Evaluation of microclimatic factors affecting ascospore release of Gremmeniella abietina var. balsamea

The ascospore release of G. abietina var. balsamea was measured every hour for a period of 1339 hours; it was analyzed with regard to microclimatic factors, such as rain, relative humidity, air temperature, wind speed, and leaf wetness, which were also recorded on an hourly basis. The spore dispersal period started in the middle of July and ended in October, with a peak of spore release during the first 3 weeks of August. Leaf wetness measurements were best correlated with spore dispersal. Relative humidity and rain also showed a good correlation with spore dispersal but not as good as leaf wetness. Dew was not responsible for ascospores release. Mist or fog were most probably the cause of free water deposition and, as a result, the cause of spore release when no rain was recorded. Mist and fog were not measured directly but could be inferred from leaf wetness readings. Temperature had no direct effect on spore release.

[1]  O. Petrini,et al.  Taxonomic position of Gremmeniella abietina and related species: a reappraisal , 1989 .

[2]  G. Laflamme.  Description et distribution du chancre scléroderrien sur Picea mariana (Mill.) B.S.P , 1988 .

[3]  J. C. Sutton,et al.  Electronic Monitoring and Use of Microprocessors in the Field , 1988 .

[4]  D. Lachance,et al.  Large Infection Center of Scleroderris Canker (European Race) in Quebec Province , 1987 .

[5]  Darroll D. Skilling,et al.  Biology and control of scleroderris canker in North America. , 1986 .

[6]  D. Bergdahl.  Dispersal of Conidia of Gremmeniella abietina Related to Weather , 1984 .

[7]  C. Luley,et al.  INOCULUM POTENTIAL OF Gremmeniella abietina IN NEW YORK , 1984 .

[8]  D. Gadoury,et al.  A 7-day recording volumetric spore trap , 1983 .

[9]  D. Shilling.  The development of a more virulent strain of Scleroderris lagerbergii in New York State , 1977 .

[10]  C. E. Dorworth,et al.  Comparisons among isolates of Gremmeniella abietina by means of growth rate, conidia measurement, and immunogenic reaction. , 1975 .

[11]  S. Yokota,et al.  Scleroderris canker of Todo-fir in Hokkaido, Northern Japan. II. Physiological and pathological characteristics of the causal fungus , 1974 .

[12]  S. Matsuzaki,et al.  Scleroderris canker of Todo-Fir in Hokkaido, Northern Japan I. Present status of damage, and features of infected plantations , 1974 .

[13]  C. E. Dorworth.  Epidemiology of Scleroderris lagerbergii in central Ontario , 1972 .

[14]  E. Donaubauer,et al.  Distribution and hosts of Scleroderris lagerbergii in Europe and North America , 1972 .

[15]  J. Rowe,et al.  Forest regions of Canada. , 1972 .

[16]  D. Skilling.  The effect of temperature on ascospore release by Scleroderris lagerbergii. Spore dispersal by Scleroderris lagerbergii under nursery and plantation conditions. , 1969 .

[17]  J. Hopkins.  A SPORE TRAP OF THE VASELINE SLIDE TYPE , 1959 .