# Evaluation of Color Change and Biodeterioration Resistance of Gewang (_Crypha utan_ Lamk.) Wood
## 3 Results and Discussion
### Resistance of the Samples to Dry-Wood Ternite  
Termite mortalities of treated specimens are displayed in Table 6, and analysis of variance is also presented in Table 4. Regarding to analysis of variance, the factors of transversal part (direction), treatment, and interaction of the both factors significantly affected termite mortality (\(p<0.05\)). In terms of transversal direction, the outer part had higher mortality than the inner part, because the outer part had a much higher density than the inner part. Such a finding was in line with [PERSON] et al. [26] who found that untreated wood with a lower density (sugi, _Cryptomeria japonica_, with density 0.34 g\(\cdot\)cm\({}^{-3}\)) had a lower dry-wood termite mortality compared to higher density wood (mindi, _Melia azdarach_, with density 0.43 g\(\cdot\)cm\({}^{-3}\)).  
Regarding the smoke treatment of the samples, termite mortality of control samples ranged from 63.6 to 71.2%, while smoked specimens had complete termite mortality. In the case of kesambi samples exposed to smoke, acetic acid was produced, followed by phenol, ketones, amines and benzene, and such chemicals created a toxic environment for the termite [22]. These chemicals also could precipitate on the samples, resulting in their discoloration. Such a conclusion was observed in two of the past studies carried out [PERSON] et al. [27,28]. [PERSON] et al. [29] found that wood smoke could penetrate the low and medium density wood (jabon wood and pine wood) until 0.69 and 0.74 mm, respectively, in smoking treatment.  
Weight loss percentage value and resistance class as well as variance analysis of dry-wood termite are displayed in Figure 6 and Table 4, respectively. The longitudinal part, transversal part, treatment, and interaction of the three factors significantly influenced the percentage wood weight loss (\(p<0.05\)). In terms of longitudinal direction, the wood from bottom part had a lowest weight loss and the values increased toward upper parts. Such results were in line with the termite mortality and the correlation could be explained by the fact that the highest termite mortality would have the lowest wood weight loss, and vice versa.  
Regarding to the transversal direction, the samples taken from the inner part of trunks had a higher weight loss compared to those taken from the outer part. In other words, the inner part was more susceptible to dry-wood termite attack, because the inner part had a lower density than the outer part. These findings were in line with [PERSON] et al. [30] who analyzed six hardwood species, and found a significant inverse association between percentage of mass lost and specific gravity; in other words, wood with a higher specific gravity has more resistance to _Reticulitermes flavipes_ Kollar termites.  
Another factor of treatment, exposed smoke on the inner part could enhance the resistance of gewang wood to dry-wood termite attack, as indicated by smoked wood having a much lower percentage wood weight loss compared to unsmoked samples. Furthermore, when considering the resistance classes in Table 7, unsmoked samples on the inner part of gewang wood belonged to class IV (poor resistance to dry-wood termite attack), but the smoked wood of inner part belonged to class III (moderately resistant). In other words, the smoked gewang wood of inner part had one class higher than unsmoked samples. Meanwhile, the exposed smoke did not affect the durability of the outer part of gewang wood, since this part already had moderate resistance to dry-wood termite attack (class III, the same class as the inner part of the smoked wood), and it had the utmost level of resistance against termite attack. This finding was in line with the findings of previous studies determined that smoke treatment could enhance the resistant of low density wood to be equal to high density smoked wood at the highest level of termite resistance in particular circumstances [12; 27; 28].