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Book Water Relations Growth and Survival of Root wrenched Douglas fir Seedlings

Download or read book Water Relations Growth and Survival of Root wrenched Douglas fir Seedlings written by Mary L. Duryea and published by . This book was released on 1981 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 Growth and Survival of Root-Wrenched Douglas-fir Seedlings Root wrenching of seedlings (severing the roots 15 cm below the soil surface) was investigated as a nursery practice to improve growth and survival of field-planted Douglas-fir from six local seed sources in the Pacific Northwest. At lifting, shoots of wrenched seedlings were shorter, lighter, and had smaller diameters than those of unwrenched seedlings. Among seedlings from four of the seed sources, wrenching resulted in significantly lighter taproots but did not significantly affect lateral root and total root weights. There were no significant differences between these measurements among wrenched and unwrenched seedlings from the other two sources. Mainly because of lighter shoots, shoot-root ratios were smaller for wrenched than for unwrenched seedlings. In no case did root wrenching improve field height growth or survival after one year, and among four of the sources shoot growth was significantly less than that of unwrenched seedlings. Chapter 2 Water Relations of Root-wrenched Douglas-fir Seedlings Root wrenching was investigated as a nursery practice to precondition Douglas-fir seedlings to droughty field conditions. Wrenching shocked the seedlings while in the nursery, lowering plant water potential and transpiration rate. After planting, however, wrenched and unwrenched seedlings transpired at equal rates when exposed to stress with osmotic solutions of Polyethylene Glycol 1000 and under field conditions. Throughout exposure in pots to a drought simulating the Pacific Northwest summer drought, wrenched and unwrenched seedlings did not differ in plant water potential, leaf relative water content, or seedling condition. However, all wrenched seedlings of four seed sources reflushed in the middle of the drought and had significantly fewer active roots than unwrenched seedlings. Among the four seed sources used, differences in ability to withstand drought were apparent.

Book Water Relations and the Root Regeneration Response of Douglas fir

Download or read book Water Relations and the Root Regeneration Response of Douglas fir written by Cheryl Anne Cobb and published by . This book was released on 1977 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of lifting date and root-pruning treatments on water potential, root regeneration, and shoot growth of six-month-old and three-year-old Douglas-fir seedlings bare-root transplanted into a growth chamber, and sawdust bed, respectively, was studied. Root growth in six-month-old and three-year-old seedlings was highest in February and August respectively. Survival was highest in November for seedlings of both ages. The time to first root growth, water potential four weeks after transplanting, and survival were correlated. The possibility that the maintenance of plant turgor above the critical level necessary to allow root growth is important for survival of an actively growing transplant is discussed. The effect of root-pruning on transplant water potential, root growth and survival varied with season. In a second study six-month-old Douglas-fir seedlings were subjected to eight drying cycles in which the seedlings were allowed to dry to a -15 bar water potential before watering. Root growth, water potential, and survival of transplants were measured under stressed and control conditions. Water potential, soil moisture content and survival of seedlings subjected to a prolonged drying period were recorded. Preconditioning treatments were effective in increasing drought resistance under stress conditions. Reductions in shoot elongation, dry matter production, and early bud set were noted. Though inadvertant watering of the transplants made conclusions impossible, survival data and' data collected prior to watering indicate that root growth and survival were improved by the treatment.

Book Wrenching Douglas fir Seedlings in August

Download or read book Wrenching Douglas fir Seedlings in August written by William I. Stein and published by . This book was released on 1984 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Research Paper PNW

Download or read book Research Paper PNW written by and published by . This book was released on 1978 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Predicting Crown Weight of Coast Douglas fir and Western Hemlock

Download or read book Predicting Crown Weight of Coast Douglas fir and Western Hemlock written by J. A. Kendall Snell and published by . This book was released on 1981 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book General Technical Report RM

Download or read book General Technical Report RM written by and published by . This book was released on 1990 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Canadian Journal of Forest Research

Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 1987 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Forest Nursery Manual Production of Bareroot Seedlings

Download or read book Forest Nursery Manual Production of Bareroot Seedlings written by Mary L. Duryea and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: ing damage ranged from odor. to general visual appearance. Attributes of seedling quality are categorized as either to cutting buds. to scraping bark to detect dead cambium. performance attributes (RGP. frost hardiness. stress resistance) One nursery reported using frost hardiness as an indicator of or material attributes (bud dormancy. water relations. nutrition. when to begin fall lifting. but none reported using it as an morphology). Performance attributes are assessed by placing indicator of seedling quality before shipping stock to customers. samples of seedlings into specified controlled environments and evaluating their responses. Although some effective short 23.4.3 Stress resistance cut procedures are being developed. performance tests tend Only three nurseries measure stress resistance. They use to be time consuming; however, they produce results on whole the services of Oregon State University and the test methods plant responses which are often closely correlated with field described in 23.2.3. One nursery reported that results of stress performance. Material attributes. on the other hand. reflect tests did not agree well with results of RGP tests and that RGP only individual aspects of seedling makeup and are often correlated better with seedling survival in the field. Most stress poorly correlated with performance. tests are conducted for reforestation personnel rather than for Bud dormancy status seems to be correlated. at least nurseries.

Book Proceedings of the Third Biennial Southern Silvicultural Research Conference Atlanta Georgia November 7 8 1984

Download or read book Proceedings of the Third Biennial Southern Silvicultural Research Conference Atlanta Georgia November 7 8 1984 written by Eugene Shoulders and published by . This book was released on 1985 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Research Paper INT

Download or read book Research Paper INT written by and published by . This book was released on 1986 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Forest and Conservation Nursery Associations

Download or read book Forest and Conservation Nursery Associations written by Thomas D. Landis and published by DIANE Publishing. This book was released on 1996-06 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: A compilation of 43 papers which covers: seed collection & processing, nursery cultural practices, harvesting storage & outplanting. Table of contents includes reforestation trends in the Eastern U.S., chemical alternatives to Methyl Bromide, Organic amendments as potential alternatives to Methyl Bromide for control of soil borne pathogens in forest tree nursuries.

Book Water Relations and Associated Morphology of Conditioned Douglas fir and Jack Pine Seedlings Subjected to Periods of Drought Stress microform

Download or read book Water Relations and Associated Morphology of Conditioned Douglas fir and Jack Pine Seedlings Subjected to Periods of Drought Stress microform written by Keith M. McClain and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 1986 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant post planting mortality of young conifer seedlings often occurs on drought prone sites because seedlings fail to either establish, or maintain favourable water relations. Survival is contingent upon growth which occurs when turgor pressure is above a threshold level. Since growth after planting is influenced by nursery cultural practices, it was hypothesized that survival may be enhanced by the effect of irrigation and nutrient conditioning on seedling water relations. Principal water relation parameters estimated by traditional and pressure-volume methods were evaluated in conditioned Douglas-fir and jack pine container seedlings during imposed drought stress in a growth room and outside in raised cold frames containing two soil types. Seedling morphology and ion concentrations in the roots were also determined. Initially, declines in plant water potential (psi) were paralleled by decreases in osmotic potential (psi pi), but as stress increased, differential declines resulted in turgor pressure (psi rho) being variously maintained depending upon irrigation and level of applied KCl. Estimates of tissue elasticity during drought stress suggested that turgor maintenance was the result of solute concentration through tissue dehydration, not osmotic adjustment. During a second drought stress, declines in (psi) and (psi pi) lead to marked increases in in some treatments. In jack pine, this continued to be the result of dehydration and concentration of solutes, but in Douglas-fir, osmotic adjustment was a factor in turgor maintenance. Variable water relations in either species could not he attributed to the accumulation of any particular ion. Only root area exhibited an increase during drought stress. Mortality during recovery was significantly higher in daily than weekly irrigated seedlings and was not influenced by the level of applied KCl. Post drought evaluation of growth potential of surviving seedlings revealed that neither conditioning treatment nor successive drought stress precluded growth. Under field conditions the progressions of water relation parameters were similar to those recorded in growth room conditions, but the rapidity of the responses were affected by soil type. Results suggested the occurrence of osmotic adjustment in Douglas-fir; restrained decline in turgor pressure in jack pine was clearly the result of concentration of salutes through dehydration. Mortality was confined entirely to Douglas-fir in the clay loam soil, but in the sandy soil both species, regardless of conditioning treatment, experienced mortality at low soil water availability.

Book General Technical Report INT

Download or read book General Technical Report INT written by and published by . This book was released on 1991 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: