TY - JOUR N2 - Nozzle type and herbicide application timing can affect herbicide efficacy. Prickly sida ( Sida spinosa) and barnyardgrass ( Echinochloa crus-galli) are problematic weeds in eastern Mississippi cotton production and have reduced yield in recent years. Field studies were conducted at two locations – Brooksville, MS (2018, 2019) and Starkville, MS (2019) to understand the nozzle type and herbicide application timing effects on prickly sida and barnyardgrass control in cotton. Studies also compared applications made by an eight-nozzle tractor-mounted sprayer with a four-nozzle backpack sprayer. Herbicide applications were made at four timings: preemergence (PRE), early-postemergence (EPOST), mid-postemergence (MPOST), and late-postemergence (LPOST) corresponding to the preemergence (immediately after planting), two-to-three leaf, four-to-six leaf, and early-bloom stages, respectively. Treatments were made at 140 l · ha−1 applied at each growth stage, with nozzle type and sprayer as variables by each timing. Results showed no differences in treatments applied with backpack and tractor-mounted sprayers. Control of barnyardgrass was significantly affected by nozzle type, but control of prickly sida was not significantly influenced by nozzle type. In all three site-years, plots receiving a MPOST only herbicide application resulted in less weed control than areas receiving a two-pass POST herbicide program. Cotton yield was significantly affected by the herbicide program at one site-year, but was not significantly affected by the herbicide program except where cotton injury exceeded 15%. A two- or three-pass herbicide program was most effective in controlling prickly sida and barnyardgrass in Mississippi cotton. L1 - http://czasopisma.pan.pl/Content/122819/PDF/OA_09_JPPR_62_1_1239_Ferguson.pdf L2 - http://czasopisma.pan.pl/Content/122819 PY - 2022 IS - No 1 EP - 101 DO - 10.24425/jppr.2022.140300 KW - acetochlor KW - clethodim KW - cotton (Gossypium hirsutum) KW - glufosinate KW - pyrithiobac sodium KW - spray droplet size KW - sprayer type KW - weed control A1 - Ferguson, J. Connor A1 - Calhoun, Justin S. A1 - Broster, Kayla L. A1 - Merritt, Luke H. A1 - Treadway, Zachary R. A1 - Wesley Jr., Michael T. A1 - Fleitz, Nicholas PB - Committee of Plant Protection PAS PB - Institute of Plant Protection – National Research Institute VL - vol. 62 DA - 2022.03.31 T1 - Effect of nozzle type selection on prickly sida ( Sida spinosa L.) and barnyardgrass ( Echinochloa crus-galli (L.) P.Beauv.) control in Mississippi cotton ( Gossypium hirsutum) SP - 93 UR - http://czasopisma.pan.pl/dlibra/publication/edition/122819 T2 - Journal of Plant Protection Research ER -