Economic returns on seed treatment combinations in Louisiana rice. (July 2022)

• Record Type: Journal Article
• Authors: Wilson, B.E.; Villegas, J.M.; Stout, M.J.
• Is Part Of: Crop protection. Volume 157(2022)
• Publication Date: 2022-07
• Subjects: Rice water weevil -- Lissorhoptrus oryzophilus -- Mexican rice borer -- Eoreuma loftini -- Insecticide -- Fungicide; Plants, Protection of -- Periodicals; 632.05
• DOI: 10.1016/j.cropro.2022.105983
• Languages: English
• ISSNs: 0261-2194

Abstract

Abstract: The use of multiple insecticidal seed treatments in combination to control a greater spectrum of pests has been increasing in rice production in the U.S. Mid-South. The economic benefits of individual seed treatments in rice are well documented, but returns on investment (ROI) on combinations are unknown. Efficacy and economic returns of insecticidal seed treatments alone and in combination were evaluated through a series of five field trials conducted in Louisiana from 2018 to 2020. In all trials, treatments containing chlorantraniliprole or cyantraniliprole provided the best control of rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), and control was not significantly improved by the addition of a second insecticide. Insecticidal control of L. oryzophilus by all seed treatments was reduced in late-planted rice fields relative to rice planted within the recommended planting window. Control of the Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), did not improve rice yields. Fungicidal seed treatments generally protected rice yields over treatments without fungicides despite having no effect on early-season plant populations. All seed treatments provided returns on investment which ranged from $94.30 (fungicide only 2018) to $519.75/ha (chlorantraniliprole + thiamethoxam + fungicides in 2019–2020). Increased yields resulting from the use of multiple insecticides in combination appears to justify the added expense. Collectively, results demonstrate the immense value of insecticidal seed treatments to rice production in Louisiana and throughout the U.S. Mid-South. Future research efforts should aim to assess returns on seed treatments across a range of rice production conditions and to quantify the impacts of sporadic pests on rice yields. Highlights: The use of insecticidal and fungicidal seed treatments is economically justified in rice production in the southern U.S. Economic returns on seed treatments result primarily from control of the rice water weevil, Lissorhoptrus oryzophilus . The use of multiple seed treatments in combination may improve economic returns over the use of single treatments alone.