@article{thomas_pline-srnic_viator_wilcut_2005, title={Effects of glyphosate application timing and rate on sicklepod (Senna obtusifolia) fecundity}, volume={19}, ISSN={["1550-2740"]}, DOI={10.1614/WT-03-223R}, abstractNote={Greenhouse experiments were conducted to examine the effect of glyphosate on reproductive development in sicklepod. Glyphosate was applied postemergence over the top at 112 and 280 g ai/ha to sicklepod at 4-leaf stage (L), 8-L, 4-L followed by 8-L, and 12-L. A nontreated control was included. Immediately after the 12-L application, number of flowers was recorded for all treatments twice per week for 8 wk. Pollen viability was measured on 1 open flower/plant/sampling time using Alexander stain. The number of pods, pod length, seeds per plant, 50-seed weight, total seed weight, seed germination, seed viability, and dry weight of aboveground biomass were also recorded. No significant differences among the treatments were found for average pod length, 50-seed weight, seed germination, seed viability, and aboveground biomass. The nontreated had 18 flowers counted over 8 wk. Glyphosate applied at 12-L and sequentially at 4-L and 8-L, averaged over glyphosate rates, reduced cumulative flower production after 8 wk by 65 and 54%, respectively, compared with the nontreated. Similarly, glyphosate at 280 g/ha, averaged over treatment timings, reduced flower production by 58% compared with the nontreated. Because the number of flowers produced was limited by glyphosate treatment due to flower abscission, pollen viability measurements could not be analyzed because of large numbers of missing data points. The number of pods, seeds, and total seed weight were reduced by 79, 80, and 81%, respectively, with 280 g/ha of glyphosate compared with the nontreated. Nomenclature: Glyphosate; sicklepod, Senna obtusifolia (L.) Irwin and Barneby #3 CASOB. Additional index words: Alexander stain, pollen viability, tetrazolium chloride. Abbreviations: fb, followed by; IAA, indoleacetic acid; L, leaf stage.}, number={1}, journal={WEED TECHNOLOGY}, author={Thomas, WE and Pline-Srnic, WA and Viator, RP and Wilcut, JW}, year={2005}, pages={55–61} }
 @article{viator_nuti_wells_edmisten_2005, title={Stem and root carbohydrate dynamics in modern vs. obsolete cotton cultivars}, volume={36}, ISSN={["1532-2416"]}, DOI={10.1080/00103620500196366}, abstractNote={Abstract Starch reserves in the lower stem and root are important sources of photoassimilates for completion of reproductive development in cotton. The objective of this research was to determine if carbohydrate levels in the lower stem and roots have been altered because of more than 100 years of breeding efforts. In 2001 and 2002, 33 cultivars released from 1900 to 2000 were evaluated. In addition, two elite lines were included in 2002. Plants were sampled at first bloom and cutout. Tissues were analyzed for starch content and concentration by using a colorimetric technique. Analysis of variance by year revealed cultivar differences for starch concentration at both sample times, but starch content was only significant at first bloom in 2002. These differences, though, did not show a strong relationship with release date, indicating that a century of breeding efforts had not altered stem and root starch dynamics. Orthogonal contrast did reveal differences in starch content and concentration between obsolete, modern, and elite lines. However, these differences were not consistent across experimental years. At first bloom in 2001, modern cultivars had lower root and stem starch concentrations, 69.8 and 63.6 mg g−1, compared to 94.5 and 84.8 mg g−1 for the obsolete lines. Modern cultivars also had lower root starch content, 537.5 mg, compared to 784.4 mg for the obsolete lines. At cutout in 2001, modern cultivars had lower root and stem starch concentrations, 20.6 and 20.9 mg g−1, compared 39.7 and 32.4 mg g−1 for the obsolete lines. Modern cultivars also had lower stem starch content, 349.0 mg, compared to 518.4 mg for the obsolete lines. These same trends were not seen in 2002. In 2002, modern cultivars did not differ from obsolete cultivars for all parameters. Elite lines, though, had higher stem starch concentrations at cutout, 56.9 mg g−1 compared to 39.5 and 46.6 mg g−1 for the obsolete and modern lines, respectively. Elite lines also had higher stem starch contents at cutout, 318.6 mg compared to 181.7 and 195.7 mg for the obsolete and modern lines, respectively. This higher stem starch concentration and content for elite lines may indicate higher photosynthetic rates. Environmental conditions seem to affect starch dynamics more than genetics when one considers the high significance of year on most data in this study.}, number={15-16}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Viator, RP and Nuti, R and Wells, R and Edmisten, K}, year={2005}, pages={2165–2177} }
 @article{viator_jost_senseman_cothren_2004, title={Effect of glyphosate application timings and methods on glyphosate-resistant cotton}, volume={52}, ISSN={["0043-1745"]}, DOI={10.1614/P2002-025}, abstractNote={Under certain conditions, application of glyphosate to glyphosate-resistant (GR) cotton can lead to fruit shedding and yield reductions. Field studies were conducted at the Texas Agricultural Experiment Station using GR cotton, cv. ‘DeltaPine 5690RR’, to determine if application method and timing affect cotton fruit retention. Glyphosate at 1.12 kg ai ha−1was precisely postdirected (PD), postdirected with 25% foliage coverage (PDFC), or applied over the top (OT) at the 8- or 18-leaf stage after an initial topical application of 1.12 kg ha−1glyphosate at the four-leaf stage. In one of the years of this study, 8 PD, 18 PDFC, and 18 OT reduced yield. In 1999 and 2000, 8 PDFC and 8 OT applications of glyphosate caused yield loss, mainly due to lower mean boll weight. Glyphosate applied topically at the eight-leaf stage also affected the Position 1 boll retention throughout the plant in both years. Glyphosate contact with leaves and stems should be avoided when applying glyphosate after the four-leaf stage to prevent possible yield loss.}, number={1}, journal={WEED SCIENCE}, author={Viator, RP and Jost, PH and Senseman, SA and Cothren, JT}, year={2004}, pages={147–151} }
 @article{thomas_pline_wilcut_edmisten_wells_viator_paulsgrove_2004, title={Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton}, volume={18}, ISSN={["1550-2740"]}, DOI={10.1614/WT-03-032R1}, abstractNote={Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glufosinate applied POST at the eight-leaf stage, (3) the first two treatments sequentially, and (4) a POST application at the four-leaf stage followed by (fb) a postemergence-directed stem application (PDS) at the eight-leaf stage. Glufosinate was consistently applied at 0.49 kg ai/ha. A nontreated control was included. Glufosinate treatments did not affect stigma height, length of the staminal column, or pollen viability. However, the distance from the top anther to the tip of the stigma was less in plants treated with an eight-leaf POST treatment than in nontreated plants, although this difference is not likely to influence pollen deposition because in both cases anthers reached above the stigma tip. Plants receiving four-leaf POST fb eight-leaf PDS treatment with glufosinate had eight seeds per boll less than nontreated plants; however, the more rigorous four-leaf POST fb eight-leaf POST treatment did not differ from the nontreated in seeds per boll.}, number={2}, journal={WEED TECHNOLOGY}, author={Thomas, WE and Pline, WA and Wilcut, JW and Edmisten, KL and Wells, R and Viator, RR and Paulsgrove, MD}, year={2004}, pages={258–262} }
 @article{viator_senseman_cothren_2003, title={Boll abscission responses of glyphosate-resistant cotton (Gossypium hirsutum) to glyphosate}, volume={17}, ISSN={["0890-037X"]}, DOI={10.1614/WT02-166}, abstractNote={Response of glyphosate-resistant cotton to various rates of topically applied glyphosate was investigated in growth chamber experiments to determine the relationship between glyphosate rate and boll abscission. Glyphosate at 0, 0.56, 1.12, or 2.24 kg ai/ha was applied to all exposed foliage at the 12-leaf growth stage. Immediately after this treatment, 14C-glyphosate was applied to the three uppermost fully expanded leaves at 0, 37, 74, or 148 kBq per leaf for the 0, 0.56, 1.12, or 2.24 kg/ha treatment, respectively. After glyphosate application, glyphosate accumulated in reproductive tissue, and bolls were abscised. Abscission increased as the amount of glyphosate translocated to fruiting sites increased. Nomenclature: Glyphosate; cotton, Gossypium hirsutum L., ‘Delta & Pine Land 5690RR’. Additional index words: Boll abscission; transgenic crops. Abbreviations: EPSPS, 5-enolpyruvylshikimate-3-phosphate synthase (EC 2.5.1.19); GR, glyphosate resistant; WAT, weeks after treatment.}, number={3}, journal={WEED TECHNOLOGY}, author={Viator, RP and Senseman, SA and Cothren, JT}, year={2003}, pages={571–575} }