STUDIES ON THE EPIDEMIOLOGY OF CROWN BUD ROT OF ALFALFA IN SOUTHERN ALBERTA

1958 ◽  
Vol 36 (2) ◽  
pp. 239-250 ◽  
Author(s):  
E. J. Hawn
Keyword(s):  
Rhizoctonia Solani ◽  
Host Plant ◽  
Growing Season ◽  
Early Spring ◽  
Disease Development ◽  
Winter Dormancy ◽  
The Third ◽  
Southern Alberta ◽  
Soil Temperatures ◽  
Occurrence Of Species

Crown bud rot is widespread in irrigated alfalfa stands in southern Alberta. Rhizoctonia solani Kühn, Fusarium roseum Link sensu Snyder & Hansen, and Ascochyta imperfecta Peck acting alone or in combination produce brown to black lesions on the crown buds of plants in their second and subsequent years of growth. The host plant is most susceptible to the disease in early spring after winter dormancy. Soil temperatures above 16 °C. appear to reduce disease development. Relative occurrence of species isolated from infected buds indicate a succession of fungi. F. roseum is the predominant isolate until the third year of alfalfa growth when its numbers are approximately equalled by R. solani. The latter then decreases in prevalence possibly because of the antibiotic action of saprophytic species of Trichoderma and Penicillium. F. roseum maintains about the same degree of activity throughout the growing season whereas R. solani generally appears most frequently in summer-sampled alfalfa and A. imperfecta in spring samples.

scholarly journals Green-up of Seeded Bermudagrass Cultivars as Influenced by Spring Scalping

2011 ◽  
Vol 21 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Filippo Rimi ◽  
Stefano Macolino ◽  
Bernd Leinauer ◽  
Umberto Ziliotto
Keyword(s):  
Cynodon Dactylon ◽  
Warm Season ◽  
Early Spring ◽  
Late Winter ◽  
Winter Dormancy ◽  
Green Cover ◽  
Mediterranean Countries ◽  
Northeastern Italy ◽  
Soil Temperatures ◽  
The University

Winter dormancy is the main impediment to a wide acceptance of warm-season turfgrasses in the Mediterranean countries of Europe due to a loss of color during the winter months. Scalping during late winter or early spring has been recommended anecdotally to enhance spring green-up of bermudagrass (Cynodon dactylon); however, information is lacking on the effectiveness of this practice. A study was conducted to investigate the effects of spring scalping on spring green-up of eight bermudagrass cultivars (Barbados, Contessa, La Paloma, Mohawk, NuMex Sahara, Princess-77, SR 9554, and Yukon) grown in a transition zone environment. The trial was carried out in Spring of 2009 and 2010 on plots established in July 2005 at the experimental farm of the University of Padova (northeastern Italy). Half of the plots for each cultivar were subjected to spring scalping, which was applied in both years on 13 Mar. with a rotary mower set at a height of 28 mm. Soil temperatures were recorded hourly during the research period at a depth of 2.5 cm. The percentage of green cover was estimated weekly from 0 to 98 days after spring scalping (DASS). Soil temperatures in scalped plots were greater than in unscalped plots. Among the cultivars tested, ‘Yukon’ showed earliest spring green-up, with no difference between the scalping treatments, reaching 80% green cover by the end of April. For all other cultivars, scalped plots reached 80% green cover 10 to 18 days earlier than unscalped plots. Results showed that scalping enhanced spring green-up, primarily for cultivars that recover slowly from winter dormancy.

In field survival of Rhizoctonia solani in soil and in diseased sugarbeets

1976 ◽  
Vol 22 (7) ◽  
pp. 983-988 ◽  
Author(s):  
Leonard J. Herr
Keyword(s):  
Rhizoctonia Solani ◽  
Sandy Loam ◽  
Soil Surface ◽  
Growing Season ◽  
Early Spring ◽  
Inoculum Density ◽  
Silty Clay ◽  
Loam Soil ◽  
Low Levels ◽  
Silty Clay Soil

Persistence of Rhizoctonia solani in the field was investigated by ascertaining survival (competitive saprophytic activity) in soil and survival in diseased plants. Except for one instance, low levels of R. solani survived overwinter in artificially and naturally infested soils. In a sandy loam soil, cropped to sugarbeets, inoculum density increased throughout the growing season from low early spring levels to high levels in July and August. In a silty clay soil, cropped to sugarbeets, inoculum density remained low with only a slight increase throughout the growing season. Survival of R. solani in diseased sugarbeets placed on the soil surface was greater than survival in diseased beets buried in soil. Little reduction in percentages of beets yielding R. solani colonies took place from November to April in either buried or unburied beets. The major reduction in survival of R. solani in buried beets occurred during the 6-week interval from April to June.

Periods of Flight and Oviposition of the Cabbage Maggot, Hylemya brassicae (Bouché) (Diptera: Anthomyiidae), in Southern Alberta

1958 ◽  
Vol 90 (7) ◽  
pp. 434-435 ◽  
Author(s):  
G. E. Swailes
Keyword(s):  
Growing Season ◽  
Early Spring ◽  
High Quality ◽  
Southern Alberta ◽  
Main Factors ◽  
Hylemya Brassicae ◽  
Cabbage Maggot

The cabbage maggot, Hylemya brassicae (Bouché), is one of the main factors limiting the production of high-quality rutabagas, Brassica napobrassica Mill., in the irrigated districts of southern Alberta. This crop is damaged late in its growing season; there is little damage to cruciferous crops in early spring except that occasionally early-transplanted cauliflowers are killed. This suggested the possibility of some change in the cropping practice if the flight and oviposition periods, recorded herein, were accurately known.

scholarly journals 801 PB 103 BIOLOGY OF GRAPE PHYLLOXERA IN OREGON

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 548a-548
Author(s):  
Anne E. Connelly ◽  
Bernadine C. Strik ◽  
Jeffrey Granett ◽  
Glenn Fisher
Keyword(s):  
Vitis Vinifera ◽  
Growing Season ◽  
Wine Grape ◽  
Life Stages ◽  
Grape Phylloxera ◽  
The Third ◽  
Soil Temperatures ◽  
Laboratory Colonies ◽  
Reproductive Rates ◽  
June July

Grape phylloxera (Daktulosphaira vitifoliae Fitch) was studied in three infested, self-rooted, European wine grape (Vitis vinifera L.) vineyards in western Oregon. Bi-weekly sampling of infested roots at two depths (15-30 cm and 30-45 cm) was done during the growing season in 1992 and 1993. Centrifuged laboratory extractions of insects were seperated into life stages and counted. Results indicate hibernants emerged in April/May when soil temperatures varied from 8 to 21°C. Viable eggs were recovered in June/July. Alates and above ground crawlers were found on sticky trunk wraps in July/August. It appears there were three generations of phylloxera with the third being significantly smaller. Replicated laboratory colonies were reared at 5 temperatures (7, 10, 13, 16, 21 °C). Reproductive rates will be contrasted with field populations.

Influence of two site preparation treatments on ecophysiology of planted Piceaengelmannii × glauca seedlings

1989 ◽  
Vol 19 (11) ◽  
pp. 1359-1370 ◽  
Author(s):  
John H. Bassman
Keyword(s):  
Water Stress ◽  
Root Growth ◽  
Soil Water ◽  
Soil Water Potential ◽  
Growing Season ◽  
Growth Patterns ◽  
Positive Effects ◽  
The Third ◽  
Soil Scarification ◽  
Soil Temperatures

The effects of mounding and soil scarification on microclimate, water relations, photosynthesis, and growth of planted Piceaengelmannii × glauca seedlings were evaluated over three growing seasons. Mounding increased soil temperatures by up to 40% at depths of 5 and 12 cm, but not at 30 cm, during periods of dry, clear weather. Scarification resulted in small increases in soil temperature only at the 5 cm depth. Soil water potential and soil water content were lower in mounds, but similar in scarified patches and controls from midsummer through fall. Transpiration, leaf conductance, and xylem pressure potentials were generally reduced by mounding and to a much lesser extent by scarification compared with controls. However, these responses were complicated by interactions with leaf to air vapor density differences and possibly by soil temperatures. Treatments had no significant effects on diurnal or light responses of photosynthesis. Mounding increased stem and needle weights during the first one-half of the growing season in the first 2 years after planting, but growth was reduced later in the season, probably as a result of increased water stress. Root growth in mounds was significantly greater than scarified patches and controls in all 3 years. Growth patterns for seedlings planted in scarified patches and control treatments were similar to each other. By the end of the third growing season after planting, seedlings in mound treatments had greater stem diameters and total seedling weight was more than double that of controls, but there was little difference in height. Seedlings in scarified patches were similar to controls in diameter and height, but had slightly greater total weights. Results suggest that the positive effects of improved soil temperatures and root growth in mound treatments were negated to a large extent by increased water stress in the first two seasons. By the third growing season, roots were beyond significant drying influence of the mound and their greater length and mass served to increase seedling biomass substantially.

The rediscovery of the Southern Swallowtail (Papilio alexanor Esper, 1799) in Bosnia & Herzegovina after 50 years of absence

2019 ◽  
Vol 70 (1) ◽  
pp. 27-30
Author(s):  
Toni Koren ◽  
Matea Martinović
Keyword(s):  
Host Plant ◽  
Bosnia And Herzegovina ◽  
Recent Observation ◽  
Conservation Status ◽  
Red List ◽  
Historical Records ◽  
Limited Extent ◽  
Current Conservation ◽  
The Third ◽  
Larval Host

The caterpillars of the Southern Swallowtail, Papilio alexanor have been recorded in the vicinity of Trebinje, Bosnia & Herzegovina. This is the first recent observation of this species in the country and the third observation so far. Opopanax chironium is confirmed as the larval host plant in Bosnia and Herzegovina, which was expected due to the recent observations from Croatia. Its status and distribution in the country are still not clear, and further surveys are recommended in order to reconfirm the historical records as well as to assess its current conservation status. Due to the limited extent of its occurrence, we propose to include it in the Red list of fauna of Bosnia & Herzegovina as Vulnerable (VU).

Effect of the Stages of Floral Development and Postharvest Temperatures to Flowering of Eremurus in Israel

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 536d-536
Author(s):  
Rina Kamenetsky
Keyword(s):  
Morphological Analysis ◽  
Developmental Disorder ◽  
Floral Development ◽  
The Third ◽  
Initial Stage ◽  
Floral Differentiation ◽  
Soil Temperatures ◽  
Very High ◽  
Development Application ◽  
Flowering Process

The influence of postharvest temperature on the flowering response of Eremurus was studied. The plants were harvested at four different stages of development and were separated into three groups. The first group was immediately exposed to 2 °C, the second group to 20 °C followed by 2 °C, and the third group to 20 °C followed by 32 °C and, subsequently, 2 °C. Scanning electron microscopy (SEM) was used for concurrent morphological analysis of floral development. Application of 2 °C to the plants in the initial stage of floral development caused plant destruction and death, while the same treatment applied at the stage of full differentiation promoted normal flowering. Temperatures of 20 °C and, especially, 32 °C, significantly improved flowering of the plants harvested in the early stages of florogenesis, whereas the same treatment applied to the plants harvested at the end of flower differentiation did not affect the flowering process. A developmental disorder, which we term “Interrupted Floral Development” (IFD), was observed only in the plants harvested when the racemes were fully differentiated. This was probably caused by the very high air and soil temperatures that prevail in Israel during the summer. The extent of floral differentiation has a determinant role in subsequent scape elongation and flowering.

scholarly journals Fire, land cover, and temperature drivers of bat activity in winter

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Marcelo H. Jorge ◽  
Sara E. Sweeten ◽  
Michael C. True ◽  
Samuel R. Freeze ◽  
Michael J. Cherry ◽  
...  
Keyword(s):  
Land Cover ◽  
Habitat Management ◽  
Deciduous Forest ◽  
Pinus Palustris ◽  
Growing Season ◽  
Early Spring ◽  
Bat Activity ◽  
White Nose Syndrome ◽  
Dormant Season ◽  
Wind Energy Development

Abstract Background Understanding the effects of disturbance events, land cover, and weather on wildlife activity is fundamental to wildlife management. Currently, in North America, bats are of high conservation concern due to white-nose syndrome and wind-energy development impact, but the role of fire as a potential additional stressor has received less focus. Although limited, the vast majority of research on bats and fire in the southeastern United States has been conducted during the growing season, thereby creating data gaps for bats in the region relative to overwintering conditions, particularly for non-hibernating species. The longleaf pine (Pinus palustris Mill.) ecosystem is an archetypal fire-mediated ecosystem that has been the focus of landscape-level restoration in the Southeast. Although historically fires predominately occurred during the growing season in these systems, dormant-season fire is more widely utilized for easier application and control as a means of habitat management in the region. To assess the impacts of fire and environmental factors on bat activity on Camp Blanding Joint Training Center (CB) in northern Florida, USA, we deployed 34 acoustic detectors across CB and recorded data from 26 February to 3 April 2019, and from 10 December 2019 to 14 January 2020. Results We identified eight bat species native to the region as present at CB. Bat activity was related to the proximity of mesic habitats as well as the presence of pine or deciduous forest types, depending on species morphology (i.e., body size, wing-loading, and echolocation call frequency). Activity for all bat species was influenced positively by either time since fire or mean fire return interval. Conclusion Overall, our results suggested that fire use provides a diverse landscape pattern at CB that maintains mesic, deciduous habitat within the larger pine forest matrix, thereby supporting the diverse bat community at CB during the dormant season and early spring.

scholarly journals In vitro analysis of host plant specificity in Rhizoctonia solani

1997 ◽  
Vol 46 (5) ◽  
pp. 659-669 ◽  
Author(s):  
J. KEIJER ◽  
M. G. KORSMAN ◽  
A. M. DULLEMANS ◽  
P. M. HOUTERMAN ◽  
J. DE BREE ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Host Plant ◽  
Host Plant Specificity ◽  
Vitro Analysis ◽  
In Vitro Analysis

The effects of burning on Festuca hallii in the parklands of central Alberta

1995 ◽  
Vol 73 (6) ◽  
pp. 937-942 ◽  
Author(s):  
Heather Sinton Gerling ◽  
Arthur W. Bailey ◽  
Walter D. Willms
Keyword(s):  
Standing Crop ◽  
Growing Season ◽  
Early Spring ◽  
Leaf Length ◽  
Tiller Number ◽  
Phenological Stages ◽  
University Of Alberta ◽  
Festuca Hallii ◽  
Tiller Density ◽  
The University

The response of Festuca hallii (Vassey) Piper to time of burning was examined on the Festuca–Stipa grasslands of the Aspen Parklands at the University of Alberta Ranch located 150 km southeast of Edmonton, Alberta. Two defoliation treatments (burning and mowing) were examined on five dates in 1978 (8 April, 27 April, 1 June, 31 July, and 18 October), corresponding to different phenological stages of F. hallii. Burning and mowing reduced the standing crop of F. hallii produced in the first growing season after treatment, but tiller densities increased. Defoliation in early spring (8 April) had little effect on the standing crop; apparently the increase in tiller density compensated for the reduction in tiller length. Inflorescence density also increased following burning or mowing from 8 April to 1 June. Soil temperature (3 cm deep) on previously burned or mown sites was greater than on the control the year after treatment. Festuca hallii tolerates single burns at any time of the year, but early spring fires have the greatest benefits by increased tillering and standing crop. Key words: standing crop, tiller number, leaf length, litter, defoliation, mowing.

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