scholarly journals A Method to Evaluate White Spruce Cone Crops

1978 ◽  
Vol 54 (2) ◽  
pp. 88-91 ◽  
Author(s):  
R. F. Calvert
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Classification System ◽  
White Spruce ◽  
Crop Quality ◽  
Seed Collection ◽  
Poor Seed ◽  
Regression Techniques ◽  
Quality Rating ◽  
The Mean

The objective of this study was to investigate variation in cone size and seed production in Manitoba white spruce so that general guides to seed collection could be developed. Relationships were established using regression techniques which permitted the development of a three category cone crop classification system based on the probable yield of sound seed from cones. It is tentatively suggested to use this system, that the mean number of filled seed on one half of longitudinal cone sections be determined from a minimum of five to ten cones taken from all aspects of the top two to three m of each of six to ten dominant or co-dominant trees. A crop quality rating is then determined by relating this to a graph which indicates a Good, Fair or Poor seed yield.

Variable paths to seed production within the Kangaroo Valley cultivar of Lolium perenne

1991 ◽  
Vol 42 (1) ◽  
pp. 151 ◽  
Author(s):  
SG Shah ◽  
CJ Pearson ◽  
AC Kirby
Keyword(s):  
Seed Production ◽  
Lolium Perenne ◽  
Seed Yield ◽  
Low Temperatures ◽  
Seed Weight ◽  
Floral Development ◽  
Dry Weight ◽  
Daily Rate ◽  
Spike Number ◽  
The Mean

Components of seed yield were measured in an erect, early-flowering biotype and a prostrate, late-flowering biotype of Lolium perenne cv. Kangaroo Valley at temperatures from 15/10 to 24/19�C (12/12 h day/night). We aimed to determine if each biotype had distinctive components of seed yield, and if these varied according to temperature. The two biotypes had distinctive paths to seed yield. Seed yield per plant in an erect biotype depended more on seed weight per spike and less on spike number than in a prostrate biotype. The distinctive paths to seed yield, and relative stability in paths across temperatures, indicated that it was possible to select genotypes from within the Kangaroo Valley cultivar which had particular correlations among components of yield. Floral development was accelerated, but seed yield per plant and most of its components were reduced, at high temperature; only the mean daily rate of dry weight accumulation by individual seeds was the same at all temperatures. At any temperature, seed weight per spike declined almost linearly with lateness of spike emergence within a plant: spikes which emerged within 21 days of the earliest spike contributed 80% of the seed yield per plant. We conclude that biotypes can be selected within the Kangaroo Valley cultivar to have distinctive components of seed yield and, based on the two biotypes we studied, commercial seed production should be based at a location having relatively low temperatures.

INCREASE IN SEED PRODUCTION FROM NITROGEN FERTILIZATION OF NATIVE BEARDLESS WHEATGRASS

1962 ◽  
Vol 42 (2) ◽  
pp. 359-364
Author(s):  
J. E. Miltimore ◽  
J. L. Mason ◽  
C. B. W. Rogers
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Nitrogen Fertilization ◽  
Mean Annual Precipitation ◽  
Native Range ◽  
Maximum Increase ◽  
Acre Yield ◽  
The Mean ◽  
Preferred Species ◽  
Nitrogen Treatments

Nitrogen fertilization greatly increased pure seed yield of native beardless wheatgrass, Agropyron inerme, where the mean annual precipitation was 11 inches in the South Okanagan area of British Columbia. In one experiment in 1959, ammonium nitrate broadcast at 450 pounds of actual nitrogen per acre increased seed yield from 3.5 pounds per acre for the unfertilized plots to 17.5 pounds, a maximum increase of 400 per cent. One hundred and fifty pounds of actual nitrogen per acre increased seed yield 330 per cent and the 50-pound rate increased the yield of seed 140 per cent. At two other locations in 1961, unfertilized plots yielded 18.8 pounds of seed per acre; 150 pounds of actual nitrogen per acre increased seed yield to 59.2 pounds and the 50-pound treatment produced 46.5 pounds of seed per acre. Yield increases resulted from increases in spike production because weight of seed per spike was not increased by fertilization. Germination was not affected and per cent pure seed was slightly increased by the nitrogen treatments. This increase in seed production is considered favorable for the restoration of preferred species on depleted native range.

scholarly journals Genetic Analyses of Seed Yield in Onion

2001 ◽  
Vol 126 (5) ◽  
pp. 575-578 ◽  
Author(s):  
Eduardo Villanueva-Mosqueda ◽  
Michael. J. Havey
Keyword(s):  
Seed Production ◽  
Allium Cepa ◽  
Inbreeding Depression ◽  
Seed Yield ◽  
Significant Relationship ◽  
Inbred Lines ◽  
Production Environment ◽  
Male Sterile ◽  
Poor Seed ◽  
Seed Yields

Development of two-way onion (Allium cepa L.) hybrids is difficult due to poor seed yields on inbred female parents. Seed yield of onion is affected by inbreeding depression and the seed-production environment. A standard diallel was used to estimate combining abilities for seed yield among seven inbred onion lines. Males and hybrids differed significantly (P < 0.05) for seed yields. Combinations of relatively high-by-high seed-yielding inbred parents were not always the best combinations; combinations of medium-by-medium or medium-by-high seed yielders also produced good F1 seed yielders. For the seven inbred lines, significant correlations (P < 0.05) were observed between mean seed yield per bulb and scape height. Parent-offspring regressions revealed no significant relationship between seed yields of randomly selected, open-pollinated bulbs and their S1 families. Results indicate that relative seed yields of individual bulbs after self-pollination cannot be used to predict seed yields of progeny families. However, the seed yield of inbred lines of onion may reflect the potential seed yield of F1 male-sterile lines.

scholarly journals Twenty Years of Natural Loblolly and Shortleaf Pine Seed Production on the Crossett Experimental Forest in Southeastern Arkansas

2001 ◽  
Vol 25 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Michael D. Cain ◽  
Michael G. Shelton
Keyword(s):  
Seed Production ◽  
Shortleaf Pine ◽  
Seed Collection ◽  
Seed Supply ◽  
Pine Regeneration ◽  
Poor Seed ◽  
Collection Period ◽  
Pinus Taeda L ◽  
Natural Stands ◽  
Seed Crops

Abstract Loblolly and shortleaf pine (Pinus taeda L. and P. echinata Mill., respectively) seed crops were monitored for 20 consecutive years (1980–1981 through 1999–2000) using seed-collection traps in natural stands on the Upper Coastal Plain of southeastern Arkansas. Each seed-collection period began on October 1 and continued through the end of February of successive years. Sound seeds were separated from void seeds by use of a cut test. During 20 yr, sound seed production ranged from 0 to 2,000,000/ac. There were six bumper seed crops (>800,000 sound seeds/ac), nine good seed crops (40,000—800,000 sound seeds/ac), and five poor seed crops (<40,000 sound seeds/ac). Because no poor seed crops occurred back-to-back, the seed supply was adequate for successful natural pine regeneration over the entire monitoring period. During 8 yr of adequate seed production, when weekly seed counts were made, seed dispersal always peaked in early November; therefore, site preparation should be completed before November to maximize seedling catch. South. J. Appl. For. 25(1):40–45.

Effect of different levels of nitrogen and phosphorus on the forage and seed yield of ryegrass (Lolium perenne L.)

2005 ◽  
Vol 53 (3) ◽  
pp. 353-356
Author(s):  
◽  
Keyword(s):  
Seed Production ◽  
Lolium Perenne ◽  
Seed Yield ◽  
Dry Matter ◽  
Block Design ◽  
Nitrogen And Phosphorus ◽  
Randomized Block Design ◽  
Green Fodder ◽  
The Mean ◽  
Four Levels

Studies were made on the fodder and seed production of ryegrass (Lolium perenne L.) using twelve treatment combinations with four levels of nitrogen (30, 60, 90 and 120 kg/ha/cut) and three levels of phosphorus (0, 50 and 100 kg P2O5/ha), laid out in a randomized block design with four replications. The mean of two years indicated that nitrogen at 120 kg/ha/cut increased the green fodder (834 q/ha) and dry matter yield (129 q/ha) significantly over the lower doses. After leaving the same crop for seed production during mid-March, nitrogen at the rate of 60 kg/ha gave the highest seed yield (7.61 q/ha). Beyond this dose the seed yield decreased drastically due to lodging. Phosphorus at the rate of 50 kg P2O5/ha gave 5% higher dry matter (99.6 q/ha) and 7.4% higher seed yield (7.26 q/ha) over the control.

scholarly journals Irrigation Requirements for Seed Production of Three Leguminous Wildflowers of the U.S. Intermountain West

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 692-697 ◽  
Author(s):  
Clinton C. Shock ◽  
Erik B.G. Feibert ◽  
Alicia Rivera ◽  
Lamont D. Saunders ◽  
Nancy Shaw ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Cultural Practices ◽  
State University ◽  
Intermountain West ◽  
Spring Precipitation ◽  
Applied Water ◽  
Seed Collection ◽  
Yield Responses ◽  
Seed Yields

Increasing the supply of native wildflower seed is essential for restoring burned and degraded wildlands in the Intermountain West. Limitations to wildland seed collection necessitate development of effective cultural practices to improve reliability of seed production in agricultural fields. Irrigation trials were conducted over multiple years for three perennial species in the Fabaceae family [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright, Dalea searlsiae (A. Gray) Barneby, and Astragalus filipes Torr. ex A. Gray]. Each of the three species was grown at the Oregon State University Malheur Experiment Station, Ontario, OR and received 0, 100, or 200 mm·year−1 of drip irrigation in four equal biweekly increments during bud formation and flowering. Seed yield responses to irrigation were evaluated by linear and quadratic regression against 1) applied water, 2) applied water plus spring precipitation, 3) applied water plus winter and spring precipitation, and 4) applied water plus fall, winter, and spring precipitation. In general, seed yields responded quadratically to irrigation. Adding fall, winter, and spring precipitation to applied water improved the accuracy of estimated water requirements for maximum seed production of D. ornata and D. searlsiae. For D. ornata, the highest yields averaged 396 kg·ha−1 and ranged from 146 to 545 kg·ha−1. Averaged over 6 years, seed yield of D. ornata was highest with applied water plus fall, winter, and spring precipitation totaling 393 mm. For D. searlsiae, the highest yields averaged 260 kg·ha−1 and ranged from 51 to 424 kg·ha−1. Averaged over 6 years, seed yield of D. searlsiae was highest with applied water plus fall, winter, and spring precipitation totaling 412 mm. Seed yields of A. filipes ranged from 7 to 110 kg·ha−1 depending on year and averaged 40 kg·ha1 over 6 years. Seed yields of A. filipes did not respond to irrigation in any of the 5 years of testing.

scholarly journals Paclobutrazol Improves Sesame Yield by Increasing Dry Matter Accumulation and Reducing Seed Shattering Under Rainfed Conditions

2021 ◽  
Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  
Keyword(s):  
Leaf Area ◽  
Seed Production ◽  
Seed Yield ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
Total Biomass ◽  
Dry Matter Accumulation ◽  
Seed Shattering ◽  
Rainfed Conditions ◽  
Leaf Greenness

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.

Increase Longleaf Pine Seed Yields by Inhibiting Conelet Abortion

1987 ◽  
Vol 11 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Robert C. Hare
Keyword(s):  
Boric Acid ◽  
Seed Production ◽  
Seed Yield ◽  
Longleaf Pine ◽  
Foliar Spray ◽  
Seed Yields

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.

Interference and Seed Production by Common Lambsquarters (Chenopodium album) in Soybeans (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 113-118 ◽  
Author(s):  
S. Kent Harrison
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Chenopodium Album ◽  
Soybean Seed ◽  
Dry Weight ◽  
Threshold Level ◽  
Yield Reduction ◽  
Significant Treatment ◽  
Weed Biomass ◽  
Common Lambsquarters

Multiple regression and response surface plots were used to analyze the effects of common lambsquarters population density and interference duration on weed growth and soybean seed yield. Under favorable growing conditions in 1986, weed biomass production at all population densities and interference durations was four to five times that produced in 1987, under less favorable conditions. However, there was no significant treatment by year interaction for soybean seed yield reduction by common lambsquarters, and production of each kg/ha weed biomass resulted in an average soybean yield reduction of 0.26 kg/ha. Utilizing 5% yield loss as an arbitrary threshold level, the regression equation predicted a common lambsquarters density threshold of 2 plants/m of row for 5 weeks of interference after crop emergence and 1 plant/m of row for 7 weeks. Seed production by individual common lambsquarters plants was highly correlated (r=0.92) with weed dry weight, and seed production ranged from 30 000 to 176 000 seeds/plant.

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