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Controlled-release fertilizers may improve productivity and mitigate environmental hazards in Southern pine plantations intensively managed for pinestraw harvesting. We examined the effects of pinestraw removal and fertilization with conventional and polymer-coated urea (PCU) on foliar, needlefall, and pinestraw nutrients and yields in a North Florida slash pine (Pinus elliottii Engelm.) plantation. Raking treatments (raked or nonraked) were applied annually in February 2014–2017. Fertilization treatments (PCU at 0, 28, 56, 140, or urea at 56 kg N ha−1 year−1) were applied annually in June 2014–2016. Four years of pinestraw removal did not affect needlefall mass or foliar and needlefall nutrient concentrations. The positive fertilization rate effect on pinestraw yield, needlefall mass, foliar, needlefall, and pinestraw total Kjeldahl nitrogen (TKN) and K concentrations, and on foliar and needlefall Ca concentrations increased in magnitude with subsequent applications. TKN, total P, and K concentrations were lower in needlefall and pinestraw relative to foliage by 65%–90%, whereas Ca concentrations were higher by 120%–180%. Three PCU applications at 140 N ha−1 year−1 increased three-year cumulative pinestraw yield over the control by 19% and TKN, K, Ca, and Mg removals by 49%, 86%, 24%, and 32%, respectively. Responses to PCU did not differ from urea.

Eucalyptus species are grown for fiber, fuel, and other uses on more than 17.8 million ha worldwide, yet some species are considered invasive and may have adverse environmental or social impacts outside their native range. Aminocyclopyrachlor (AMCP) and standard applications of imazapyr and triclopyr herbicides were compared for eucalyptus control using a basal stem application method. At 6 and 12 mo after treatment (MAT), basal stem applications using 5% (vol/vol) AMCP (120 g ae L−1) in methylated soybean oil (MSO) resulted in 97% to 99% eucalyptus crown reduction and generally provided greater control across all diameter classes than standard treatments of 28% imazapyr (240 g ae L−1) or 75% triclopyr ester (480 g ae L−1). AMCP at 5% was as effective as 40% vol/vol. Increases in stem live height at 24 MAT suggest that the effect of triclopyr ester basal stem treatment may be impermanent. AMCP treated trees did not have regrowth by 24 MAT.

Eucalyptus amplifolia and Corymbia torelliana genetic improvement has been conducted in the lower southeastern USA by UF and collaborators since 1980. The collective accomplishments in genetic resources and potential commercial uses are summarized. For example, fast-growing, freeze-resilient E. amplifolia seeds are provided by 1st and 2nd generation seedling seed orchards (SSO) and a 2nd generation clonal seed orchard (CSO), while C. torelliana seed are available from 1st and 2nd generation SSOs. Breeding values (BV) have been developed for guiding the deployment of improved genotypes. Collaborative genetic improvement of these species is ongoing, including testing E. amplifolia in 11 countries and development of hybrid clones. Short Rotation Woody Crop (SRWC) systems may increase productivity and extend uses beyond conventional mulchwood to products such as medium density fiberboard (MDF), biochar, and energywood, while other possible applications include honey production, windbreaks, dendroremediation, and carbon sequestration. C. torelliana may be paired with E. grandis in two-row windbreaks to maximum windbreak effectiveness and may sequester as much carbon as E. grandis.

Pinestraw harvesting is an important industry in the southeastern United States. There is a need to understand how fertilization can be used efficiently to sustain or increase long-term pinestraw yields and avoid adverse environmental consequences. The effects of fertilization on needlefall nutrient concentrations, pinestraw yields, and nutrient removals on soils with contrasting soil nutrient sorption potential (Entisol vs. Ultisol) were compared using two midrotation slash pine plantations in North Florida. Diammonium phosphate was applied at 0, 144, 430, or 718 kg ha–1 in the spring of 2009 and 2010. Pinestraw was harvested annually in 2009–12. Needlefall mass, pinestraw yields, total Kjeldahl nitrogen concentrations in needlefall and pinestraw, and total Kjeldahl nitrogen, P, K, Ca, and Mg removals increased with fertilization. Diammonium phosphate at 718 kg ha–1 year–1 increased pinestraw yield over the control by 37 and 35 percent 2 years after the second fertilization, and by 11 percent (from 21.5 to 23.8 Mg ha–1) and 12 percent (from 25.0 to 28.1 Mg ha–1) over the 4-year control totals, at Entisol and Ultisol sites, respectively. Differences between sites were larger than fertilization response for most variables. Yields, nutrient concentrations, and removals were higher at the more fertile Ultisol than Entisol and, at both sites, higher than most reported in the literature.

Hen’s eyes (Ardisia crenataSims) is a shade-tolerant invasive shrub displacing native understory in forests of the Coastal Plain of the southeastern United States. Few studies have explored herbicide effectiveness onA. crenata, with foliar applications of triclopyr amine or triclopyr ester typically referenced as the standard treatments. This study evaluated efficacy of eight foliar herbicide treatments and a nontreated check at three locations at 12 mo after the first treatment (12MAT1) and 12 mo after the second treatment (12MAT2) on established (greater than 8-cm high) and seedling (less than 8-cm high)A. crenata. Treatments were four triclopyr formulations: amine, ester, choline, and acid (all at 4.04 kg ae ha−1); imazamox (1.12 and 2.24 kg ae ha−1); flumioxazin (0.43 kg ai ha−1); and triclopyr amine plus flumioxazin (4.04 + 0.43 kg ae ha−1). At 12MAT1, triclopyr ester, the high rate of imazamox, and triclopyr acid resulted in greater control of establishedA. crenatathan any other herbicide (68%, 66%, and 64%, respectively). At 12MAT2, all herbicides except flumioxazin resulted in some control ofA. crenata. Triclopyr ester, triclopyr acid, and the high rate of imazamox provided 95%, 93%, and 92% control, respectively. Triclopyr choline did not perform as well as the acid or ester formulations, and the tank mix of flumioxazin and triclopyr amine did not improve control over triclopyr amine alone. This study identified triclopyr acid and imazamox (2.24 kg ae ha−1) as new options forA. crenatacontrol and indicated variation in the performance among the four triclopyr formulations.

Competition control is essential for successful eucalyptus plantation establishment, yet few selective herbicides have been identified. Five herbicides, flumioxazin, imazamox, imazapic, oxyfluorfen, and sulfometuron methyl, were evaluated at either pre- or post-weed emergence timing for selective weed control in the establishment of Eucalyptus benthamii, a frost-tolerant species showing promise for commercial plantations in the southeastern United States and southern Brazil. Herbicides were applied at two or three rates and compared to a non-treated control and to near-complete weed control obtained with repeated glyphosate directed sprays. Herbicides were most efficacious when applied prior to weed emergence, at 2 weeks after planting 16-week-old containerized eucalyptus seedlings. Pre-emergence imazapic treatments resulted in broad-spectrum and persistent weed control, with 77–82% bare-ground at 60 days after treatment, but both pre- and post-emergence applications of imazapic caused excessive eucalyptus injury at the highest rate tested. Imazapic, sulfometuron, and imazamox were most effective for grass control. Both timings of flumioxazin were effective for forb control at the early assessment. All pre-emergence treatments enhanced stem volume compared to the non-treated control, but post-emergence treatments did not, suggesting the need for early weed control to facilitate E. benthamii growth. Pre-emergence applications of medium and high sulfometuron, low imazapic, high imazamox, and high oxyfluorfen rates increased stem volume four-fold to six-fold compared to the non-treated control. Repeated glyphosate directed sprays increased stem volume nearly three-fold compared to the control. These results confirm one early report of flumioxazin effectiveness and identify imazamox and imazapic as new selective herbicides for eucalyptus culture.

The effects of four rates of phosphorus (P) fertilization (0, 0.56, 5.6 and 56.0 mg l−1) in soilless medium on the growth and physiology of mahogany seedlings were examined. The greatest response o...

Changes in land use over the past century have contributed to substantial losses of longleaf pine (Pinus palustris) woodlands in the southeastern USA and replacement with higher density, mixed pine and hardwood stands that suppress understory development and limit application of prescribed fire. To increase understanding of limiting factors and identify potential approaches for restoring longleaf pine woodlands, we studied initial availability of light and soil water and 2-year (2018–2019) plant community responses after controlling overstory hardwoods in five remnant longleaf pine woodlands having no evidence of previous agriculture at the Savannah River Site near Aiken, SC, USA. Seven hardwood control treatments and a non-treated check were compared in a randomized compete block experiment: cutting, cutting + shredding of logging residues, stem injection with imazapyr herbicide, cutting + basal spray with imazapyr herbicide, cutting + basal spray with triclopyr herbicide, cutting + directed foliar spray with a mixture of glyphosate and imazapyr herbicides, and cutting + broadcast foliar spray with the same herbicide mixture. In the year prior to hardwood cutting (2016), understory light availability averaged 23% of full sun. Throughout the year of treatment installation (2017), average soil water content (SWC) was below permanent wilting point (5.5% SWC) where overstory hardwoods were retained; whereas, it was above wilting point (7.5%) where they had been cut. Thus, combined effects of shade and root competition from overstory hardwoods probably limited cover of herbaceous species in the non-treated check. In the 2 years following treatment, hardwood survival averaged > 99%, 62%, 42% and

Pine straw raking and fertilization effects on phosphorus (P) removals, total and mobile P in foliage and straw, and soil extractable P pools, were examined in 15 and 17-year-old slash pine ( Pinus elliottii Engelm.) stands on soils (an Ultisol and an Entisol) with contrasting nutrient sorption potentials and internal drainage. A factorial study of P fertilization (0, 29, 87 kg P ha −1 for two years) and commercial straw raking (no raking vs. annual raking) was used to investigate P removals and changes in total and mobile P pools in foliage, pine needle litter and surface mineral soil. After three years of raking at the Ultisol site, litter in the non-raked plots had approximately 15% more Pi (TCA extractable) than did litter in the raked plots. Raking removed mobile P and broke the P cycle in these stands. Also, pine straw raking depleted extractable soil P, as evidenced by the change in soil P in the surface 10 cm. After five or four raking events, the difference between non-raked and raked treatments ranged from 4 to 11 kg P ha −1 at the two sites. An estimate of the number of rakings that would move the sites’ surface soil into P deficiency, was linked to the soil’s ability to sorb P. These results indicate that Best Management Practices for pine straw raking should include specific P fertilization recommendations to replace depleted soil extractable P, based on raking frequency and the soil sorption capacity.

Cogongrass (Imperata cylindrica (L.) Beauv.) is a warmseason perennial grass species found throughout tropical and sub-tropical regions of the world (Hubbard 1944). Native to Southeast Asia, cogongrass is an aggressive invasive plant that that has spread to all continents except Antarctica (MacDonald 2004) and is considered among the worst problematic weeds on a global scale (Holm et al. 1977). In the United States, it is naturalized in Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Texas, and Oregon (USDA Plants 2017). It was first accidentally introduced in the United States near Mobile Alabama in 1912 (Tabor 1949 and 1952, Dickens 1974) and subsequently intentionally introduced from the Philippines into Mississippi as a forage crop in 1921 (Tabor 1949 and 1952, Patterson et al. 1979, Tanner and Werner 1986). Plants from Mississippi were replanted in Florida for forage and soil stabilization in the 1930s (Tabor 1949, Hall 1983, USDA NISIC 2017), though its high silica and low protein content made cogongrass an inadequate forage crop (Coile and Shilling 1993, Garrity et al. 1993). These early regional introductions contributed to the establishment of cogongrass in the Southeast. Points of introduction, including forage trials, are often areas where cogongrass remains most well established (Willard et al. 1990). Cogongrass is regulated as a federal noxious weed (USDA Plants 2017).

Aminocyclopyrachlor (AMCP) is a pyrimidine carboxylic acid herbicide that is being evaluated for weed control on highway right-of-ways. The goal of this study was to evaluate weed control capabilities and tolerance of desirable turf to AMCP. The objective of the weed efficacy trial was to determine if AMCP (66, 132, and 263 g ai ha−1) was as effective as aminopyralid (18, 53, and 88 g ai ha−1) for controlling two weed species, mat lippia andBidens alba. In 2011, AMCP applied at 132 g ai ha−1resulted in 93% control of mat lippia at 2 mo after treatment (MAT) and 65% control at 3 MAT. In 2012, AMCP at 66 or 132 g ha−1resulted in 93 to 97% control of mat lippia, respectively, at 3 MAT. Aminopyralid, applied POST, never exceed 10% control of mat lippia in 2011 and 60% control in 2012. AMCP, applied POST, at 66 g ha−1, controlled ofB. alba84%, similar to the 89% control seen with aminopyralid at 88 g ha−1. The level of control from AMCP of the two weed species was equal to or greater than aminopyralid. An additional objective was to determine the tolerance of common bermudagrass and ‘Pensacola' bahiagrass to AMCP (66, 132, and 263 g ai ha−1) and imazapic (35 and 70 g ai ha−1) applied alone and in combination. Applications were made in late spring during seedhead initiation. No additional chlorosis was detected when imazapic was applied in combination with AMCP for either turf species. Averaged across imazapic rates, AMCP at 66 and 132 g ha−1, within the suggested rate range (48.5–132 g ai ha−1), did not cause greater than 25% chlorosis at any time. Chlorosis observed for AMCP applied alone and in combination with imazapic was acceptable and decreased to zero by 8 to 10 wk after treatment.

A study was conducted to refine herbicide rates for sequential applications of sulfometuron methyl over newly planted Eucalyptus benthamii seedlings in the Coastal Plain of the southeastern United States. Container-grown, 6-wk-old seedlings were planted in July 2011 on a nonbedded agricultural site in Quincy, FL and on a bedded forestry site in Wing, AL. Treatments included a single sulfometuron application at 13, 26, 39, or 52 g ha−1, 2 wk after planting; sequential applications at the same rates, 2 and 8 wk after planting; and a nontreated check. All sulfometuron treatments provided effective control of all vegetation groups at both sites, with the exception of 13 g ha−1 for forbs in Quincy. Sparse weed cover in Wing was eliminated by any sulfometuron treatment. In Quincy, two applications provided better weed control than a single one, resulting in more bare ground and less grass and vines. Bare ground increased with increasing sulfometuron rate from 0 to 26 g ha−1. The 26 g ha−1 rate resulted in 95 and 88% bare ground 6 and 12 wk after the first application, respectively, compared to 62 and 51%, respectively for the nontreated check. All sulfometuron treatments had a small positive effect on Eucalyptus seedling growth at the Quincy site, resulting in greater stem diameter (6.0 to 6.7 mm) than the nontreated check (5.0 mm), despite slight foliar necrosis. At the Wing site, in addition to slight foliar necrosis, sulfometuron decreased final seedling survival, height, and stem diameter (48 to 68%, 77.8 to 81.6 cm, and 8.7 to 9.2 mm, respectively), compared to the nontreated check (99%, 88.3 cm and 11.2 mm, respectively). Two sulfometuron applications at 13 to 26 g ha−1 provided selective weed control at both sites, but further refinement is needed for various Eucalyptus genotypes, soil, and vegetation types.

To assess the potential invasiveness of common eucalyptus species planted for pulpwood, mulch wood or bioenergy crops, field surveys of eucalyptus seedling recruitment were conducted in north and central Florida locations within seed bearing eucalyptus stands and in the proximate plant communities where seed dispersal may occur. Plant communities included non-grazed pasture, intensively site-prepared forestland, abandoned forest road and upland mixed pine- hardwood forest. No eucalyptus seedlings were found in any of the 310 1-m2 survey plots across the two locations. Second, seed addition studies were conducted to determine the relative potential for seedling emergence and survival among Eucalyptus amplifolia, E. camaldulensis and E. grandis added into plots at two seed densities, under disturbed and nondisturbed conditions, in the understory of the eucalyptus stands and in each of the aforementioned proximate plant communities. Overall, the probability of emergence of added seed was very low (P = 0.0 to 0.0032), and seed density effects were not significant. Emergence was significantly greater in disturbed conditions compared to nondisturbed conditions for seedlings originating from natural seed rain from the eucalyptus canopy in central Florida. The amount of time that seedlings survived was greater for E. camaldulensis compared to the other species but no seedlings survived more than 13 wk. These data indicate that under specific favorable conditions, eucalyptus seedlings may establish within or proximate to planted stands, but the overall level of invasiveness demonstrated by E. amplifolia and E. grandis is low for north or central Florida. The demonstrated role of disturbance in facilitating eucalyptus seedling recruitment suggests that a stable perennial plant community (native grasses) should be established instead of bare soil buffer zones to mitigate spread.

As eucalyptus cultivation increases in the southeastern United States to provide feedstock for pulpwood, landscape mulch and an emerging bioenergy market, there is concern regarding potential invasiveness. Recently, models to predict the likelihood of invasiveness have produced conflicting results. Our uncertainty about invasion risk and the relative values we hold for environmental and industry protection will influence which management options and policies are pursued. Here we synthesize the essential practices and barriers to potential eucalyptus spread relative to different stages of the invasion process. Additionally, we offer a discussion of social and economic implications of the possible policies and regulatory techniques for mitigating future problems, with an emphasis on the often-recommended precautionary approach. We highlight future research needs and emphasize a landscape level, collaborative adaptive management approach.

Tung tree seed produce an oil that is valuable in wood finishing and for various other uses. Development of a later-flowering tung tree cultivar has sparked renewed interest in tung seed as a potential alternative crop for northern and central Florida on sites having relatively well-drained, fertile soils and adequate moisture. This 3-page fact sheet written by Pat Minogue and published by the UF/IFAS School of Forest Resources and Conservation presents a history of tung oil production in Florida and provides the ecology and cultivation of the fast-growing trees. It outlines a plan for additional research to determine whether tung oil could again be produced in Florida. http://edis.ifas.ufl.edu/fr420

Sewage sludge has long been successfully used in the production of nursery plants; however, some restriction may apply due to its high pathogenic characteristics. The process of charring the organic waste significantly reduces that undesired component and may be as effective as the non-charred residue. The aim of this study was to evaluate the effect of sewage sludge biochar on the growth and morphological traits of eucalyptus ( Eucalyptus grandis L.) seedlings, and compare results with those observed when using uncharred sewage sludge. Treatments were arranged in a completely randomized design, in a 2 x 2 factorial scheme, with four replications. Charred and non-charred sewage sludge were tested with and without NPK addition. A control treatment was also evaluated. Ten weeks old eucalyptus seedlings were transferred to the pots and grew for eight weeks. Chlorophyll content, plant height and stem diameter were measured at 0, 30 and 60 days after transplant. Shoot and root biomass were measured after plant harvest. Dickson Quality Index was calculated to evaluate the overall quality of seedlings. Biochar was effective in improving the seedlings quality, and had similar effects as the non-charred waste. Therefore, sewage sludge biochar has the potential to improve the process of production of forest species seedlings and further reduce the environmental risks associated with the use of non-charred sewage sludge. RESUMO: O lodo de esgoto tem sido usado com sucesso há muito tempo na produção de mudas de espécies florestais em viveiro. Contudo, algumas restrições se aplicam devido às suas características patogênicas. O processo de carbonização desse resíduo orgânico reduz significativamente esse componente, resultando num material que pode ser tão efetivo quanto a matéria prima original. O objetivo do estudo foi avaliar o efeito do biocarvão de lodo de esgoto no crescimento e nos parâmetros morfológicos de mudas de eucalipto ( Eucalyptus grandis L.), e comparar os resultados com aqueles observados para as mudas tratadas com lodo de esgoto. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, em esquema fatorial 2 x 2, com quatro repetições. O lodo de esgoto, carbonizado e não carbonizado, foi testado com e sem a adição de adubação NPK. Um tratamento controle foi avaliado também. Mudas de eucalipto com 10 semanas foram transferidas para vasos contendo os tratamentos, onde cresceram por 60 dias. Teor de clorofila, altura da planta e diâmetro do coleto foram avaliados aos 0, 30 e 60 dias. A biomassa da parte aérea e da raiz foi avaliada após a colheita. O índice de qualidade de Dickson foi calculado para avaliar a qualidade geral das mudas. O biocarvão foi eficiente em melhorar a qualidade das mudas e seu efeito foi similar ao do lodo de esgoto. Portanto, esse biocarvão tem o potencial de melhorar o processo de produção de mudas de espécies florestais em viveiro, e pode ainda reduzir os riscos ambientais associados ao uso de lodo de esgoto.

Various progenies of Eucalyptus grandis and E. amplifolia, and clones of Populus deltoides, were evaluated for plant removal of nitrogen (N) and phosphorus (P) for 26 months at a municipal waste spray field in north Florida. Tertiary treated wastewater containing 2.73 mg L(-1) nitrate N and 0.30 mg L(-1) total P was applied using sprinkler irrigation (93.8 m3 ha(-1) d(-1)) to fast growing trees utilized for bioenergy. Eucalyptus amplifolia and E. grandis survived and grew very poorly as the result of severe winter injury in two successive years and were not evaluated for nutrient removal. Survival and growth of P. deltoides demonstrated suitability for phytoremediation, and selected clones were evaluated for biomass and nutrient content. Removals of total N (TN) and total P (TP) were greatest for main stem (36% and 44%, respectively) and foliage (44% and 36%, respectively). Low biomass producing clones generally had higher nutrient concentrations, but high biomass producing clones removed more TN and TP. Approximately 789 kg ha(-1) TN and 103 kg ha(-1) TP were removed by the highest biomass producing P. deltoides clone, representing 215% of N and 615% of P inputs.

Studies were conducted in 2007 and 2008 to evaluate herbicides having both PRE and POST activity for selective weed control in bald cypress plantings. Five herbicides were applied at two or three rates at two different timings. The first timing was to dormant seedlings without foliage and prior to weed emergence (i.e., PRE). The second timing was to foliated seedlings with established weed seedlings present (i.e., POST). Herbicide treatments included aminopyralid at 70 and 120 g ae ha−1, hexazinone at 420 and 560 g ai ha−1, imazapyr at 140 and 210 g ae ha−1, sulfometuron methyl at 110, 160, and 210 g ai ha−1, and flumioxazin at 290 and 430 g ai ha−1. Herbicide rate had little effect on vegetation control. PRE-applied sulfometuron methyl was most effective, providing nearly complete control of graminoids and broadleaves at 60 d after treatment (DAT). POST-applied treatments were generally less effective, though in the 2008 study imazapyr and sulfometuron methyl resulted in approximately 60% bare ground at 60 DAT. Growth of bald cypress seedlings was enhanced by both PRE- and POST-applied sulfometuron methyl, flumioxazin, or hexazinone and by PRE imazapyr. The best bald cypress growth response followed POST-applied sulfometuron methyl at 210 g ha−1, which resulted in 63 cm3mean volume index, more than fivefold greater than the nontreated check. Aminopyralid caused severe and lasting seedling injury. POST-applied imazapyr resulted in fasciculation and no growth benefit, despite providing the most efficacious weed control among POST treatments. Survival and growth of bald cypress can be greatly enhanced with a single selective herbicide treatment using sulfometuron methyl, flumioxazin, or hexazinone applied before or following foliation in the spring.

Kudzu is an invasive perennial climbing vine characterized by fast growth rates and tolerance to control measures. Repeated applications with high rates of 2,4-D plus picloram provide effective kudzu control, but picloram use is not permitted in certain states due to groundwater pollution concerns. Studies were conducted in Alabama and Florida to compare kudzu control with aminocyclopyrachlor, a new herbicide, to control provided by aminopyralid, clopyralid, metsulfuron methyl, and picloram plus 2,4-D, which are common treatments for kudzu management. Two annual applications of the same herbicide treatment were evaluated for effects on kudzu cover, kudzu volume index, and cover of other vegetation. Aminocyclopyrachlor at 140 to 280 g ae ha−1 (2 to 4 oz ae ac−1) was as effective as the standard 4.48 kg ae ha−1 (4 lb ae ac−1) 2,4-D amine plus 1.2 kg ae ha−1 picloram for kudzu control. There were no differences in kudzu control among the three rates of aminocyclopyrachlor tested. Colonization by graminoids, forbs, and Rubus spp. at 2 yr was greatest for herbicides providing the best kudzu control: aminocyclopyrachlor, and 2,4-D plus picloram. Herbicide treatments were more effective in controlling kudzu at the Alabama location, but repeated annual applications for 2 yr did not completely eliminate kudzu with any treatment at either site.

Japanese climbing fern ( Lygodium japonicum ) is an invasive species prevalent through the southeastern United States that grows on, around, and intermingles with native groundcover in a variety of forest ecosystems. Management of this species can be problematic because herbicide control must also ensure minimal impact to native plants, particularly in ecosystems undergoing restoration and recovery from disturbance. We tested 3 herbicides (glyphosate, imazapyr, and metsulfuron methyl) at various rates, alone and in combination, to evaluate their efficacy for fern control and impacts to non-target, native groundcover in a longleaf pine ( Pinus palustris ) ecosystem subject to dormant season burns and hurricane and salvage logging disturbances. All herbicide treatments reduced Japanese climbing fern cover by 77-98% at 1 yr following treatment, but at 2 yr there was considerable re-growth on imazapyr and metsulfuron-methyl treated plots. Glyphosate applied alone as a 2 or 4% solution provided 91-98% fern control after 2 yr, and there was no significant improvement using combinations of glyphosate with other herbicides. Climbing fern cover increased by 70% in the untreated control. We found a significant correlation between reduction in fern cover and increase in other vegetation, though species composition changed minimally. Species richness at 2 yr after treatment increased by 2-3 species following application of glyphosate alone or in combination, and decreased on the untreated control. We recommend directed spray applications using 2% glyphosate solutions for efficient control. Using this approach on matted fern should result in little detriment to native groundcover, even with this broad-spectrum herbicide.

Eucalyptus is a diverse genus with over 700 species, most of which are native to Australia. Numerous Eucalyptus species and hybrid clones have been introduced in temperate climates throughout the world and grown as ornamental trees as well as for fuel and fiber. There is renewed interest in planting this fast-growing tree in the southeastern United States for mulch, pulpwood, and bioenergy. However, several silvicultural challenges exist, and competing vegetation control is a significant one. This 7-page fact sheet was written by Anna Osiecka and Patrick Minogue and published by the UF Department of School of Forest Resources and Conservation, February 2013. http://edis.ifas.ufl.edu/fr378

Absorption and translocation patterns of radio-labelled glyphosate (N-(phosphonomethyl)glycine) were examined in four species of woody plants to determine mechanisms of herbicide tolerance in species common to the southeastern United States. Loblolly pine (Pinustaeda L.) and yaupon (Ilexvomitoria (L.) Ait.), both tolerant to the herbicide, absorbed significantly less glyphosate than did red maple (Acerrubrum L.) or white oak (Quercusalba L.), indicating the importance of foliar absorption as a barrier to glyphosate entry. Although herbicide absorption was similar between the sensitive white oak and the tolerant red maple, white oak accumulated more glyphosate in the roots than did red maple, indicating that translocation patterns also contribute significantly to glyphosate tolerance in some woody species.

Growth response and mortality of loblolly pine were examined 5 or 6 years after broadcast applications of four rates of pellet and liquid (applied as a foliar spray) hexazinone formulations for pine release at seven locations across the South varying in soil characteristics. Adjusted hardwood rootstock density 2 years following treatment was significantly affected by treatment and rate at all locations, and by formulation at five of the seven locations. Pine mortality was positively related to hexazinone rate at four of the study locations. Mortality was significantly higher for the pellet formulation compared to the liquid at the two locations with loamy sand surface soils. Mortality averaged less than 10% for the prescribed rate of both formulations at five of the seven locations, and at a sixth location for the pellet formulation. Mean pine height and dbh responses across hexazinone rates were greater than no treatment (check) at three and five locations, respectively. Response in dbh was positively related to hexazinone rate at three locations, and inversely related to rootstock density 2 years after treatment at six of seven locations. Mean treatment response for pine basal area and total volume (outside bark) per acre were significantly greater than the check at only two locations due to high pine mortality at some locations for 1.4X and 2.0X the prescribed rate. Mean increases in volume of the prescribed rate over the check were 9 and 7% for the pellet and liquid formulations, respectively. Maximum volume production increases across locations were 13% for the pellet formulation and 15% for the liquid formulation. South J. Appl. For. 15(1):54-61.

Vegetation-management practices allocate available resources and provide favorable conditions to promote the growth of desirable species. Animals, chemicals, fire, hand tools, and machinery are used to control interfering vegetation in established pine stands, improving survival, growth, and stand value. Following site preparation, herbaceous plants, shrubs, and vines may interfere with pine stand establishment and early growth to a greater extent than hardwood tree species, whereas hardwoods can most significantly affect pine growth later in the rotation, particularly after the fifth or sixth growing season. Weed community development is a function of the species composition of the previous stand and adjacent areas, environmental conditions, and the timing and intensity of disturbances such as mechanical or chemical site preparation and fire. The magnitude of pine growth response to weed control depends on the nature of interfering vegetation, stand age at treatment, site productivity, and treatment effectiveness. Removing weeds accelerates stand development, yielding more volume in less time. Increases in diameter growth, generally more responsive than height growth to weed control, may shift product classes to favor the more valuable sawtimber and veneer materials. Although nonchemical vegetation management (cultivation, mowing, grazing, and prescribed fire) can be effective, silvicultural herbicide technology is emphasized. Herbicide characteristics, application equipment, worker safety, and prescription of appropriate treatments are discussed relative to current technology for herbaceous plant control, pine release, and timber stand improvement. Understanding the biology of interfering vegetation, stand development, and limitations of weed-control practices should help managers implement effective vegetation managers implement effective vegetation management.

Four growing seasons after aerial applications of glyphosate at 1.0, 1.5 or 2.0 lb ai/ac in a three-year-old loblolly pine (Pinus taeda L.) plantation in late summer, diameter at breast height (dbh) and total height of pines were greater on treated compared to untreated areas. Pines on treated plots averaged 2.5 in. dbh and 15.2 ft in height while pines on untreated plots averaged 1.9 in. dbh and 13.5 ft in height. Height growth curves of treated pines through four growing seasons following treatment. In general, reduction in hardwood density and pine response each increased with increasing glyphosate rate. Relative composition of red maple in the stand increased two years after treatment for all rates of glyphosate, but did not change in the plots without treatment. South. J. Appl. For. 12(1):54-58.

Broadcast applications of hexazinone (3-cyclo- hexyl-6-(dimethylamino)-1-methyl-1,3,5 - triazine- 2,4(1H,3H)- dione) pellets and foliar sprays were tested at four rates for hardwood control and safety to loblolly pine (Pinus taeda L.) at each of eight study locations differing in soil characteristics. Reduction in the number of hardwoods in the stand (hardwood density reduction) was greater with the pellet on soils with more than 60% sand, while the liquid formulation was most efficacious for finely textured soils. Hardwood density reduction with the pellet was negatively correlated with percent silt, clay, soil organic matter, and cation exchange capacity, and positively correlated with percent sand. With foliar sprays, hardwood density reduc- tion was positively correlated with hexazinone rate and negatively correlated with soil pH. Pine mortality was positively correlated to percent sand with the pellet and negatively correlated to soil pH with broadcast sprays. Re- gression models incorporating pine height, herbicide rate, soil texture, cation exchange capacity, soil organic matter, and acidity could explain up to 78% of the variation in hard- wood density change and 77% of the variation in pine mor- tality. Selective control of hardwoods in young loblolly pine stands is a function of hexazinone rate, formulation, and various soil factors. Additional index words. Hardwood control, pine tolerance, soil texture, soil organic matter, soil acidity, cation exchange

The effects of competition on loblolly pine (Pinus taeda L.) development during the initial 4 years of a plantation were investigated on an Upper Coastal Plain site in east-central Alabama. Height and diameter response to competition control in relation to time following treatment and amount of herbaceous competition were examined. Trees on plots receiving broadcast weed control for 2 years were twice the height and diameter of trees with no weed control after 4 years, while trees receiving banded weed control for 2 years were 1.6 times taller and 1.75 times larger in diameter. Broadcast and banded 1-year treatments were 1.4 times larger in both measures.

A 63‐house public authority scheme was chosen to monitor the energy performance of three house types: ‘standard’, ‘well insulated’ and ‘passive solar’, all essentially based on a prize‐winning house design in an EEC competition. However, inadequate space heating — since replaced —vitiated many of the expected energy savings, and in the passive solar design heat losses from the uninsulated south‐facing conservatory largely offset the solar gains. Experience also showed that some form of curtaining should be assumed when considering direct solar gain through windows. The author is a Senior Research Officer at An Foras Forbartha.