scholarly journals Assessing How Cultural Practices Influence Long-term Productivity in Asparagus

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 749D-749
Author(s):  
R. Seth Peterson* ◽  
Daniel Drost
Keyword(s):  
Root Biomass ◽  
Cultural Practices ◽  
Growth Dynamics ◽  
Growing Season ◽  
Plant Populations ◽  
Irrigation Methods ◽  
Site Monitoring ◽  
The Ideal ◽  
Harvest Pressure

Asparagus producers have reported a decrease in plant longevity and plant productivity in asparagus fields. Eleven commercial sites (6 in California and 5 in Washington) were monitored starting in Spring 2003. The purpose in monitoring was to evaluate how long-term growth dynamics are affected by harvest pressure. Sites were planted as crowns in Spring 2002 and farm irrigation methods included furrow, sprinkler, and drip. Most sites were harvested starting in Spring 2003 at varying pressures. Harvest yields ranged from 0 to 1300 kg·ha-1. Carbohydrate (CHO) levels in the roots were sampled over the entire growing season and assessed with AspireUS (www.aspireus.com). At the last sampling in Oct. and Nov. 2003, CHO levels ranged from 438 mg·g-1 to 712 mg·g-1 (97% to 158% of the ideal). This resulted in a root CHO load of 2.6 to 6.3 megagrams/hectare. Root mass and distribution was sampled in Spring 2003 and again at the end of the growing season. Root biomass increased by 18% to 487% of the previous year's growth. Fern number, fern mass and plant population were also sampled. Fern number ranged from 3.2 to 6.4 stems per plant and total fern weight ranged from 8.9 to 36.2 megagrams/hectare. Plant populations were reduced by 3% to 19% when compared to the initial planted population. Findings suggest that excessive harvest pressure in the year after planting adversely affects storage CHO accumulation and root growth. Additional site monitoring will occur through 2005.

Growth dynamics of cotton-grass (Eriophorum vaginatum)

1988 ◽  
Vol 66 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Jochen Kummerow ◽  
James N. Mills ◽  
Barbara A. Ellis ◽  
Andre Kummerow
Keyword(s):  
Root Biomass ◽  
Leaf Growth ◽  
Growth Dynamics ◽  
Growing Season ◽  
Root Surface ◽  
Early Spring ◽  
The Arctic ◽  
Leaf Biomass ◽  
Root Surface Area ◽  
Eriophorum Vaginatum

Root and leaf growth of the arctic sedge Eriophorum vaginatum L. were studied from early spring (June 7) to early fall (August 7) in the foothills of the Brooks Range in northern Alaska. The observations were designed to test the hypothesis that root and leaf growth occur at similar rates. The results confirmed this hypothesis. The root/leaf biomass ratio remained constant over the growing season. Thus, root biomass can be estimated based on harvested leaf biomass. It was also shown that root and leaf surface areas can be calculated from the respective biomass values. However, changes in the specific weights of leaves and roots over the growing season would affect the accuracy of root biomass or root surface area predictions.

Influence of Pruning and Irrigation on Root Longevity of `Concord' Vines

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 511a-511
Author(s):  
L.H. Comas ◽  
D.M. Eissenstat ◽  
A.N. Lakso ◽  
R. Dunst
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Cultural Practices ◽  
Growing Season ◽  
Root Production ◽  
Root Dynamics ◽  
Supplemental Irrigation ◽  
Root Longevity ◽  
Root Lifespan ◽  
Median Lifespan

Improved cultural practices in grape require a better understanding of root growth and physiology. Seasonal root dynamics were examined in mature `Concord' vines with balanced or minimal-pruning, and with or without supplemental irrigation in Fredonia, N.Y. Fine roots were continuously produced during the growing season starting in mid-June around time of bloom. Roots began to die in September at verasion. Minimal-pruned vines produced more roots than balanced-pruned vines, with the minimal-pruned/unirrigated vines producing the most roots. Irrigation and pruning delayed fine root production at the beginning of the growing season. Peak fine root flush was 16 June to 21 July 1997 for the minimal-pruned/unirrigated treatment, while peak flush was 7 July to 2 Sept. 1997 for balanced-pruned/irrigated treatment. In minimal-pruned vines, many roots were observed down to depths of 120 cm. In contrast, balanced-pruned vines had very few fine roots deeper than 40 cm. From initial observations, median lifespan of fine roots was 5 to 9.5 weeks, depending on treatment and depth in soil. Fine roots lived longer in the top 15-cm than in the 16- to 30-cm layer of soil in all treatments. Both minimal pruning and irrigation increased root lifespan. Fine roots had the shortest lifespan in the balanced-pruned/unirrigated treatment and the longest lifespan in the minimal-pruned/irrigated treatment.

scholarly journals Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 943
Author(s):  
Katri Nissinen ◽  
Virpi Virjamo ◽  
Antti Kilpeläinen ◽  
Veli-Pekka Ikonen ◽  
Laura Pikkarainen ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Root Biomass ◽  
Growing Season ◽  
Silver Birch ◽  
Shoot Biomass ◽  
Growth Responses ◽  
Growing Seasons ◽  
Simulated Climate ◽  
Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

scholarly journals Development of single-cell-level microfluidic technology for long-term growth visualization of living cultures of Mycobacterium smegmatis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Han Wang ◽  
Gloria M. Conover ◽  
Song-I Han ◽  
James C. Sacchettini ◽  
Arum Han
Keyword(s):  
Drug Treatment ◽  
Single Cell ◽  
Mycobacterium Smegmatis ◽  
Culture Media ◽  
Low Cost ◽  
Bacterial Pathogen ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Phenotype

AbstractAnalysis of growth and death kinetics at single-cell resolution is a key step in understanding the complexity of the nonreplicating growth phenotype of the bacterial pathogen Mycobacterium tuberculosis. Here, we developed a single-cell-resolution microfluidic mycobacterial culture device that allows time-lapse microscopy-based long-term phenotypic visualization of the live replication dynamics of mycobacteria. This technology was successfully applied to monitor the real-time growth dynamics of the fast-growing model strain Mycobacterium smegmatis (M. smegmatis) while subjected to drug treatment regimens during continuous culture for 48 h inside the microfluidic device. A clear morphological change leading to significant swelling at the poles of the bacterial membrane was observed during drug treatment. In addition, a small subpopulation of cells surviving treatment by frontline antibiotics was observed to recover and achieve robust replicative growth once regular culture media was provided, suggesting the possibility of identifying and isolating nonreplicative mycobacteria. This device is a simple, easy-to-use, and low-cost solution for studying the single-cell phenotype and growth dynamics of mycobacteria, especially during drug treatment.

On the long-term strength of metals and the ideal-creep model

2007 ◽  
Vol 52 (7) ◽  
pp. 388-390
Author(s):  
A. M. Kovrizhnykh
Keyword(s):  
Creep Model ◽  
Term Strength ◽  
The Ideal

Long‐term growth dynamics of natural forests in Hokkaido, northern Japan

1999 ◽  
Vol 10 (6) ◽  
pp. 815-824 ◽  
Author(s):  
Kiyoshi Umeki ◽  
Kihachiro Kikuzawa
Keyword(s):  
Growth Dynamics ◽  
Natural Forests ◽  
Northern Japan

Long-term experimentally deepened snow decreases growing-season respiration in a low- and high-arctic tundra ecosystem

2016 ◽  
Vol 121 (5) ◽  
pp. 1236-1248 ◽  
Author(s):  
Philipp R. Semenchuk ◽  
Casper T. Christiansen ◽  
Paul Grogan ◽  
Bo Elberling ◽  
Elisabeth J. Cooper
Keyword(s):  
Growing Season ◽  
Arctic Tundra ◽  
High Arctic ◽  
Tundra Ecosystem

Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) Populations and Fisheries of the Red Lakes, Minnesota, 1930–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.
Keyword(s):  
Growth Rate ◽  
Yellow Perch ◽  
Climatic Factors ◽  
Perca Flavescens ◽  
Growing Season ◽  
Commercial Fishery ◽  
Class Strength ◽  
Parent Stock ◽  
Catch Statistics

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield

Precision in Central Venous Catheter Tip Placement: A Review of the Literature

2010 ◽  
Vol 15 (3) ◽  
pp. 112-125 ◽  
Author(s):  
Russell Hostetter ◽  
Nadine Nakasawa ◽  
Kim Tompkins ◽  
Bradley Hill
Keyword(s):  
Central Venous Catheter ◽  
Selection Criteria ◽  
Weighted Average ◽  
Venous Catheter ◽  
Central Venous ◽  
Catheter Tip ◽  
Tip Position ◽  
Landmark Technique ◽  
The Ideal

Abstract Background: Long term venous catheters have been used to deliver specialized therapies since 1968. The ideal tip position of a central venous catheter provides reliable venous access with optimal therapeutic delivery, while minimizing short-and long-term complications. Ideal position limits have evolved and narrowed over time, making successful placement difficult and unreliable when depending exclusively on the landmark technique. Objective: To review and analyze contemporary literature and calculate an overall accuracy rate for first attempt placement of a PICC catheter in the ideal tip position. Methods: Key PICC placement terms were used to search the database PubMED-indexed for MEDLINE in June and October, 2009. The selection of studies required: a patient cohort without tip placement guidance technology; a documented landmark technique to place catheter tips; data documenting initial catheter placement and, that the lower third of the SVC and the cavo-atrial junction (CAJ) were included in the placement criteria. With few exceptions, articles written between 1993 and 2009 met the stated selection criteria. A composite of outcomes associated with tip placement was analyzed, and an overall percent proficiency of accurate catheter tip placement calculated. Results: Nine studies in eight articles met the selection criteria and were included for analysis. Rates of first placement success per study ranged from 39% to 75%, with the majority (7/9) being single center studies. The combined overall proficiency of these studies calculated as a weighted average was 45.87%.

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