doi: 10.1093/forestscience/22.4.z4pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1976 by the Society of American Foresters
doi: 10.1093/forestscience/22.4.z1pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1976 by the Society of American Foresters
Zaerr, Joe B.; Holbo, H. Richard
doi: 10.1093/forestscience/22.4.378pmid: N/A
A technique is described for measuring shoot elongation in seedlings of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) under various levels of water potential. The seedlings were grown from seed in plastic pots. A recording micrometer, with two displacement-sensing transducers, was attached to the shoot of one seedling in a pot. Changes in shoot length were measured and recorded continuously before and after soil in the pot was watered. This technique of using two devices that are differentially connected, instead of a single device, makes possible a significant reduction in errors of measurement. Two phases of shoot elongation were observed after watering. In phase I, the rate was rapid and probably caused by rehydration of plant tissue. In phase II, the rate was more constant and probably caused by cell elongation. Forest Sci. 22:378-382.
Zaerr, Joe B.; Holbo, H. Richard
doi: 10.1093/forestscience/22.4.378pmid: N/A
A technique is described for measuring shoot elongation in seedlings of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) under various levels of water potential. The seedlings were grown from seed in plastic pots. A recording micrometer, with two displacement-sensing transducers, was attached to the shoot of one seedling in a pot. Changes in shoot length were measured and recorded continuously before and after soil in the pot was watered. This technique of using two devices that are differentially connected, instead of a single device, makes possible a significant reduction in errors of measurement. Two phases of shoot elongation were observed after watering. In phase I, the rate was rapid and probably caused by rehydration of plant tissue. In phase II, the rate was more constant and probably caused by cell elongation. Forest Sci. 22:378-382.
Sullivan, Alfred D.; Reynolds, Marion R.
doi: 10.1093/forestscience/22.4.382pmid: N/A
Some consequences of using ordinary least squares estimation procedures with remeasurement data are explained. Of particular concern is the bias of variance estimates and alteration of the confidence coefficient for confidence intervals which result from correlations in the data. Results are presented allowing consideration of the problem's severity for data with two repeated measurements. Finally, alternative estimation procedures including generalized least squares and maximum likelihood are discussed. Forest Sci. 22:382-385.
Sullivan, Alfred D.; Reynolds, Marion R.
doi: 10.1093/forestscience/22.4.382pmid: N/A
Some consequences of using ordinary least squares estimation procedures with remeasurement data are explained. Of particular concern is the bias of variance estimates and alteration of the confidence coefficient for confidence intervals which result from correlations in the data. Results are presented allowing consideration of the problem's severity for data with two repeated measurements. Finally, alternative estimation procedures including generalized least squares and maximum likelihood are discussed. Forest Sci. 22:382-385.
Goyer, Richard A.; Nachod, Lothar H.
doi: 10.1093/forestscience/22.4.386pmid: N/A
Insects destroyed 75 percent of developing loblolly pine cones and caused an additional 10 percent reduction in seed yield of the surviving cones. Coneworms, Dioryctria spp., were responsible for most of the destruction, killing 56.7 percent of the cones. Other insects responsible for lesser amounts of damage were the seedbugs Tetrya bipunctata (H & S) and Leptoglossus corculus (Say), the Nantucket pine tip moth Rhyacionia frustrana (Comstock), and a thrips, possibly Gnophothrips fuscus (Morgan). More than 88 percent of the total damage occurred in 1973 during the first 6 months of conelet development. Damage to cones in 1974 was attributed almost entirely to Dioryctria spp. Radiographs of seed from surviving cones revealed that seedbug feeding accounted for the 10 percent seed loss, and seedworms, Laspeyresia spp., less than 1 percent. Damage by the various pest species to the different clones was not significantly different when analyzed statistically. Forest Sci. 22:386-391.
Goyer, Richard A.; Nachod, Lothar H.
doi: 10.1093/forestscience/22.4.386pmid: N/A
Insects destroyed 75 percent of developing loblolly pine cones and caused an additional 10 percent reduction in seed yield of the surviving cones. Coneworms, Dioryctria spp., were responsible for most of the destruction, killing 56.7 percent of the cones. Other insects responsible for lesser amounts of damage were the seedbugs Tetrya bipunctata (H & S) and Leptoglossus corculus (Say), the Nantucket pine tip moth Rhyacionia frustrana (Comstock), and a thrips, possibly Gnophothrips fuscus (Morgan). More than 88 percent of the total damage occurred in 1973 during the first 6 months of conelet development. Damage to cones in 1974 was attributed almost entirely to Dioryctria spp. Radiographs of seed from surviving cones revealed that seedbug feeding accounted for the 10 percent seed loss, and seedworms, Laspeyresia spp., less than 1 percent. Damage by the various pest species to the different clones was not significantly different when analyzed statistically. Forest Sci. 22:386-391.
Solomon, Dale S.; Shigo, Alex L.
doi: 10.1093/forestscience/22.4.391pmid: N/A
Vertical extension of discolored wood associated with 8-year-old pruning wounds on yellow birch was shown by regression analysis to be significantly associated with wound size. All columns of discolored wood were associated with wounds and were confined to the tissues present when the trees were pruned. There were no significant relationships between presence or absence of Hymenomycetes associated with decay and time of closure or size of wound. Forest Sci. 22:391-392.
Solomon, Dale S.; Shigo, Alex L.
doi: 10.1093/forestscience/22.4.391pmid: N/A
Vertical extension of discolored wood associated with 8-year-old pruning wounds on yellow birch was shown by regression analysis to be significantly associated with wound size. All columns of discolored wood were associated with wounds and were confined to the tissues present when the trees were pruned. There were no significant relationships between presence or absence of Hymenomycetes associated with decay and time of closure or size of wound. Forest Sci. 22:391-392.
Showing 1 to 10 of 52 Articles