Treesearch

The use of biological agents to control plant diseases is an attractive approach, especially at a time when managers and other stakeholders seek to limit the impact of synthetic pesticides. Further, chemical pesticides cannot be used in natural habitats because of their expense and potential negative effects on ecosystems.

In collaboration with the Suzano Papel and Celulose SA company, we identified an anomaly derived from a full-sib population in a controlled cross between two Eucalyptus grandis individuals. Abnormal seedlings died in a few months and showed significant phenotypic differences (P < 0.05), including seedling height, seedling stem-base diameter, and individual leaf area, compared with normal seedlings. Previous genetic analysis of the full-sib progeny showed a Mendelian segregation of 3 (normal): 1 (abnormal) (X2 = 2.32, P > 0.1), suggesting that the lethality phenotype is controlled by a...

Coir is a natural, lignin rich, fber that can be found between the hard internal shell and the outer coat of a coconut. There are multiple products made from coir fbers but a signifcant amount of fbers accumulating from coconut processing remains unutilized. Coir fbers obtained from ripe (brown fbers) and unripe (white fbers) have a high lignin content about 41–42 wt%, a low ash content < 15 wt% and a high heating value of about 18.5–19 mj kg−1. The pelletizing properties were studied in a laboratory scale, single pellet press, and produced pellets were of high mechanical properties....

Mass timber structures have the potential to change wooden construction on a global scale. Numerous mass timber high-rise buildings are in planning, under development or already built and their performance will alter how architects and engineers view wood as a material. To date, the discussion of material durability and biodegradation in these structures has been limited. While all materials can be degraded by wetting, the potential for biodegradation of wood in a mass timber building requires special consideration. Identifying and eliminating the conditions that might lead to this...

Wooden bridges, such as historic covered bridges or modern railroad and highway bridges, can become susceptible to subterranean termite feeding. This can result in weakened structural integrity of the wooden members of these bridges, and possibly even structural failure if damage is not discovered early and control measures are not implemented. The goal of this study was to evaluate the use of various remote detection methods, including acoustic emission sound waves, interruption of light transmission, radar and microwave transmission, moisture monitoring, and changes in gas concentrations...

The collective U.S. housing market, on a monthly basis, was mixed in April 2018. Encouraging were the year-over-year readings, which were overwhelmingly positive, except for existing house sales. Single-family housing starts, permits, and under construction improved on a monthly basis. Existing house sales were negative on a month-over-month and year-over-year basis. Regionally, data were mixed across all sectors.

Sugar pine (Pinus lambertiana) is a five-needle pine native to the mixed-conifer forests of the Sierra Nevada and Cascade Ranges of western North America. Sugar pine has great aesthetic, ecological, and economic value and is among the largest of all pines. Like other five-needle pines, sugar pine is susceptible to white pine blister rust (WPBR), caused by the nonnative pathogen Cronartium ribicola. Although tree-breeding efforts have been the most successful strategy against WPBR, artificial pruning by removing the lowest branches (where infections are most common) can potentially enhance...

The breakdown of host resistance to plant pathogens is of critical concern in agriculture, forestry, and the management of natural systems. Evolution of the fungal poplar rust pathogen Melampsora larici-populina has been shown to have been dramatically influenced by the deployment of resistance genes in commercial poplar (Populus spp.) plantations, with pathogen populations inundated by virulent genotypes (Xhaard et al. 2011). The deployment and subsequent breakdown of resistance genes in poplar plantations provide an experimental system for understanding the dynamics of pathogen evolution...

White pine blister rust (WPBR; causal agent: Cronartium ribicola) has been a threat to both forest resources and agricultural commodities since its introduction to North America in the early 1900s. Eastern white pine (Pinus strobus) is the most economically important timber species in New Hampshire (USA). From 1917 to 1970 Ribes throughout the State was eradicated to protect the timber industry. After the lifting of the Federal Quarantine Act (USDA Bureau of Entomology and Plant Quarantine Federal Domestic Plant Quarantine number 63 [1938]) restricting Ribes and the more recent availability...

Surveys of two stem rust diseases of Pinus kesiya were implemented in Da Lat, Lam Dong province, in the Central Highlands of Vietnam. Symptoms of the first disease, a gall rust, are very similar to those of Cronartium quercuum in North America. Our surveys found many Quercus cambodiensis trees severely infected by the uredinial and telial states of a Cronartium species, later identified by microscopic characteristics as Cronartium orientale, which is native to eastern Asia. The aecial state of C. orientale occurs on various two-needle pines. We tentatively identified the gall rust on P....