Orientador: Maria Aparecida Carvalho de Medeiros / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-27T04:43:14Z (GMT). No. of bitstreams: 1 Vilella_KellyAdrianaRibeiroTagliaferro_M.pdf: 2403765 bytes, checksum: 91f29c165c5f2b7217d7fc43cb9b5daf (MD5) Previous issue date: 2015 / Resumo: Os resíduos de herbicidas triazínicos são compostos com moderada toxicidade, altamente persistentes no ambiente, contaminando os mananciais e águas subterrâneas e são muito utilizados em várias culturas, inclusive da cana-de-açúcar. Os herbicidas atrazina e simazina foram oxidados com 'H IND.2O IND.2' na presença de catalisadores biomiméticos (metaloporfirinas de ferro e rutênio) e os produtos gerados na reação foram analisados via cromatografia gasosa (GC, do inglês gás chromatography) associada à espectrometria de massas (MS, do inglês mass spectrometry), buscando elucidar os subprodutos. As reações de oxidação dos herbicidas triazínicos e os subprodutos gerados foram monitoradas por espectrofotometria na região do ultra violeta e visível (UV-Vis) e cromatografia gasosa (GC), utilizando-se o detector de captura de elétrons (ECD, do inglês elétron capture detector). Os rendimentos das reações de oxidação das triazinas com 'H IND.2O IND.2' e catalisadas pelas metaloporfinas de ferro (Fe(FTTPCl)) e rutênio (Ru(OCTTPP)), variaram de acordo com as condições de reações catalíticas. Foi observado que houve degradação significativa dos analitos (94,70% para a atrazina e 92,60% para a simazina utilizando a (Fe(FTTPCl)) e; 94,38% para a atrazina e 67,19% para a simazina utilizando a (Ru(OCTTPP))) e também foi observado a transformação dos herbicidas nos subprodutos desetilatrazina (DEA) e o deisopropilatrazina (DIA). Os dados de monitoramento das reações catalíticas por UV-Vis revelaram as estabilidades dos catalisadores (Fe(FTTPCl)) e (Ru(OCTTPP)), nas condições oxidantes das reações. Os resultados obtidos com a cromatografia gasosa acoplada com a espectrometria de massas (GC-MS), utilizando a técnica de ionização por impacto de elétrons ¿ (EI, do inglês electron ionization), full scan, com o modo positivo (EI+), associado a este pico revelaram o pico do íon molecular (m/z= 215, associado ao herbicida atrazina [M]+ e os principais fragmentos (m/z): 200(associado ao íon [M ¿ CH3]+), 173 e 138; sendo que o espectro de massa obtido após a reação de oxidação revelou o desaparecimento do pico associado aos herbicidas e formação de novos picos, associados a fragmentos de subprodutos. Similarmente, a identificação da simazina foi obtida com o modo positivo (EI+), tendo sido revelado o pico do íon molecular (m/z= 201) e os principais fragmentos (m/z): 186, 173 e 138 / Abstract: Waste triazine herbicides are compounds with moderate toxicity, highly persistent in the environment, contaminating water sources and groundwater are widely used in various cultures, including the cane sugar. The atrazine and simazine herbicides were oxidized with 'H IND.2O IND.2' in the presence of biomimetic catalysts (iron and ruthenium metalloporphyrins) and the products generated in the reaction were analyzed by gas chromatography (GC) associated with mass spectrometry (MS), to elucidate the by-products. The oxidation reaction of the triazine herbicide and by-products generated were monitored by spectrophotometry in the ultraviolet region and visible (UV-Vis) and gas chromatography (GC), using electron capture detector (ECD). Proceeds from the triazines oxidation reactions with 'H IND.2O IND.2' catalyzed by iron and metalloporphyrins (Fe (FTTPCl)) and ruthenium (Ru (OCTTPP)), varied according to the conditions of catalytic reactions. It was observed that there was significant degradation of the analytes (94.70% to 92.60% for atrazine and simazine using the (Fe(FTTPCl)) and; 94.38% to 67.19% for atrazine and simazine using the (Ru(OCTTPP))) and was also observed the transformation of herbicides in desethyl atrazine products (DEA) and the deisopropil atrazine (DIA). The monitoring data of catalytic reactions by UV-Vis revealed the stability of the catalysts (Fe(FTTPCl)) and (Ru(OCTTPP)) in oxidizing conditions of the reactions. The results obtained with gas chromatography coupled with mass spectrometry (GC-MS) using the electron impact ionization technique (EI), full scan, positive mode (EI+), associated this peak revealed molecular ion peak (m/z = 215, associated with atrazine [M]+ and major fragments (m/z): 200 (associated with the ion [M - CH3]+), 173 and 138, and the mass spectrum obtained after the oxidation reaction revealed the disappearance of the peak associated with the herbicides and formation of new peaks associated with byproducts fragments. Similarly, the identification of simazine was obtained in the positive mode (EI+) and been revealed molecular ion peak (m / z = 201) and the principal fragments (m / z): 186, 173 and 138 / Mestrado / Tecnologia e Inovação / Mestra em Tecnologia

Orientador: Wilma De Grava Kempinas / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Campinas / Made available in DSpace on 2018-08-31T09:26:34Z (GMT). No. of bitstreams: 1 Fernandes_GlauraScantamburloAlves_M.pdf: 2208578 bytes, checksum: d3b7d19f0c07858ed0bc399fa4af2b7d (MD5) Previous issue date: 2005 / Resumo: O diuron (3-(3,4-diclorofenil)-1,1-dimetilurea) é um herbicida uréico cuja DL50 oral aguda em raios é igual a 3400 mg/Kg. É muito utilizado na agricultura e seus efeitos no organismo animal ainda são pouco conhecidos, principalmente no sistema reprodutor. O objetivo deste trabalho foi avaliar o possível efeito tóxico do diuron no sistema reprodutor masculino. Para tanto, ratos machos adultos (9 ou 10 animais por grupo) receberam durante trinta dias consecutivos, por gavage (via oral). 125 ou 250 mg/Kg/dia de diuron (grau técnico) dissolvido em óleo de milho. O grupo controle recebeu apenas o veículo, segundo o mesmo protocolo experimental. Ao final do tratamento, os órgãos reprodutores, fígado e rins foram coletados e pesados. Alguns dos testículos e epídídimos foram utilizados para a contagem de espermatozóides e amostras de fígado e rins para quantificar resíduos de diuron por cromatografia gasosa. Um outro grupo de animais foi avaliado quanto ao comportamento sexual e fertilidade, sendo acasalados com fêmeas em estro natural. Ao final do tratamento, resíduos de diuron foram encontrados no fígado de todos os ratos tratados e houve aumento do peso desse órgão nas duas doses. A exposição ao diuron não provocou diferenças estatisticamente significativas nas concentrações de testosterona. produção espermática diária, reservas espermáticas no epidídimo e morfologia dos espermatozóides. O comportamento sexual não se alterou devido ao tratamento, porém houve diminuição estatisticamente significativa do número de fetos produzidos por ratas que acasalaram com machos tratados com a menor dose. Concluiu-se que a dose de 125 mg/Kg de diuron administrada nessas condições experimentais, foi tóxica do ponto de vista reprodutivo. / Abstract: Diuron (3,4-dichlorophenyl)-1,1-dimethylurea) is a ureic herbicide whose acute oral LD50 in rats is 3400 mg/Kg. It is widely utilized in agriculture and its effects in the animal organism are still poorlv known, especially in the reproductive system. The aim of this work was to evaluate a possible toxic effect of diuron on the male reproductive system. For this, adult male rats (9 or 10 animals per group) received, for 30 consecutive days, by oral gavage. 125 or 250 mg/Kg/day of diuron (technical grade) dissolved in corn oil. The control group received only the vehicle, following the same experimental protocol. At the end of the treatment, male reproductive organs, liver and kidneys were collected and weighed. Some of the testis and epididymis were utilized for sperm counts, and samples of liver and kidneys to quantify diuron residues, by gas chromatography, Another group of animals was evaluated with respect to sexual behavior and fertility, being mated with females in natural estrous. At the end of the treatment, residues of diuron were found in the liver of all treated rats and there was an increase of the weight of this organ in both doses. The exposure to diuron did not provoke statistically significant differences in testosterone concentration, daily sperm production, sperm reserves in the epididymis or sperm morphology. Sexual behavior was not altered due to the treatment, however there was statistically significant diminution in the number of fetuses produced by rats that mated with males treated with the lower dose. It was concluded that the dose of 125 mg/Kg of diuron. administered in these experimental conditions, was toxic from the reproductive point of view. / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural

Pre-harvest glyphosate is often applied to cereal crops, such as oats, to insure uniform grain ripeness at harvest. However, some buyers have claimed that this practice negatively affects oat end product quality. Oat samples were grown in two different growing locations for each of two crop years, and glyphosate was applied at the soft dough, physiological maturity, or not applied. Groat quality and starch quality parameters were analyzed, and rolled oats were produced to analyze end product quality. Groat hardness, groat percentage, and percent plump groats were significantly (P<0.05) affected by glyphosate application at the soft dough stage. However, application of glyphosate at physiological maturity did not appear to detrimentally affect groat starch or end product quality. Therefore, pre-harvest glyphosate application isappropriate for oats providing it occurs after plants reach physiological maturity.

Medusahead (Taeniatherum caput-medusae (L.) Nevski) is currently one of the biggest threats to rangelands and livestock operations in the Western US. High silica concentrations in medusahead contribute to its invasiveness. I developed a model to explain how silica is involved in the invasion process, and attempted to manipulate silica to increase use of the grass by livestock. Experiments were conducted to determine: 1) whether rotational grazing on established forages of improved nutritional quality would provide supplemental nutrients to increase cattle use of medusahead; 2) evaluate intake of and preference for medusahead treated with a glyphosate herbicide at different rates by sheep; and 3) evaluate intake and selection of medusahead by cattle by separating the effects of a glyphosate herbicide (Roundup®) from other chemicals in the formulation (salt, adjuvant). Additionally, experiments were conducted to 4) determine the nutritional value and digestibility of medusahead treated with Roundup® at different rates and at different plant particle sizes; and 5) determine if cattle grazing with trampling can increase seeding success on medusahead-invaded rangelands. Rotational grazing from supplemental pastures to medusahead-invaded pastures increased medusahead use by cattle during the second year of the study. Furthermore, glyphosate did not increase medusahead consumption in a choice between three glyphosate treatments, but did in a two-way choice test. Cattle grazed glyphosate-treated medusahead more than that of the non-treated grass and completely avoided the salt-treated grass. The active ingredient in a glyphosate herbicide increased consumption of medusahead while other ingredients in the herbicide (i.e., salt and adjuvant) had no influence on this choice. A smaller particle size increased the digestibility of medusahead compared to larger particle sizes. Glyphosate also increases digestibility, but not as much as particle size. Finally, cattle trampling did not help establish seeded plant species, and the seeding attempt was unsuccessful. Thus, grazing rotations between improved pastures and medusahead-infested rangeland, and the combined glyphosate application-grazing are new approaches for medusahead control, as they prepare a seed bed for revegetation and increase the nutritional quality of the grass for improved livestock nutrition.

<p>  </p> <p>In Midwestern soybean [<em>Glycine max </em>(L.) Merr.] systems, especially in Indiana, three summer annual weed species are among the most common and troublesome for soybean producers: tall waterhemp (<em>Amaranthus tuberculatus</em>), giant ragweed (<em>Ambrosia trifida</em>), and horseweed (<em>Conyza canadensis</em>). Evolved resistance to current herbicides [e.g. glyphosate and acetolactate synthase (ALS) ihibitors], coupled with a dearth of new herbicide active ingredients being commercialized in the last two decades, has made controlling these problematic weeds particularly challenging. Trifludimoxazin is a novel protoporphyrinogen oxidase (PPO)-inhibiting herbicide that is currently under development for use in soybean and is likely to be commercially applied either alone or in combination with the herbicide saflufenacil. Research herein was conducted to investigate foliar control of tall waterhemp (including genotypes that are resistant to applications of other PPO inhibitors), giant ragweed, and horseweed following applications of trifludimoxazin alone and in combination with other herbicides. Additionally, the efficacy of soil-residual applications of trifludimoxazin and trifludimoxazin plus saflufenacil was evaluated for tall waterhemp and compared to other preemergence herbicides commonly used in soybean. Finally, soybean response to preplant applications of trifludimoxazin and trifludimoxazin plus saflufenacil at various preplant timings was investigated along with impact of adding the WSSA Group 15 herbicides acetochlor, pyroxasulfone, and <em>S</em>-metolachlor to preemergence applications of trifludimoxazin plus saflufenacil.</p> <p>Applications of 12.5 g ha-1 trifludimoxazin were highly efficacious in foliar applications on tall waterhemp (94% control) at 28 days after application (DAA), less effective when applied to giant ragweed (78% control, 21 DAA), and ineffective on horseweed (9% control, 28 DAA). When applied in combination with glufosinate, glyphosate, paraquat, or saflufenacil, foliar control for these species was 91% to 100%, except for trifludimoxazin plus glyphosate applied to a glyphosate-resistant population of horseweed (17%). Furthermore, foliar efficacy of trifludimoxazin applied to tall waterhemp or Palmer amaranth (<em>Amaranthus palmeri</em>) was not impacted by the presence of target-site mutations (ΔG210 or R128 in waterhemp, ΔG210 or V361A in Palmer amaranth) that confered resistance to saflufenacil and fomesafen.</p> <p>Near complete soil residual control [≥ 98% at 2 weeks after application (WAA)] of tall waterhemp was initially observed with 12.5 to 50 g ha-1 of trifludimoxazin but were less effective (39% to 69%) relative to commercial standards of pyroxasulfone (91%) or sulfentrazone (95%) by 6 WAA. Combining saflufenacil at 25 or 50 g ha-1 with soil-residual applications of trifludimoxazin improved efficacy on tall waterhemp at 6 WAA relative to trifludimoxazin alone. With the exception of 12.5 + 25 g ha-1 (74%), applications of trifludimoxazin plus saflufenacil, respectively, resulted in comparable residual tall waterhemp control (84% to 92%) as the commercial standards. </p> <p>Soybean injury following applications of trifludimoxazin was relatively low (< 10%), regardless of preplant application timing [0 to 28 days before planting (DBP)] or rate (6.25 to 25 g ha-1). However, the addition of saflufenacil increased soybean injury, especially when environmental conditions were more conducive to soybean response. For instance, at Pinney Purdue Agriculture Center (PPAC) in 2019 soybean injury 4 weeks after planting (WAP) was 28%, soybean population was reduced by 39%, and yield was reduced by 27% when trifludimoxazin plus saflufenacil was applied at 25 + 50 g ha-1. The experimental conditions that corresponded to this elevated soybean injury were coarse-texture soil, low temperatures, and high precipitation at the time of soybean emergence. Lower rates of this herbicide combination resulted in less injury, and soybean response was minimized (≤ 8%) when applications were made at least 14 DBP. The addition of Group 15 herbicides to applications of trifludimoxazin plus saflufenacil at planting did not impact soybean response, except for at PPAC in 2019, where the addition of acetochlor (51%) or pyroxasulfone (46%) to 25 + 50 g ha-1 was greater than without these Group 15 herbicides at 4 WAP (22%). Field research indicated soybean response to combinations of trifludimoxazin plus saflufenacil differed by cultivar in some instances, and greenhouse experiments determined the response was attributable to differential soybean cultivar sensitivity to the saflufenacil component of the mixture.  </p>

Using Radioautography 14C simazine, 14C EPTC, 14C 2,4-D, 1414 DCPA and 14C pyrazon absorption by seeds of bean (Phaseolus vulgaris L.), squash (Cucurbita maxima), corn (Zea mays), onion (Allium cepa) and oat (Avena sativa) was studied. Simazine, EPTC, 2,4-D and pyrazon were absorbed through the seed coat of bean, squash, corn and onion, the amount increasing with time. Little DCPA was absorbed by seeds of bean, squash, onion and oat. Distribution and translocation of 14C simazine, 14C EPTC and 14C pyrazon occurred in the young plants of bean, squash, corn and onion. Simazine and pyrazon accumulated in the leaf margins of bean, EPTC and pyrazon were found in the cotyledon margins of squash, and pyrazon was found in the coleoptile tips and leaf tips of corn. The translocation of 14C 2,4-D in bean, onion and squash showed a characteristic fixation along the path of the translocation. Very little translocation or distribution of 14C DCPA were found in bean, squash, onion or oat. In bean leaf, 14C pyrazon was absorbed and moved acropetally in the apoplast. Basipetal movement of 14C pyrazon was limited. Microadioautography was used to determine the tissues involved in the translocation of 14C simazine, 14C EPTC, 14C 2,4-D and 14C pyrazon. Simazine and EPTC were found in the vascular bundle tissues of bean leaf. EPTC was found in the cortex of squash root. 2,4-D was found in the vascular tissues and surrounding the vascular bundle of squash cotyledon and onion hypocotyl. Pyrazon was found intercellularly and intracellularly in bean cotyledon.

No description available.

In an effort to reduce application costs and to integrate plant health management strategies in soybean, growers may combine POST herbicides with foliar fertilizers or cytokinin mixtures. Field experiments were conducted at the Delta Research and Extension Center in Stoneville, MS in 2015 and 2016 to evaluate soybean [Glycine max (L.) Merr.] injury, weed control, and agronomic performance when combining blended or single-nutrient foliar fertilizers with POST herbicide applications. Field experiments were also conducted at the Delta Research and Extension Center in Stoneville, MS in 2015 and 2016 to evaluate the influence of cytokinin mixtures on soybean injury and weed control when combined with common POST soybean herbicides.

Tomato is a major horticulture crop grown across the globe. Unfortunately, its yield is reduced by 25% because of auxin herbicides and glyphosate drift. In this present study, wild germplasm of tomato was screened for herbicide tolerance. From the greenhouse study nine accessions for glyphosate and 2,4-D, eleven accessions for dicamba, five accessions for quinclorac, eight accessions for aminocyclopyrachlor, and two accessions for picloram and aminopyralid were identified to be tolerant. A few accessions were selected from each herbicide tolerant group for field trials at two locations in Mississippi in 2016 and 2017. Results indicated that TOM18 was most tolerant to dicamba herbicide, while TOM87 and TOM129 to glyphosate and quinclorac herbicide, respectively, on the basis of yield and injury. Molecular experiments were conducted to measure the genetic diversity among diverse germplasm. Genetic diversity analysis showed wild accessions to be highly diverse as compared to cultivated tomato.

Studies were conducted in the field and in containers in Mississippi from 2017-2019 to optimize Italian ryegrass control in corn production. Most fall-applied residual herbicides provided ≥ 90% Italian ryegrass control 56 days after treatment (DAT) in both field and container experiments. Oxyflurofen provided 95% Italian ryegrass control 28 DAT but only 81% control 56 DAT in field plots. S-metolachlor plus atrazine followed by paraquat produced the highest return on investment for both site-years. The timing of removal study indicates the optimum time to remove Italian ryegrass relative to corn planting is approximately three to four weeks prior to planting. In the droplet size study, Italian ryegrass control when S-metolachlor was sprayed with the TTI was lower than when S-metolachlor was sprayed with the AIXR in containers 28 DAT. Italian ryegrass control when paraquat was sprayed with the AIXR was greater than when paraquat was sprayed with the TTI.