Field and labratory studies were conducted to determine the efficacy of saflufenacil alone and with mixture partners for burndown. Field studies were conducted in 2009 and 2010 to evaluate saflufenacil in mixtures with glyphosate, glufosinate, or paraquat for control of glyphosate-resistant (GR) horseweed prior to planting cotton. Saflufenacil and saflufenacil mixtures were applied 7 days before planting (DBP). Saflufenacil at 25 and 50 g ai ha-1 in mixture with all three non-selective herbicides provided similar GR horseweed control when compared to the current standard of glyphosate plus dicamba. Control of GR horseweed was also not different at the 25 and 50 g ai ha-1 of saflufenacil across all mixtures from the standard of glyphosate plus dicamba. Laboratory studies were initiated to determine the uptake and translocation of saflufenacil alone and when mixed with glyphosate and paraquat. It was found that glyphosate plus saflufenacil had a greater absorption of saflufenacil at 2 and 8 HAT. By 24 HAT there were not any differences between the amount of saflufenacil absorbed into GR horseweed between treatments. Translocation data also confirmed that the majority of saflufenacil stayed in the treated leaf at 72 HAT.

Russian knapweed (Acroptilon repens) is an invasive perennial forb that has become well established in much of the western United States and Canada since the late 1800s. Aminopyralid is a relatively new pyridine carboxylic acid herbicide registered for use on rangelands and has provided excellent control of Russian knapweed in many studies. Research trials were conducted on two adjacent plot sites at Dinosaur National Monument to evaluate the effects of a single spring goat grazing paired with a fall application of aminopyralid at 0, 53, 70, 88, and 105 g ae ha-1 on Russian knapweed control. Russian knapweed density, canopy cover, and biomass were reduced to 0 or near 0 by all rates of aminopyralid, regardless of grazing treatment. Conversely, desirable grass cover and biomass increased at all rates of aminopyralid regardless of grazing treatment. Aminopyralid provided excellent control of Russian knapweed at all rates tested. Desirable perennial grass species have the potential to be injured when growth regulator herbicides are used for broadleaf weed control. Greenhouse trials performed at Utah State University and field trials performed in Logan, UT from 2009&ndash2011 evaluated tolerance and response of six native perennial bunchgrasses to growth regulator herbicides. Grasses used in the study included tall wheatgrass, bluebunch wheatgrass, Great Basin wildrye, Indian ricegrass, big bluegrass, and bottlebrush squirreltail. Two rates each of aminopyralid, aminocyclopyrachlor, and clopyralid were evaluated. Herbicide test rates were based on the labeled rate for control of Russian knapweed and other creeping perennials. Tolerance to herbicides varied among grass species. Petri&ndashdish trials showed reductions in root length by all three herbicides in all six speceis 14 days after treatment (DAT). Shoot length was significantly reduced by both rates of aminopyralid (123 and 246 g ae ha-1) and 280 g ai ha-1 of amincyclopyrachlor. The same species were evaluated in the field and greenhouse in response to postemergence applications of the same herbicides. Of the six grass species tested, &lsquoSherman&rsquo big bluegrass appeared to be highly tolerant to aminopyralid, clopyralid, and aminocyclopyrachlor, and &lsquoMagnar&rsquo Great Basin wildrye and Anatone bluebunch wheatgrass appeared to be the most sensitive to aminopyralid and aminocyclopoyrachlor in both the field and the greenhouse.

Dark tobacco (Nicotiana tabacum L.) has historically been produced usingconventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed effectively and efficiently. With the recent expansion of no-till practices throughout the agricultural community, many crops have had success in producing comparable yields while reducing input costs and saving soil resources. For this experiment, a traditional tobacco transplanter was modified for use in a no-till environment. All modifications were fabricated without using specialty tools and made possible to be removed if desired or necessary. Frame extensions were designed and built to accommodate row cleaners and coulters. Tillage shanks were also added to aid in optimal furrow formation. Double-disc opening shoes replaced the original round point shoes and the curved edges of the rear drive wheels were removed, creating a flat surface to increase soil contact. Experimental no-till plots in fescue sod and soybean chaff residues were conducted alongside conventional tillage plots at the Western Kentucky University Agricultural Research and Education Complex in summer 2011. Five treatments, one conventionally tilled (Conv) and four no-till, were replicated three times within a randomized complete block design and used to determine the efficacy of transplanter modifications (consistency of depth, furrow closure, observed plant damage), survival of the transplants, and the amount of residue displacement. The four no-till treatments utilized different combinations including: coulter, row cleaner and shank (CRS), row cleaner and shank (RS), coulter and shank (CS), and shank only (S). These treatments demonstrated the functionality of each combination in comparison to conventional treatments. No treatment performed equally well in both residue locations. Plots in fescue residue utilizing a combination of coulter, row cleaner, shank (CRS), exhibited the lowest amount of root exposure, highest survival rate, and comparable cured weight when compared to conventionally tilled treatments. In soybean residue plots, the treatment operating with row cleaners and shanks (RS) had equivalent amounts of furrow closure to conventionally tilled plots. Pairing specific modification combinations with previous crop residue can provide furrow closure, transplant survival, and cured yield equivalent to conventionally tilled dark tobacco.

Apios priceana is a native endangered species plant found in the Southeast United States. It is characterized as a leguminous species that bears wisteria like clusters with pea like flowers, a large tuberous root and four to six inch long seed pods. It is believed the Native Americans and early European settlers relied on this species as a source of protein and utilized the seeds for cultivation of the tuberous “potato” which formed. Apios priceana contains an average of 13% fiber, 6.9% protein, 71% carbohydrate and 9 of the 11 essential amino acids needed in human diets (Walter et al.,1986). In addition, A. priceanatuberous roots contain anti-carcinogenic properties known to be used to treat prostate and breast cancer as well as lowering blood pressure and cholesterol with an added use for diabetes. If removed from the endangered species list it could prove to be a valuable agronomic crop. Its use spans human and animal consumption, bio fuel, medicinal and horticultural purposes. This research was initiated to investigate a biological symbiosis between A. priceana and known beneficial soil bacteria which may indicate growth potential of known colonies. Experimental treatments were 1) no inoculation 2) Azospirillum brasilense inoculate 3) Bradyrhizobium japonicum inoculate and 4) Rhizobium leguminosarum biovar viceae inoculate. Specimens were evaluated at 30, 60 and 90 day’s growth from emergence for taproot length, number of lateral roots and taproot girth. Due to non-germination of seeds, data presented is for treatments 2 and 3. The correlation coefficient for average taproot length, number of lateral roots developed and taproot girth per treatment was as follows: taproot length to number of lateral roots, positive correlation coefficient 0.996; taproot length to taproot girth, positive correlation coefficient 0.999; and number of lateral roots to taproot girth, positive correlation coefficient 0.991. All correlation coefficients are significant at the 0.01 level.

In the fall of 2011, a study was initiated at the Western Kentucky University Farm in Bowling Green, Kentucky on a Crider silt loam (Typic Paleudalf). The objective of this study was to determine cultivar, mowing height, and herbicide effects on bermudagrass, Cynodon dactylon [L.] Pers., suppression in tall fescue, Schedonorus arundinaceus [Schreb.] Dumort., nom. cons. The experimental design was a split plot design with whole plots consisting of varying mowing heights and split plots consisting of different herbicide treatments with three replications. Two separate experiments were conducted. The tall fescue variety ‘KY 31’ was utilized for one study and the turf type cultivar ‘Bullseye’ was utilized in the other. In the fall of 2011, glyphosate (Roundup Pro) was applied to selected plots at the rate of 0.36 kg ae/ha. ‘KY 31’ and ‘Bullseye’ tall fescues were sown into an existing mixed stand of common and hybrid bermudagrass at 342 kg pls/ha. Mowing heights were maintained at 7.62 cm, 10.16 cm, and 12.70 cm. In the spring of 2012, treatments containing fenoxaprop (Acclaim Extra), mesotrione (Tenacity), and fluazifop (Fusilade II) were applied to selected plots at the rates of 0.07 kg ai/ha, 0.48 kg ai/ha, and 0.24 kg ai/ha respectively. A non-ionic surfactant at 0.25% (v/v) was utilized in treatments containing mesotrione and fluazifop. Three weeks later these treatments were applied a second time. Data were collected visually on turf quality, tall fescue cover, broadleaf weed cover, and bermudagrass cover. The study was repeated in 2012 – 2013. Fluazifop and glyphosate + fluazifop resulted in significantly lower turf quality than all other treatments up until ten weeks after initial treatment. Treatments containing fluazifop significantly reduced tall fescue cover but also significantly suppressed bermudagrass cover the greatest. However, these treatments also resulted in the greatest amount of broadleaf weed cover. High mowing heights may play a role in achieving high turf quality ratings and better broadleaf weed and bermudagrass suppression in forage type tall fescue than in turf type tall fescue.

Increased adoption of compost bedded pack dairy barns (CBP), a relatively new housing and manure handling strategy, warrants study to facilitate proper use of CBP waste as a soil amendment. This study: 1) characterized in situ nutrient content and availability of CBP waste in terms of nitrogen (N) and phosphorus (P); 2) examined the decomposition of surface-applied CBP waste compared to an alternative processed solid waste amendment; 3) examined nutrient dynamics of incorporated CBP waste in high and low soil test phosphorus (STP) environments. Quick anaerobic mineralization assays revealed that bed management affects nutrient content and availability of CBP waste. A Fall surface-applied litter bag study showed that different particle sizes of CBP waste and a biosolid decomposed at similar rates. The biosolid had greater nutrient density and availability, but the decomposition was similar to CBP waste in terms of mineralization dynamics. Aerobic mineralization of CBP waste in high and low STP soils amended on a uniform P basis was compared with fresh manure. In general, CBP increased STP more and yielded more plant available P than fresh manure. These studies provide recommendations for CBP management and further study to ensure the proper land application of CBP waste.

Corn nitrogen (N) applications are still done on a field basis in Kentucky, according to previous crop, soil tillage management and soil drainage. Soil tests, as well as plant analysis for N, are not very useful in making N fertilizer rate recommendations for corn. Recommended rates assume that only 1/3 to 2/3 of applied N is recovered, variability largely due to the strong affect of weather on the release of soil N and fertilizer N fate. Many attempts have been made to apply N in a more precise and efficient way. Two experiments were conducted at Spindeltop, the University of Kentucky’s experimental farm near Lexington, over two years (2010, 2011), using a commercially available active optical sensor (GreanSeekerTM) to compute the normalized difference vegetative index (NDVI), and with this tool/index assess the possibility of early (V4-V6) N deficiency detection, grain yield prediction by NDVI with and without side-dressed N, and determination of the confounding effect of soil background on NDVI measurements. Results indicated that the imposed treatments affected grain yield, leaf N, grain N and grain N removal. Early N deficiency detection was possible with NDVI. The NDVI value tended to saturate in grain yield prediction models. The NDVI was affected by tillage management (residue/soil color background differences), which should be taken into account when using NDVI to predict grain yield. Side-dress N affected NDVI readings taken one week after side-dressing, reducing soil N variability and plant N nutrition. There is room for improvement in the use of this tool in corn N management.

Corn or maize (Zea mays L.) has been grown in North America for many centuries, and an increase in corn production will continue to be needed. Agriculture producers must meet the demands of feeding and providing for an increasing population of people. In order to meet those needs, different production practices are being investigated as a way to increase grain yield. Field plots were conducted across the state of Kentucky in 2011 and 2012 to evaluate the interaction between hybrid, row width, and plant density on corn yield. The primary objectives were to test if 1) narrower rows increase grain yield, 2) higher plant densities increase yield in narrow and twin rows, and 3) the interactions among all factors. Three hybrids were evaluated in three row widths (76, 38 cm or twin) at target densities ranging from 74 000 to 124 000 plants ha-1. Interactions between hybrid, row width, and plant density occurred; however, effects on grain yield and plant physiological characteristics were small and variable across all environments. Plant density had the greatest impact on IPAR and grain yield. Field trials were conducted near Lexington and Princeton, Kentucky in 2011 and 2012 to evaluate the effects of row width on different weed management treatments in corn. The objectives were to 1) evaluate five weed management methods in three row widths (76, 38 cm or twin) and 2) estimate the effect of these practices on corn yield. Herbicides used within each weed management strategy included the residual herbicide S-metholachlor + atrazine (1.4 + 1.8 kg/ha) applied preemergence (PRE) and/or glyphosate (0.86 kg/ha) postemergence (POST). Weed management treatments consisted of a PRE only, PRE followed by POST, POST only, POST + PRE, and an untreated control. Row spacing had little effect on weed suppression and control except for two cases. In general, PRE followed by POST and POST + Residual treatments controlled weeds better compared to PRE only and POST only treatments. Corn yields were higher when a herbicide was used compared to applying no herbicide application. KEYWORDS: Row spacing, Plant Density, Corn Hybrids, Weed Management, Herbicide Application Timing

Reduced tillage and living mulches are alternative management strategies that can improve soil quality by minimizing disturbance and building soil organic matter. Weed suppression by these two practices alone is often insufficient to avoid crop yield losses, but their performance in an integrated system is not well understood. This project investigated the production of bell pepper (Capsicum annuum L.) and dry bean (Phaseolus vulgaris L.) in conventional tillage and strip tillage with a living mulch of teff (Eragrostis tef Zucc.) and Korean lespedeza (Kummerowia stipulacea Maxim.). Yields of pepper and bean were generally higher under conventional tillage without living mulch. Weed biomass was not influenced by tillage, and was adequately suppressed by teff in a year when conditions for teff growth were favorable. Mowing appeared to suppress weed growth but not living mulch growth. Soil nitrate and ammonium concentration was generally higher under conventional tillage without living mulch. Delaying living mulch seeding by 15 days after crop establishment generally did not affect weed suppression or crop yield. Soil aggregate stability was not consistently affected by tillage or living mulch. Increased mowing frequency, living mulch planting delay, or distance between the crop row and the living mulch may be necessary to achieve acceptable yields with living mulches.

Made available in DSpace on 2015-03-26T13:33:50Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1657845 bytes, checksum: 2a422c0161af3961c3d9cf9303297d41 (MD5) Previous issue date: 2012-06-26 / This thesis assumes the existence of different approaches of the extension action by Incaper-ES. To support this statement was defined how purposes to identify and analyze the consequences of the presence of distinct approaches guiding of the extensionist action by Incaper in two main analytical plans, the extensionist action and the organization, evaluating the influences of one exerts on the other. The field research was conducted in two distinct stages. In the first, with 44 extensionists of the four regional administrative centers of the Incaper-ES. In the second stage, a case study in the city of Iconha, trying to understand how the extensionist action occurs in practice, from its involvement in a commercialization network of organic products of family farmers. By the history of the Technical Assistance and Rural Extension (Ater) public state of Espírito Santo we verify that certain approaches are from one way to make extensionist action that were designed together with the own origin of Emater-ES to the Incaper-ES. A theoretical analysis relates the concepts of organization and institution, habitus, identity and socialization, action and structure and agency as builders of a historic social construction of approaches, that makes updates in the extensionist action. With the research it was possible to verify the existence of different ways to perform the extensionist action, allowing finding variables in common, similarities in the way of acting and aggregating these similarities in three types of approaches: Conservative, Humanist and Interactive. It was identified that these approaches have different ways of understanding the Incaper-ES; research & technology; Ater s role in rural development; the role of agribusiness and family farming. In the commercialization network of organic products, distinct extension agents of the Incaper-ES acted at different times, triggering a Conventional approach, and after Interactive. These differents ways that extensionist action works reflected in the network, sometimes as an element of friction, reducing their action and ability to articulate; sometimes as a catalyst, increasing its ability to create bonds of solidarity and cooperation, increasing its range of action. / Nesta dissertação parte-se da premissa que existem diferentes abordagens da ação ex-tensionista do Incaper-ES. Para sustentar esta afirmação definiu-se como objetivo iden-tificar e analisar as consequências da presença de distintas abordagens orientadoras da ação extensionista do Incaper em dois planos analíticos principais: o da ação extensio-nista e o da organização, avaliando as influências que uma exerce sobre a outra. A pes-quisa de campo foi desenvolvida em dois momentos distintos. No primeiro momento, com 44 extensionistas nas quatro regionais administrativas do Incaper-ES; e no segun-do, um estudo de caso, no município de Iconha, procurando compreender como a ação extensionista ocorre na prática, a partir do seu envolvimento em uma rede de comercia-lização de produtos orgânicos dos agricultores familiares. Pela história da Assistência Técnica e Extensão Rural (Ater), pública estatal do Espírito Santo, verificou-se que de-terminadas abordagens são oriundas de uma forma de fazer ação extensionista, que fo-ram concebidas junto com a própria origem da Emater-ES ao Incaper-ES. A análise teórica relaciona os conceitos de organização e instituição, hábitos, identidade e sociali-zação, ação e estruturação e agência como edificadores de uma construção histórico-social das abordagens, que se atualiza na ação extensionista. Com a pesquisa foi possí-vel verificar a existência de diferentes formas de fazer a ação extensionista, o que per-mitiu encontrar variáveis em comuns e semelhanças no modo de atuar, e também agre-gar essas semelhanças em três tipos de abordagens: Conservadora, Humanista e Intera-tiva. Constatou-se que essas abordagens têm formas diferenciadas de compreender o Incaper; a pesquisa e a tecnologia; o papel da Ater no desenvolvimento rural; e o papel do agronegócio e da agricultura familiar. Na rede de comercialização de produtos orgâ-nicos atuaram distintos agentes de extensão do Incaper, em diferentes momentos, acio-nando uma Abordagem Convencional e, depois, Interativa. Essas diferentes formas de atuar da ação extensionista refletiram na rede, ora funcionando como elemento de atrito, diminuindo sua ação e capacidade de articulação, ora como elemento catalisador, au-mentando sua capacidade de criar laços de cooperação e solidariedade, aumentando seu leque de ação.