A group of plant scientists at NC State University are trying to help ornamental plant growers get to the root of their weed problems.

With herbicide-resistant weeds on the rise, and a zero-tolerance threshold for weed pests in the nursery, Drs. Alexander Krings, Joe Neal and Bridget Lassiter have created a web “app” that helps the nursery owner identify container weeds. Upon completion, WeedIT Mobile could potentially save ornamental plant producers millions of dollars a year in preemergence herbicide and hand weeding costs. Growers currently spend about $550 per acre every year on herbicides, coupled with hand weeding costs at $2,400 to $5,500 per acre every year.

The value of container nursery plants is largely based on size and appearance, , with one stray weed capable of reducing crop plant growth as much as 60%, it is imperative to control these pests. Like any pest management system, identifying the weed is the first step in developing an effective weed management plan. Ornamental plant growers often lack access to trained weed management professionals and have to make treatment decisions based on their own knowledge. Weed identification can be difficult, especially at the cotyledon growth stage.

Based on the success of Weeds of Container Nurseries (2005), a publication written by Neal and Jeffrey Derr at Virginia Tech, Krings, Neal and Lassiter brainstormed about how they could put the information in the publication into a handheld device, so growers and Cooperative Extension agents could identify weeds while they were in the field.

“The first version was produced using SLIKS[1], a tool for developing customized on-line identification keys, and our first mobile platform was the PDA,” says Neal. “After two years, technology flew past the PDA, and smart phones were becoming the predominant mobile devices. We could transfer the code over to the smart devices, but the script had some issues operating on some of the devices, so we had to adapt it for smart phones and tablets.

Because weed identification is crucial to correctly treating a weed, it was the focus of the app. As the specialists further developed the program, they added herbicide treatment options, but kept weed identification at the forefront.

Ultimately, WeedIT Mobile should aid Extension professionals and growers with the main question of “what is this weed?” by guiding the user through a series of identifying features such as leaves, stems and flowers. Questions like these are typically part of a dichotomous key for plant identification. But, as Lassiter explains, the beauty of this program is that the user can input information about any part of the plant.

“A grower will come in [to the Extension office] with a weed and it’ll have leaves but it won’t have a flower,” Lassiter says. “A dichotomous key won’t get us very far because it normally starts questioning the user about floral characteristics first, in order to distinguish species from one another. A polyclave will pull all species with the characteristics you choose so you can see all of them at one time. The species are often not taxonomically related.”

A polyclave is a multi-access key that allows the user to choose any characteristic of the weed that he or she knows, and returns a list of possible plant species that meet those requirements. For instance, if the stem is hairy but the user isn’t sure about the leaf shape, he or she can pick the characteristic of “hairy stem” and get a list of results. The more characteristics that the user can identify, the shorter the list is.

With money from a 2011 Southern IPM Center IPM Enhancement grant, the team hired a programmer from AgRenaissance to make changes to the existing app, (originally designed for a PDA), so that it would be smartphone and TabletPC-friendly. In addition, a beta test gave them feedback about the changes. With a few more tweaks to improve the user-friendliness of the app, they hope it will be ready to release and expand. They are now pursuing funding to hire someone to make those changes.

“The system works, but it needs some revisions,” says Krings. “It needs some aesthetic improvements and more links and pictures to lead the user through their decision-making.”

Once they have finished the app for nursery growers, they would like to expand the program to add other plants, including weeds of other cropping systems, invasive weeds, and perhaps the entire collection of plants in the Carolinas. In addition to being a management tool, it could then be a teaching tool and reach people far beyond the University.

“There’s a community out there that doesn’t know what Extension has to offer,” Krings says. “We reach 800 people a year with a rare plant app that we’ve made available, people we may otherwise never have reached. We can reach communities that may not even know about Extension, and it could pull people in to what Extension may provide. That’s what the land grant mission is all about: Empowering people, providing solutions.” [1] SLIKS: Stinger’s Lightweight Interactive Key Software (developed by Stinger Guala; http://www.stingersplace.com/SLIKS/)

Contacts:

Dr. Alexander Krings, Assistant Professor and Director of the Vascular Plant Herbarium, NC State University, alexander_krings@ncsu.edu

Dr. Joe Neal, Professor /Extension Specialist, NC State University joe_neal@ncsu.edu

Dr. Bridget Lassiter, Research Assistant, NC State University

Written by: Rosemary Hallberg, Communication Specialist, Southern Region IPM Center