sustainable pest management when non-chemical strategies aren’t enough.

Pests can be a serious economic threat to nursery producers. Pesticide applications increase production costs, and pests that aren’t adequately controlled threaten plant sales by decreasing plant quality and desirability by retail consumers. In Georgia, losses due to plant disease alone were estimated at more than $37 million in 2010. The economic threat from native and naturalized, as well as new exotic pests, will likely continue. It is estimated that 72 percent of infested plant shipments cross our nation’s border undetected.
 

IPM success

What can growers do about pests? Whether you are tech savvy or old school, there are options for you. Integrated Pest Management (IPM) is a sustainable approach to pest management. IPM strives to keep pests and their damage at a market-acceptable level using a suite of techniques:

• Prevention (including proper cultural practices)
• Scouting, trapping and monitoring
• Pest identification
• Action thresholds
• A combination of control measures (mechanical, biological and chemical controls)

An ounce of prevention is worth a pound of cure (active ingredient, that is). A container grower frequently lets a small patch of crabgrass go to seed near the potting substrate, container storage and production area, in effect contaminating all plants being potted up with a dose of weed seeds. A minute of weed-eating or applying herbicides could have prevented thousands of dollars of hand weeding and post-emergent herbicide. Another grower eliminated a pest-susceptible red maple cultivar. Even though he was eliminating a popular plant, his customers were more interested in buying plants produced with fewer pesticides than a specific red maple cultivar. Many pest-resistant crabapples and dogwoods such as the UT Appalachian series can be selected over more susceptible trees.

Other preventive cultural practices include placing plants in the soil best suited to that crop and avoiding overhead irrigation in the evening or nighttime on plants that are susceptible to foliar diseases. Disease problems can also be prevented by refining irrigation so that plants are only irrigated with the volume of water they need.

A Tennessee grower uses containers with open sidewalls on some plants within an irrigation zone to prevent the substrate from staying wetter than that particular crop can tolerate. In other zones, this grower uses cutting edge sensor technology to irrigate based on plant need, preventing over-irrigation and ensuing root rot.

With IPM, when pests are detected, growers only control them when they reach a population level that could damage plant health and/or marketability. For some pests, such as fireblight, scales and borers, there is a zero tolerance threshold, yet for other pests, such as most aphids and foliar leaf spots, a high threshold is tolerated before spraying, except in the year of sale.
 

IPM in action

Sounds great, so why don’t growers use more IPM strategies and more frequently than they are? The Southern Nursery IPM Working Group (SNIPM) asked growers just that. Growers stated they want the return on investment to be demonstrated and that ornamental-specific IPM information isn’t available. The following information represents several years of working with nurseries and examining the return on investment of IPM techniques. We hope this changes your mind about IPM.

One of the best ways growers can manage pests that aren’t excluded from the nursery is by detecting them early, before they spread throughout the nursery. The advantages include

• Less plant damage occurs
• Pest development is monitored so applications are appropriately timed – something crucial to controlling borers and scale pests with contact insecticides
• A smaller area is sprayed
• The least toxic product can be applied

Scouting protocols were developed as part of a statewide Nursery Crops IPM program to aid growers in detecting pests efficiently. Scouting definitely won’t be cost effective if you don’t know what to look for, where to look on the plant or when to look. By using these protocols and scouting weekly, growers had many successes to share. Here are just a few: One grower saved $20,000 in maple sales by detecting a new scale pest early and eradicating it from his nursery. Three growers who trapped granulate ambrosia beetles saved a combined $34,500 due to improved control. By the end of the fifth year of the scouting program, growers estimated they’d saved an average of $9,179 per nursery, a significant return on investment.

Our survey results told us that growers worry there isn’t enough IPM information specific to nursery crops but a lot has changed in the last several years. For example, do you want specific scouting protocols for each of the major tree pests? If so, see Scouting and Monitoring Pests of Deciduous Trees during Nursery Production, https://utextension.tennessee.edu/publications/Documents/W142.pdf. If you are more tech-savvy or just spend more time in your “field office,” check out IPMPro, an interactive app for nursery and landscape professionals available for Android and iOS (Apple) mobile devices. IPMPro generates text-like alerts for the most significant pests and plant care practices, tailored to your business’s location. Instead of waiting for the damage to occur before controlling the pest let IPMPro alert you to start scouting early. IPMPro also provides identification, lifecycle, monitoring, and management information. When a pesticide is necessary, IPMPro provides recommendations and has a pesticide recordkeeping feature. With the press of a button your records can be emailed, printed and/or saved to your computer.

See http://wiki.bugwood.org/IPMPro_app for more information and most appropriate regions of the United States. IPM for Select Deciduous Trees in Southeastern US Nursery Production, a 300+ page multimedia book with video was published by SNIPM and is available free via iTunes for the iPad and at http://wiki.bugwood.org/SNIPM. This website also contains information about our IPM blog for southeastern nursery growers. And, the Manual for IPM in Shrub Production and companion IPM Calendar for Shrub Production were recently published, see http://plantsciences.utk.edu/tnsustainablenurserycrops.htm. Take advantage of these resources and develop a profitable IPM program for your nursery.

The authors acknowledge the following sources of funding: Southern Region IPM Center, University of Tennessee Institute of Agriculture, University of Tennessee Research Foundation, and a USDA Extension IPM Grant and all of our nursery cooperators.

For more: Amy Fulcher, University of Tennessee, Department of Plant Sciences, afulcher@utk.edu.

The following co-authors contributed to this article: Anthony LeBude, North Carolina State University; Sarah White, Clemson University; Juang-Horng (JC) Chong, Clemson University; Craig R. Adkins, NCSU; S. Kristine Braman, University of Georgia; Matthew R. Chappell, University of Georgia; Jeffrey F. Derr, Virginia Polytechnic Institute and State University; Winston C. Dunwell, University of Kentucky; Steven D. Frank, NCSU; Stanton A. Gill, University of Maryland; Frank A. Hale, University of Tennessee; William E. Klingeman, University of Tennessee; Gary Knox, University of Florida; Joseph C. Neal, NCSU; Mathews Paret, UFL; Karen Rane, University of Maryland; Nicole Ward, University of Kentucky; Jean L. Williams-Woodward, University of Georgia; Alan S. Windham, University of Tennessee.