This research was done with the aim of investigation on the natural durability of poplar (populous deltoides) in natural situation and treated with nano silver against the white rot. Testing samples was treated with the method of modified soaking and nano silver in 3 treating level of 0,200 and 400ppm.
In this study effect of coriolus versicolor fungus (identificated as white rot) on populous deltoides in natural and treated situation was analyzed.
In conducting mentioned evaluation, kolleschal method according to DIN 52176 and B.S. 838:1961 was used in completely randomized block design.
Specimens were contaminated with cultured fungus for 14 weeks(22ºc,%75relative humidity).after this period weight reduction, compressive strength(parallel to grain), impact strength were measured.
Results have shown that the effect of treated nano silver on durability of populous deltoides was positive and the average of weight reduction of control sample and 200ppm was measured more than 400ppm,so that according to Findlay 1967 classify this type was promoted from completely non durability to Slightly durability.
Comparisons of averages have shown that the effect of treated nano silver on compressive strength (parallel to grain), in both moods after and before effect of fungus was positive and leads to its increase.
Comparison of average results in impact strength test shown that there was no significant difference in non contaminated samples and at the treating level of 0 (control),200ppm and 400ppm at the level of 5%,but there was significant difference between contaminated samples and at the treating level of 400ppm had more average strength in comparison to200ppm and control.
Keywords: natural durability, white rot, populous deltoides, nano silver, compressive strength (parallel to grain), impact strength