Birch foliar responses to simulated acidic fog and Septoria betulae inoculations

2001 ◽  
Vol 31 (3) ◽  
pp. 392-400
Author(s):  
K B Kouterick ◽  
J M Skelly ◽  
S P Pennypacker ◽  
R M Cox
Keyword(s):  
Bay Of Fundy ◽  
Betula Papyrifera ◽  
Mature Trees ◽  
The Past ◽  
Foliar Symptoms ◽  
Foliar Symptom ◽  
Foliar Senescence ◽  
Symptomatic Leaf ◽  
Acidic Fog ◽  
Ph Level

The effects of simulated acidic fog and inoculation with Septoria betulae Pass. on foliar symptom development and foliar senescence of Betula papyrifera Marsh. and Betula cordifolia Regel seedlings were investigated in 1997 and 1998 under greenhouse conditions. An interactive role may exist between acidic fog events and S. betulae in causing birch foliar browning, a disease reported over the past decade to occur on mature trees growing adjacent to the Bay of Fundy, Canada. Seedlings received applications of simulated fog adjusted to pH 3.2, 4.2, and 5.6 or a no-fog treatment. Inoculation treatments at each fog pH level were accomplished through spray atomization with S. betulae conidial suspensions and by placing naturally infected birch leaves bearing pycnidia of the fungus on plastic nets suspended above seedlings in enclosed chambers. Percent symptomatic leaf area of seedlings inoculated with S. betulae was nearly double that recorded for non-inoculated seedlings. Foliar browning resembled symptoms observed on mature trees in the field. Foliar symptoms were observed on non-inoculated seedlings, with greater severities associated with seedlings exposed to the most acidic fog treatment. Leaf senescence was also greatest for spray-inoculated leaves that had been exposed to the pH 3.2 fog treatment. Pycnidial development was not influenced by the pH of the fog treatments but was greater in all fog treatments than in no-fog treatments. Although both acidic fog and S. betulae infection are able to cause symptoms independently, the data suggest that an interactive role may exist in causing birch foliar browning. However, to obtain the same severity of foliar browning as observed on natural forest-grown trees in the Bay of Fundy region, S. betulae must be present.

scholarly journals Exploring the past of Mavrovouni forest in the Pindus Mountain range (Greece) using tree rings of Bosnian pines

Trees ◽  
2021 ◽  
Author(s):  
Anastasia Christopoulou ◽  
Nikolaos M. Fyllas ◽  
Barbara Gmińska-Nowak ◽  
Yasemin Özarslan ◽  
Margarita Arianoutsou ◽  
...  
Keyword(s):  
Fire History ◽  
Ring Width ◽  
Severe Drought ◽  
Mountain Range ◽  
Degree Days ◽  
Mature Trees ◽  
The Past ◽  
Natural Agent ◽  
Fire Ignition ◽  
Animal Grazing

Abstract Key message Long Bosnian pine chronologies from different mountains are shaped by different climatic parameters and can help identify past drought events and reconstruct landscape histories. Abstract We developed a 735-year-long Pinus heldreichii chronology from the southern distribution limit of the species, expanding the available database of long Bosnian pine chronologies. Tree-ring growth was mainly positively correlated with growing degree days (GDD: r1950–2018 = 0.476) while higher temperatures during both winter and growing season also enhanced growth (TWT: r1950–2018 = 0.361 and TGS: 0.289, respectively). Annual precipitation, during both calendar and water years, had a negative but weaker impact on annual tree growth. The newly developed chronology correlates well with chronologies developed from the neighboring mountains. The years with ring width index (RWI) lower than the average were found to correspond to cool years with dry summers. Still, the newly developed chronology was able to capture severe drought events, such as those in 1660, 1687, and 1725. Several old living trees had internal scars presumably caused by fires. Therefore, old mature trees could be used for fire history reconstruction in addition to climate reconstruction. Although the presence of lightning scars indicates an important natural agent of fire ignition, human activities associated with animal grazing could also be an underlying reason for fires in the region.

scholarly journals Occurrence and Distribution of Physiological Races of Exserohilum turcicum in Ontario, Canada

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1450-1457 ◽  
Author(s):  
Krishan K. Jindal ◽  
Albert U. Tenuta ◽  
Tsegaye Woldemariam ◽  
Xiaoyang Zhu ◽  
Dave C. Hooker ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Exserohilum Turcicum ◽  
Corn Hybrids ◽  
Physiological Races ◽  
The Past ◽  
Geographical Regions ◽  
Symptomatic Leaf ◽  
New Races ◽  
Corn Leaf Blight ◽  
Virulence Frequency

Northern corn leaf blight (NCLB) caused by Exserohilum turcicum is the most common and economically significant fungal leaf disease of corn in Ontario, Canada. During the past 10 years in Ontario, severity and incidence of NCLB have increased, possibly owing to the appearance of new races. Several races have been identified in various parts of the world; however, information on occurrence and distribution of races in Ontario is lacking. In the current study, 677 single conidial isolates of E. turcicum were isolated from 687 symptomatic leaf samples collected between 2012 and 2016. These isolates were evaluated for pathogenicity on six corn differential inbreds (A619, A619Ht1, A619Ht2, A619Ht3, A632Htn1, and H102Htm1) under controlled environmental conditions and then grouped into 17 physiological races (0, 1, 2, 3, M, N, 12, 1M, 1N, 3M, 13M, 12N, 13N, 1MN, 12MN, 13MN, 123MN) based on the reaction of the inbreds to infection (resistant or susceptible). Four races (0, 1M, 1N, and 1MN) were most frequent, with an isolation frequency of 13, 10, 12, and 41%, respectively. Seventy-six percent of the isolates were virulent on more than one Ht resistance gene, with 2.4% (16 isolates) virulent on all five Ht resistance genes used in this study. Further analysis of the distribution of races in four regions over the years revealed that the occurrence and distribution of the races changed with time in Ontario. Overall, the frequency of virulence of the 677 isolates screened on the differentials with resistance genes Ht1, Ht2, Ht3, Htm1, and Htn1 varied from 6 to 81% (Ht1 81%, Ht2 6%, Ht3 12%, Htm1 64%, and Htn1 64%). Virulent isolates produced fewer lesions on the Htm1 differential, and smaller lesions that were slower and having less sporulation on the Htn1 differential, compared with infection of the differentials with Ht1, Ht2, and Ht3 resistance genes. Virulence frequency also changed within the four geographical regions of Ontario, with fewer isolates virulent on all resistance genes in eastern Ontario compared with southern and western Ontario. Isolates from southern Ontario had greater virulence frequency against Ht1 and Htm1, whereas isolates from western Ontario were more frequently virulent on Ht1 and Htn1. The information generated in this study on the distribution of E. turcicum races in Ontario corn will help growers to select appropriate hybrids with required resistance genes and will assist seed companies in deploying resistance genes in corn hybrids across the province or within a particular region.

Shoot development in Betula papyrifera. VI. Development of the reproductive structures

1987 ◽  
Vol 65 (3) ◽  
pp. 466-475 ◽  
Author(s):  
Alastair D. Macdonald ◽  
D. H. Mothersill
Keyword(s):  
Male Flower ◽  
Female Flower ◽  
Bud Burst ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Mature Trees ◽  
Male And Female ◽  
Shoot Bud ◽  
Growing Seasons ◽  
Northwestern Ontario

Reproductive buds and developing inflorescences were collected weekly from mature trees during three successive growing seasons in northwestern Ontario. Material was prepared to show all stages of inflorescence and flower development and meiosis. Male inflorescence induction, involving the long-shoot bud apex and one or two proximal axillary apices, occurred in early May, before bud burst. Female induction involved the short-shoot bud apex and occurred in late June – early July. Both male and female partial inflorescences resembled a simple dichasium. The male flower consisted of usually two stamens and two or three tepals variably arranged. Meiosis occurred in late July – early August. Each female flower consisted of two stigmas, two connate tepals that were not noticeable at maturity, and a parietal placenta bearing two unitegmic ovules. Meiosis occurred in mid-June, after pollination in mid-May. It is concluded that developmental data do not help elucidate whether the inferior portion of the gynoecial wall is cauline or appendicular and whether the placenta is derived from axial or carpellary tissue. It is suggested that the trigger(s) evoking male and female inflorescence induction may be different and that the metabolic prerequisites for induction and early development would be supplied by winter-stored material for male development and by current metabolic processes for female development.

scholarly journals FIRST VERIFIED RECORD FOR SHORTNOSE STURGEON, Acipenser brevirostrum LeSueur, 1818, IN MINAS BASIN, BAY OF FUNDY, NOVA SCOTIA, CANADA

2013 ◽  
Vol 47 (2) ◽  
Author(s):  
Michael J. Dadswell ◽  
George Nau ◽  
Michael J.W. Stokesbury
Keyword(s):  
Nova Scotia ◽  
New Record ◽  
Fork Length ◽  
Fish Fauna ◽  
Bay Of Fundy ◽  
Shortnose Sturgeon ◽  
Acipenser Brevirostrum ◽  
The Past ◽  
Photographic Evidence ◽  
Fish Weir

A shortnose sturgeon was caught in fisherman Wayne Linkletter’s intertidal fish weir in Minas Basin near Economy, Nova Scotia, on June 29, 2013. It was an adult, 73.7 cm fork length and weighed ~4.5 kg. Fishers in Minas Basin relate that they have captured shortnose sturgeons in their weirs in the past decade (1 or 2 fish/y) but this is the first sighting verified by photographic evidence. In Canada shortnose sturgeons were previously known only from the Saint John River and Harbour. The new record extends the coastal range of the species by approximately 165 km and is a new addition to the fish fauna of Nova Scotia.

Shoot development in Betula papyrifera. I. Short-shoot organogenesis

1983 ◽  
Vol 61 (12) ◽  
pp. 3049-3065 ◽  
Author(s):  
Alastair D. Macdonald ◽  
D. H. Mothersill
Keyword(s):  
Axillary Buds ◽  
Axillary Bud ◽  
Bud Burst ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Mature Trees ◽  
Shoot Buds ◽  
Female Inflorescence ◽  
Terminal Bud ◽  
Short Shoots

Buds and developing branches of Betula papyrifera were collected weekly from mature trees during three successive growing seasons. Material was prepared to show stages of bud inception, development, and flushing and female inflorescence inception. Short shoots develop from (i) proximal axillary buds on long shoots (ii) short-shoot terminal buds, or (iii) axillary buds on flowering short shoots. An axillary bud apex forms a terminal bud after bud burst. An axillary bud possesses one outer rudimentary leaf, but all other short-shoot buds have three outer rudimentary leaves. All short-shoot buds possess, in addition, one–three embryonic foliage leaves and, distally, three primordial rudimentary leaves which form the outermost appendages of the succeeding terminal bud. Rudimentary leaf stipules form the cataphylls. Foliage leaf primordia are initiated in May – early June and rudimentary leaves arise in late June – July. If a bud apex is initiated in year n, female inflorescence induction occurs in late June of year n + 1 or any succeeding year. An axillary bud develops on a short shoot as a consequence of flowering; it is initiated concurrently with inflorescence development and its development is completed during flowering and seed maturation. Short- and long-shoot buds can be distinguished, upon dissection, in mid-July when buds are forming. Hence, determination of potential long and short shoots occurs the year before bud burst.

The effect of boron supply on the growth and seed production of subterranean clover (Trifolium subterraneum L.)

1987 ◽  
Vol 38 (3) ◽  
pp. 537 ◽  
Author(s):  
BS Dear ◽  
J Lipsett
Keyword(s):  
Seed Yield ◽  
Seed Set ◽  
Acid Soils ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Formation ◽  
The Past ◽  
Foliar Symptoms ◽  
Buried Seed ◽  
Seed Yields

There has been little research on the boron (B) status of subterranean clover, despite strong indications of deficiency of B in southern Australia where clover decline has been reported. This paper describes glasshouse experiments to vary the level of B supply to clover grown on soils low in B. On a soil farmed in a cereal clover rotation, herbage yields of clover increased by 25% with applied B, but seed yields, negligible without B, increased 21-fold. On two other acid soils, from pastures, there were also large responses to B in seed yield (1.5- and 5.1-fold respectively); liming increased the responses (8- and 55.2-fold). However, herbage production was less responsive to B (25% and 1.7-fold with liming); on the unlimed soils, application of B depressed yield (- 1 and -21%). This is attributed to there being enough B to sustain herbage growth, but inadequate for seed formation. These results show that herbage yield, conventionally employed in the past, is not a satisfactory index of B status for total performance in subterranean clover. The response to B in seed yield was associated with increases in: numbers of seed set (75% to 22.6-fold, depending on the particular combination of soil and liming); size of seed (10% to 1.2-fold); proportion of buried seed (20%-70%). It is suggested that these favour establishment and persistence of clover and that clover decline may well involve deficiency of B. It was shown that concentration of B in the plant does not necessarily relate predictably to yield of herbage and that reduction in seed yield may not be heralded by foliar symptoms, since seed requirement exceeds that of herbage.

scholarly journals Current knowledge on Grapevine Trunk Diseases with complex etiology: a systemic approach

2020 ◽  
Vol 59 (1) ◽  
pp. 29-53
Author(s):  
Marion CLAVERIE ◽  
Martin NOTARO ◽  
Florence FONTAINE ◽  
Jacques WERY
Keyword(s):  
Conceptual Model ◽  
Current Knowledge ◽  
Management Strategies ◽  
Symptom Expression ◽  
Grapevine Trunk Diseases ◽  
Foliar Symptoms ◽  
Starting Point ◽  
Foliar Symptom ◽  
Botryosphaeria Dieback ◽  
Trunk Diseases

Among all causes of grapevine decline, Grapevine Trunk Diseases (GTDs) are major concerns for grape growers. This paper reviews knowledge and proposes hypotheses on two major GTDs, esca and Botryosphaeria dieback, and assembles a conceptual model. The objective was to collect information into a sequence, from grapevine nursery propagation processes, through foliar symptom expression, to plant death in mature vineyards. Pathogen infection and colonization steps in woody vine tissues, and the hypotheses that have been formulated to explain the outburst of foliar symptoms, are reported and discussed. Factors that could aggravate or repress GTD symptoms and incidence expansion are also addressed. Vine physiology and pathology together could expand understanding of these diseases. Knowledge and hypotheses that need validation are summarized, and a conceptual model is proposed to explain the occurrence of symptoms and the influencing factors. The model could be useful to cope with the complexity of GTDs, and as a starting point for research to unravel knowledge gaps and suggest new disease management strategies.

scholarly journals Foliar Symptom Expression of Wood Decay in Actinidia deliciosa in Relation to Environmental Factors

Plant Disease ◽  
2008 ◽  
Vol 92 (8) ◽  
pp. 1150-1157 ◽  
Author(s):  
Stefano Di Marco ◽  
Fabio Osti
Keyword(s):  
Wood Decay ◽  
Soil Characteristics ◽  
Annual Incidence ◽  
Actinidia Deliciosa ◽  
Symptom Expression ◽  
Foliar Symptoms ◽  
Foliar Symptom ◽  
Different Types ◽  
Wood Deterioration ◽  
First Time

Kiwifruit vines (Actinidia deliciosa var. deliciosa) have recently been affected by a new form of decay caused by several fungi that produce different types of wood deterioration in the trunk and cordons. Surveys were conducted over a period of 5 years to investigate epidemiological aspects of the disease in a typical Italian growing area (Emilia-Romagna), where kiwifruit is widely cultivated and where the disease was noted for the first time. The disease was widespread over the kiwifruit growing area surveyed, and its incidence increased over the course of the survey. No relationship was found between vineyard soil characteristics or management methods and the annual incidence of symptomatic vines. Foliar symptoms did not consistently express every season even on obviously infected vines. The time of appearance and the development of the disease were correlated with plant phenology and temperature. In particular, from June to August, temperature seemed to affect the annual incidence of the disease in terms of both symptomatic shoots and symptomatic vines. The aspects in common between the decay of kiwifruit and esca of grapevine could be hypothesized and are discussed.

scholarly journals PENGARUH FERMENTASI MENGGUNAKAN BAKTERI ASAM LAKTAT YOGHURT TERHADAP CITARASA KOPI ROBUSTA (COFFEA ROBUSTA)

2018 ◽  
pp. 90-97 ◽  
Author(s):  
Abu Bakar Tawali ◽  
Nurlailah Abdullah ◽  
Benny Suhardi Wiranata
Keyword(s):  
Lactic Acid ◽  
Color Parameter ◽  
Robusta Coffee ◽  
Caffeine Content ◽  
The Past ◽  
Coffee Plants ◽  
Ph Level ◽  
Coffea Robusta ◽  
Caffeine Level

Coffee plants ( coffea sp ) is one type of biodiversity in Indonesia.Coffee is one of the most popular drink in the world.The high caffeine content in coffee has bad effect for health.One kind of coffee used in this research was Robusta, because caffeine content in robusta coffee is higher than arabica coffee, otherwise the type of arabica contain more sugar and volatile oil.To improve the quality of coffee then one of the process that need attention is on the process in the past harvest.One technology in the post harvested to fix tastes coffee is by fermentation using lactic acid bacteria ( BAL ).This research aimed to produce coffee with the caffeine levels lower by fermentation using BAL on yoghurt. Parameter this research include caffeine level, ph level, the water level, the ashes level and testing the like parameter of organolepticflavor, aroma, and colour of the coffee. The best experiment resulting from research coffee fermented with isolate yogurt for 48 hours, it had caffeine content of 1,09 % ,Ph of 4.73, water contentof 2.34, ashes content of 3.16, flavor parameter scored of 3.08, aroma parameter scored of 3, and color parameter scored of 2.09.

scholarly journals Optimum Time for Harvesting Cassava Tubers to Reduce Losses Due to Cassava Brown Streak Disease in Northeastern DRC

2020 ◽  
Vol 12 (5) ◽  
pp. 70
Author(s):  
Honoré Muhindo ◽  
François Wembonyama ◽  
Odette Yengele ◽  
Médard Songbo ◽  
Willy Tata-Hangy ◽  
...  
Keyword(s):  
Negative Relationship ◽  
Harvest Time ◽  
Optimum Time ◽  
Whitefly Population ◽  
Tuber Necrosis ◽  
Foliar Symptoms ◽  
Root Necrosis ◽  
Foliar Symptom ◽  
Cassava Brown Streak Disease ◽  
Brown Streak

The present study aimed to determine the appropriate time to harvest cassava tuberous root which minimize the losses due to cassava brown streak disease (CBSD) in the region of Yangambi, DRC. To achieve the aim of the study, 38 cassava cultivars were evaluated in Yangambi INERA’s Research Center for CBSD in the roots at harvest time between 9 and 13 months after planting (MAP). All the 38 cultivars tested showed CBSD root necrosis symptoms. Foliar symptoms occurred on 37.6% of the evaluated cultivars while CBSD root necrosis varied significantly among cultivars (7.0% to 82.5%) depending on susceptibility and the age of plant. This indicates the differential response of the cultivars to CBSD infection. Whitefly population density decreased with age of cassava, it was of 3 whiteflies per plant (9 MAP) to 1 (10 MAP). We noticed that in older plants, whitefly population decreased from 1 at 11 MAP to none at 13 MAP. Although, some cultivars did not show CBSD symptoms up to 12 MAP, they were not necessarily less attractive to whitefly. Negative relationship (r = -0.08 and r = -0.25) has been found between whitefly number and foliar symptom severity or between whitefly and tuber necrosis severity. Beyond 12 MAP, CBSD necrosis (severity score 4) was present in the tubers of 3 cultivars (EUR/2011/0148, Yafelamonene and Ybi/2011/258). Our study shows that in order to mitigate the losses due to CBSD necrosis, the optimum harvesting time for cassava tubers in Yangambi is 9 MAP.

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