scholarly journals Cold Tolerance of Container-grown Green Ash Trees Is Influenced by Nitrogen Fertilizer Type and Rate

2010 ◽  
Vol 20 (2) ◽  
pp. 292-303 ◽  
Author(s):  
Carolyn F. Scagel ◽  
Richard P. Regan ◽  
Rita Hummel ◽  
Guihong Bi

A study was conducted to determine whether nitrogen (N) application rate and fertilizer form are related to cold tolerance of buds and stems using container-grown ‘Summit’ green ash (Fraxinus pennsylvanica) trees. Trees were grown with different rates of N from either urea formaldehyde (UF) or a controlled-release fertilizer (CRF) containing ammonium nitrate during the 2006 growing season; and growth, N and carbon (C) composition, and cold tolerance were evaluated in Oct. 2006, Dec. 2006, and Feb. 2007 by assessing the lowest survival temperature (LST) of stem and bud tissues on current season (2006) stems. Both fertilizer type and rate influenced the bud and stem LSTs. The influence of fertilizer rate was most evident on midwinter (December) stem LSTs and the influence of fertilizer type was observed in bud and stem LSTs during the deacclimation period in February. Higher LSTs were associated with higher N concentrations and lower C/N ratios; however, stems and buds of trees fertilized with UF were more cold-tolerant (had lower LSTs) than stems and buds on trees fertilized with CRF. Fertilizer type resulted in several differences in N and C translocation and metabolism during the fall and winter. Our results indicate trees with a similar N status are able to withstand different levels of cold depending on the rate of N and the type or form of fertilizer used during production. This may have to do with differences in how trees metabolize the different fertilizer forms, where and when the N is stored, and how it is remobilized in the spring, especially in relation to C metabolism.

2009 ◽  
Vol 141 (1) ◽  
pp. 31-39 ◽  
Author(s):  
M.L. Evenden

AbstractThe ash leaf cone roller, Caloptilia fraxinella (Ely), is a leaf-mining moth that has recently become a significant pest of horticultural ash, Fraxinus L., species in communities throughout the western prairie provinces of Canada. The study examines the spatial and temporal within-host distribution of immature stages of C. fraxinella on green ash, Fraxinus pennsylvanica Marsh. Female C. fraxinella showed a preference for oviposition sites in the lower canopy and on the south side of the tree at the beginning and middle of the 3-week oviposition period, respectively, but no preference at the end of the period. Oviposition was constrained temporally and occurred mainly just after green ash bud flush. Immature stages were sampled throughout the growing season, and measured widths of larval head capsules showed five instars. Fourth-instar larvae disperse from the mined leaflet to a new leaflet, roll it into a cone, and pupate. Neither canopy height nor ordinal direction affected the position of larvae in the canopy, but numbers of immature stages varied by tree within a site. Female and male moths eclose from rolled leaf cones synchronously throughout the emergence period. The study provides some of the basic biological information required to design an integrated pest management program to target this emerging pest of horticultural ash trees.


2010 ◽  
Vol 20 (1) ◽  
pp. 206-212 ◽  
Author(s):  
Carolyn F. Scagel ◽  
Richard P. Regan ◽  
Guihong Bi

A study was conducted to determine whether the nitrogen (N) status of nursery-grown green ash (Fraxinus pennsylvanica ‘Summit’) trees in the autumn is related to bud necrosis during the following spring. In 2005, different rates of N from urea formaldehyde (UF) or a controlled-release fertilizer (CRF) containing ammonium nitrate were applied during the growing season to green ash trees and leaves were sprayed or not with urea in the autumn. Biomass and N content was determined in Autumn 2005 and Spring 2006, and stem biomass and bud necrosis were evaluated for necrosis in Spring 2006. Trees with low N content in Autumn 2005 grew less in Spring 2006 but bud necrosis was more prevalent on trees grown at the highest N rate. Compared with trees grown with a similar amount of N from UF, growing trees with CRF altered N allocation in 2005 and the relationship between carbon (C) and N dynamics (import, export, and metabolism) in stems in 2006. Additionally, trees grown with CRF had less total shoot biomass in Spring 2006 and more bud failure than trees grown with a similar N rate from UF. Significant relationships between bud failure and N status and C/N ratios in different tissues suggest that a combination of tree N status and the balance between N and C in certain tissues plays a role in the occurrence of bud failure of green ash trees in the spring.


2014 ◽  
Vol 12 (3) ◽  
pp. 286-297 ◽  
Author(s):  
Constance E. Hausman ◽  
Michelle M. Bertke ◽  
John F. Jaeger ◽  
Oscar J. Rocha

The USA is experiencing a prolific invasion of the wood-boring emerald ash borer,Agrilus planipennis. Native to Asia, this beetle completes its life cycle on ash trees and results in nearly complete mortality of all infested trees. In the present study, we examined the levels of genetic diversity and differentiation among eight populations ofFraxinus pennsylvanica(green ash) using five polymorphic microsatellite loci. Genetic information was used to design guidelines for the establishment of a seed collection sampling strategy to conserve the genetic diversity of ash trees. We found high levels of genetic diversity, as indicated by the allelic richness, both across the populations (16.4 ± 5.18 alleles per locus) and within them (8.03 ± 1.21 alleles per locus). The expected and observed heterozygosity was also high (0.805 ± 0.38 and 0.908 ± 0.04, respectively), and there was moderate genetic differentiation among the populations (FST= 0.083) with members of these eight populations grouped into three distinct clusters. We examined the relationship between the number of individuals sampled and the number of alleles captured in a random sample taken from a population of 10,000 individuals. Only sample sizes of 100 individuals captured most of the alleles (average = 78.74 alleles), but only seven of 50 samples effectively captured all the 82 alleles. Smaller samples did not capture all alleles. A probabilistic model was used to determine an optimal sampling strategy, and it was concluded that a collection of 200 seeds from each of five mother trees would have the highest likelihood of capturing all alleles in a population.


2011 ◽  
Vol 28 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Toby R. Petrice ◽  
Robert A. Haack

Abstract Efforts to eradicate or slow the spread of emerald ash borer (EAB) (Agrilus planipennis Fairmaire [Coleoptera: Buprestidae]) include cutting infested and nearby uninfested ash (Fraxinus spp.) trees. However, ash trees readily sprout after they have been cut, providing potential host material for EAB. In 2004–2005, we conducted studies to determine how different cutting times (midspring, late spring, and late summer), different cutting heights (0–5, 10–15, and 20–25 cm above the ground), and triclopyr (44% active ingredient) stump treatment of green ash (Fraxinus pennsylvanica Marsh.) trees affected subsequent stump sprouting and colonization by EAB. We also cut white ash (Fraxinus americana L.) and black ash (Fraxinus nigra Marsh.) trees 20–25 cm above the ground in late spring. Some stumps of each ash species tested sprouted and were colonized by EAB. All green ash stumps treated with triclopyr died and were not colonized by EAB. Stump sprouting was significantly lower for stumps cut in late spring compared with stumps cut in midspring or late summer. Stump sprouting did not vary significantly among cutting heights. None of the green ash stumps cut in midspring or cut 0–5 cm above the ground were colonized by EAB; however, the frequency of stump colonization by EAB did not vary significantly among cutting times or cutting heights.


2010 ◽  
Vol 36 (5) ◽  
pp. 206-211
Author(s):  
David Smitley ◽  
Joseph Doccola ◽  
David Cox

Green ash (Fraxinus pennsylvanica Marsh.) street trees ranging in size from 25 to 45 cm dbh were trunk injected with emamectin benzoate at rates of 0.10–0.60 g ai/2.54 cm dbh at three Michigan, U.S., locations in 2005 or 2006. Tree health was monitored by annual canopy thinning and dieback ratings for up to four years after a single treatment. Branch samples were collected in the autumn and the bark removed to count emerald ash borer larvae for most treatments over the same period of time. A single trunk injection treatment of emamectin benzoate at the 0.1, 0.2, or 0.4 g ai rate gave 100% control of emerald ash borer larvae in 98 of 99 treated trees for 2–3 years. Canopy ratings for treated trees remained similar for 2–4 years following trunk injection, while >50% of the control trees died during the same period of time. Ash trees that received a combination of an imidacloprid trunk injection and an imidacloprid basal drench or an annual imidacloprid basal drench had similar canopy ratings, but more larvae were found in branches from trees receiving the annual basal drench.


2014 ◽  
Vol 44 (7) ◽  
pp. 768-776 ◽  
Author(s):  
Stephen J. Burr ◽  
Deborah G. McCullough

Assessing emerald ash borer (Agrilus planipennis Fairmaire) impacts in North American forests is essential for projecting future species composition of stands invaded by this phloem-feeding pest. We surveyed all species of overstory trees and regeneration in 2010 and 2011 in 24 forested sites with a major component of green ash (Fraxinus pennsylvanica), representing the Core, Crest, and Cusp of the A. planipennis invasion wave across southern Michigan. By 2011, an average of 78.6% ± 0.10%, 44.8% ± 0.11%, and 19.8% ± 0.07% of overstory ash trees representing 87%, 57%, and 14% of the total ash basal area had been killed in Core, Crest, and Cusp sites, respectively. Green ash seedlings, saplings, and recruits were abundant in all sites, but newly germinated ash seedlings were absent in Core sites and scarce in Crest sites. Canopy gaps resulting from current ash decline and mortality increased available photosynthetically active radiation (PAR) and sapling growth in Crest sites, but PAR was low in Core and Cusp sites. Lateral ingrowth of non-ash overstory trees has largely filled canopy gaps in Core sites, and there was little evidence of green ash recruitment into the overstory. Green ash appears unlikely to persist as a dominant species in forests invaded by A. planipennis.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 579d-579
Author(s):  
Rita L. Hummel ◽  
Richard Regan

Cold hardiness of Fraxinus americana `Autumn Purple', Fraxinus oxycarpa `Raywood' and Fraxinus pennsylvanica `Summit' was measured in laboratory tests. Current season stem growth was collected from trees in Willamette Valley nurseries at 3 to 6 week intervals from November 1994 to February 1995 and from October 1995 to March 1996. Replicated 9-cm stem samples with two buds each were placed in tubes and immersed in an ethylene glycol bath. Samples were nucleated with crushed ice, held overnight at –2°C and then frozen at 3°C/hour. After freezing, samples were thawed overnight, incubated at room temperature and 100% relative humidity for 10 to 14 days, then sample viability was determined by visual browning. A Tk50, the temperature at which 50% tissue injury occurred, was calculated for buds and stems. Buds were generally less hardy than stems. `Raywood' was slower to cold acclimate in the fall and did not become as cold hardy in midwinter as `Summit' and `Autumn Purple'. Cold acclimation and midwinter hardiness of `Summit' and `Autumn Purple' was similar; however, `Summit' deacclimated more rapidly. Between the 11 Dec. 1995 and 9 Jan. 1996 freeze tests, `Summit' stems lost about 9 °C of freeze tolerance. In both the 1995 and 1996 February freeze tests, `Summit' stems were less hardy than `Raywood' stems.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jie Gao ◽  
Tongxin Dou ◽  
Weidi He ◽  
Ou Sheng ◽  
Fangcheng Bi ◽  
...  

Abstract Background Banana is a tropical fruit with a high economic impact worldwide. Cold stress greatly affects the development and production of banana. Results In the present study, we investigated the functions of MaMAPK3 and MaICE1 involved in cold tolerance of banana. The effect of RNAi of MaMAPK3 on Dajiao (Musa spp. ‘Dajiao’; ABB Group) cold tolerance was evaluated. The leaves of the MaMAPK3 RNAi transgenic plants showed wilting and severe necrotic symptoms, while the wide-type (WT) plants remained normal after cold exposure. RNAi of MaMAPK3 significantly changed the expressions of the cold-responsive genes, and the oxidoreductase activity was significantly changed in WT plants, while no changes in transgenic plants were observed. MaICE1 interacted with MaMAPK3, and the expression level of MaICE1 was significantly decreased in MaMAPK3 RNAi transgenic plants. Over-expression of MaICE1 in Cavendish banana (Musa spp. AAA group) indicated that the cold resistance of transgenic plants was superior to that of the WT plants. The POD P7 gene was significantly up-regulated in MaICE1-overexpressing transgenic plants compared with WT plants, and the POD P7 was proved to interact with MaICE1. Conclusions Taken together, our work provided new and solid evidence that MaMAPK3-MaICE1-MaPOD P7 pathway positively improved the cold tolerance in monocotyledon banana, shedding light on molecular breeding for the cold-tolerant banana or other agricultural species.


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