Validation method for assessing intensity of mistletoe infestation in teak

Abstract

Occurrences of mistletoe infestations fluctuate depending on the environment and the biodiversity status, which includes anthropogenic factors. Recently, we have observed a potential hemiparasite in a teak clonal seed orchard located in Padangan, Central Java that caused a significant decrease in fruit (drupe) production. Almost one-third ( ) of the existing trees were affected. The dead teak clones reduced the value of the clonal seed orchard as the ex-situ genetic resources conservation. Details on the use of the assessment method for assessing the intensity of infestation have not been validated, although results of preliminary assessment were available. The objective of this study was to validate the assessment method for the intensity of mistletoe infestation using the modified TMR-8 class rating. The validation was carried out based on the results of the Spearman correlation coefficient for the rating (numbers of mistletoes per host teak) and ANOVA for sub-rating (intensity of infected branches). The results showed that numbers of mistletoes grown on an individual teak tree was significantly affected by different classes of tree diameter, crown leaf ratio (LCR) and crown diameter. Besides, the crown diameter showed significant levels of difference on mistletoes infestation.