Pensacola News Journal

For: Saturday, June 14, 2003

By: Daniel E. Mullins

Extension Horticulture Agent

Santa Rosa County

Gardening “Quick Fixes” Not Always Available

Last week I attended a meeting with one of the major companies that develop, manufacture and market lawn and garden products. The purpose of the meeting was to help identify local pest control issues that the company might consider when developing new products.

Preparation for the meeting resulted in a list of some of the more serious landscape pests. Many of the pest problems on the list have been addressed and we already have practices or products to recommend that provide effective control.

The list also revealed that there are several pests for which there are currently no safe, effective, labeled control products or practices. A second list containing these became my “wish list,” and was submitted as current needs that we have in the area of pest control in area landscapes.

The fungal disease Gaeumannomyces graminis var. graminis that contributes to Centipedegrass Decline and Take-all Root Rot in St. Augustine grass was at the top of my list. The number of cases of this lawn disease, and samples submitted, dominate our days at work for about 4 months of the year.

Much has been learned about this disease, particularly by researchers at the University of Florida and the University of Georgia. We now know that disease incidence is related to maintenance of the grass. Heavy nitrogen applications on centipedegrass for example, increase the odds of attack.

Many fungicides have been tested and though there are some that help if used preventatively, none are able to cure the disease once it is present. A fungicide that cures this disease would be a real breakthrough.

There is currently no effective chemical treatment for nematode infestations in home landscapes. Several years ago there was one that provided remarkable results. It was used to reduce populations of these soilborne pests in boxwood, gardenia, hollies, centipede lawns and other susceptible plants. This product was removed from the market due to environmental concerns and there has been no effective replacement that has become available since.

“Is there anything to control nutgrass in the vegetable garden?” This is a common question and currently there is no herbicide labeled for this use. Although there are two products approved for nutsedge control in home lawns, the number of vegetable species grown in the typical vegetable garden makes for a complicated approval process.

Other needs include a product that will control ground pearls in centipede lawns, post-emergent control of grassy weeds in St. Augustine lawns and better control of Virginia Buttonweed and torpedograss in all home lawns. A longer lasting product for treating daylily rust would also be helpful. The current recommendation includes alternating two classes of fungicides on a regular basis.

There is also no chemical treatment for bacterial wilt disease of tomato or an approved control for eastern flower thrips which transmit tomato spotted wilt virus in the vegetable garden.

So why hasn’t someone already developed control products or management practices for these pests? There are several reasons for this – most of which are economic. In some cases the specific pest has not been recognized as being a serious problem. In most cases, a company cannot justify the millions of dollars and years of research required to develop and market a new product for some uses.

The Land Grant University System also has talented faculty and staff to address pest problems, but budgetary constraints limit the amount of research projects that can be undertaken.

Obviously there isn’t a “magic bullet” for every pest problem encountered in the world of gardening, and never will be. On the other hand, watch for some exciting new products in the future. The providers of lawn and garden products are paying attention to our concerns.