@article{moore_jennings_monks_boyette_leon_jordan_ippolito_blankenship_chang_2023, title={Evaluation of electrical and mechanical Palmer amaranth (Amaranthus palmeri) management in cucumber, peanut, and sweetpotato}, volume={1}, ISSN={["1550-2740"]}, url={https://doi.org/10.1017/wet.2023.1}, DOI={10.1017/wet.2023.1}, abstractNote={Abstract Field studies were conducted to assess the efficacy of physical weed management of Palmer amaranth management in cucumber, peanut, and sweetpotato. Treatments were arranged in a 3 × 4 factorial in which the first factor included a treatment method of electrical, mechanical, or hand-roguing Palmer amaranth control and the second factor consisted of treatments applied when Palmer amaranth was approximately 0.3, 0.6, 0.9, or 1.2 m above the crop canopy. Four wk after treatment (WAT), the electrical applications controlled Palmer amaranth at least 27 percentage points more than the mechanical applications when applied at the 0.3- and 0.6-m timings. At the 0.9- and 1.2-m application timings 4 WAT, electrical and mechanical applications controlled Palmer amaranth by at most 87%. Though hand removal generally resulted in the greatest peanut pod count and total sweetpotato yield, mechanical and electrical control resulted in similar yield to the hand-rogued plots, depending on the treatment timing. With additional research to provide insight into the optimal applications, there is potential for electrical control and mechanical control to be used as alternatives to hand removal. Additional studies were conducted to determine the effects of electrical treatments on Palmer amaranth seed production and viability. Treatments consisted of electricity applied to Palmer amaranth at first visible inflorescence, 2 wk after first visible inflorescence (WAI) or 4 WAI. Treatments at varying reproductive maturities did not reduce the seed production immediately after treatment. However, after treatment, plants primarily died and ceased maturation, reducing seed production assessed at 4 WAI by 93% and 70% when treated at 0 and 2 WAI, respectively. Treatments did not have a negative effect on germination or seedling length.}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. D. and Jennings, Katherine M. M. and Monks, David W. W. and Boyette, Michael D. D. and Leon, Ramon G. G. and Jordan, David L. L. and Ippolito, Stephen J. J. and Blankenship, Colton D. D. and Chang, Patrick}, year={2023}, month={Jan} } @article{batts_moore_ippolito_jennings_smith_2022, title={Effect of simulated synthetic auxin herbicide sprayer contamination in sweetpotato propagation beds}, volume={36}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2022.26}, abstractNote={Abstract Field studies were conducted to determine the effects of synthetic auxin herbicides at simulated exposure rates applied to ‘Covington’ sweetpotato propagation beds on the quality of nonrooted stem cuttings (slips). Treatments included diglycolamine salt of dicamba, 2,4-D choline plus nonionic surfactant (NIS), and 2,4-D choline plus glyphosate at 1/10, 1/33, or 1/66 of a 1X application rate (560 g ae ha −1 dicamba, 1,065 g ae ha −1 2,4-D choline, 1,130 g ae ha −1 glyphosate) applied at 2 or 4 wk after first slip harvest (WASH). Injury to sweetpotato 2 wk after treatment was greatest when herbicides were applied 2 WASH (21%) compared to 4 WASH (16%). More slip injury was caused by 2,4-D choline than by dicamba, and the addition of glyphosate did not increase injury over 2,4-D choline alone. Two weeks after the second application, sweetpotato slips were cut 2 cm above the soil surface and transplanted into production fields. In 2019, sweetpotato ground coverage 8 wk after transplanting was reduced 37% and 26% by the 1/10X rates of dicamba and 2,4-D choline plus NIS, respectively. Though dicamba caused less injury to propagation beds than 2,4-D choline with or without glyphosate, after transplanting, slips treated with 1/10X dicamba did not recover as quickly as those treated with 2,4-D choline. In 2020, sweetpotato ground coverage was 90% or greater for all treatments. Dicamba applied 2 WASH decreased marketable sweetpotato storage root yield by 59% compared to the nontreated check, whereas treatments including 2,4-D choline reduced marketable yield 22% to 29%. All herbicides applied at 4 WASH reduced marketable yield 31% to 36%. The addition of glyphosate to 2,4-D choline did not increase sweetpotato yield. Results indicate that caution should be taken when deciding whether to transplant sweetpotato slips that are suspected to have been exposed to dicamba or 2,4-D choline.}, number={3}, journal={WEED TECHNOLOGY}, author={Batts, Thomas M. and Moore, Levi D. and Ippolito, Stephen J. and Jennings, Katherine M. and Smith, Stephen C.}, year={2022}, month={Jun}, pages={379–383} } @article{moore_jennings_monks_jordan_leon_boyette_2021, title={Evaluating shade cloth to simulate Palmer amaranth (Amaranthus palmeri) competition in sweetpotato}, volume={69}, ISSN={["1550-2759"]}, DOI={10.1017/wsc.2021.21}, abstractNote={Abstract Field studies were conducted in 2019 and 2020 to compare the effects of shade cloth light interception and Palmer amaranth ( Amaranthus palmeri S. Watson) competition on ‘Covington’ sweetpotato [ Ipomoea batatas (L.) Lam.]. Treatments consisted of a seven by two factorial arrangement, in which the first factor included shade cloth with an average measured light interception of 41%, 59%, 76%, and 94% and A. palmeri thinned to 0.6 or 3.1 plants m −2 or a nontreated weed-free check; and the second factor included shade cloth or A. palmeri removal timing at 6 or 10 wk after planting (WAP). Amaranthus palmeri light interception peaked around 710 to 840 growing degree days (base 10 C) (6 to 7 WAP) with a maximum light interception of 67% and 84% for the 0.6 and 3.1 plants m −2 densities, respectively. Increasing shade cloth light interception by 1% linearly increased yield loss by 1% for No. 1, jumbo, and total yield. Yield loss increased by 36%, 23%, and 35% as shade cloth removal was delayed from 6 to 10 WAP for No. 1, jumbo, and total yield, respectively. F -tests comparing reduced versus full models of yield loss provided no evidence that the presence of yield loss from A. palmeri light interception caused yield loss different than that explained by the shade cloth at similar light-interception levels. Results indicate that shade cloth structures could be used to simulate Covington sweetpotato yield loss from A. palmeri competition, and light interception could be used as a predictor for expected yield loss from A. palmeri competition.}, number={4}, journal={WEED SCIENCE}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Leon, Ramon G. and Boyette, Michael D.}, year={2021}, month={Jul}, pages={478–484} } @article{moore_jennings_monks_boyette_jordan_leon_2021, title={Herbicide systems including linuron for Palmer amaranth (Amaranthus palmeri) control in sweetpotato}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2020.63}, abstractNote={Abstract Field studies were conducted to determine sweetpotato tolerance to and weed control from management systems that included linuron. Treatments included flumioxazin preplant (107 g ai ha −1 ) followed by (fb) S -metolachlor (800 g ai ha −1 ), oryzalin (840 g ai ha −1 ), or linuron (280, 420, 560, 700, and 840 g ai ha −1 ) alone or mixed with S -metolachlor or oryzalin applied 7 d after transplanting. Weeds did not emerge before the treatment applications. Two of the four field studies were maintained weed-free throughout the season to evaluate sweetpotato tolerance without weed interference. The herbicide program with the greatest sweetpotato yield was flumioxazin fb S -metolachlor. Mixing linuron with S -metolachlor did not improve Palmer amaranth management and decreased marketable yield by up to 28% compared with flumioxazin fb S -metolachlor. Thus, linuron should not be applied POST in sweetpotato if Palmer amaranth has not emerged at the time of application.}, number={1}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Boyette, Michael D. and Jordan, David L. and Leon, Ramon G.}, year={2021}, month={Feb}, pages={49–56} } @article{moore_jennings_monks_leon_boyette_jordan_2021, title={Influence of herbicides on germination and quality of Palmer amaranth (Amaranthus palmeri) seed}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2021.71}, abstractNote={Abstract Laboratory and greenhouse studies were conducted to evaluate the effects of chemical treatments applied to Palmer amaranth seeds or gynoecious plants that retain seeds to determine seed germination and quality. Treatments applied to physiologically mature Palmer amaranth seed included acifluorfen, dicamba, ethephon, flumioxazin, fomesafen, halosulfuron, linuron, metribuzin, oryzalin, pendimethalin, pyroxasulfone, S -metolachlor, saflufenacil, trifluralin, and 2,4-D plus crop oil concentrate applied at 1× and 2× the suggested use rates from the manufacturer. Germination was reduced by 20% when 2,4-D was used, 15% when dicamba was used, and 13% when halosulfuron and pyroxasulfone were used. Use of dicamba, ethephon, halosulfuron, oryzalin, trifluralin, and 2,4-D resulted in decreased seedling length by an average of at least 50%. Due to the observed effect of dicamba, ethephon, halosulfuron, oryzalin, trifluralin, and 2,4-D, these treatments were applied to gynoecious Palmer amaranth inflorescence at the 2× registered application rates to evaluate their effects on progeny seed. Dicamba use resulted in a 24% decrease in seed germination, whereas all other treatment results were similar to those of the control. Crush tests showed that seed viability was greater than 95%, thus dicamba did not have a strong effect on seed viability. No treatments applied to Palmer amaranth inflorescence affected average seedling length; therefore, chemical treatments did not affect the quality of seeds that germinated.}, number={5}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Leon, Ramon G. and Boyette, Michael D. and Jordan, David L.}, year={2021}, month={Oct}, pages={786–789} } @article{moore_jennings_monks_leon_jordan_boyette_2021, title={Safety and efficacy of linuron with or without an adjuvant or S-metolachlor for POST control of Palmer amaranth (Amaranthus palmeri) in sweetpotato}, volume={35}, ISSN={["1550-2740"]}, DOI={10.1017/wet.2021.27}, abstractNote={Abstract Field studies were conducted to evaluate linuron for POST control of Palmer amaranth in sweetpotato to minimize reliance on protoporphyrinogen oxidase (PPO)-inhibiting herbicides. Treatments were arranged in a two by four factorial in which the first factor consisted of two rates of linuron (420 and 700 g ai ha −1 ), and the second factor consisted of linuron applied alone or in combinations of linuron plus a nonionic surfactant (NIS; 0.5% vol/vol), linuron plus S -metolachlor (800 g ai ha −1 ), or linuron plus NIS plus S -metolachlor. In addition, S -metolachlor alone and nontreated weedy and weed-free checks were included for comparison. Treatments were applied to ‘Covington’ sweetpotato 8 d after transplanting (DAP). S -metolachlor alone provided poor Palmer amaranth control because emergence had occurred at applications. All treatments that included linuron resulted in at least 98% and 91% Palmer amaranth control 1 and 2 wk after treatment (WAT), respectively. Including NIS with linuron did not increase Palmer amaranth control compared to linuron alone, but it resulted in greater sweetpotato injury and subsequently decreased total sweetpotato yield by 25%. Including S -metolachlor with linuron resulted in the greatest Palmer amaranth control 4 WAT, but increased crop foliar injury to 36% 1 WAT compared to 17% foliar injury from linuron alone. Marketable and total sweetpotato yields were similar between linuron alone and linuron plus S -metolachlor or S -metolachlor plus NIS treatments, though all treatments resulted in at least 39% less total yield than the weed-free check resulting from herbicide injury and/or Palmer amaranth competition. Because of the excellent POST Palmer amaranth control from linuron 1 WAT, a system that includes linuron applied 7 DAP followed by S -metolachlor applied 14 DAP could help to extend residual Palmer amaranth control further into the critical period of weed control while minimizing sweetpotato injury.}, number={3}, journal={WEED TECHNOLOGY}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Leon, Ramon G. and Jordan, David L. and Boyette, Michael D.}, year={2021}, month={Jun}, pages={471–475} } @article{moore_jennings_monks_jordan_boyette_leon_mahoney_everman_cahoon_2021, title={Susceptibility of Palmer amaranth accessions in North Carolina to atrazine, dicamba, S-metolachlor, and 2,4-D}, volume={11}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20136}, DOI={10.1002/cft2.20136}, abstractNote={Core Ideas All of the 120 accessions of Palmer amaranth collected in the Coastal Plain of North Carolina were controlled by atrazine and dicamba applied at field use rates in the greenhouse. Reduced sensitivity among accessions was noted when S ‐metolachlor and 2,4‐D were applied to Palmer amaranth at field use rates in the greenhouse. Additional research is needed to determine if reduced sensitivity of Palmer amaranth to S ‐metolachlor and 2,4‐D is associated with evolved resistance.}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, publisher={Wiley}, author={Moore, Levi D. and Jennings, Katherine M. and Monks, David W. and Jordan, David L. and Boyette, Michael D. and Leon, Ramon G. and Mahoney, Dennis J. and Everman, Wesley J. and Cahoon, Charles W.}, year={2021}, month={Nov} }