EFFECTIVENESS OF TRUNK-IMPLANTED ACEPHATE FOR THE PROTECTION OF CONES AND SEEDS FROM INSECT DAMAGE IN FRANCE AND CHINA

1996 ◽  
Vol 128 (3) ◽  
pp. 391-406 ◽  
Author(s):  
Alain Roques ◽  
Jiang-Hua Sun ◽  
Xu-Dong Zhang ◽  
Gwennael Philippe ◽  
Jean-Paul Raimbault
Keyword(s):  
Seed Germination ◽  
Siberian Larch ◽  
Northeastern China ◽  
Insect Damage ◽  
European Larch ◽  
Conifer Species ◽  
Gall Midges ◽  
Year Effect ◽  
Cone Flies ◽  
Filled Seeds

AbstractFrom 1989 to 1993, trunk implants of acephate were tested for the control of seed and cone insect damage to conifer species in France and northeastern China. The treatments were promising for the control of the major pests that feed on cone and seed tissues, including cone flies, coneworms, and seedworms, in European and Siberian larch, Norway spruce, Scots and mountain pine. In contrast, acephate implants did not prevent seed chalcid damage nor that of gall midges in Douglas-fir, European larch, and Siberian larch. Treatment generally increased seed yield, but a significant increase in the number of filled seeds was seen only when chalcids and midges were absent. The 2-year effect of implants seemed limited. Acephate implantation did not seem to affect seed germination.

Factors affecting red-osier dogwood seed germination

1992 ◽  
Vol 70 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
S. N. Acharya ◽  
C. B. Chu ◽  
R. Hermesh ◽  
G. B. Schaalje
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Collection Site ◽  
Moisture Condition ◽  
Seed Formation ◽  
Factors Affecting ◽  
Year Effect ◽  
Wide Range ◽  
Cornus Stolonifera ◽  
Moisture Conditions

Seeds from 55 populations of native Alberta red-osier dogwood (Cornus stolonifera Michx.) were collected over 2 years (1984 and 1985) to determine the range of variability for seed germination and the effect of ecoregion and moisture conditions in the collection sites on this trait. Each year the unscarified seeds were stored at 3 °C for 30 days, stratified at 3 °C for an additional 30 days and then incubated on an 8 h light: 16 h dark cycle at a temperature of 25:10 °C (light:dark) for germination. A wide range of germination percentages was observed among populations collected in any 1 year. However, the variability was not due to the ecoregion or moisture condition of the collection site. Germination percentage of populations collected in 1984 and 1985 formed five and seven groups, respectively. A study involving eight sites that were common to 1984, 1985, and 1986 revealed a significant effect of population on seed germination. This population effect was not obscured by the combined effects of year, precipitation, temperature, and seed size. The year effect was significant only when population was used as a covariate. Precipitation during seed formation significantly influenced germination performance even after adjustments were made for population and year. Seed germination in red-osier dogwood appears to be influenced by the population from which the seeds are collected and by yearly environmental fluctuations. Therefore, germination studies in this species must include seeds from diverse populations collected over several years. Key words: red-osier dogwood, Cornus stolonifera Michx., germination, population, environment.

Seed cone traits and insect damage in Tsuga canadensis (Pinaceae)

2004 ◽  
Vol 34 (1) ◽  
pp. 261-265 ◽  
Author(s):  
Jean J Turgeon ◽  
Chuck Jones ◽  
M Isabel Bellocq
Keyword(s):  
Seed Production ◽  
Tsuga Canadensis ◽  
Insect Damage ◽  
First Report ◽  
Seed Cone ◽  
Length Width ◽  
Maximum Proportion ◽  
Sterile Seed ◽  
The Impact ◽  
Filled Seeds

We measured seed cones of Tsuga canadensis (L.) Carrière, assessed seed potential (number of fertile scales × 2) and seed efficiency (number of filled seeds/seed potential), and estimated the impact of Eupithecia mutata Pearsall (Lepidoptera: Geometridae) and Megastigmus hoffmeyeri Walley (Hymenoptera: Torymidae) on seed production. Mean length, width, and volume of healthy cones varied little among sites from Ontario. Cones had about 28 scales; 13 were sterile. Seed potential and seed efficiency differed among sites, ranging from 25 to 31 ovules and 24% to 72%, respectively. The number of scales (both sterile and fertile) increased with cone volume, but the proportion of fertile scales was independent of cone size. The maximum proportion of cones infested by E. mutata was 21%. On average, each larva destroyed >90% of the filled seeds from each cone, thus from a practical perspective, the proportion of T. canadensis seeds destroyed per site was equivalent to the proportion of seed cones infested. The proportion of cones infested by M. hoffmeyeri ranged from 9% to 40%, but the proportion of seeds destroyed per site (range: 1.1%–6.1%) was much lower than that of E. mutata. The maximum number of M. hoffmeyeri-infested seeds per cone was seven. To our knowledge, this is the first report documenting cone traits of T. canadensis and the impact of E. mutata and M. hoffmeyeri.

scholarly journals INDIVIDUAL VARIABILITY OF MORPHOLOGICAL FEATURES OF POLISH LARCH IN THE CONDITIONS OF INTRODUCTION

2020 ◽  
Vol 9 (4) ◽  
pp. 33-40
Author(s):  
Maksim Lavrenov ◽  
Sergey Vasil'ev ◽  
Vladimir Nikitin ◽  
Vera Savchenkova
Keyword(s):  
Siberian Larch ◽  
Taxonomic Status ◽  
Individual Variability ◽  
Morphological Features ◽  
European Larch ◽  
Average Value ◽  
European Part Of Russia ◽  
The Difference ◽  
Growing Conditions ◽  
Independent Species

Polish larch trees are among the most valuable among forest species both in natural growing conditions and in the conditions of introduction. However, its taxonomic status is not fully resolved due to the similarity in morphological features with European and Siberian larch. We conducted a comparative analysis of these species of larch on the morphological features of cones and needles. The studies were carried out in the conditions of introduction in the center of the European part of Russia. We present the average value of the trait (XSR ± Sx) and the degree of its variation (V %). The reliability of the difference between the samples according to these characteristics was determined based on the calculation of the student's criterion t. As a result, we found that the Polish larch has smaller cones and significantly differs from the European and Siberian larch in all studied features (length of cones, width of cones, number of scales in cones, length of needles). These results indicate the isolation of the Polish larch, but this pattern can be expressed not only when referring to the Polish larch in the rank of an independent species – Larix polonica Racib., but also as a subspecies of European larch (Larix decidua var. polonica (Racib. ex Wóycicki) Ostenf. & Syrach).

scholarly journals Study results of pine and larch provenance trial in Serebryanoborsky experimental forest district

2020 ◽  
Vol 24 (6) ◽  
pp. 34-43
Author(s):  
M.D. Merzlenko ◽  
◽  
P.G. Melnik ◽  
Yu.B. Glazunov ◽  
A.A. Kozhenkova ◽  
...  
Keyword(s):  
Siberian Larch ◽  
Japanese Larch ◽  
Stem Volume ◽  
Larix Kaempferi ◽  
Provenance Trial ◽  
European Larch ◽  
Southern Sakhalin ◽  
Study Results ◽  
Larch Species ◽  
Forest District

The results of the cultivation of Scots pine (Pinus sylvestris L.) in the provenance trial in the Serebryanoborsky experimental forest district of the Institute of Forestry of the Russian Academy of Sciences are summarized. The silvicultural effect was assessed by a comprehensive indicator of the feasibility of introducing specific pine conventions. It was established that the use of pine seeds of exclusively local provenances cannot be considered justified. In the vast area of pine there are very remote populations of a local nature, the seed of which, when moved, can be successfully used to create highly productive artificial stands. The 68 year old geographical plantations of larch growth and production rates of 18 climotypes of 14 larch species were compared. These species are Polish larch (Larix polonica Racib.), European larch (Larix decidua Mill. f. Sudetica), Larix sukaczewii Dylis, Siberian larch (Larix sibirika Ledeb.), Larix cajanderi Mayr., Larix gmelinii Rupr., Larix Czekanovskii Szaf, Larix amurensis Kolesn., Olgan larch (Larix olgensis Henry), Japanese larch (Larix kaempferi (Lamb.) Carrière), Larix kurilensis Maur., Larix principis Rupprechtii Maur., Larix potaninii Bat, American larch (Larix laricina (Duroi) K. Koch). Polish larch, Japanese larch, European larch and Olgan larch have the best growth rate results. Climotypes from Siberia and American larch showed worst results. Polish larch (812 m3/ha) and Japanese (804 m3/ha) larch from the Southern Sakhalin have the highest stem volume. The final estimations showed that the climotypes of Polish larch, European larch from Sudetes and Japanese larch from the Southern Sakhalin are suitable for introduction in the Moscow Region. The climotypes from the Far East, namely Larix amurensis Kolesn., Olgan larch and Larix kurilensis Maur., had positive silvicultural effect. The inland climotypes from Asia together with American larch showed negative results.

Drought response of five conifer species under contrasting water availability suggests high vulnerability of Norway spruce and European larch

2013 ◽  
Vol 19 (10) ◽  
pp. 3184-3199 ◽  
Author(s):  
Mathieu Lévesque ◽  
Matthias Saurer ◽  
Rolf Siegwolf ◽  
Britta Eilmann ◽  
Peter Brang ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Water Availability ◽  
Drought Response ◽  
European Larch ◽  
Conifer Species

Insect damage to cones of exotic conifer species introduced in arboreta

1993 ◽  
Vol 115 (1-5) ◽  
pp. 113-133 ◽  
Author(s):  
N. da Ros ◽  
R. Ostermeyer ◽  
A. Roques ◽  
J. P. Raimbault
Keyword(s):  
Insect Damage ◽  
Conifer Species

Factors affecting seed and cone development in Pacific silver fir (Abies amabilis)

1998 ◽  
Vol 28 (8) ◽  
pp. 1146-1163 ◽  
Author(s):  
John N Owens ◽  
Sheila J Morris
Keyword(s):  
Anatomical Study ◽  
Silver Fir ◽  
Insect Damage ◽  
Factors Affecting ◽  
Abies Amabilis ◽  
Seed Loss ◽  
Seed Maturity ◽  
Cone Axis ◽  
Cone Development ◽  
Filled Seeds

The reproductive development from pollination until seed maturity for Pacific silver fir (amabilis fir; Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes) was studied at two sites in British Columbia. Ten trees growing at varying elevations at each site were flagged and two or more cones were collected from each tree every 1 or 2 weeks. Following size measurements, cones were dissected and 20 ovules from each cone were sampled, fixed, embedded in paraffin, sectioned, and stained for anatomical study. Ovule, megagametophyte, and embryo size was measured and stage of ovule or seed and embryo was determined. At both sites the phenology and details of development were similar. The major causes of cone loss were frost at pollination and insect damage following pollination. The seed potential per cone was 359-408, but the filled seeds per cone based on cutting tests and X-raying was only 18-22%. The major causes of seed loss were insect damage (32-39%) during ovule and seed development and failure of ovules to be pollinated (26-31%). Although the amount of insect damage was similar at both sites, damage at Site 1 was primarily caused by Megastigmus sp. larvae in the seeds whereas at Site 2, damage was to seeds, scales, and the cone axis and due to Earomyia abietum larvae. Megagametophyte and embryo development is described and the time and causes of the seed loss are related to development. Anomalous types of development are described and possible causes discussed.

Effects of aspen (Populus tremuloides) sucker removal on postfire conifer regeneration in central Alaska

2005 ◽  
Vol 35 (2) ◽  
pp. 483-486 ◽  
Author(s):  
Jill F Johnstone
Keyword(s):  
Seed Germination ◽  
Populus Tremuloides ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Negative Response ◽  
Treatment Results ◽  
Conifer Species ◽  
Canopy Development

This experiment tests the effects of early canopy development by asexually regenerating aspen (Populus tremuloides Michx.) on conifer recruitment after fire in central Alaska. The establishment and growth of three conifer species were observed in response to aboveground removal of aspen suckers for three seasons after burning by wildfire. Of the three species, Pinus contorta Dougl. ex Loud. had the most widespread seed germination and showed the strongest negative response to the presence of the aspen canopy. Picea mariana (Mill.) BSP and Picea glauca (Moench) Voss had low germination and weak or neutral responses to aspen removal. Seedlings of all species accumulated more biomass in the removal treatment. Results from the experiment suggest that competition by aspen early after disturbance can significantly reduce conifer recruitment and growth, an effect that may reinforce the long-term dominance of aspen in asexually regenerating stands.

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