Inland spruce cone rust (Chrysomyxapirolata) control: relation of ferbam application to basidiospore production, rainfall, and cone phenology

1986 ◽  
Vol 16 (2) ◽  
pp. 360-362 ◽  
Author(s):  
D. Summers ◽  
Jack R. Sutherland ◽  
T. A. D. Woods

Experiments were conducted over a 3-year period (1982–1984) at a white spruce (Piceaglauca (Moench) Voss) seed orchard near Salmon Arm, British Columbia, to relate the control of inland spruce cone rust (Chrysomyxapirolata Wint.) by ferbam to the number of fungicide applications, basidiospore production, rainfall, and cone phenology. Either multiple or single applications of ferbam during the period starting about 1 week before and through the pollination period reduced the incidence of the disease by 5- to 10-fold without any reduction in seed yield per cone, although seed germination was reduced slightly.

1998 ◽  
Vol 28 (3) ◽  
pp. 418-426 ◽  
Author(s):  
Michael U Stoehr ◽  
Sylvia J L'Hirondelle ◽  
Wolfgang D Binder ◽  
Joe E Webber

Seed orchards for the production of conifer seed in British Columbia are usually located in areas favorable (warm and dry) for flowering and seed development, often considerably south of the source location of the parent trees. Differences in environmental conditions between seed orchard location and location of origin can affect progeny performance. It is suspected that this is caused by environmental factors that affect reproductive processes of parent trees and lead to altered physiological traits (aftereffects). This study examined if aftereffects are present in white spruce (Picea glauca (Moench) Voss). Control pollinations were made at two locations, Red Rock, near Prince George (53°N) in central British Columbia, and Kalamalka, near Vernon (50°N) in southern British Columbia, on five female trees using a four-male polymix. Identical genotypes through grafting were present at the two locations. Pollen maturing at each site was only used in the polymix at that particular location. Progeny were raised and germination traits, number of needle primordia, greenhouse and field heights, and frost hardiness were evaluated in a common environment. The location of seed development significantly affected all traits evaluated. Height growth aftereffects in the second field season were much less than those observed in the first field season. These results suggest that aftereffects are detectable in white spruce progeny performance in British Columbia.


1990 ◽  
Vol 70 (4) ◽  
pp. 1071-1080 ◽  
Author(s):  
LUCIUS BELZILE

For five years, the effect of cultivars and vegetative stage of cutting were measured on red clover (Trifolium pratense L.) seed production. The first group of cultivars included Hungaropoli, Ottawa and Lakeland harvested in 1981 and 1982. The second group included Arlington, Florex and Prosper I harvested in 1984, 1985 and 1987. The total annual seed yield differed within cultivars and the highest seed yield was obtained with Hungaropoly and Florex. In the first cultivar group, the tetraploid Hungaropoly obtained a kernel weight higher than the diploids Lakeland and Ottawa. In the second group of cultivars, all diploids, Arlington yielded the highest kernel weight. The percentage of seed germination of Hungaropoly was higher than Lakeland and Ottawa while for Florex it was slightly higher than Arlington and Prosper I. A prior vegetative cutting is essential for good seed yield. In the absence of vegetative cutting seed weight seemed improved. The stage of development at which vegetative cutting is done has little influence on percentage seed germination. These results have shown that despite the strong effect of climatic conditions on seed production, the choice of the optimum stage for vegetative cutting and a well adapted cultivar are important aspects in successful seed production.Key words: Red clover, seed production, cultivar, stage of cutting


Author(s):  
Melusi Rampart

Maternal effects were assessed by germinating seeds sourced over multiple years from the same cloned mother trees, comparing germination capacity and rate between crop years. The relationships between climatic variables, seed characteristics and germination capacity were determined, and thermal time parameters were used to predict seed dormancy release and germination under the climatic conditions in the year after seed collection. There were significant differences in seed weight (P < 0.05), seed length and embryo occupancy (both P < 0.001) among crop years. Temperature during the seed development period explained 70% of the variation in seed weight and 63% of the variation in embryo occupancy. Germination capacity was significantly (P <0.001) different among crop years, among temperatures and among chilling durations, and thermal time requirements for germination increased from older (2007) to younger (2012) seeds. The mean base temperature without chilling was 7.1°C, while after chilling it was 4.6°C and 3.6°C for four and eight weeks chilling respectively. The mean thermal time to 50% germination without chilling was 135.1°Cd, while after chilling it was 118.3°Cd and 154.0°Cd for four and eight weeks chilling respectively. This experiment demonstrates that year-to-year differences in the environment experienced by mother trees during seed maturation can affect seed germination characteristics.


Author(s):  
G. F. Laundon

Abstract A description is provided for Pucciniastrum americanum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pycnia and aecia on Picea glauca (=P. canadensis), uredia and telia on Rubus idaeus (incl. R. strigosus) and R. leucodermis (raspberries). DISEASE: Needle rust of white spruce. Late leaf rust or late yellow rust of raspberry, infecting canes, leaves, petioles, calyces and fruits. GEOGRAPHICAL DISTRIBUTION: Canada and U.S.A. (widely distributed, recorded from British Columbia, Connecticut, Idaho, Illinois, Iowa, Mass., Md, Me, Montana, North Dakota, New Hamp., New Jersey, Nova Scotia, New York, Ohio, Ontario, Quebec, Vermont, Wisconsin, West Virginia). TRANSMISSION: Although the basidiospores infect Picea glauca (white spruce) (Darker, 1929) in some areas they probably play little part in the life cycle on raspberry since this rust is found on the latter host year after year in regions remote from any spruce trees (Anderson, 1956).


Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1212 ◽  
Author(s):  
Qasim Ali ◽  
Rashida Perveen ◽  
Mohamed A. El-Esawi ◽  
Shafaqat Ali ◽  
Syed Makhdoom Hussain ◽  
...  

The present study was conducted to investigate the effects of Cuscuta reflexa extract (CRE) on the activities of germination enzymes, seed germination vigor, biomass production, physio-biochemical attributes, and seed yield of water-stressed wheat plants. Different levels of CRE (0, 10, 20, 30, 40, and 50%), including water soaking, were used as seed priming. Water stress negatively affected the seed germination, germination enzyme activities, growth, yield, and different physio-biochemical attributes of wheat plants. Low doses of CRE (10, 20, and 30%) ameliorated the adverse effects of water stress on seed germination attributes, and activities of germination enzymes, but negative impacts were recorded at higher doses (40 and 50%) of CRE. Water-stressed wheat plants grown from seeds pre-treated with low doses of CRE also showed better growth and yield as compared with non-treated ones, and that was associated with an improvement in water relations, photosynthetic pigments, nutrient acquisition, reduced lipid peroxidation, and better antioxidative defense mechanisms. The maximum increase in seed yield was 14.77 and 12.32%, found in plants grown from seeds treated with 20% and 10% CRE, respectively. In conclusion, it is suggested that using low doses of CRE as seed priming can contribute to better wheat yield under water stress, especially in semi-arid and arid areas.


1993 ◽  
Vol 23 (7) ◽  
pp. 1306-1313 ◽  
Author(s):  
G.E. Caron ◽  
B.S.P. Wang ◽  
H.O. Schooley

The effects of cone storage period and pregermination treatment on seed maturity and dormancy were compared for cones of white spruce (Piceaglauca (Moench) Voss) collected from individual trees in 1984 and 1988. Seeds were extracted from cones and germinated after 2 or 6 weeks of cone storage in 1984 and after 2, 4, 6, 10, or 14 weeks in 1988. Based on cumulative degree-days, seeds were more mature at collection time in 1988 than in 1984. Seeds from 1984 cones stored for 6 weeks matured during storage, and both germination percentage (GP) and rate of germination (GR) were significantly improved. In contrast, storage up to 14 weeks in 1988 did not increase GP and GR, as seed had attained maturity prior to cone collection. Seed dormancy was present in both 1984 and 1988. Significant improvements in GP and GR were achieved in 1984 with a pregermination treatment even before seed maturity was attained. Prechilling of seed after 6 weeks of cone storage increased GP from 60 to 95% in 1984 and 64 to 89% in 1988.


1976 ◽  
Vol 52 (5) ◽  
pp. 225-228 ◽  
Author(s):  
R. C. Dobbs

Seed dispersal of white spruce (Picea glauca) (Moench) Voss) from stands bordering a large clearcut and a strip cut was studied. Seedfall fell sharply with distance from the clearcut edge to 100 m, but even at 300 m the average dispersed seed density exceeded 740 000 seeds/ha or 3% of that recorded within the stand. Dispersed seed density in the middle of the 200-metre-wide strip cut exceeded 1 300 000 seeds/ha or 20% of that recorded within the bordering stands. About one-third of the seeds was disseminated by the end of September.


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