Submitted by PAULO ROBERTO FIDELIS GIANCOTTI null (paulogiancotti@gmail.com) on 2016-01-17T13:09:22Z No. of bitstreams: 1 Tese - Paulo Giancotti.pdf: 604609 bytes, checksum: 5380cd245b316215f5206eef774e7315 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-01-18T16:23:41Z (GMT) No. of bitstreams: 1 giacontti_prf_dr_jabo.pdf: 604609 bytes, checksum: 5380cd245b316215f5206eef774e7315 (MD5) / Made available in DSpace on 2016-01-18T16:23:41Z (GMT). No. of bitstreams: 1 giacontti_prf_dr_jabo.pdf: 604609 bytes, checksum: 5380cd245b316215f5206eef774e7315 (MD5) Previous issue date: 2015-12-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O sorgo sacarino (Sorghum bicolor) é caracterizado por conter elevados teores de açúcares fermentescíveis em seu colmo, sendo considerado atualmente de alto potencial para compor a matriz energética nacional, ao produzir álcool durante a entressafra da cultura da cana-de-açúcar. A interferência das plantas daninhas é um dos fatores de maior importância durante a condução de uma lavoura. Uma vez que pouco tem sido estudado sobre esse tipo de sorgo, especificamente, estudos da interação entre as plantas daninhas e a cultura do sorgo sacarino são muito bem-vindas no desenvolvimento da agricultura energética. Os objetivos do trabalho foram: (I) determinar os períodos de interferência e índices fitossociológicos da comunidade infestante da cultura do sorgo sacarino; (II) analisar o desenvolvimento inicial de sorgo sacarino sob alta infestação de plantas daninhas; (III) estudar o efeito do exsudado do sorgo sacarino em outras espécies de plantas e avaliar o extrato radicular de uma potencial planta estimuladora da produção de sorgoleone pelo sorgo; (IV) avaliar o efeito supressor de restos culturais de sorgo sacarino sobre as plantas daninhas. Para o primeiro objetivo, os tratamentos consistiram de períodos crescentes da cultura em convivência e controle da comunidade infestante, em duas safras; sendo avaliada a biometria e a produção comercial do sorgo sacarino, além da determinação de índices fitossociológicos da comunidade infestante (densidade, dominância e importância relativa das espécies daninhas, além dos índices de diversidade e equitabilidade da comunidade). Em vasos, foi instalado o experimento para avaliar o terceiro objetivo, no qual híbridos de sorgo sacarino foram submetidos à presença de cinco plantas daninhas em alta densidade; sendo avaliadas as características morfofisiológicas do sorgo sacarino e a massa seca acumulada pela cultura e pelas plantas daninhas. Os estudos sobre a alelopatia foram realizados em laboratório, utilizando diferentes metodologias de química analítica, além de bioensaios avaliando a atividade de exsudados de híbridos de sorgo sacarino sobre germinabilidade e o desenvolvimento de plântulas teste e o crescimento de coleóptilo de trigo. No estudo do efeito supressor de restos culturais de sorgo sacarino, este foi comparado, no campo, com outros tipos de coberturas, e avaliada a reinfestação da comunidade infestante por meio de estudos fitossociológicos e a avaliação do banco de sementes do solo. Durante a produção de colmos de sorgo sacarino, a densidade de plantas daninhas foi o fator determinante para a importância das mesmas dentro da comunidade infestante, uma vez que o desenvolvimento e acúmulo de biomassa destas foram suprimidos pela competição estabelecida pela cultura. O sorgo sacarino se mostrou extremamente competitivo no campo, sendo que a interferência das plantas daninhas não acarretou em redução da produtividade da cultura, em duas safras. A supressão das plantas daninhas proporcionada pelos restos culturais da cultura de sorgo sacarino se equiparou a da cobertura de mucuna-cinza, suprimindo as plantas daninhas no campo por, pelo menos, quatro meses, durante a época seca. Em vasos, quatro plantas daninhas tiveram sua massa seca reduzida pela presença de sorgo sacarino, mesmo em reduzida densidade; além disso, o sorgo foi insensível à presença de três espécies daninhas presentes em alta densidade. Os bioensaios não apresentaram o esperado resultado de inibição alelopática do exsudado de sorgo sacarino sobre plantas teste. Devido ao elevado coeficiente de variação, a produção de sorgoleone pelo sorgo submetido ao extrato de A. theophrasti, não apresentou resultados conclusivos. / Sweet sorghum (Sorghum bicolor) is featured by the high level of fermentable sugars present in its stalk. The crop is currently considered of high potential to compose the national energetic system, by producing alcohol during the sugarcane off season. The weed interference is one of the most important factors during a crop management. Because not too much have been studied about sweet sorghum, studies about the interaction between weeds and sweet sorghum crop are very welcome for the development of the bioenergy nationwide. The aim of this research were: (I) determine the periods of weed interference and the phytosociological indexes of the weed community on the sweet sorghum crop; (II) analyze the initial growth of sweet sorghum under high weed infestation; (III) study the effect of the sweet sorghum root exudate in other plant species and also evaluate the root extract of an potential stimulant plant on the production of sorgoleone by sorghum; (IV) evaluate the suppressive effect of sweet sorghum crop residues on weeds. For the first objective, the treatments were composed by increasing periods of weed presence and weed absence at two crop seasons; when it was evaluated the sweet sorghum biometry and yield, besides the determination of phytosociological indexes of the weed community (the relative indexes of density, dominance and importance, and the weed community indexes of diversity and equitability). In pots, it was carried out an assay in order to evaluate the third aim, in which hybrids of sweet sorghum were submitted to the presence of five weed species in higher density. It was evaluated the morphophysiological features of sweet sorghum and the dry mass of both crop and weeds. The studies about allelopathy were carried out in laboratory, using different methods of analytical chemistry. Bioassays was carried out in order to evaluate the activity of exudates of sweet sorghum hybrids on test plants seed germinability and seedling development. In the study of the suppressor effect of sweet sorghum residues, it was compared at field with other cover crops and it was evaluated the reinfestation of the weed community by phytosociological studies and seed soil bank evaluation. During the sweet sorghum crop, the weed density was the determinant factor for the weed importance in the weed community, once the weed development and dry mass accumulation were suppressed by the competition established by the crop. The sweet sorghum showed an extremely competitive behavior on field and the interference of weeds did not cause yield loss, in two crop seasons. The weed suppression provided by the sweet sorghum crop residues was similar to the one provided by Mucuna pruriens, controlling the weeds on field for at least four months, during the dry season. In pots, four weed species had their dry mass reduced by the presence of sweet sorghum, even in lower density of the crop. Besides that, the sweet sorghum was insensitive to the presence of three weed species that were present in higher density. The bioassays didn’t show the expected result of allelopathic inhibition of sweet sorghum exudate on test plants. Due to the high coefficient of variation, the production of sorgoleone by sorghum subjected to root extract of A. theophrasti, did not show conclusive results. / FAPESP: 2012/11464-5

Johnsongrass (Sorghum halepense L.) presents a serious problem in the production of corn and soybeans in Kentucky. Various rates of the thiocarbamates, dinitroanilines, carbamates, amides, ureas, and triazines were used in association with the crops corn (Zea mays L.) and soybeans (Glycine max L.) to determine the degree of suppression on rhizomatous johnsongrass infesting the previously named crops. Suppression was determined by selecting areas within each treated plot, counting the number of culms, then harvesting johnsongrass rhizomes. Dry weights of rhizomes were then determined as a measure of rhizome suppression. Results show that of the various herbicides and rates used, none were significantly different in their degree of rhizome suppression.

Johnsongrass is one of the more limiting factors in soybean production and is the most serious weed problem in the Southeastern United States. Actually, different herbicides are used in johnsongrass control, and still there are new herbicides which are being tested. Two experimental herbicides for johnsongrass control in soybeans are BAS 9052 and S-734. The experiments were conducted in 1980 and 1981 with the objective to evaluate the effectiveness of S-734 alone and in combination with mefluidide and BAS 9052, BAS 9052 applied early or late postemergence, trifluralin, alachlor, and fluchloralin for seedling and rhizome johnsongrass control. In both areas S-734 was applied at 0.8, 1.1, and 1.7 kg/ha, S-734 at rates of 0.8, 1.1, and 1.7 kg/ha was combined with mefluidide at 0.3 kg/ha, S-734 at rates of 1.1 and 1.7 kg/ha was also combined with BAS 9052 at 0.6 kg/ha, BAS 9052 was applied at 0.6, 0.8, and 1.1 kg/ha early or late postemergence. Trifluralin and fluchloralin were applied at rate of 1.1 kg/ha in seedling study and 2.2 kg/ha in rhizome study. Alachlor was applied at rates of 3.4 and 4.5 kg/ha in seedling study. The results of the experiments showed that there were similarities and differences in the response of rhizome and seedling johnsongrass to the treatments. The control of johnsongrass, and the resulting soybean yields, was higher in the seedling area than in the rhizome area. There were no differences among rates of herbicides. Good seedling johnsongrass control was obtained with all treatments although there were differences among herbicides. In 1980 there were differences between BAS 9052 applied early and late postemergence, but there were no differences in 1981. BAS 9052 might be used as a late postemergence application for best seedling johnsongrass control. There were no differences among herbicides on soybean yields. In both years good rhizome johnsongrass control was obtained with BAS 9052 applied early or late postemergence. Poor rhizome johnsongrass control was obtained with S-734, trifluralin, and fluchloralin. High soybean yields were obtained with BAS 9052.

ABSTRACT UNDERSTORY PLANT COMMUNITY STRUCTURE IN FORESTS INVADED BY GARLIC MUSTARD (ALLIARIA PETIOLATA) MAY 2016 JASON ALLEN AYLWARD, B.S., PAUL SMITH’S COLLEGE M.S. UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Kristina Stinson Plant invasions represent a significant threat to the structure and function of natural ecosystems. Garlic mustard (Alliaria petiolata) has been identified as a threat to native communities mostly through small-scale studies and focused experiments. In this in situ observational study I examined the effects of garlic mustard invasion on species composition across multiple sites by comparing plant diversity and composition in invaded and adjacent non-invaded communities. Mean Shannon diversity was higher in invaded compared to non-invaded plots and invasion was associated with greater densities of invasive species such as burning bush (Euonymus alatus), and greater celandine (Chelidonium majus). In ordination space, the sites grouped more closely by geographic region than by invasion status, suggesting that regional environmental variation is important for community structure. My findings indicate that garlic mustard invasion is associated with other invasive plants, and that the understory plant community varies considerably across the region regardless of invasion status. Overall we show that community structure in garlic mustard invaded forest understories is not consistent across the landscape.

Horseweed (Conyza canadensis (L.) Cronq.) is prevalent in Kentucky and can be difficult to control. Research has shown multiple weed control methods to be more sustainable than relying on chemical control alone, so the use of multiple methods for horseweed management was examined in this study. The main objective was to determine best practice(s) to reduce horseweed prior to soybean [Glycine max (L.) Merr.]. Treatments included: fall-planted cover crop [CC; cereal rye (Secale cereale L.) or none], fall-applied herbicide (saflufenacil or none), and spring-applied herbicides (dicamba, 2,4-D ester, or none). We hypothesized horseweed densities would be reduced the most where all factors were combined. Saflufenacil suppressed horseweed densities from application through March, when densities increased due to a lack of competition from other winter weeds. Spring herbicides decreased horseweed densities until soybeans reached V1 in 2017, but in 2018 lost efficacy after CC termination. CC alone resulted in the longest horseweed suppression. The combination of spring herbicides and CC usually reduced horseweed densities to near zero between the CC termination and soybean planting. However, some low densities seen soon after soybean planting could be problematic. Further research must be conducted to determine the best integrated horseweed management system until soybean canopy closure.

Drift is a point of contention with pesticide applications, causing the need to research application methods that provide consistent efficacy while minimizing off-target movement. Experiments were conducted to evaluate eight undiluted herbicides on invasive woody plants, Chinese tallow (Triadica sebifera) and Callery pear (Pyrus calleryana), when applied individual plant treatment (IPT) via hack-and-squirt. Applications of undiluted aminocyclopyrachlor or imazapyr at 1 ml per 7.6 cm of tree diameter at breast height (DBH) made in the spring provided superior control over other herbicides or application timings. CamelBak® hydration reservoirs were evaluated for storage durability with eight undiluted herbicides. A third study was conducted to assess droplet size and distribution of Roadside Inc.’s new sprayer head for driftable fines. All nozzles were evaluated in a wind tunnel and produced droplet sizes above the benchmark for driftable fines (≤150 μm). The spray head also distributed droplets effectively from 2-30 feet from spray origin.

To combat herbicide resistance among weeds, non-herbicide methods of control, such as cover crops, are becoming widely adapted. Experiments were conducted to determine how to effectively establish and manage cover crops in order to suppress tall waterhemp and Italian ryegrass and to assess their overall impact on soybean growth and yield. Various cover crop establishment methods were evaluated, and it was determined that interseeding at the R7 growth stage of soybean was the least effective method for proper cover crop establishment. Biomass data demonstrated that interseeding created the least amountof cover crop biomass, with no differences found among the other establishment methods that included drilling and sowing broadcast. At soybean planting timing, treatments with tillage had greater control of tall waterhemp than those without tillage. Wheat was shown to have the greatest weed suppressive capabilities, largely due to its ability to create high levels of residual biomass. Daikon radish produced the least biomass residue and had the poorest tall waterhemp control. The termination experiment of Elbon rye determined that treatments with rolling could impact soybean emergence and plant height largely due to dense biomass that lay flat onto the soil surface

Eucalyptus globulus is the subject of intense debate in California. Its invasive potential, aggressive growth, reproductive biology, and association with fire make the prediction of spread important in California. Two modeling simulations, Climex and Maxent, will illustrate the distribution and potential growth range of E. globulus in California based on climate and presence. Modeling the potential range of growth will predict invasive spread. The anticipated result is the continued spread of E. globulus in coastal regions with adequate moisture and suitable climate. Predicting the range of E. globulus in California dictates management strategy and is key for preventing further introduction, establishment, and dispersal.

The Guadalupe Nipomo Dunes Complex (GNDC) is located within the California Floristic Province, a biodiversity hotspot characterized by high rates of endemism and exceptional loss of habitat. In 1980, the US Fish and Wildlife Service described the GNDC as, “the most unique and fragile ecosystem in the State of California,” and ranked it first on a list of 49 habitat areas needing state protection. It is the largest coastal dune area in California and it is one of the last remaining, relatively intact ecosystems of its type and size in the western United States. The growing recognition of species decline and the limited number of dollars allocated to conservation and restoration have led to development of new conservation planning software and conservation strategies. Marxan and Zonation were selected for this project due to their worldwide acceptance in biodiversity conservation planning as well as their specialization in identifying priority zones for conservation. This document describes the unique use of conservation planning software to select areas for resource allocation. It outlines the process of selecting conservation targets, the habitats and species important to overall health of an ecosystem, by using the expert involvement approach. Most importantly, this document outlines areas of high biodiversity that will later be used to allocate resources for the preservation and protection of biodiversity within the Guadalupe Nipomo Dunes Complex. Introduced species are the second-leading cause (after habitat degradation/loss), causing or contributing to the decline in species abundance and diversity. Ehrharta calycina Smith has become highly invasive in the coastal dune communities of Central and Southern California and currently holds a “high” CAL-IPC inventory rating, defined as a species with severe ecological impacts on physical processes, plant and animal communities and vegetation structure as well as reproductive biology and other attributes conducive to moderate to high rates of dispersal and establishment. Ehrharta calycina is a prolific seeder and stores its seeds annually in the soil, collecting a substantial seedbank. Little is known about E.calycina outside its native range, as its invasion into California coastal ecosystem is fairly recent. A field experiment in the Guadalupe Nipomo Dunes Complex assessed the contribution of seeds originating from the seedbank as compared to seeds from above ground either dropping from maternal plants or blown in from outside the plots to the establishment of new E. calycina cover. After a nine month perios, new E. calycina cover from both sources was not significantly different. Visible coverage of E. calycina began 77 days (November 24, 2015) after plot installation. After nine months of surveying, coverage reached 19% in the Seedbank Present treatment and 21% in the Seedbank Absent treatment. There was no significant effect associated with the slope and aspect of the experimental locations. This experiment will aid in management of this invasive species by educating land managers to focus on preventing current seed production of established individuals as those sources of seed were as important as those originating in the seedbank. Stimulating germination of seeds from the seedbank with a concomitant management strategy such as herbicide application or physical removal will likely be the most effective methods for dealing with seeds in the seedbank.

Annual grassy weeds are problematic in intensively managed turfgrass systems due to a lack of selective and affordable control options. Four projects were conducted from 2020-2023 to evaluate novel techniques for Annual bluegrass (Poa annua L.), goosegrass (Eleusine indica L. Gaertn.), and smooth crabgrass (Digitaria ischaemum Schreb.) control on golf course putting greens or putting green surrounds. Hybrid bermudagrass Cynodon transvaalensis Burtt. Davy. x dactylon L. Pers.) tolerated cumyluron regardless of application timing, endothall when applied during full dormancy, and methiozolin when applied during mid-transition. Methiozolin half-life in the upper 2-cm of 12 hybrid bermudagrass putting greens was approximately 14 days and was prolonged in similar studies by seven orders of magnitude when herbicide was applied to bare ground compared to adjacent Kentucky bluegrass (Poa pratensis L.) turf. In a study conducted in Alabama, California, Florida, and Virginia, methiozolin at labeled use rates applied biweekly controlled smooth crabgrass >80% in creeping bentgrass (Agrostis stolonifera L.) and hybrid bermudagrass turf. Although similar programs also controlled goosegrass, acceptable control required more applications than are allowed on the product label. Targeted application devices (TAD), such as spot sprayers and dabbers that are used for individual plant treatment of escaped weeds, were tested for uniformity of fluid delivery. Fluid output of dabbing devices was highly variable and dependent on reservoir fill level, reservoir air seal, human user, and contact time, but largely independent of peak force exerted during the dabbing event. These studies suggest that new products are available to improve annual grassy weed control in turfgrass systems, but proper application timing and device calibration is important to achieve best results. / Doctor of Philosophy / Annual grasses are difficult to control in "high-end" golf turf because few herbicides can be safely used near greens and key weeds have become resistant to the most common products. Several new products were tested for safety on hybrid bermudagrass greens. Methiozolin (PoaCure) was safe for use after post-dormancy greenup, endothall was safe when used while turf was still dormant, and cumyluron was safe regardless of application timing. The duration of preemergence weed control with methiozolin is reduced as temperatures increase and in turfgrass compared to bare ground systems. Half of the methiozolin product will dissipate in 14 days or less when applied to hybrid bermudagrass putting greens or Kentucky bluegrass lawns in spring. Methiozolin controlled smooth crabgrass for the entire season in several Southeastern states, but goosegrass control was slightly below acceptable levels when the product was used within annual dose restrictions. Applicators, such as dabbers and spot sprayers, that are used to treat individual plants improve turf safety and reduce chemical cost, but these devices had not been previously tested for uniformity of fluid output. Studies found that these devices can vary in output by several orders of magnitude depending on the type of devices used, the person using the device, and duration of contact with the turf as the user presses a dabbing device over a weed. Within-device errors were equally problematic and governed by the amount of downward pressure exerted by the fluid contained in the device reservoir. For every 10% of fluid capacity added, fluid dispense rate increases approximately 33%. When the air seal of the fluid fill cap is broken, fluid output approximately doubles compared to when this seal is maintained because loss of vacuum increases downward force of the fluid column. These studies suggest that new products are available to improve annual grassy weed control in ornamental turf, but proper application timing and device calibration is important to achieve best results.