Integrated Pest Management Strategies in Alabama Row Crops

Abstract

Tobacco thrips (Frankliniella fusca Hinds) and nematodes are widespread pests of cotton (Gossypium hirsutum L.) across the Southeastern US. Recently, cotton varieties genetically modified with resistance to thrips (i.e., ThryvOn, Bayer CropScience, St. Louis, MO) have been released. Field experiments were conducted in 2022 and 2023 in Alabama to determine the effects of at-plant insecticides and ThryvOn cotton varieties on thrips management in nematode infested fields. A total of four tests were conducted in a Meloidogyne incognita (root-knot nematode) infested field at the Plant Breeding Unit in Tallassee, AL and in a Rotylenchulus reniformis (reniform nematode) infested field at the Tennessee Valley Research and Extension Center in Belle Mina, AL. Plots were sampled for thrips injury and populations at the 2nd, 4th and 6th true leaf stages. Additionally, plots were sampled for nematodes between 30 and 45 days after planting. Treatments included ThryvOn and non-ThryvOn cotton treated with AgLogic, Gaucho Insecticide Seed Treatment or Admire Pro + Velum fungicide/nematicide. Across years and locations, ThryvOn cotton provided consistent control of thrips. Similarly, at-plant insecticides provided consistent control compared to the non-treated, non-ThryvOn check. Additionally, both the ThryvOn and non-ThryvOn cotton benefited from the addition of the Admire Pro + Velum and AgLogic with reduced nematode populations. Tarnished plant bug (TPB), Lygus lineolaris, is a key insect pest of cotton in the Midsouth and Southeast, and management programs increasingly rely on integrating host-plant resistance traits such as ThryvOn technologies with insecticide use strategies. This study evaluated the influence of low- and high-input insecticide programs on TPB populations, plant injury, and yield in ThryvOn and non-ThryvOn cotton under large-plot field conditions. A non-replicated strip trial was conducted in 2023 and 2024 at the Tennessee Valley Research and Extension Center in Belle Mina, AL, using a ThryvOn variety (DP2131 B3XTF) and a non-ThryvOn variety (DP2038 B3XF) planted in eight-row × 175-ft strips and managed under non-treated, low-input or high-input insecticide programs. Weekly sampling of TPB included sweep nets, pinhead square retention, drop cloths, dirty bloom assessments, with additional internal boll examinations for stink bugs. Agronomic measurements were recorded at first bloom, and lint yield was quantified from the center two rows of each strip. ThryvOn cotton had significantly fewer small, large, and total TPB nymphs during bloom. High-input insecticide programs reduced total TPB regardless of variety. Dirty blooms and internal boll damage were lower in ThryvOn and treated plots. First-position fruit retention and node of first fruiting branch differed between varieties, and both insecticide programs increased yield relative to the control, with no yield differences between insecticide input levels. These results demonstrate that ThryvOn technology and insecticide inputs both contribute to TPB suppression and yield protection in Alabama cotton production systems. Thrips, (Frankliniella spp.), are a key pest of seedling cotton throughout the Southeast. This study evaluated the impact of starter fertilizer and soil temperature on thrips management In ThryvOn and non-ThryvOn cotton. Field experiments were conducted in 2024 and 2025 at the Tennessee Valley Research and Extension Center in Belle Mina, AL, using a ThryvOn variety (DP2211 B3XTF) and a non-ThryvOn (DP2127 B3XF) variety planted at 4 planting dates based on soil temperature (55, 60, 65, and 70°F) with or without ammonium polyphosphate (10-34-0) fertilizer. Seedling data collection included stand counts, vigor and thrips injury ratings, and thrips population estimates were made at the 2nd and 4th true leaf stages. Plant heights and fresh shoot weights were obtained when the cotton began squaring, and lint yield was quantified from the center two rows of each plot. Vigor, thrips injury, thrips populations, and fresh shoot weight were each impacted by variety and soil temperature. Plant heights and yield were only influenced by soil temperature. The results demonstrate that ThryvOn technology and soil temperature both contribute to thrips pressure and plant growth, however, starter fertilizer has no impact on thrips management or any yield. Ultimately, soil temperature was the only yield limiting factor. Tobacco Thrips (Frankliniella fusca) are a key early-season pest of peanut and vector tomato spotted wilt virus (TSWV) both of which can reduce yield when not managed effectively. This study evaluated the effects of peanut cultivar and at-plant insecticide on thrips injury, TSWV incidence, canopy development, nematode (Meloidogyne arenaria) infestation and yield in Alabama from 2023 to 2025. Two cultivars (GA 06-G and GA 12-Y) were planted with four treatments: a non-treated control and at-plant applications of aldicarb (7.8 kg/ha), phorate (5.6 kg/ha), and oxamyl (1.3 L/ha). Thrips injury (0-5), seedling vigor (0-10), fractional green canopy cover, TSWV incidence and nematode population estimates were done at various timings through 56 days after planting (DAP) and yield was collected at the end of the season. At-plant insecticides reduced thrips injury compared to the non-treated control. Seedling vigor was greatest in Georgia-12Y peanuts and where AgLogic was applied. TSWV was greater and FGCC was lower in non-treated plots and where GA-06G was used. Peanut root knot nematode egg counts did not differ among treatments. Yield was greater in the GA-06G overall and where at-plant insecticides were applied. These results demonstrate that at-plant insecticides contribute to thrips and TSWV suppression and protect yield in Alabama peanut production.