Effects of gibberellin A4/7 stem injection on seed cone production in mature black spruce

1997 ◽  
Vol 27 (8) ◽  
pp. 1325-1328 ◽  
Author(s):  
E G Brockerhoff ◽  
R H Ho
Keyword(s):  
Black Spruce ◽  
Cone Production ◽  
Seed Cone ◽  
Stem Injection

Gibberellin A4/7 enhances seed-cone production in field-grown black spruce

1988 ◽  
Vol 18 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Rong H. Ho
Keyword(s):  
Vitamin E ◽  
Black Spruce ◽  
Seed Orchard ◽  
Shoot Elongation ◽  
Bud Burst ◽  
Lateral Shoot ◽  
Cone Production ◽  
Seed Cone ◽  
Vegetative Bud ◽  
Needle Primordia

Black spruce (Piceamariana (Mill.) B.S.P.) grafts growing in a seed orchard were sprayed with gibberellin A4/7, and grafts and trees in families growing in arboreta were sprayed with gibberellin A4/7 and (or) vitamin E from vegetative bud burst to the end of shoot elongation. Gibberellin A4/7 was very effective in promoting seed cones and 400 mg/L appeared optimal. Vitamin E at 1000 mg/L was not effective. Vegetative bud burst occurred in mid-May and shoot elongation ended in late June. Needle primordia were visible on the apices of newly formed buds at the end of June. Reproductive buds had fewer bud scales than vegetative buds. It appeared that potential reproductive buds terminated their bud scale initiation earlier. Gibberellin A4/7 application to promote seed-cone production should be carried out before bud-type differentiation. This coincides with the end of lateral shoot elongation.

Some Factors Influencing Cone Production on Young Black Spruce in New Brunswick

1981 ◽  
Vol 57 (6) ◽  
pp. 267-269 ◽  
Author(s):  
J. D. Simpson ◽  
G. R. Powell
Keyword(s):  
New Brunswick ◽  
Picea Mariana ◽  
Black Spruce ◽  
Tree Height ◽  
Tree Age ◽  
Cone Production ◽  
Factors Influencing ◽  
Seed Cone ◽  
Pollen Cone

Ten young black spruce (Picea mariana [Mill.] B.S.P.) plantations in northern and central New Brunswick were examined to de termine the influence of aspect, slope, tree age and tree height on pollen-cone and seed-cone production. It was found that a greater proportion of trees growing on southerly aspects produced pollen cones and seed cones than trees growing on northerly aspects. Trees growing on southerly aspects bore 2.5 and 5 times more seed cones and pollen cones, respectively, than trees growing on northerly aspects. Cone production on south-sloping sites was approximately double that on level sites. The number of seed cones was most significantly correlated with tree height. The number of pollen cones was most significantly correlated with number of seed cones.

Reproductive development and insect damage on white and black spruce seed trees treated with ammonium nitrate and carbofuran

1993 ◽  
Vol 23 (9) ◽  
pp. 1786-1792
Author(s):  
W.H. Fogal ◽  
S.M. Lopushanski ◽  
H.O. Schooley ◽  
D.A. Winston
Keyword(s):  
Ammonium Nitrate ◽  
Black Spruce ◽  
Spruce Budworm ◽  
Reproductive Development ◽  
White Spruce ◽  
High Rate ◽  
Insect Damage ◽  
Cone Production ◽  
Seed Cone ◽  
Needle Senescence

Granular ammonium nitrate and carbofuran were applied to soil beneath white spruce (Piceaglauca (Moench) Voss) and black spruce (Piceamariana (Mill.) B.S.P.) seed trees to stimulate reproductive development and protect them from defoliating and cone-feeding insects. Rates of carbofuran application were 0, 10.8, or 21.6 g/cm DBH for white spruce, and 0, 5, or 10 g/cm DBH for black spruce. Both species received 0,224, or 448 kg N/ha of ammonium nitrate. Trees were assessed for defoliation by the eastern spruce budworm (Choristoneurafumiferana Clem.), cone insect damage, seed-cone bud production, cone production, seed yields, and needle senescence for 3 years in white spruce, and 2 years in black spruce. On white spruce, carbofuran reduced defoliation and number of spruce budworm at both application rates in the year of treatment and at the high rate in the second year; no protection was observed in the third year. Seed-cone bud production was stimulated by carbofuran for 3 years following treatment. Needle senescence was increased by carbofuran. Ammonium nitrate decreased needle senescence but had no effects on other assessment variables. On black spruce, carbofuran did not reduce spruce budworm numbers or protect cones in the year of application but, in the year after treatment, both foliage and cones were protected. Defoliation was reduced by the low rate of applied ammonium nitrate. Treatments did not influence the number of seed-cone buds or cones or amount of needle senescence in black spruce.

Patterns of seed-cone and pollen-cone production in young Piceamariana trees

1989 ◽  
Vol 19 (3) ◽  
pp. 359-364 ◽  
Author(s):  
G. E. Caron ◽  
G. R. Powell
Keyword(s):  
Black Spruce ◽  
Annual Production ◽  
Tree Age ◽  
Cone Production ◽  
Seed Cone ◽  
Warm Weather ◽  
Old Trees ◽  
Pollen Cone

Production of seed cones from 1978 to 1987 and of pollen cones from 1980 to 1982 by young black spruce (Piceamariana (Mill.) B.S.P.) trees was recorded in five plantations aged 8, 10, 12, 14, and 16 years in 1980. Variations in cone production and percentages of trees bearing cones were assessed in relation to changing tree age and cone numbers per tree. The first seed cones and pollen cones were noted on 7- and 10-year-old trees, respectively. After ages 10–12 for seed cones and 12–14 for pollen cones there were substantial yearly fluctuations of average numbers of cones per tree. Similarly, the percentages of trees bearing cones fluctuated among years, but differences between poorer and better years decreased as the proportion of bearing trees gradually increased. Up to age 14, the number of seed cones borne per tree was generally higher than the number of pollen cones. Thereafter, pollen-cone production was always higher than seed-cone production and reached 6.6 pollen cones per seed cone by age 18. Pollen cone bearing trees were good indicators of seed cone bearing trees at all ages. Most 12-year-old and older seed cone bearing trees were good indicators of pollen cone bearing trees. Annual production of seed cones was correlated with warm weather in early May and early July, and with relatively low rainfall in early June of the previous year.

Seed-cone and pollen-cone production models for young black spruce seedling seed orchards: a first approximation

1995 ◽  
Vol 25 (6) ◽  
pp. 921-928 ◽  
Author(s):  
G.-É. Caron
Keyword(s):  
Standard Error ◽  
Black Spruce ◽  
Seed Orchard ◽  
Tree Age ◽  
Seed Orchards ◽  
Crop Models ◽  
Cone Production ◽  
Production Models ◽  
Seed Cone ◽  
Pollen Cone

Seed orchard managers wanting to predict potential seed-cone (Sc) and pollen-cone (Pc) production 1 year in advance of seed release and pollen dissemination need predictive models. The present study proposes the use of cone-crop models based on tree age in young black spruce (Piceamariana (Mill.) B.S.P.) orchards. Sc and Pc production was monitored from 1987 to 1993 in each of five seedling seed orchards. Some trees began bearing Sc and Pc by tree age 6. The relationships of Sc and Pc production with tree age were each represented by three sigmoid equations: one for light crop years, one for heavy crop years, and one for light plus heavy crop years. The rate of cone increase for heavy and light crop years differed for both Sc and Pc. Sigmoid equations representing heavy Sc and Pc crop years in orchards had the highest r2 (0.8462 and 0.9381, respectively) and the lowest standard error. Sigmoid model of heavy crop years with plantation data also had the highest r2 value (0.8066) and the lowest standard error. The rate of Sc and Pc increase versus tree age was higher for orchards than for plantations. To select the best of three sigmoid models, one must take into account the early buildup phase of cone production in young trees, the yearly fluctuation in cone crops, previous-year cone production, and environmental factors that can affect cone crops.

Timing of gibberellin A4/7 application for cone production in potted black spruce grafts

1991 ◽  
Vol 21 (7) ◽  
pp. 1137-1140 ◽  
Author(s):  
Rong H. Ho
Keyword(s):  
Black Spruce ◽  
Foliar Spray ◽  
Shoot Elongation ◽  
Bud Break ◽  
Bud Burst ◽  
Lateral Shoot ◽  
Cone Production ◽  
Best Response ◽  
Seed Cone ◽  
Vegetative Bud

Potted 5-year-old grafts of black spruce (Piceamariana (Mill.) B.S.P.) growing in either a heated greenhouse or an outdoor holding area were sprayed weekly at 200 mg•L−1 gibberellin A4/7 for various durations and timings. The application began 1 to 6 weeks after vegetative bud break and continued until the end of lateral shoot elongation. Sprayings ended at the same time for all treatments, about 1 week before leaf primordial differentiation on the shoot apices. The best response in seed-cone production occurred when application began 2 weeks after bud break (midstage of rapid shoot elongation) and continued for 5 weeks; treatments were also effective when applications began 3 weeks after bud break or earlier and continued for 4 to 6 weeks. Treatments initiated later (4 to 6 weeks after bud break) were not effective. Grafts kept outdoors produced more seed cones than those kept indoors. The effects on cone production of gibberellin A4/7 application at four different concentrations were compared by spraying for 6 weeks, beginning 1 week after vegetative bud burst. Gibberellin A4/7 at 200 mg•L−1 was the lowest foliar spray concentration found to be effective in promoting seed-cone production.

Cone size and seed yield in young Piceamariana trees

1989 ◽  
Vol 19 (3) ◽  
pp. 351-358 ◽  
Author(s):  
G. E. Caron ◽  
G. R. Powell
Keyword(s):  
Seed Yield ◽  
Black Spruce ◽  
Pollen Grains ◽  
Production Potential ◽  
Cone Production ◽  
Seed Cone ◽  
Highly Correlated ◽  
Cone Potential ◽  
Pollen Cone ◽  
Filled Seeds

Black spruce (Piceamariana (Mill.) B.S.P.) cones were collected in 1980, l981, and 1982 from young trees in four plantations of different ages. Nine measures of cone size, seed yield per cone, and seed weight were determined by cone analysis, and the variation among plantations and years was assessed by analysis of variance. Relationships among the nine measures were assessed by correlation. Cone length, cone weight, total scales per cone, potential filled seeds per cone, total seeds per cone, total filled seeds per cone, and seed efficiency were all depressed in 1981, the year of poorest cone production. Potential filled-seed yield and actual filled-seed yield were highly correlated with most cone-size measures but poorly correlated with each other. Pollen availability in 1982 was assessed by trapping and by counting pollen cones. The catch of pollen grains was positively correlated with the numbers of pollen cones per tree. Total filled seeds per cone in 1982 was strongly related to pollen availability. Seed efficiencies of less than 35%, which occurred in the younger plantations and in the year of poorest pollen-cone and seed-cone production (1981), indicated excessive loss of potential seed.

Cost of reproduction in Douglas-fir

1992 ◽  
Vol 70 (7) ◽  
pp. 1429-1432 ◽  
Author(s):  
Yousry A. El-Kassaby ◽  
Hugh J. Barclay
Keyword(s):  
Pseudotsuga Menziesii ◽  
Annual Ring ◽  
Ring Width ◽  
Energy Allocation ◽  
Douglas Fir ◽  
Environmental Correlations ◽  
Annual Ring Width ◽  
Trade Off ◽  
Cone Production ◽  
Seed Cone

The balance between allocating energy resources to reproduction or growth has considerable theoretical interest. Conflicting ecological requirements and evolutionary pressures often necessitate a trade-off in energy allocation. We obtained measurements on seed-cone production and annual ring width of 365 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees from 29 open-pollinated families for 8 years. Phenotypic, genetic, and environmental correlations were computed for seed-cone production and ring width for each year. Five of the eight environmental correlations were negative (range −0.077 to −0.305), reflecting the reality of the trade-off in physiological terms. Six of the eight genetic correlations were negative (range −0.199 to −0.776), indicating that a trade-off exists at the genetic level between energy allocation to reproduction and to somatic growth. These findings agree with the current theory of life-history evolution. Key words: Pseudotsuga menziesii, cone production, annual ring width, genetic correlation.

Effects of stem injections of gibberellin A4/7 and paclobutrazol on sex expression and the within-crown distribution of seed and pollen cones in black spruce (Picea mariana)

1998 ◽  
Vol 28 (5) ◽  
pp. 641-651 ◽  
Author(s):  
Ronald F Smith
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Sex Expression ◽  
Bud Burst ◽  
Seed Orchards ◽  
Adjunct Treatment ◽  
Cone Production ◽  
Pollen Cone ◽  
Dose Dependent ◽  
Vegetative Bud

Two experiments in black spruce (Picea mariana (Mill.) BSP) seedling seed orchards were established to determine if a stem injection of paclobutrazol (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl) could be used as an adjunct treatment to increase the efficacy of stem injections of gibberellins A4 and A7 (GA4/7). Trees received a single injection of GA4/7 and (or) paclobutrazol shortly after vegetative bud burst. There was a dose-dependent but nonlinear increase in the production of cones of both sexes in response to stem injections of either GA4/7 or paclobutrazol. The optimum rate of GA4/7 for stimulating pollen-cone production was 3.3 mg, whereas the most seed cones were induced on trees receiving 11 mg. The sex ratio (number of seed cones/number of pollen cones) increased with the rate of GA4/7 applied. Injecting paclobutrazol also promoted cones of both sexes equally, resulting in sex ratios comparable with that of the control trees. Treatments did not affect the total numbers of buds (vegetative, latent, and cone) produced. Seed- and pollen-cone buds occurred in positions that would have otherwise developed vegetatively and become latent, respectively. The mechanisms whereby paclobutrazol could affect flowering in black spruce are discussed. The use of paclobutrazol as an adjunct to GA4/7 treatments in black spruce seedling seed orchards appears effective, practical, and safe.

Promotion of flowering in western hemlock by gibberellin A4/7 applied at different stages of bud and shoot development

1989 ◽  
Vol 19 (8) ◽  
pp. 1051-1058 ◽  
Author(s):  
John N. Owens ◽  
Anna M. Colangeli
Keyword(s):  
Effective Treatment ◽  
Shoot Elongation ◽  
Shoot Development ◽  
Western Hemlock ◽  
Bud Burst ◽  
Cone Production ◽  
Seed Cone ◽  
Pollen Cone ◽  
Vegetative Bud

Cone buds were induced on container-grown and field-grown western hemlock (Tsugaheterophylla (Raf.) Sarg.) clones during a 3-year period to study the effects of time and duration of gibberellin A4/7 treatment on cone induction, sexuality of cones, and to relate these results to bud and shoot development. The most effective treatment times preceded anatomical differentiation. The most abundant pollen cones and seed cones were produced when trees were sprayed with gibberellin A4/7 before vegetative bud burst and early shoot elongation. Two to three weekly gibberellin A4/7 applications starting at preswollen and swollen-bud stages were adequate for pollen-cone production. Pollen-cone production decreased when the applications were started at vegetative bud burst or during early shoot elongation. A minimum of three weekly applications were required for seed-cone production, and applications were equally effective when started at preswollen, swollen, and vegetative bud burst stages. Seed-cone production decreased when three weekly applications were started during early shoot elongation; however, this was overcome by increasing the number of applications.

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