Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 75-78). Also available via the Internet.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains iv, 61 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Loblolly pine (Pinus taeda L) is the leading Southern (USA) pine, in terms of acres planted (Fortson et al.,1996). Since commercial forest acreage is predicted to remain fairly constant over the next 50 years, productivity must be increased if the South is going to meet a larger share of the nation'­s timber supply needs (Gjerstad and Barber, 1987). Hardwoods have been shown to have a consistent negative growth impact on pines, and uncontrolled hardwoods continue to compete aggressively with pines throughout a rotation, especially when hardwoods remain in the pine canopy. Competing vegetation can be efficiently controlled by herbicides, which need to be formulated either in-can or in-tank to allow them to perform optimally. Adjuvants have proven essential to increasing the efficacy of herbicides, due to their ability to consistently improve the performance of the basic pesticide product. There are, broadly speaking, two routes by which adjuvants can do this. The first is the minimization of off target deposition and second, by the maximization of the herbicidal effect once it is placed on the target ( Reeves, 1989). The major contributors to off- target deposition and retention are drift, in-flight volatilization, droplet shatter, bounce or runoff, washoff, and removal by wind. These losses result in pesticides never reaching the target or achieving only transitory deposition. There are two basic methods of maximizing the effect of the pesticide once it is on the target. The first is to improve coverage by the spray solution, which can be accomplished by lowering the surface tension of the spray with surfactant materials. The second is by improving the penetration or uptake into the target. Organosilicone surfactants can reduce the surface tension of aqueous pesticides far below that which is possible with nonsilicone surfactants, resulting in efficient wetting of even the most hydrophobic leaf surfaces. Additionally, by virtue of their low surface tension, these adjuvants can significantly increase the uptake of active chemicals directly into the plant via stomatal infiltration ( Stevens et al., 1991). Triclopyr ([(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid) has been found to be an effective herbicide for hardwood control. Its two commercial formulations, a triethylamine (TEA) salt (Garlon 3A) and a butoxyethyl ester ( Garlon 4 ), vary considerably in their acceptability. The current ester formulation has two undesirable characteristics. One is that all ester formulations, regardless of chain length, have some volatility which is usually more than that of water-soluble salts. The second is that the current ester formulation utilizes a kerosene solvent which is known to cause rapid foliar necrosis (possibly inhibiting herbicide translocation) and is a suspected carcinogen ( Zedaker et al., 1995). In most applications, the ester formulation has been more efficacious than the amine formulation on both an equal active ingredient basis and on an equal cost basis. Research had demonstrated a potential to enhance the uptake of triclopyr through the use of organosilicones; however, significant problems still existed. It was found that the commercial TEA formulation of triclopyr (Garlon 3A) was "antagonistic" to the organosilicone surfactant Silwet L-77. To take full advantage of the properties of organosilicones, the antagonistic co-formulants of Garlon 3A needed to be removed or replaced, the best surfactant formulation identified, and a cost-effective concentration of the surfactant(s) needed to be found. To do this adequately required that both physico-chemical processes and biological processes be studied. The relevant physico-chemical processes involved in a formulation's effect on spray impaction on the target plant include adhesion, reflection, retention and run-off. The important biological processes include the uptake and translocation of the herbicide into the plant. The objectives of this study were: to evaluate the influence of formulation, active ingredient concentration, droplet size and leaf surface (adaxial vs. abaxial) on contact phytotoxicity, adhesion and retention to Acer rubrum, Liquidambar styraciflua and Quercus rubra by triclopyr formulations containing organosilicone surfactants and mixtures of silicone plus conventional surfactants. The adhesion and retention studies also evaluated the influence of leaf angle. Further objectives were to evaluate the influence of formulation and active ingredient concentration on spray retention by the adaxial and abaxial leaf surface of the selected species under field and track-sprayer conditions and to determine whether leaf characteristics (wax character and leaf angle ) could explain adhesion / retention. Garlon 4, Garlon 3A and Triclopyr TEA + sequestrant (each at 0.32%, 1.6% and 3.2% ae) plus various concentrations of the surfactants Polyglycol 26-2, Rhodasurf DA-630, Surfadone LP-100, Silwet L-77 and Silwet 408, were tested for contact phytotoxicity, adhesion and retention on the adaxial and abaxial leaf surfaces of sweetgum, red oak and red maple. Little or no contact phytotoxicity was observed with any formulation applied to the adaxial surface within 6 hours; some phytotoxicity was noted within 24 hours. Abaxial surface treatments showed much greater contact phytotoxicity. Contact phytotoxicity was caused by (1) increasing concentrations of stock triclopyr products, and (2) the influence of the organosilicone surfactants. However, these results were very species dependent. Conclusions made from the contact phytotoxicity study were: if the droplet size becomes too big, then efficacy will be reduced; increasing the concentration of active ingredient above a certain limit will not increase efficacy, and may in fact reduce it; the addition of the organosilicone surfactants Silwet L-77 and Silwet 408 delayed and reduced phytotoxicity in red oak ( the most susceptible species to contact phytotoxicity), and to a lesser extent in red maple, but increased the rate in sweetgum. Major influences on adhesion were: droplet size ( increasing droplet size decreased adhesion); adaxial/abaxial leaf surface (abaxial adhesion less than adaxial); product concentration (increasing product concentration increased adhesion); leaf angle (increasing leaf angle decreased adhesion); and addition of surfactants (variable adhesion). All new formulations gave greater adhesion than the commercial formulations, with Triclopyr TEA plus sequestrant plus n-octyl pyrrolidone plus Silwet 408 giving, overall, the greatest adhesion. Increasing product concentration gave greater adhesion. Increasing droplet size and angle of impact reduced adhesion. The adaxial leaf surface showed higher adhesion than the abaxial leaf surface. Adhesion was higher on sweetgum, followed by red oak, with red maple being the most difficult species to get formulations to adhere to. Whereas increasing product concentration improves adhesion, the lowest contact phytotoxicity result would be from lowering product concentration. Looking at both sets of results, the best product concentration of those studied would then be 1.6% ae as this can provide high adhesion, while still enabling us to choose a formulation which gives minimal contact phytotoxicity. In the laboratory, formulation had no significant effect on retention. However, there are other considerations which affect retention that need to be kept in mind. It was observed that droplets containing organosilicone could impact an already wetted surface and still adhere or be retained, whereas those droplets not containing any organosilicone surfactant would bounce quite a distance on impact with a pre-wetted surface. Impaction with an already wetted surface was not part of this study, and therefore was not studied quantitatively. Also, formulations containing organosilicone surfactants provide greater "wrap-around" to the lower surface ( Forster and Zabkiewicz, 1998), which is of great benefit when stomata are only on the abaxial surface, as is the case with these species. Concentration and leaf angle also had no significant effect on retention. Droplet size was significant, with retention decreasing with increasing droplet size. Retention by the adaxial surface was significantly higher than retention by the abaxial surface. There was no significant difference overall between sweetgum and red oak, but retention by red maple was significantly lower. Spray retention by the adaxial and abaxial leaf surfaces of the three tree species was also characterized in a field experiment conducted on a right of way site in North Anna, Virginia, USA. Amine ( Garlon 3A) formulations of triclopyr combined with Silwet 408, and the commercial triclopyr ester formulation, Garlon 4, were applied using a Radiarc sprayer equipped with 0.508 mm nozzles (approx. 1000 um droplets) applying 140 l/ha. The addition of the organosilicone surfactant Silwet 408 to the amine formulation gave the same total deposition as the commercial ester formulation, Garlon 4, while enhancing the abaxial retention as a percentage of total deposition. Thus the addition of organosilicone surfactant may have the ability to enhance herbicide uptake via the abaxial leaf surface, and therefore enhance efficacy. Field trial results showed that the alcohol ethoxylate, DA6, is not an essential component of the triclopyr amine / Silwet 408 formulation, in terms of retention. The field trial application was also simulated on sweetgum, using a track-sprayer at the NZ Forest Research Institute Ltd. As in the field trial, the addition of Silwet 408 to triclopyr amine greatly enhanced abaxial retention as a percentage of total deposition, compared to that of Garlon 4. However, the track-sprayer results were very different from the field results, with amounts of adaxial and abaxial retention and total deposition much lower. In agreement with published literature, it was found that the micro-roughness of the leaf surface can be used as a guide to explain adhesion results. The difference among trees in terms of leaf angles appeared to be much less important in explaining retention. / Master of Science

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 84-87). Also available on the World Wide Web.

Chemical pollutants are one of the main threats against biodiversity and chemicals affecting non-target organisms are of great environmental concern. The herbicide triclopyr is commonly used to keep weeds under control and is believed to be weakly toxic to animals and only lethal in high doses. However, the knowledge of possible sub-lethal behavior effects in low doses is scarce. This study investigates whether the wood ant (family Formica) show behavioral changes when exposed to sub-lethal doses of triclopyr. The main hypotheses tested were; i) ants behaving normally show a preference for dark surfaces (i.e. scototaxis); and ii) triclopyr affect this behavior trait among ants. The hypotheses were tested by exposing ants to diets containing 1, 10 and 100 mg/L triclopyr for 24 hours (acute) and 7 days (chronic). To what extent ants preferred the white surface (proportion of frames with the ant visible), their activity (proportion of speed above 1 mm/s) their exploration (proportion area covered) and their average velocities was measured using a newly developed tracking software (ToxTrac). The results clearly show that ants have preference for dark surfaces and thus, that the first hypothesis is valid. However, the second hypothesis appear invalid as the different exposures to triclopyr did not affect the examined behaviors. Based on the results, triclopyr appear to not affect non-target organism such as ants, although possible behavioral effects in other organisms and other behavioral traits cannot be excluded.

A rapid primary herbicide screening experiment was conducted to determine if synergism or antagonism occurs with imazapyr(Arsenal&#174;) plus triclopyr ester (Garlon 4®) and imazapyr plus glyphosate(Accord®) mixtures applied to woody weed seedlings. Using a booth sprayer, 66 herbicide treatments were applied to greenhouse grown black cherry (Prunus serotina), winged elm (Ulmus alata), sweetgum (Liquidambar styraciflua), red maple (Acer rubrum), black locust (Robinia psuedoacacia), loblolly pine (Pinus taeda), water oak (Quercus nigra) and cabbage palmetto (Sabel palmetto). The seedlings were rapidly screened and percent mortality, height and dry weight measurements were obtained five months after treatment. The sweetgum, red maple and black locust experienced unacceptable mortality in the control treatments, and were excluded from further analysis. A determination of synergistic or antagonistic interactions was made using response surface analysis, the nonlinear blending method, the isobologram method, and the Colby method. Imazapyr plus triclopyr ester mixtures were found to be synergistic on black cherry (p < 0.05), with antagonism occurring at high rates of both herbicides. Imazapyr plus triclopyr ester was additive on the remaining species. The imazapyr plus glyphosate mixtures were found to be additive for all tested species. / Master of Science

Two experiments were designed to study efficacy and uptake and translocation of an ester formulation of triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) in four solvents, aromatic solvent, aliphatic solvent, vegetable oil, and kerosene following stem applications to red maple (Acer rubrum), white oak (Quercus alba), and Virginia pine (Pinus virginiana). Another objective was to explore correlations between efficacy and uptake and translocation. Additional objectives included examining the influence of concentration, dose, and stem diameter on efficacy and the influence of bark thickness and season of treatment on uptake and translocation. Concentration ranged from 0.25 to 1 lb a.e./gallon in the efficacy study and was 1 lb a.e./gallon in the uptake study. Dose ranged from 0.4 to 2 ml/cm of stem diameter in the efficacy study and was 0.15 ml/cm of stem diameter in the uptake study. Efficacy evaluations were made 14 months following treatment in June. C¹⁴- triclopyr was used to determine uptake and translocation. Saplings in the uptake study were harvested three weeks following treatments in February, May, and July. Aliphatic solvent, vegetable oil, and kerosene treatments resulted in excellent crown volume control, largely independent of concentration, dose, and stem diameter. Aromatic solvent gave poorer results, dependent on concentration, dose, and stem diameter, except among the maples. Herbicide uptake with the vegetable oil treatment was greatest. The other solvents provided similar levels of uptake. Uptake was greatest among the maples, the thinnest-barked species, and about equal in the oaks and pines. Discrepancies between solvent differences in the efficacy and the uptake studies may have been, in part, a consequence of smaller doses used in the uptake study along with conditions which likely promoted greater solvent evaporation than those under which the efficacy study was performed. Faster evaporation of the kerosene and aliphatic solvents may have reduced their penetration of the outer bark while slower evaporation of aromatic solvent and vegetable oil likely had less influence on their penetration. Stem diameter correlated negatively with crown volume control, despite basing dose on stem diameter, suggesting that the square of diameter, or stem volume, may be a more appropriate basis for determining doses. Uptake correlated negatively with bark thickness. Uptake did not vary significantly among seasons but translocation did. Movement to the leaves occurred following the May and July treatment but virtually none to leaves or buds following the February treatment. The high degree of sprouting which occurred among saplings in the May treatment compared with none among saplings in the July treatment would suggest that downward translocation of herbicide was greater in July. / Master of Science

Atualmente, com o aumento no número de estudos sobre invasões biológicas, sabemos como ocorre o processo, suas causas e conseqüências. A prevenção ainda é a melhor maneira de limitar e diminuir o aumento no número de problemas associados às espécies exóticas e invasoras biológicas. A jaqueira, Artocarpus heterophyllus Lamk. (Moraceae), é uma espécie exótica invasora que foi introduzida no Brasil no período colonial. A principal estratégia de controle de A. heterophyllus tem sido o método mecânico conhecido como anelamento e o arranque de plântulas. Utilizando o Manual da TNC para Controle de Espécies Invasoras, este estudo objetivou propor um novo método de controle da jaqueira, e caracterizar a estrutura populacional da espécie. O estudo foi conduzido na Ilha Grande, localizada no município de Angra dos Reis, RJ, que é coberta por Mata Atlântica em diferentes estágios sucessionais. Testou-se um novo método químico que consistiu na injeção de herbicida Garlon diluído a 4% no tronco de árvores com DAP>15 cm. Ao todo 684 indivíduos distribuídos em 10 parcelas medindo 0,64 ha cada foram encontrados. A densidade media encontrada foi de 107 ind. / ha, com densidades variando entre 3340 ind. / ha, na classe Juvenis 1 (DAP < 5 cm) a 13 ind / ha na classe Adltos 2 (20.1 <DAP> 25.0). A área basal média encontrada foi de 3,692 m / ha. Os resultados mostraram que o método químico foi mais eficiente que o método mecânico. Após 60, 150 e 240 dias do tratamento inicial, os métodos diferiram significativamente. Os resultados demonstram que não há correlação entre a eficiência do método mecânico em relação ao DAP. Entretanto o método químico é dependente do DAP. Os resultados das taxas de mortalidade foram significantes para o tempo de resposta aos 60 dias (p = 0,009), 150 dias (p = 0,039) e 240 dias (p = 0.013), após teste estatístico Kruskal Wallis. As vantagens do método químico em relação ao mecânico são claras, onde menos dinheiro é gasto e mais resultados são gerados. / Currently, with the increasing number of studies on biological invasions, we know how this process occurs, its causes and inherent consequences. Prevention is still the best way to limit and reduce the increasing number of problems associated with exotic and invasive species biology. Jackfruit, Artocarpus heterophyllus Lamk. (Moraceae) is an invasive alien species that was introduced in Brazil during the colonial period. The main strategy for controlling A. heterophyllus has been a mechanical method known as girdling and remove seedlings. Using the Manual for the Nature Conservancy Invasive Species Control, this study aimed at proposing a new control method of jackfruit, and characterize the population structure of the species. The study was conducted in Ilha Grande, located in Angra dos Reis, RJ, which is covered by Atlantic forest in different successional stages. We tested a new chemical method which consisted of injecting herbicide Garlon diluted to 4% into the trunk of trees with DBH> 15 cm. The total of individuals sampled in 10 plots mesuring 0,64 ha each, was 684 plants. The average density was 107 individuals / ha, with densities ranging from 3340 ind / ha on the class Youth 1 (DBH <5) to 13 ind. / ha on class Adults 2 (20.1 <DBH> 25.0). The average basal area was 3,692 m / ha. The results showed that the chemical method was more efficient than the mechanical method. The methods differed significantly after 60, 150 and 240 days of initial treatment. The results show no correlation of the mechanical method to DBH. However, the chemical method is dependent on DBH. The results showed significance with time 60 days (p = 0,009), 150 days (p = 0,039) and 240 days (p = 0.013), after analysis with the statistical test of KruskalWallis. Its now clear what the advantages of the chemical method are when comparing to the mechanical method. Less money is spent and more results are generated.

Atualmente, com o aumento no número de estudos sobre invasões biológicas, sabemos como ocorre o processo, suas causas e conseqüências. A prevenção ainda é a melhor maneira de limitar e diminuir o aumento no número de problemas associados às espécies exóticas e invasoras biológicas. A jaqueira, Artocarpus heterophyllus Lamk. (Moraceae), é uma espécie exótica invasora que foi introduzida no Brasil no período colonial. A principal estratégia de controle de A. heterophyllus tem sido o método mecânico conhecido como anelamento e o arranque de plântulas. Utilizando o Manual da TNC para Controle de Espécies Invasoras, este estudo objetivou propor um novo método de controle da jaqueira, e caracterizar a estrutura populacional da espécie. O estudo foi conduzido na Ilha Grande, localizada no município de Angra dos Reis, RJ, que é coberta por Mata Atlântica em diferentes estágios sucessionais. Testou-se um novo método químico que consistiu na injeção de herbicida Garlon diluído a 4% no tronco de árvores com DAP>15 cm. Ao todo 684 indivíduos distribuídos em 10 parcelas medindo 0,64 ha cada foram encontrados. A densidade media encontrada foi de 107 ind. / ha, com densidades variando entre 3340 ind. / ha, na classe Juvenis 1 (DAP < 5 cm) a 13 ind / ha na classe Adltos 2 (20.1 <DAP> 25.0). A área basal média encontrada foi de 3,692 m / ha. Os resultados mostraram que o método químico foi mais eficiente que o método mecânico. Após 60, 150 e 240 dias do tratamento inicial, os métodos diferiram significativamente. Os resultados demonstram que não há correlação entre a eficiência do método mecânico em relação ao DAP. Entretanto o método químico é dependente do DAP. Os resultados das taxas de mortalidade foram significantes para o tempo de resposta aos 60 dias (p = 0,009), 150 dias (p = 0,039) e 240 dias (p = 0.013), após teste estatístico Kruskal Wallis. As vantagens do método químico em relação ao mecânico são claras, onde menos dinheiro é gasto e mais resultados são gerados. / Currently, with the increasing number of studies on biological invasions, we know how this process occurs, its causes and inherent consequences. Prevention is still the best way to limit and reduce the increasing number of problems associated with exotic and invasive species biology. Jackfruit, Artocarpus heterophyllus Lamk. (Moraceae) is an invasive alien species that was introduced in Brazil during the colonial period. The main strategy for controlling A. heterophyllus has been a mechanical method known as girdling and remove seedlings. Using the Manual for the Nature Conservancy Invasive Species Control, this study aimed at proposing a new control method of jackfruit, and characterize the population structure of the species. The study was conducted in Ilha Grande, located in Angra dos Reis, RJ, which is covered by Atlantic forest in different successional stages. We tested a new chemical method which consisted of injecting herbicide Garlon diluted to 4% into the trunk of trees with DBH> 15 cm. The total of individuals sampled in 10 plots mesuring 0,64 ha each, was 684 plants. The average density was 107 individuals / ha, with densities ranging from 3340 ind / ha on the class Youth 1 (DBH <5) to 13 ind. / ha on class Adults 2 (20.1 <DBH> 25.0). The average basal area was 3,692 m / ha. The results showed that the chemical method was more efficient than the mechanical method. The methods differed significantly after 60, 150 and 240 days of initial treatment. The results show no correlation of the mechanical method to DBH. However, the chemical method is dependent on DBH. The results showed significance with time 60 days (p = 0,009), 150 days (p = 0,039) and 240 days (p = 0.013), after analysis with the statistical test of KruskalWallis. Its now clear what the advantages of the chemical method are when comparing to the mechanical method. Less money is spent and more results are generated.