Paired-tree study suggests 20-year recurrent slash pine blight

1991 ◽  
Vol 21 (7) ◽  
pp. 1145-1148 ◽  
Author(s):  
Paul C. Van Deusen ◽  
Glenn A. Snow
Keyword(s):  
Radial Growth ◽  
Metropolitan Areas ◽  
Gulf Coast ◽  
Slash Pine ◽  
The Other ◽  
Late Winter ◽  
Pair Member ◽  
Growth Loss ◽  
Needle Blight

In the late winter of 1988, pairs of slash pine (Pinuselliottii Engelm.) trees were chosen and marked on the Harrison Experimental Forest in Gulfport, Mississippi. One tree of each pair had a blight and the associated fungi Lophodermellacerina Darker on all mature needles, while the other tree had healthy needles. The blight recurred on the same study trees in 1989 and 1990. Analysis of tree cores shows that the blighted member of each pair has had less radial growth than the clean (nonblighted) pair member since about 1971, when a severe needle blight occurred throughout the slash pine region. It appears that the needle blight is causing growth loss and possibly a genetic narrowing of the slash pine resource. The evidence suggests that the most severe occurrence of the blight is near metropolitan areas of the Gulf Coast.

scholarly journals The Effects of Defoliation by the Larch Casebearer on the Radial Growth of Tamarack

1988 ◽  
Vol 64 (3) ◽  
pp. 190-192 ◽  
Author(s):  
Paul Benoit ◽  
Robert Blais
Keyword(s):  
Key Words ◽  
Radial Growth ◽  
The Other ◽  
Larix Laricina ◽  
Increment Core ◽  
Core Samples ◽  
Coleophora Laricella

Tamarack (Larix laricina [DuRoi] K. Koch) was severely defoliated by the larch casebearer (Coleophora laricella) in most areas of Quebec during 1979 and 1980. Increment core samples were taken in late September 1982 from 20 tamaracks in each of two stands to determine the effect of defoliation on radial growth. In one stand, the trees were 80% defoliated in 1980 and during this year radial growth was reduced by 52%. Growth returned to predefoliation level the following year when the trees were not defoliated. In the other stand, trees were 60% defoliated in 1979 and 70% in 1980. During these years, radial growth was reduced by 48 and 70% respectively. Growth in this stand had not fully returned to predefoliation level two years after the collapse of the infestation. In both stands, variations in defoliation among trees did not exceed 10% of the average. Key Words: Coleophora laricella, larch casebearer, tamarack, larch, defoliation.

Reproduction in the Macropod Marsupial Potorous tridactylus (Kerr).

1962 ◽  
Vol 10 (2) ◽  
pp. 193 ◽  
Author(s):  
RL Hughes
Keyword(s):  
Post Partum ◽  
Cell Types ◽  
Early Spring ◽  
The Other ◽  
Late Winter ◽  
Polymorphonuclear Leucocytes ◽  
Marsupial Species ◽  
Heat Period ◽  
Breeding Seasons ◽  
Made In

Thirty-five female Tasmanian rat-kangaroos, Potorous tridmtylus (Kerr), were studied. This marsupial is both polyoestrous and monovular. The length of the oestrous cycle is approximately 42 days (range 39-44 days). Study of vaginal smears over intervals that included 14 oestrous periods revealed that the proportions of cornified cells reached a maximum of over 80% at oestrus, and conversely the other cell types (i.e. nucleated epithelial cells and polymorphonuclear leucocytes) were at minimal concentrations. In four females copulation was apparently permitted at any time during the period of rapid increase in the proportion of cornified cells. One female repeatedly received a male over a 12-day heat period. Copulations were brief and were observed only between 4.00 p.m. and 1.45 a.m. In two females coitus was found to precede ovulation. The gestation period (defined as the interval between copulation and parturition) varied between 30 and 43 days in four animals. In one instance parturition was witnessed 37.5 days after copulations that were restricted to a 12-hr period. A marked increase in pouch vascularity occurred a few hours prior to parturition. Parturition was witnessed on one occasion and is described. The time taken to reach the pouch was 10 min; attachment was made in a further 12 min. On another occasion a neonatus removed from a teat shortly after parturition took 5 min to locate the teat and a further 15 min to complete reattachment. Permanent attachment of the offspring to a teat occupied 64 days in one instanc; in another it lasted 46 days but as the offspring died 6 days later it may be that the teat was vacated prematurely. The manner in which permanent nipple attachment is achieved is discussed and a description of the development of external features of pouch young is given. Nipples increased in both length and diameter during the first 115 days of suckling, after which regresslon began. The regresslon was correlated wlth the process of weanlng. An indication of three successive lactations was obtained from nipple dimensions. Pregnancy (occupying about 38 days) did not prevent oestrus from appearing at the normal time (i.e. approximately 42 days after the preceding oestrus). Mating occurred at the post-partum oestrus but lactation inhibited further oestrous cycles as well as delaying the development of the resultant uterine embryo. The period of delayed pregnancy can be as long as 4+ months. During most of this period the embryo remained free in the uterus as a dormant blastocyst, diameter 0.25-0.28 mm. Embryonic development was resumed during the weaning period when suckling was intermittent and diminishing or when the offspring was prematurely lost. Observations on both captive and wild populations suggested the existence of two breeding seasons, one in late winter and early spring, the other in summer. However, the evidence on which these breeding seasons are based is extremely limited. Reproduction in Potorous is compared with that in other marsupial species.

Tooth Root Stresses of Helical Gear Pairs With Unequal and Offset Face Widths

2011 ◽  
Author(s):  
Carlos H. Wink
Keyword(s):  
Load Distribution ◽  
Element Model ◽  
Helical Gear ◽  
The Other ◽  
Gear Pair ◽  
Tooth Root ◽  
Pair Member ◽  
Face Width ◽  
The Face ◽  
Root Stress

In this study, tooth root stresses of helical gear pairs with different combinations of face width increase and offsets were analyzed. Contact face width was kept constant. The variables studied were face width and gear faces offset. The well-known LDP – Load Distribution Program was used to calculate tooth root stresses using a finite element model. The results presented show that the face width increase and offset have a significant influence on tooth root stresses. In some cases, increasing face width of one gear pair member resulted in significant increase of tooth root stress of the other member. For gear pairs with unequal and offset face widths, tooth root stresses were mostly affected when face widths were increased to the same direction of the contact line travel direction.

HISTOLOGICAL STUDIES OF SYMPTOMS IN SEMIMATURE-TISSUE NEEDLE BLIGHT OF EASTERN WHITE PINE

1967 ◽  
Vol 45 (1) ◽  
pp. 133-143 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Pinus Strobus ◽  
Pine Needles ◽  
The Other ◽  
White Pine ◽  
Eastern White Pine ◽  
Histological Studies ◽  
Endodermal Cells ◽  
Needle Blight

The incipient symptoms of needle blight of eastern white pine (Pinus strobus L.) appear only in semimature tissues of current year needles, and the orange-red lesions then spread acropetally throughout adjacent, more mature, tissues. Semimature tissue of white pine needles is characterized by the start of the suberization of the radial and transverse walls of the endodermal cells. The first cells to break down in blighted semimature tissue occur in the mesophyll region of one of the ventral faces of the needle. Mesophyll necrosis spreads laterally to the other ventral face and finally to the dorsal face of the needle, before proceeding distally through mature tissue. Anatomical differences exist between needles collected from susceptible and non-susceptible white pines.

Effect of timing of pasture grass removal on subsequent take-all incidence and yield in wheat in southern New South Wales

2002 ◽  
Vol 42 (8) ◽  
pp. 1087 ◽  
Author(s):  
C. R. Kidd ◽  
G. M. Murray ◽  
J. E. Pratley ◽  
A. R. Leys
Keyword(s):  
Grain Yield ◽  
New South ◽  
New South Wales ◽  
The Other ◽  
Gaeumannomyces Graminis ◽  
Wheat Crop ◽  
Late Winter ◽  
Pasture Grass ◽  
South Wales ◽  
Take All

Winter cleaning is the removal of grasses from pasture using selective herbicides applied during winter. We compared the effectiveness of an early (June) and late (July) winter cleaning with an early spring herbicide fallow (September), spring (October) herbicide and no disturbance of the pasture on development of the root disease take-all in the subsequent wheat crop. Experiments were done at 5 sites in the eastern Riverina of New South Wales in 1990 and 1991. The winter clean treatments reduced soil inoculum of Gaeumannomyces graminis var. tritici (Ggt) compared with the other treatments at all sites as measured by a bioassay, with reductions from the undisturbed treatments of 52–79% over 5 sites. The winter clean treatments also significantly reduced the amount of take-all that developed in the subsequent wheat crop by between 52 and 83%. The early and late winter clean treatments increased the number of heads/m2 at 3 and 1 sites, respectively. Dry matter at anthesis was increased by the winter clean treatments at 3 sites. Grain yield was increased by the winter cleaning treatments over the other treatments at the 4 sites harvested, with yield increases of the early winter clean over the undisturbed treatment from 13 to 56%. The autumn bioassay of Ggt was positively correlated with spring take-all and negatively correlated with grain yield of the subsequent wheat crop at each site. However, there was a significant site and site × bioassay interaction so that the autumn bioassay could not be used to predict the amount of take-all that would develop.

scholarly journals Antagonistic Potentiality of Some Soil Fungi Against Six Fungal Pathogens Isolated From Cotton (Gossypium Hirsutum L.) Seeds

2021 ◽  
Vol 46 (2) ◽  
pp. 143-153
Author(s):  
Amina Khatun ◽  
Shamim Shamsi ◽  
Abul Bashar
Keyword(s):  
Gossypium Hirsutum ◽  
Growth Inhibition ◽  
Radial Growth ◽  
Fungal Pathogens ◽  
Soil Fungi ◽  
The Other ◽  
Dual Culture ◽  
Gossypium Hirsutum L ◽  
Volatile Metabolites ◽  
Other Hand

The antagonistic potentials of four soil filamentous fungi viz., Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tieghem and Trichoderma viride Pers. against six pathogens isolated from 14 varieties of cotton (Gossypium hirsutum L.) were evaluated by "dual culture colony interaction”, volatile and non-volatile metabolites. In dual culture colony interaction, out of four soil fungi, T. viride was found be the most effective to control the growth of the cotton pathogens. T. viride showed the highest growth inhibition against Curvularia lunata, Fusarium moniliforme, Mucor sp. and Rhizoctonia solani. On the other hand A. niger showed the highest growth inhibition against Fusarium nivale and A. fumigatus showed the maximum growth inhibition against C. gloeosporioides. The highest inhibition of radial growth of C. lunata, F. nivale and F. moniliforme was observed might be due to the secretion of volatile metabolites of T. viride whereas, the maximum inhibition of radial growth of C. gloeosporioides was observed because of the volatile metabolites of A. flavus. Mucor sp. and R. solani were inhibited due to the volatile metabolites of A. fumigatus. The greatest radial growth inhibition of C. lunata and F. moniliforme were noticed in case of T. viride owing to the effect of non-volatile metabolites. On the other hand, the radial growth of C. gloeosporioides and F. nivale were inhibited highest amount for the effect of non-volatile metabolites of A. niger, whereas highest growth inhibition of Mucor sp. and R. solani was observed due to the non-volatile effect of A. fumigatus. The present investigation suggests that the isolates of Aspergillus and Trichoderma may be further exploited as potential biocontrol agents against the fungal pathogens of cotton in field trial. Asiat. Soc. Bangladesh, Sci. 46(2): 143-153, December 2020

scholarly journals Litterfall and growth in three forests in Montseny massif

2014 ◽  
Author(s):  
Antonia Caritat Compte ◽  
Marina Pi ◽  
Lluís Vilar ◽  
Jordi Bou
Keyword(s):  
Water Availability ◽  
Radial Growth ◽  
Summer Temperature ◽  
The Other ◽  
Mediterranean Species ◽  
Deciduous Species ◽  
Central European ◽  
Accumulated Rainfall ◽  
Strong Gradient ◽  
Positive Effect

The nemoral forests of the montane level are especially interesting, because they are on the edge of their distribution. We want to see the influence of some environmental conditions (temperature and rainfall) on the litterfall and growth, in three kinds of these forests. The Montseny massif in the NE part of Iberian Peninsula, with a maximum altitude of 1.706 m, has a strong gradient of climate and vegetation, from the lowlands to the top of the mountains. We analyze three forests in the Montseny massif, two of them are composed by deciduous species not very extensive in the region (beech and sessile oak) and the other is a Mediterranean species, the mountain holm oak. We recollect data since 2007, monthly litterfall was measured and radial growth, and correlated with the climate of the study area. Our results shows that Fagus sylvatica recorded the biggest drop in annual litterfall (6.3 Mg / ha), followed by Q. ilex (5.3 Mg / ha) and Q. petraea (4.6 Mg / ha) all recorded values ​​are similar to those observed in other forests and mountains of the same state of maturity equivalent. The start of the growth took place in the spring and Quercus spp. occurred more gradually than in F. sylvatica. We found that the accumulated rainfall in late spring has had a positive effect specially on the growth of Quercus species while the effect of summer temperature has been especially prominent in beech. Mediterranean species show larger fluctuations growth than Central European ones in response to lower water availability.

scholarly journals Seasonal variation in the vertical distribution of zone over Oakshin Gangotri, Antarctica

MAUSAM ◽  
2021 ◽  
Vol 42 (3) ◽  
pp. 275-278
Author(s):  
A.L. KOPPAR ◽  
S.C. NAGRATH
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Early Spring ◽  
The Other ◽  
Late Winter ◽  
Double Peak ◽  
The Vertical Distribution

Ozone soundings made from Dakshin Gangotri, Antarctica during 1987 are presented. The vertical distribution of ozone over Antarctica is characterised by a double peak profile, one around 200-150 hPa and the other around 50 hPa. During late winter-early spring the upper peak is considerably depleted. Tropospheric ozoe remains low and nearly constant throughout the year.  

scholarly journals The relation of the concentration of macronutrients in the substrate and in the foliage to cell wall thickness and cellulose concentration in the xylem of slash pine (Pinus elliotti)

1970 ◽  
Vol 27 (0) ◽  
pp. 295-333
Author(s):  
E. Malavolta ◽  
J.R. Sarruge ◽  
H.P. Haag ◽  
R. Vencovsky ◽  
C.F.O. Santos ◽  
...  
Keyword(s):  
Cell Wall ◽  
Chemical Analysis ◽  
Factorial Design ◽  
Slash Pine ◽  
The Other ◽  
Other Hand ◽  
Calcium Magnesium ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus ◽  
Cellulose Concentration

Sand culture experiments, using a sub-irrigation technique, were installed in order to find out the effects of the macronutrients N, P, K, Ca, Mg and S on growth, aspect, mineral composition, length of fibers, thickness of cell wall and cellulose concentration in slash pine. The aim was to obtain, under controlled conditions, basic information which could eventually lead to practical means designed to increase the rate of growth and to make of slash pine a richer source of cellulose. Nitrogen, Phosphorus, Potassium Experiment A 3 x 3 x 3 factorial design with two replicates was used. Nitrogen was supplied initially at the levels of 25, 50 and 100 ppm; phosphorus was given at the rates of 5, 10 and 20 ppm; potassium was supplied at the rates of 25, 50 and 100 ppm; six months after the experiment was started the first level for each element was dropped to zero. Others macro and all micronutrients were supplied at uniform rates. Fifteen hours of illumination per day were provided. The experimental technique for growing the slash pine seedlings proved quite satisfactory. Symptoms of deficiency of nitrogen, phosphorus and potassium were observed, described and recorded in photographs and water colors. These informations will help to identify abnormalities which may appear under field conditions. Chemical analysis of the several plant parts, on the other hand, give a valuable means to assess the nutritional status of slash pine, thus confirming when needed, the visual diagnosis. The correctness of manurial pratices, on the other hand, can be judged with the help of the analytical data tabulated. Under the experimental conditions nitrogen caused the highest increases on growth, as measured by increments in height and dry weights, whereas the effects of phosphorus and potassium were less marked. Cellulose concentration was not significantly affected by the treatments used. Higher levels of N seemed to decrease both length of fiber elements and the thickness of cell wall. The effects of P and K were not well defined. Calcium, Magnesium, Sulfur Experiment A 3 x 3 x 3 factorial design with two replicates was used. Calcium was supplied initially at the levels of 12.5, 25 and 50 ppm; magnesium and sulfur were given at the rates of 6, 12.5 and 25 ppm. Other macro and micronutrients were supplied at uniform rates, common to all treatments. Three months after starting the experiment the first level for each element was dropped to zero. Symptoms of deficiency of calcium, magnesium and sulfur were observed, described and recorded as in the case of the previous experiment. Chemical analysis were made, both for mineral content and cellulose concentration. Length of fibers and thickness of cell wall were measured. Both calcium and magnesium increase height, sulfur failing to give significant response. Dry weight was beneficially affected by calcium and sulfur. The levels of calcium, magnesium and sulfur in the needles associated with deficiency and maximum growth are comparable with those found in the literature. Cellulose concentration increased when the level of sulfur in the substrate was raised. The thickness of cell wall was negatively affected by the treatments; no effect was observed with regards to length of fibers.

Haematotrephus limnodromi n. sp. (Digenea: Cyclocoelidae) from the Long-billed dowitcher, Limnodromus scolopaceus (Scolopacidae) from the central flyway of North America

Zootaxa ◽  
2006 ◽  
Vol 1153 (1) ◽  
pp. 51 ◽  
Author(s):  
NORMAN O. DRONEN ◽  
SCOTT L. GARDNER ◽  
F. AGUSTÍN JIMÉNEZ
Keyword(s):  
North America ◽  
Gulf Coast ◽  
The Other ◽  
Undescribed Species ◽  
Texas Gulf Coast ◽  
University Of Oklahoma ◽  
Air Sacs ◽  
Cheyenne Bottoms ◽  
Limnodromus Scolopaceus ◽  
Central Flyway

During a study of the endohelminths of wading birds from the Texas Gulf coast, 5 specimens of an undescribed species of Haematotrephus (Cyclocoelidae) were studied and described. These specimens were collected by Dr. J. Teague Self, former professor, Department of Zoology, University of Oklahoma, Norman, Oklahoma from the air sacs of a long-billed dowitcher, Limnodromus scolopaceus, that was collected from the Cheyenne Bottoms, Roger Mills County, Oklahoma on August 3, 1963 and deposited in the Manter Laboratory of Parasitology. Haematotrephus limnodromi n. sp. can be distinguished from all the other species in the genus that lack an oral sucker (H. capellae, H. chengi, H. dollfusi, H. fasciatum, H. kossacki, H. lanceolatum, H. longisacculatum, H. nebularium, H. nigropunctatum, and H. phaneropsolus) by having intertesticular uterine loops. Corpopyrum brazilianum (originally described as Cyclocoelum brazilianum) is transferred as the second species in Selfcoelum, Corpopyrum dendrei is transferred to Neohaematotrephus, and Haematotrephus facioi is transferred to Wardianum. This is the first report of a species of Haematotrephus from a species of Limnodromus.

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