Evaluation of ornamental species (Order: Lamiales) for phytotoxic response to various pesticides in Southeastern U.S. for Interregional Research Project (IR-4)

Authors: Fraelich, Benjamin - Ben; Scully, Brian; PALMER, CRISTI - Rutgers University

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Proceedings
Publication Acceptance Date: 5/8/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: The Interregional Research Project #4 (IR-4) is a national program which provides pest management solutions for specialty crop growers and was started at the Tifton GA location in 1977. In the last ten years, the IR-4 Project on the U.S. southeastern coastal plain has completed 18 phytotoxicity experiments on six ornamental Lamiales genera including Buddleia, Lantana, Ligustrum, Salvia, Torenia, and Verbena. Four herbicides were applied at label rates as either a broadcast granular or as “over-the-top” foliar sprays. Over this same period, six fungicides and two insecticides were applied using foliar sprays. Field experiments were designed as randomized complete blocks with application method and pesticide treatments assigned to a specific Lamiales species. Phytotoxicity was recorded on a 0 to 10 scale (0 = no injury; 10 = dead) at intervals required by the protocol which differed for each species and chemical combination. Plant height and width were also measured at initial and final evaluations to assess any adverse chemical impact on plant growth and marketability. Data were analyzed in ARM (Agricultural Research Manager) using ANOVA, with means separated using Fisher’s Protected LSD at a level of 0.05. Results indicated no injury among any of the fungicide or insecticide treatments, but significant differences in phytotoxicity between the nontreated controls and some of the herbicide treatments. IR-4 research data have contributed to the registration of Actigard, Alibi Flora, Dimension, Echelon, Freehand, Kontos, Orkestra Intrinsic, QRD 416, Tourney, Tower, and Trinity on these Lamiales ornamental horticulture specialty crops.

Technical Abstract: The Interregional Research Project #4 (IR-4) is a national program which provides pest management solutions for specialty crop growers and was started at the Tifton GA location in 1977. In the last ten years, the IR-4 Project on the U.S. southeastern coastal plain has completed 18 phytotoxicity experiments on six ornamental Lamiales genera including Buddleia, Lantana, Ligustrum, Salvia, Torenia, and Verbena. Four herbicides were applied at label rates as either a broadcast granular or as “over-the-top” foliar sprays. Over this same period, six fungicides and two insecticides were applied using foliar sprays. Field experiments were designed as randomized complete blocks with application method and pesticide treatments assigned to a specific Lamiales species. Phytotoxicity was recorded on a 0 to 10 scale (0 = no injury; 10 = dead) at intervals required by the protocol which differed for each species and chemical combination. Plant height and width were also measured at initial and final evaluations to assess any adverse chemical impact on plant growth and marketability. Data were analyzed in ARM (Agricultural Research Manager) using ANOVA, with means separated using Fisher’s Protected LSD at a level of 0.05. Results indicated no injury among any of the fungicide or insecticide treatments, but significant differences in phytotoxicity between the nontreated controls and some of the herbicide treatments. IR-4 research data have contributed to the registration of Actigard, Alibi Flora, Dimension, Echelon, Freehand, Kontos, Orkestra Intrinsic, QRD 416, Tourney, Tower, and Trinity on these Lamiales ornamental horticulture specialty crops.