Seed production in forests of Chamaecyparislawsoniana

1979 ◽  
Vol 9 (3) ◽  
pp. 327-335
Author(s):  
Donald B. Zobel
Keyword(s):  
Seed Production ◽  
Reproductive Potential ◽  
Basal Area ◽  
Annual Production ◽  
Forest Community ◽  
Regional Pattern ◽  
Crop Size ◽  
Seed Collection ◽  
Open Forest ◽  
Seed Crops

In 3 years of seed collection throughout the range of Chamaecyparislawsoniana (A. Murr.) Parl., 30 seed crops varied from 20 000 to 4 600 000 seeds per hectare. The overall mean was 829 000 seeds per hectare per year. Annual production per square metre of basal area (BA) varied from 600 to 185 000. Only 6 of 30 seed crops exceeded 50 000 seeds/m2 BA per year but these were produced by the youngest (65 year old) and oldest (450 + year old) stands and throughout the environmental range of the species. Of other seed crops, 11 had 10 000–50 000 seeds/m2 BA per year and 13 had fewer than 10 000 seeds/m2 BA per year. Year-to-year variation had a local, not regional, pattern. An open-forest community produced more seed per square metre of basal area than a denser one at two mixed evergreen zone sites. Seedfall peaked from October to November, with a smaller spring peak, but some seeds fell throughout the year. Most sites differed little in the timing of peaks. Germination of trapped seed from seven sites in 1 year was 11–44% and showed no correlation with crop size. Other species in this genus produce many more seeds per hectare than C. lawsoniana but there is no evidence that seed production limits reproductive potential of this species. In mixed forests, C. lawsoniana and especially Tsugaheterophylla (Raf.) Sarg. were over represented in the seedfall (compared with their basal area), whereas Pseudotsugamenziesli (Mirb.) Franco and Abiesconcolor (Gordon and Glend.) Lindl. ex Hildebr. produced less than their share.

scholarly journals Consistency of Cone Production in Individual Red Pine

1988 ◽  
Vol 64 (6) ◽  
pp. 480-484 ◽  
Author(s):  
W. M. Stiell
Keyword(s):  
Seed Production ◽  
Tree Growth ◽  
Basal Area ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Tree Size ◽  
Total Production ◽  
Crop Size ◽  
Cone Production ◽  
Production Area

A plantation of red pine (Pinus resinosa Ait.) produced heavy cone crops in 1970 and 1984. Established at 6.5 × 6.5 m, the stand was 18-years old in 1970 and still open-grown; crowns were closed before 1984. Cone production at the two dates was compared for 28 trees. While total production was similar for 1970 and 1984, distribution within the sample differed. Although 18% of the trees maintained their rank in 1984, some large changes in production ranking took place from one crop to the next. Despite a tendency at both dates for crop size to increase with current dbh, exceptions were evident and the largest trees did not necessarily bear the most cones. Crop size in 1970 was the variable most closely associate with 1984 crop size and was significantly correlated with it independently 1984 dbh. High cone production did not seem to depress tree growth, based on a comparison of 1970-72 basal area increment of more versus less prolific cone bearers. Before a stand has borne its first good cone crop, expectations for highest yields would have to be based on tree size. For subsequent crops, previous production by individuals would be the best guide. The two top cone bearers far surpassed all others in both crop years and would be the first individuals selected for seed trees in a seed production area.

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.

Structure and Regeneration of Sal (Shorea robusta Gaertn. f.) Forests in Shiwalik Region of Kumaun Himalaya, India

2017 ◽  
Vol 40 (1) ◽  
pp. 1-8
Author(s):  
Bhawna Adhikari ◽  
◽  
Bhawana Kapkoti ◽  
Neelu Lodhiyal ◽  
L.S. Lodhiyal ◽  
...  
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Tree Canopy ◽  
Canopy Density ◽  
Kumaun Himalaya ◽  
Shorea Robusta ◽  
Canopy Trees ◽  
Dense Forest ◽  
Open Forest ◽  
Sal Forest

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.

Sugar beet seed production and marketing in the United Kingdom

1975 ◽  
Vol 8 (5) ◽  
pp. 284-289
Keyword(s):  
United Kingdom ◽  
Sugar Beet ◽  
Seed Production ◽  
The United Kingdom ◽  
Seed Crops ◽  
The Impact

Sugar beet differs from most other farm seed crops, in that “varieties” are mixtures of hybrids from a blend of genotypes. Growing and processing are two equally important aspects of seed production. In this article, cultural and harvesting methods are described, and processing and marketing procedures are briefly outlined. The impact of EEC regulations affecting seeds is also considered.

scholarly journals Container Flow-Transport Technology of Selection Grain Production

2018 ◽  
Vol 12 (6) ◽  
pp. 20-24
Author(s):  
Mikhail L. Kryukov ◽  
Viktor K. Pyshkin ◽  
Andrey S. Chulkov ◽  
Svetlana V. Vlasova ◽  
Maksim V. Ivanov ◽  
...  
Keyword(s):  
Seed Production ◽  
Central Region ◽  
Technical Equipment ◽  
Grain Production ◽  
Crop Processing ◽  
Seed Collection ◽  
Flow Transport ◽  
Cargo Capacity ◽  
Complex Technology ◽  
And Storage

Abstract. Low-level mechanization is one of the main reasons for the high costs in selection and primary seed production. Crop breeders use transport and loading facilities for seed material transporting in an unsystematic manner. (Research purpose) Development of technology of transport support in selection and seed production, including all transport and loading processes of the delivery of grain seeds from selection combines to storage facilities using containers for seed collection, transportation, drying, and storage. (Materials and methods) The authors have described a container flowtransport technology of selection grain harvesting at the stage of primary reproduction and developed a machine complex technology and a database of harvesting and transport machines for seed collection, transportation, drying, and storage. (Results and discussion) The authors have determined the type of transport and loading means for the container method of seed harvesting, transportation and storage recommended for use in selection and seed production. There are four distinctive novelty positions of the presented type: the ability to transport containers in 2 rows; increased loading height from 2 m to 3 m; maximum operating radius reaches 3.8 m (vs. 2.7 m); increased cargo capacity – by 460 kg. (Conclusions) The authors suggest using the developed methodology to improve the technological process of harvesting, transportation and postharvest processing of seed grain, organize this process, as well as select machine parameters and technical equipment on the farms of the Central region of Russia. It has been suggested that test prototypes of containers and a loader with a container tilter should be designed and manufactured for use in primary crop processing.

Insects Affecting Seed Production in Red Pine: Part I Conophthorus resinosae Hopk. (Coleoptera: Scolytidae)

1956 ◽  
Vol 88 (10) ◽  
pp. 599-608 ◽  
Author(s):  
L. A. Lyons
Keyword(s):  
Seed Production ◽  
Pacific Coast ◽  
Large Numbers ◽  
The Pacific ◽  
Future Success ◽  
Loblolly Pines ◽  
Unfavourable Weather ◽  
Cone And Seed Insects ◽  
Seed Crops ◽  
Seed Insects

Natural and artificial reforestation, which basically depend on an abundance of sound seed, are adversely affected when insects destroy large numbers of cones, seeds, and cone-bearing shoots. Other factors, such as unfavourable weather, incomplete seed development, and damage by birds and mammals also reduce seed production, but they are rarely of such widespread importance as insects, whose damage often results in the failure of seed crops over large areas. Cone and seed insects sometimes restrict the natural regeneration of trees for a few years at a time, as, for example, in conifers on the Pacific coast (16), loblolly pines in Virginia (13), and oak in Michigan (5), but they become particularly important when the seeds they destroy are required for use in artificial reforestation. The future success of much reforestation, which is inclining more and more toward the use of seed obtained from trees cultivated especially for that purpose, may largely depend on a thorough understanding of cone and seed insects and their effect on seed production.

scholarly journals Shortleaf Pine Seed Production in Natural Stands in the Ouachita and Ozark Mountains

1996 ◽  
Vol 20 (2) ◽  
pp. 74-80 ◽  
Author(s):  
Michael G. Shelton ◽  
Robert F. Wittwer
Keyword(s):  
Seed Production ◽  
Natural Regeneration ◽  
Stand Age ◽  
Good Seed ◽  
Pinus Echinata ◽  
Ozark Mountains ◽  
Shortleaf Pine ◽  
Natural Stands ◽  
Seed Crops ◽  
Production Areas

Abstract Seed production of shortleaf pine (Pinus echinata Mill.) was monitored from 1965 to 1974 to determine the periodicity of seed crops in both woods-run stands and seed-production areas. One bumper and two good seed crops occurred during the 9-yr period. The two largest crops occurred in successive years, then seed production was low for 4 yr before another good crop occurred. Mean annual seed production ranged from 84,000/ac in the western Ouachitas to 167,000/ac in seed-production areas in the southern Ozarks. Certain stand-level variables significantly influenced seed production. Seed production was positively related to stand age and negatively related to pine and hardwood basal areas; although frequently significant, no consistent relationship occurred with stand elevation. Results indicate that shortleaf pine seed production will usually be adequate for natural regeneration within most of the study area. South. J. Appl. For. 20(2):74-80.

scholarly journals Substantiation of the parameters of a typical seed-growing farms of the republic of kazakhstan on the basis of digitalization of seed production

2019 ◽  
Vol 126 ◽  
pp. 00064
Author(s):  
A.S Alchimbayeva ◽  
Lyudmila Shibryaeva ◽  
Zharylkasyn Sadykov ◽  
Mikhail Chaplygin ◽  
Rizvankoul Kaimova
Keyword(s):  
Seed Production ◽  
The State ◽  
Seed Collection ◽  
Average Area ◽  
First Category ◽  
The Republic ◽  
Total Seed ◽  
Second Category ◽  
Seed Growing ◽  
Research Institute

In general, the state of seed production in Kazakhstan can be characterized by the following figures. According to Kostanay branch of Kazakh research Institute of mechanization and electrification of agriculture total requirement of seeds is around 2 million tons. These farms provide 70% of the Republic'sfarms with seeds, the remaining 30% are imported from Russia. The studies have shown that all grain-producing regions of Kazakhstan can be classified into three categories according to the annual gross grain harvest, respectively, 16; 15; 3.26 and 2.9 million tons. It is advisable that typical seed farms have the following characteristics: in the first category of regions — the average area of one farm — 2.8 thousand hectares, the average annual grain harvest — 8.06 thousand tons, agro term — 10 days, the required total seed collection -1.78 million tons for all seed farms in the amount of 220 units. Accordingly, in the second category of regions — 1100 hectares; 2.82 thousand tons; 9.5 days 360 thousand tons and 128 units. In a third category — 322 hectares of 1.02 million tons, or 9.1 days, 320 thousand tons and 312 units. Total number of typical specialized farms should be approximately 660 units.

Long-Term Development of Regeneration Under Longleaf Pine Seedtree and Shelterwood Stands

1993 ◽  
Vol 17 (1) ◽  
pp. 10-15 ◽  
Author(s):  
William D. Boyer
Keyword(s):  
Seed Production ◽  
Seedling Establishment ◽  
Longleaf Pine ◽  
Basal Area ◽  
Pinus Palustris ◽  
Stand Density ◽  
Distribution Characteristic ◽  
Volume Increment ◽  
Potential Impact

Abstract Well-stocked mature longleaf pine (Pinus palustris Mill.) stands were cut to five residual basal areas in 1957, namely 9, 18, 27, 36, and 45 ft² per ac, to observe the effect of stand density on seed production and seedling establishment. Seedlings, mainly from the 1955 or 1961seed crops, were established in treated stands. All pines on net 0.9 ac plots were remeasured in 1991 to determine the effect of residual pine density on development of the regeneration. Even the lightest residual overstory converted the structure of 29- to 35- yr-old ingrowth into the reverse-Jdiameter class distribution characteristic of uneven-aged stands. Four or six residual trees, now comprising 7 to 10 ft² basal area (ba)/ac, reduced ingrowth basal area to about half that of same-aged stands released from overstory competition. Merchantable volume of ingrowth under theselow residual densities averaged 40% of that in released stands. Mean annual per ac volume increment of ingrowth averaged 21 to 22 ft³ under the 9 ft² density but did not exceed 7 ft³ under any residual density above this. The potential impact of significant growth reductionsshould be taken into account when considering uneven-aged management methods for longleaf pine. South. J. Appl. For. 17(1):10-15.

Effect of shallow, rotary cultivation with vertical tines and nitrogen fertilization on the seed productivity of creeping red fescue

2002 ◽  
Vol 82 (4) ◽  
pp. 709-719
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Yield Response ◽  
Physiological Status ◽  
Rotor Speed ◽  
Red Fescue ◽  
Time Of Application ◽  
River Region ◽  
Harvest Year ◽  
Seed Crops

A field study in the Peace River region of north-western Canada evaluated the effect of shallow rotary cultivation with vertical tines on the seed production of stands of creeping red fescue (Festuca rubra L. var. rubra). At four sites, rotary cultivation treatments (None, Low, Medium and High tine rotor speed) were applied after the harvest of the first and second seed crops, in factorial combination with the time of application of 68 kg ha-1 N fertilizer (Early fall, Late fall, and Split 1:1 early:late fall). In harvest years 2 and 3, the effect of site on seed yield per unit land area was modified by both N and rotary cultivation. In harvest year 2, seed yield at Site 1 was increased greatly by rotary cultivation, regardless of the tine rotor speed, but there was little difference among the four cultivation treatments at the other three sites. In harvest year 3, seed yield was increased with Low, Medium and High rotary cultivation to 6- to 11-fold that without rotary cultivation at Sites 1 and 2 but only to 1.4- to 2-fold at Sites 3 and 4. Seed yield response to rotary cultivation was dependent on site and year, a reflection of the physiological status of the fescue plants at each specific site. Rotary cultivation treatments may have been too detrimental to tiller growth and development for sustaining and enhancing seed yield, particularly at Sites 3 and 4 prior to harvest year 2. There was no consistent pattern of response in seed yield among the four sites to the three N treatments in either harvest year 2 or 3. Although there was a significant (P < 0.001) N × rotary cultivation interaction for seed yield in harvest year 3, the pattern among cultivation treatments was generally similar for each N treatment; compared to no cultivation, the three cultivation treatments more than doubled seed yield to 255–322 kg ha-1 with Early and Split N and increased it 4- to 6-fold to 203–288 kg ha-1 with Late N. There is some potential for rotary cultivation, but the selected treatments were generally too aggressive in suppressing tillers. Key words: Rejuvenation of creeping red fescue, mechanical rejuvenation, rotary cultivation, power-harrowing, grass seed production

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