Several items need consideration when products are evaluated for use as transition agents. These are (1) efficacy of ryegrass removal [rate of ryegrass decline and appearance of turf during transition], (2) tolerance and performance of incoming bermudagrass and (3) application safety for next season’s repeat overseed operations. This test was designed to evaluate application safety for the next overseeding which occurs in the early fall. Therefore, AEF was applied in the summer to bermudagrass turf prior to overseed operations. Most responses of the perennial ryegrass (overseed) turf to previous treatments of AEF 130360 occurred immediately after overseeding, from mid-October to early November. AEF 130360 applied 2 weeks before overseeding caused a significant decrease in seedling vigor, percent plot ryegrass cover, and percent bermudagrass plot straw present. Both AEF treatments applied closest to overseeding (2 weeks prior) had the least amount of initial ryegrass, the greatest amount of green bermudagrass, and later in the season, the most amount of straw (dormant) bermudagrass. Differences in turfgrass quality were not significant due to treatments at any time throughout the test, and most treatments ranked higher than the control in overall quality. Under the conditions of this test, application of AEF 130360 at either 0.64 or 1.28 ounces/product/M made one month before actual oversseding did not cause detrimental effects to ryegrass emergence, ryegrass cover, turfgrass color or overall quality.

Proxy (ethephon) was applied to 100% pure stands of Poa annua as either a single or repeat application 24 days apart at both a five and ten-ounce product rate per 1000 square feet. Percent plot seed heads were decreased significantly on three of five evaluation dates before either the loss of treatment effect and/or environmental conditions triggered profuse flowering (by 20 April, 2000). The five-ounce rate produced moderate seed head suppression at 16 and 25 days after the first treatments by which afterwards, control was minimal. By April, the five-ounce repeat applications were no better in suppression of seed heads than either of the single applications, regardless of application timing (March 3 or 29). The ten-ounce rates generally produced 40% - 80% greater seed heads suppression than the five-ounce rate treatments. Maximum seed head control was achieved by the repeat applications (March 3 and 29) of the ten-ounce rate, which consistently produced between 8% and 19%, seed head cover up until the first ten days of April 2000. Proxy, when applied at the five-ounce/M rate had the greatest effect in seed head suppression early in the test (10 March). Perhaps earlier season applications at the five-ounce rate may be necessary to manifest greater suppression initially, and perhaps in a cumulative fashion for season long control.

Several new sulfonylurea products have (or are being) brought to market for use in turf. One use of these products is for removing ryegrass from overseeded bermudagrass, since perennial ryegrass has become too persistent due to improvements in heat, drought, and close mowing tolerance. The soil half life of sulfonylurea is greatly increased in high pH soils, which are typical in the southwest. Superintendents may need to re-establish seeded bermudagrass after use of a S.U. transition agent if the underlying bermudagrass is sparse. With this in mind, a replicated field trial was conducted in summer 2004 to evaluate three rates of foramsulfuron (0.4, 0.8, 1.2 ounce /product/1000 ft2) herbicide at 0, 7, 14, and 28 days after seeding. Foramsulfuron is sold as Revolver. Revolver applied at time of seeding (0DAS) and 1 week after seeding (7 DAS) caused the greatest amounts of bermudagrass suppression in terms of bermudagrass plot cover and visible seedling vigor. When applied (7 DAS), bermuda cover (averaged over all three applied rates of Revolver) at 21, 28, and 36 DAS was 8%, 22% and 32% bermuda cover, respectfully, versus NTC mean values of 22, 49 and 54% cover, respectively. The second greatest degree of Bermuda suppression occurred from Revolver applied at the day of seeding (0 DAS). The effects lasted up until and included the end of the test on 29 Sept (36 DAS). When averaged over all 3 applied rates of Revolver, percent plot bermudagrass cover at 21, 28, and 36 DAS was 10%, 30% and 40% respectively for the 0 DAS treatments. The NTC cover for these same dates was 22%, 50% and 53% respectively. Vigor visual scores were minimal as well for all rates applied at (0 DAS) and at (7 DAS). Plots remained stunted up to 36 DAS for Revolver turfs applied at (7 DAS) and (0 DAS). Application at the time of seeding (0 DAS) resulted in more bermudagrass plot cover than if applied at (7 DAS). Rate reduction responses were realized only for Revolver application timings made at 0 DAS and 7 DAS (Table 1, 5, Figs. 1-4). No rate responses resulted for Revolver when applied at 14 DAS, 28 DAS. In conclusion, Revolver was safest when applied 14 DAS or later, with little rate effects.

Khakiweed (Alternanthera pungens) was treated late in the season with select herbicides for initial screening of herbicides for post emergence control. Treatments were applied on October 7, 2004 and evaluated five weeks after treatment on Nov 16, 2004. The F ratio for the treatment main affect was highly significant for percent weed control. All rate affect contrasts were not significant for those treatments applied at two or more active ingredient levels. The "S.U. herbicides" vs. "all others" contrast was significant at P=0.05, as the S.U.. chemicals as a whole provided better coverage than the 2-4, D type and Penoxsulam. Percent weed control ranged from 7% to 99% late season control of Khakiweed. There were noticeable differences between S.U. products, as Revolver provided minimal weed control (7%) while Manor and Monument provided very good to excellent control (94% to 99%). Both Manor rates resulted in 99% control, while the three rates of Monument produced 94%-98% mean percent weed control values. Penoxsulam was intermediate, providing 56% and 70% control for the SC and G formulations, respectively. Banvel, 2-4, D and Buctril produced 22%-24% Khakiweed control. Tranxit had minimal affect (12%), as did Revolver at 6%.

No description available.

<p>U okviru doktorske disertacije razvijena je brza i selektivna metoda za<br />određivanje i praćenje ostataka herbicida na bazi sulfonilurea (nikosulfuron,<br />oksasulfuron, tribenuron metil, tritosulfuron, triasulfuron, rimsulfuron i<br />prosulfuron) u zemlji&scaron;tu primenom visoko pritisne tečne hromatografije sa<br />UV detektor sa nizom fotoosetljivih dioda (HPLC-UV-DAD). Razdvajanje<br />sulfonilurea je izvedeno uz primenu Zorbax Eclipse XDB-C18 kolone. U cilju<br />definisanja odgovarajućih uslova analize, ispitan je i definisan uticaj<br />najznačajnijih eksperimentalnih faktora. Usvojeni su sledeći optimalni uslovi<br />gradijentne elucije: mobilna faza acetonitril (A) i 0,1% sirćetna kiselina (B) t<br />= 0 min, 52% A; t = 2-2,5 min, 47% A; t = 2,5-5 min, 52% A, pri konstatnom<br />protoku od 1 mL min-1 i temperaturi kolone od 250C. Na osnovu odziva<br />analitičkog signala, njegove reproduktivnosti i linearnosti, talasna dužina od<br />240 nm je usvojena kao odgovarajuća. Utvrđeno je da je uticaj matriksa bio<br />izražen te je stoga za kvantitativno određivanje sadržaja SU u uzorcima<br />zemlji&scaron;ta primenom HPLC-UV-DAD metode kori&scaron;ćena MMC kalibraciona<br />kriva. Pri analizi ekstrakata nekontaminiranog zemlji&scaron;ta ostvarena je granica<br />kvantitativnog određivanja za nikosulfuron, oksasulfuron, tribenuron metil,<br />tritosulfuron, triasulfuron, rimsulfuron i prosulfuron od 3,16 &mu;g kg-1, 3,40 &mu;g<br />kg-1, 3,76 &mu;g kg-1, 4,13 &mu;g kg-1, 3,60 &mu;g kg-1, 3,04 &mu;g kg-1 i 2,97 &mu;g kg-1,<br />redom. Za potrebe osetljivijih, selektivnijih i tačnijih određivanja SU u<br />zemlji&scaron;tu, definisana je metoda uz primenu tečne hromatografije sa<br />tandemskom masenom spektrometrijom (HPLC-MS-MS). HPLC-MS-MS je<br />kori&scaron;ćena kao referntna tehnika za proveru rezultata koji su dobijeni<br />primenom HPLC uz UV-DAD detektor. Definisan je efikasan postupak za<br />pripremu uzoraka zemlji&scaron;ta u cilju hromatografskog određivanja SU.<br />Najefikasnija ekstrakcija ostvarena je primenom sme&scaron;e dihlormetanacetonitril<br />(2:1, v/v), zaki&scaron;eljene sirćetnom kiselinom (0,8%, v/v), uz dodatak<br />uree (0,3 g/ 10g zemlji&scaron;ta). Postupak mikrotalasne estrakcije u zatvorenom<br />sistemu omogućio je najbolje uslove za ekstrakciju SU. U cilju izdvajanja SU,<br />iz matriksa ekstrakata zemlji&scaron;ta, primenjena je ekstrakcija na čvrstoj fazi (SPE) sa silika gelom kao adsorbensom. Definisana metoda za određivanje<br />ispitivanih SU, kao i razvijeni postupak pripreme uzoraka, uspe&scaron;no je<br />primenjen u analizi realnih uzoraka zemlji&scaron;ta. Veoma dobre vrednosti testa<br />povrata ostvarene pri analizi primenom HPLC-UV-DAD metode, potvrdile su<br />pre svega ispravnost postupka pripreme uzoraka, a delom i kompletne<br />metode. Tačnost razvijene metode za određivanje SU u zemlji&scaron;tu potvrđena je<br />paralelnim analizama uzoraka zemlji&scaron;ta kori&scaron;ćenjem HPLC-MS-MS.<br />Primenom Studentovog t-testa (upareni), utvrđeno je da se rezultati paralelnih<br />analiza statistički značajno ne razlikuju (P=95%). Istraživanja u okviru<br />disertacije obuhvatila su i praćenje disipacije nikosulfurona, rimsulfurona,<br />oksasulfurona i prosufurona u različitim komercijalnim dozama primene<br />tokom 50 dana u polju na tri različite dubine (0-15 cm, 15-30 cm i 30-45 cm),<br />kao i laboratorijskim uslovima na dve temperature (250C i 300C). Vreme<br />polurazgradnje (DT50) ispitivanih SU (nikosulfuron, oksasulfuron i<br />prosulfuron) definisano Mitttag-Lefler-ovom funkcijom u ogledima u<br />laboratorijskim uslovima na 250C iznosilo je 0,65 dana (50 g ha-1 a.k.), 0,64<br />dana (160 g ha-1 a.k.) i 0,66 dana (30 g ha-1 a.k.), redom, a na 300C za<br />nikosulfuron 0,20 dana (50 g ha-1 a.k.) i prosulfuron 0,49 dana (50 g ha-1 a.k.).<br />DT50 za ispitivane SU u polju, takođe definisano Mitttag-Lefler-ovom<br />funkcijom, iznosilo je 72 minuta (0,05 dana), 0,23 dana, 0,12 dana i 0,15<br />dana, za nikosulfuron, rimsulfuron, oksasulfuron i prosulfuron, redom.<br />Značajno veća disipacija koja je utvrđena istraživanjima u okviru ove<br />disertacije najverovatnije je uzrokovana uticajem abiotičkih i biotičkih<br />procesa, kao i faktora spolja&scaron;nje sredine.</p> / <p>In this thesis a fast and selective method for determination and monitoring<br />of residues sulfonylurea herbicides (SU) (nicosulfuron, oxasulfuron,<br />tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and prosulfuron)<br />in soil, by applying high-performance liquid chromatography with UV<br />detector with diode array diodes (HPLC-UV-DAD) was developed. The<br />separation of the sulfonylurea was performed by use of a Zorbax Eclipse<br />XDB-C18 column. In order to define appropriate conditions of analysis,<br />the influence of the most significant the experimental factors was<br />investigated and defined. The following optimal conditions for gradient<br />elution: mobile phase acetonitrile (A) and 0.1% acetic acid (B) t = 0 min,<br />52% A; t = 2-2.5 min, 47% A; t = 2.5-5 min, 52% A were adopted at a<br />constant flow rate of 1 mL min-1 and column temperature of 250C. On<br />basis of the response of the analytical signal, its reproducibility and<br />linearity, the wavelength of 240 nm was adopted as an appropriate. The<br />influence of the matrix was expressed and therefore for the quantitative<br />determination of investigated SU in soil samples application of HPLCUV-<br />DAD methods was used MMC calibration curve. In the analysis of<br />extracts of nocontaminated soil limits of quantitation for nicosulfuron,<br />oxasulfuron, tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and<br />prosulfuron was achieved 3.16 &mu;g kg-1, 3.40 &mu;g kg-1, 3.76 &mu;g kg-1, 4.13 &mu;g<br />kg-1, 3.60 &mu;g kg-1, 3.04 &mu;g kg-1 and 2.97 &mu;g kg-1, respectively. The method<br />by using liquid chromatography-tandem mass spectrometry (HPLC-MSMS)<br />was defined in order to find more sensitive, more selective and more<br />accurate way to determine concentration SU in soil. HPLC-MS-MS was<br />used as the reference technique for checking results that have been<br />obtained by HPLC with UV-DAD detector. An efficient procedure<br />preparation of soil samples for the purpose chromatographic determination<br />of SU was defined. Using a mixture of dichloromethane-acetonitrile (2: 1,<br />v / v), acidified with acetic acid (0.8%, v / v), with the addition of urea (0.3<br />g / 10 g soil) was applied as the most effective way for extraction SU.<br />Microwave extraction process in a closed system allowed the best<br />conditions for the extraction of SU. In order to extract SU from matrix<br />exctracts soil the solid phase the extraction (SPE) with silica gel as an<br />adsorbent was used. The defined method for determination of investigated SU, as well as the developed procedure of sample preparation, was<br />successfully applied in the analysis of real samples of soil. The correctness<br />of procedure of sample preparation was confirmed with very good values<br />of recovery test which was applied in the analysis by using HPLC-UVDAD.<br />The accuracy of the developed method for determination of SU was<br />confirmed by coupled analysis soil samples using HPLC-MS-MS. The<br />results of parallel analysis does not differ significantly at 95% confidence<br />level. It was obtained using Student t-test (paired). The method developed<br />in this thesis was used for monitoring the dissipation of nicosulfuron,<br />rimsulfuron, oxasulfuron prosufuron, in different commercial doses of<br />application during 50 days in field at three different depths (0-15 cm, 15-<br />30 cm and 30-45 cm) and for laboratory conditions at two temperatures<br />(25&ordm;C and 30&ordm;C). The half-life time (DT50) of investigated SU were<br />calculated by use of Mitttag-Lefler function in experiments under<br />laboratory conditions at 25&ordm;C. The values of DT50 for nicosulfuron,<br />prosufuron and oxasulfuron read: 0.65 days (50 g ha-1 a.k.), 0.64 days (160<br />g ha-1 a.k.) and 0.66 days (30 g ha-1 a.k.), respectively. In the same type of<br />experiments at 30&ordm;C we get DT50 for nicosulfuron equals 0.20 days (50 g<br />ha-1 a.k.) and for prosulfuron equals 0.49 days (50 g ha-1 a.k.). The values<br />of DT50 on experiments in field were obtain also by use of Mitttag-Lefler&#39;s<br />function, and half-life times for nicosulfuron, rimsulfuron, oxasulfuron and<br />prosufuron from the commercially recommended doses, equal 72 minutes<br />(0.05 days), 0.23 days, 0.12 days and 0.15 days, respectively. Significantly<br />greater dissipation which was determined in this thesis was probably<br />caused by the influence of abiotic and biotic processes as well as<br />environmental factors.</p>

Qualitative and microcosm models were used to predict effects of herbicide application for control of Myriophyllum spicatum. Predictions were compared to data from Pat Mayse Lake, a Texas reservoir, where localized areas were treated with endothall. Although milf oil was temporarily eliminated, when endothall was used according to manufacturer's directions, no ecologically significant direct or indirect effects were observed on nontarget species or abiotic water quality. Comparisons of the predictions with field data confirmed the capabilities of this approach for estimating risk and emphasizing the importance of identifying regulating or driving factors that modify environmental impacts of aquatic weed control programs so they can be incorporated into future risk assessments.

Orientador: Marcelo da Costa Ferreira / Banca: Otávio Jorge Grigoli Abi Saab / Banca: Pedro Luís da Costa Aguiar Alves / Resumo: A cana-de-açúcar é uma das culturas que possui expressiva representatividade para o Brasil em termos de produtividade. Mas existem limitações no seu desempenho, principalmente através da interferência imposta pelas plantas daninhas, podendo considerar perdas em até 85% quando não controladas de forma adequada. E o controle químico ainda é o mais utilizado devendo-se atentar aos conhecimentos e cuidados a serem tomados com a utilização dos herbicidas que serão aplicados como a dosagem, época de aplicação, estádio fenológico, condições fisiológicas e bioquímicas da cultura e das características das plantas daninhas. Nessa perspectiva, o objetivo deste trabalho foi avaliar a eficácia no controle de plantas daninhas em modalidades pré e pós-emergente com diferentes volumes de aplicação e concentrações de caldas, na cultura da cana-de-açúcar. Foram realizados dois experimentos em casa de vegetação. As plantas daninhas tomadas como alvos foram: IPOHF e PANMA na modalidade pré-emergente e ERICA e DIGIN pós-emergente, em vasos semeados com substrato. O produto utilizado foi o herbicida indaziflam e as aplicações foram realizadas através do delineamento experimental inteiramente ao acaso em esquema fatorial (4 x 2), quatro volumes (50, 75, 100 e 125 L/ha) e duas concentrações (150 e 200 mL/ha), além de uma testemunha sem aplicação, para as plantas pré-emergentes e quatro volumes (75, 100, 125 e 150 L/ha) com as mesmas concentrações do produto (150 e 200 mL/ha) e uma testemunha sem apl... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sugarcane is one of the most important crops for Brazil in terms of productivity. However, there are limitations for this crop when it comes to field performance, mainly due to interference imposed by weeds, resulting in production losses up to 85% when weeds are not adequately controlled. The chemical control is still the most efficient, with the use of herbicides, and attention should be paid to the dosage, application time, plant phenological stage, physiological and biochemical conditions of the crop, as well as the characteristics of the weeds. In this perspective, the objective of this work was to evaluate the efficacy in weed control in pre and post emergent modalities with different application volumes and product concentrations in the sugarcane crop. Two experiments were carried out under greenhouse conditions. Chosen weeds for this study were: IPOHF and PANMA in the pre-emergent modality and ERICA and DIGIN for the post-emergence control. Seeds were sown in pots with substrate. The indaziflam herbicide was used and the treatments were carried out in a completely randomized design in a factorial scheme (4 x 2). Four volumes (50, 75, 100 and 125 L/ha), two concentrations (150 and 200 mL/ha) and a control treatment without any application were used for the pre-emergent control, and four volumes (75, 100, 125 and 150 L/ha) with the same concentrations of the product (150 and 200 mL/ha), plus another control treatment without any application were used for the post-emerge... (Complete abstract click electronic access below) / Mestre

Abstract
 Acetyl-CoA
carboxylase
(ACC)
is
a
key
enzyme
of
fatty
acid
metabolism
with
multiple
 isozymes
often
expressed
in
different
eukaryotic
cellular
compartments.

 In
agriculture,
inhibitors
of
plastid
ACC
are
used
as
efficient
herbicides
against
grass
 weed.
However,
grass
weed
populations
resistant
to
aryloxyphenoxypropionate
(APP)
and
 cyclohexanedione
(CHD)
herbicides
represent
a
major
problem
for
sustainable
agriculture.
 Using
PCR
and
sequencing
it
was
found
out
that
five
amino
acid
substitutions
in
plastid
ACC
 were
 correlated
 with
 herbicide
 resistance
 of
 Avena
 sterilis
 ssp.
 ludoviciana
 Durieu
 populations
from
the
northern
grain-growing
region
of
Australia:
Trp-1,999-Cys,
Trp-2,027- Cys,
 Ile-2,041-Asn,
 Asp-2,078-Gly
 and
 Gly-2,096-Ala.
 We
 showed,
 using
 a
 yeast
 gene- replacement
 system,
 that
 these
 single-site
 mutations
 also
 confer
 herbicide
 resistance
 to
 wheat
plastid
ACCase:
Asp-2,078-Gly
confers
resistance
to
APPs
and
CHDs,
Trp-2,027-Cys
 and
Ile-2,041-Asn
confer
resistance
to
APPs,
and
Trp-1,999-Cys
confers
resistance
only
to
 fenoxaprop.
These
mutations
are
very
likely
to
confer
resistance
to
any
grass
weed
species
 under
selection
imposed
by
the
extensive
agricultural
use
of
the
herbicides.

...

Orientador: Dagoberto Martins / Banca: Carlos Gilberto Raetano / Banca: Mario Sergio Tomazela / Resumo: Este trabalho teve como objetivo avaliar a seletividade do herbicida saflufenacil de forma isolado e em mistura, aplicado em pós-emergência inicial sobre 10 variedades de cana-de-açúcar em condição de cana-soca. O experimento foi instalado no município de Botucatu/SP. O delineamento experimental utilizado foi o de blocos casualizados em parcelas subdivididas com quatro repetições, sendo as variedades dispostas nas parcelas e os herbicidas nas subparcelas. Os tratamentos utilizados foram: saflufenacil + Assist (0,07 kg ha-1 + 0,5% v/v); saflufenacil + Break Thru (0,140 kg ha-1 + 0,05% v/v); saflufenacil (0,280 kg ha-1) e ametryne + clomazone (3,0 + 2,0 L i. a. ha-1), aplicados aos 49 DAC (dias após o corte), além de uma testemunha sem aplicação. As plantas encontravam-se por ocasião da aplicação com 2 a 4 folhas. As dez variedades utilizadas foram: SP83-2847, SP80-3280, RB855453, SP80-1842, SP89-1115, RB867515, PO8862, RB855156, SP80-1816 e SP81-3250. Para a aplicação das caldas herbicidas utilizou-se um pulverizador costal pressurizado a CO2 equipado com barra de aplicação com seis pontas Teejet XR 110 02 VS, à 200 kPa no volume de aplicação de 200 L ha-1. As avaliações visuais de controle foram realizadas aos 3, 7, 15, 21, 30, 45 e 60 dias após a aplicação. As injúrias visuais observadas nas plantas de cana-de-açúcar foram dependentes da variedade analisada e dos herbicidas e doses em teste. Todos os tratamentos químicos foram seletivos as diferentes variedades estudadas, não afetando o rendimento de colmos / Abstract: This study aims to evaluate the selectivity of the herbicide saflufenacil applied alone and mixed, in post-emergence over ten sugarcane varieties in the second year after planting. The experiment was carried out in Botucatu/SP. The experimental design was a randomized split plot with for replications, and the varieties in the plot and subplot herbicides. The treatments were: saflufenacil + Assist (0.07 kg ha-1 + 0,5 v/v); saflufenacil + Break Thru (0.140 kg ha-1 + 0.05% v/v); saflufenacil (0.280 kg ha-1) and ametryne + clomazone (2.0 + 3.0 L ha-1) applied to the 49 DAH (days after first harvest), and a control without application. The plants were at 2 to 4 leaves in the application time. The varieties were: SP83-2847, SP80- 3280, RB855453, SP80-1842, SP89-1115, RB867515, PO-8862, RB855156, SP80-1816 and SP81-3250. For herbicide application was used the Teejet XR 11002 VS spray equipment with six spray nozzles type, at 200 kPa and, 200 L ha-1 spray volume. The visual injuries observed in plants of sugarcane were dependent of varieties and the herbicides and, doses tested. All chemical treatments tested were selective to different varieties studied, without affecting the crop production / Mestre