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Full-Text Articles in Life Sciences

Wood Of Giant Sequoia: Properties And Unique Characteristics, Douglas D. Piirto May 1985

Wood Of Giant Sequoia: Properties And Unique Characteristics, Douglas D. Piirto

Natural Resources Management and Environmental Sciences

Wood properties of giant sequoia (Sequoia gigantea [Lindl.] Decne.) were compared with those for other coniferous tree species. Wood properties such as specific gravity, various mechanical properties, extractive content, and decay resistance of young-growth giant sequoia are comparable to or more favorable than those of coast redwood (Sequoia sempervirens [D. Don] Endl.). It is recommended that giant sequoia be considered for planting stock in managed production forests to increase future supplies of wood having the characteristics so highly valued in coast redwood and other decay-resistant species


Heat Tolerance Of Kentucky Bluegrass As Influenced By Pre- And Post-Stress Environment, David J. Wehner, D. D. Minner, P. H. Dernoeden, M. S. Mcintosh May 1985

Heat Tolerance Of Kentucky Bluegrass As Influenced By Pre- And Post-Stress Environment, David J. Wehner, D. D. Minner, P. H. Dernoeden, M. S. Mcintosh

Office of the Dean (CAFES) Scholarship

An understanding of the natural variation in heat tolerance of Kentucky bluegrass is needed to develop predictive models for stress tolerance. The variation in heat tolerance of ‘Adelphi’ Kentucky bluegrass (Poa pratensis L.) over the growing season and the effect of recovery environment on the perceived heat tolerance of the plants was determined. Field-grown plants (Chillum silt loam, fine-silty, mixed, mesic Typic Hapludults) were exposed to heat stress on 11 dates over two growing seasons by immersion in a water bath for 30 min at either 42, 44, or 46°C and then placed in either a greenhouse, or one ...


Lectotypification Of Pectis L. (Asteraceae), David J. Keil May 1985

Lectotypification Of Pectis L. (Asteraceae), David J. Keil

Biological Sciences

Linnaeus (1975a) described Pectis and included within it two species, P. ciliaris and P. linifolia. In 1913 Britton and Brown designated P. ciliaris as the lectotype for Pectis. This lectotypification was accepted by the editors of Index Nominum Genericorum (Plantarum) (Farr et al., 1979). I will present evidence below that the lectotypification of Pectis by Britton and Brown was superfluous and that Pectis was actually lectotypified over 90 years earlier by Cassini.


A Microecosystem For Fertilizer And Pesticide Fate Research, B. E. Branham, David J. Wehner, W. A. Torello, A. J. Turgeon Jan 1985

A Microecosystem For Fertilizer And Pesticide Fate Research, B. E. Branham, David J. Wehner, W. A. Torello, A. J. Turgeon

Office of the Dean (CAFES) Scholarship

A microecosystem was designed to study the behavior of pesticides, fertilizers, or related compounds applied to plant stands. The system consists of three parts: a brass base that holds the plant growth media, a glass atmospheric chamber that rests on the base, and a set of analytical traps. The brass base is fitted with a porous ceramic plate so that tension can be applied to the water in the growing media. Air enters the bottom of the glass atmospheric chamber and exits through the top into appropriate trapping systems to recover volatilized pesticides, ammonia, or metabolized 14CO2 from ...


Estimates Of Soil Solution Ionic Strength And The Determination Of Ph In West Australian Soils, P. J. Dolling, G. S.P. Ritchie Jan 1985

Estimates Of Soil Solution Ionic Strength And The Determination Of Ph In West Australian Soils, P. J. Dolling, G. S.P. Ritchie

Food Science and Nutrition

The average ionic strength of 20 West Australian soils was found to be 0.0048. The effects of three electrolytes (deionized water, CaCl2 and KNO3), three ionic strengths (0.03, 0.005 and soil ionic strength at field capacity, Is) and two soil liquid ratios (1:5 and 1:10) on the pH of 15 soils were investigated. pH measurements in solutions of ionic strength 0.005 differed the least from measurements made at Is. The differences that occurred in comparisons with distilled water or CaCl2 of ionic strength 0.03 (0.01 M) were ...


The Fate Of Diazinon Applied To Thatched Turf, B. E. Branham, David J. Wehner Jan 1985

The Fate Of Diazinon Applied To Thatched Turf, B. E. Branham, David J. Wehner

Office of the Dean (CAFES) Scholarship

Diazinon (0,0-diethyl-0-(2-isopropyl-6-methyl-4-primidinyl) phosphorothioate) is widely used to control turfgrass insect pests. Poor control of soil-inhabiting insects has been found where diazinon has been applied to thatched turfgrass stands. The purpose of this study was to evaluate the environmental fate of diazinon applied to turfgrass stands. A microecosystem was used to follow the fate of radiolabeled diazinon surface applied to Kentucky bluegrass (Poa pratensis L.) turfs, with or without a thatch layer, growing on Flanigan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) irrigated daily or every 4 days. Loss of diazinon by volatilization, leaching, and degradation accompanied by release ...


The Role Of Organic Matter In Soil Acidification, G. S.P. Ritchie, P. J. Dolling Jan 1985

The Role Of Organic Matter In Soil Acidification, G. S.P. Ritchie, P. J. Dolling

Food Science and Nutrition

The pH and buffer capacity of two soils increased or remained constant after incubation with different amounts of plant material (lucerne cham at field capacity and when air dry. For both soils, the pH changes were greater at field capacity, whereas the buffer capacities were independent of the water treatments. The pH changes observed could be explained in terms of the organic anion concentration of the plant material. The results indicate that the initial soil pH and the anion concentration (i.e. the per cent dissociation of soluble organic acids when released into the soil) determine the acidifying effect of ...