Theoretical effects of seed orchard roguing on selfing and percent filled seeds

1983 ◽  
Vol 13 (1) ◽  
pp. 187-190 ◽  
Author(s):  
Craig R. McKinley ◽  
Michael W. Cunningham

Roguing of seed orchards decreases potential seed yields and increases the percentage of selfed seed produced. Calculations indicate that a potential seed loss per cross of about 10% could be expected by roguing a 15-clone orchard to 5 clones, provided certain assumptions are met. Simultaneously, the theoretical percentage of selfed seed rose from 1 to 3% with the same roguing intensity. Roguing to fewer than five clones resulted in greater losses in potential seed yield.


1987 ◽  
Vol 4 (4) ◽  
pp. 177-180 ◽  
Author(s):  
Peter A. Rush ◽  
Ronald P. Overton ◽  
Raymond P. Guries ◽  
David J. Hall ◽  
Robert S. Perry

Abstract Seed and cone insects can drastically reduce seed yields from pine seed orchards and consequently reduce the profitability of entire tree improvement programs. Liquid and granular formulations of carbofuran both controlled the eastern pine seedworm, the red pine coneworm, the webbing coneworm, and a cone resin midge in field trials at a red pine seed orchard in southern Wisconsin. Both formulations substantially reduced the frequency of insect attacks when applied at the rate of 0.8 oz of active ingredient per inch of tree diameter. The percent of cones attacked by insects declined from 96% in untreated trees to 32% in trees treated with granular carbofuran and 11% in trees treated with liquid carbofuran. Some phytotoxicity was noted on trees treated with liquid carbofuran; phytotoxicity was much less apparent on trees treated with the granular formulation. Label amendments have been made to allow the operational use of carbofuran in northern pine seed orchards, and this may make northern tree improvement programs more profitable. North. J. Appl. For. 4:177-180, Dec. 1987.



1991 ◽  
Vol 21 (12) ◽  
pp. 1721-1729 ◽  
Author(s):  
Teresa K. Boes ◽  
James R. Brandle ◽  
William R. Lovett

Forty-two Eurasian Scots pine (Pinussylvestris L.) clones in a Nebraska seed orchard were observed over 3 years for the phenology of pollen release and seed-cone receptivity and for the production of cones and filled seed. A preliminary investigation had indicated that seed yields were less than expected, and nonsynchronous flowering phenology due to wide genetic diversity was considered as a possible cause. The clones were divided into six regions based on geographic origin and analyzed for variation between regions and between clones within regions. Most variation in cones per tree and filled seeds per cone was due to differences between clones. Most variation in weight per seed was due to differences between regions. The order in which clones began releasing pollen and became receptive remained the same from year to year, but the duration of these events differed between years. Results indicated that nonsynchronous flowering phenology due to genetic diversity is not a likely cause of low seed yield. Seed crops (19.3 kg/ha, 97 000 seeds/kg) were not necessarily lower than should be expected, but 90% of a given year's crop was produced by an average of only 26 clones. With the paternal contribution of each clone to the seed crop unknown, collecting and sowing seed separately by clone is recommended.



1994 ◽  
Vol 18 (3) ◽  
pp. 122-127 ◽  
Author(s):  
Gregory L. Powell ◽  
Timothy L. White

Abstract The Cooperative Forest Genetics Research Program (CFGRP) initiated a slash pine (Pinus elliottii Engelm. var. elliottii) seed orchard management recording system (SOMRS) in 1985 to quantify cone and seed yields of slash pine orchards in the cooperative program. First, historical data were obtained from CFGRP slash pine seed orchards. Secondly, starting in 1985, cultural treatments and production yield data have been collected annually from 56 slash pine seed orchards located throughout Florida, Georgia, and Alabama. The vast majority of these orchards are intensively managed for seed production including the use of fertilizer, herbicide, and up to 10 applications of insecticide annually. From 1980 through 1990, the average seed yield from mature orchards (orchards greater than 14 yr old) was 25.1 bushels of cones, and 27.3 lb of seed/ac. For pounds per acre, orchards reach 50% and 90% of full production at ages 11 and 18 yr from grafting, respectively. The use of insecticides in slash pine seed orchards approximately doubles orchard yields. The CFGRP slash pine seed orchard management recording system (SOMRS) can aid orchard managers in determining factors that limit or promote seed production. South. J. Appl. For. 18(3):122-127.



1999 ◽  
Vol 23 (2) ◽  
pp. 117-123
Author(s):  
T. D. Byram ◽  
J. W. Richardson ◽  
W. J. Lowe

Abstract Simulation was used to predict seed yields for loblolly pine seed orchards in the Western Gulf Region of the United States. This approach allows a seed orchard manager to incorporate site-specific information as well as estimates about the effects of alternative management plans on predicted seed yields. Furthermore, the risks associated with different alternatives can be evaluated by calculating confidence limits for predicted yields. The utility of the simulation approach was demonstrated by comparing alternatives that assumed reduced yield variability, shortened orchard rotations, and reduced age to first seed production. South. J. Appl. For. 23(2):117-123.



1982 ◽  
Vol 6 (2) ◽  
pp. 100-104 ◽  
Author(s):  
F. E. Bridgwater ◽  
D. L. Bramlett

Abstract Supplemental mass pollination was evaluated in a young and a mature loblolly pine (Pinus taeda L.) seed orchard in two successive years. Supplemental mass pollination reduced both conelet and ovule abortion in one year in the young seed orchard and resulted in a 222 percent greater potential seed yield than untreated check ramets. The response was small and statistically nonsignificant in the other year. The potential seed yield was not increased in either year in the mature seed orchard.



Author(s):  
A.J. Cresswell

This paper, as well as being a testimonial to the benefit the writer has received from the Grassland Association, shows how the knowledge of scientists has been used to increase lucerne seed yields by methods of growing resistant cultivars especially for seed production as opposed to growing for hay, silage or grazing. It shows how new cultivars can be multiplied quickly by growing two crops in one year, one in each hemisphere, by using low seeding rates, wide plant spacing and very good weed control. Increased flowering of the crop has been achieved by the use of boron and the choice of time of closing; better pollination has been achieved by the use of more efficient bees - two varieties of which have been imported from North America. Weed and insect pest control and the use of a desiccant at harvest are contributing to a four-fold increase in seed yield, which should double again soon,



1987 ◽  
Vol 11 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Robert C. Hare

Abstract A single foliar spray with either antiethylene compounds or cytokinins shortly after anthesis reduced conelet abortion by half and doubled seed production. Spraying with boric acid plus Cytex® , a relatively economical form of cytokinin derived from seaweed, was equally effective,and addition of certain antiethylene compounds further improved seed yield. South. J. Appl. For. 11(1):6-9.



2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Maricel Andrea Gallardo ◽  
Héctor José Milisich ◽  
Silvina Rosa Drago ◽  
Rolando José González

In order to determine the effect of cultivars and planting date on flax fatty acid profile, seed yield, and oil content, an assay with seven cultivars (Baikal, Prointa Lucero, Prointa Ceibal, Panambí INTA, Curundú INTA, Carapé INTA, and Tape INTA) was carried out at Parana Agricultural Experimental Station, Argentina. Significant differences among cultivars were found for content of palmitic (5–7 g/100 g), stearic (5–8 g/100 g), linoleic (13–19 g/100 g), saturated (11–15 g/100 g), and unsaturated acids (92–96 g/100 g) within the seven cultivars. The best seed yields were observed in Prointa Lucero and Carapé INTA varieties (2091.50 kg·ha−1and 2183.34 kg·ha−1, respectively) in the first planting date and in Carapé INTA and Prointa Lucero (1667 kg·ha−1and 1886 kg·ha−1, respectively) in the second planting date. A delayed planting date had a negative effect on seed yield (1950 kg·ha−1and 1516 kg·ha−1) and oil content (845 kg·ha−1and 644 kg·ha−1) but did not affect oil composition.



2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen

We present results from early tests and field trials of offspring from two Norway spruce ( Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.



2020 ◽  
Vol 18 (1) ◽  
pp. 50-56
Author(s):  
S.O. Olanipekun ◽  
A.O. Togun ◽  
S.A. Adejumo ◽  
O.N. Adeniyan ◽  
A.K. Adebayo

Kenaf is a multi-purpose crop with numerous industrial uses. Its production is constrained by poor cultural and agronomic practices which reduce yield. Inappropriate spacing among others could result in low yield. Effect of plant spacing on growth and yield of kenaf was investigated in Ibadan, Nigeria. Kenaf seed was sown (2 plants/stand) at three plant spacing: 50×15, 50×20, 50×25 cm was assessed for seed and bast fibre yields using randomized complete block design (RCBD) with three replicates. The analysis was done using statistical analysis system (SAS). Plant spacing differed significantly for bast fibre and seed yields. Highest bast fibre yield (0.9±0.03) and seed yield (0.5±0.01) were obtained at 50×20 cm and 50×25 cm spacing, respectively, while the lowest bast fibre yield (0.7±0.01) and seed yield (0.3±0.01) were obtained at 50×15 cm spacing. Spacing of 50 × 15 cm and 50 × 20 cm are appropriate when planting for fibre while 50 × 25cm is appropriate for seed production. Keywords: Kenaf, Spacing, Fibre and Seed yield.



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