Dalbergia sissoo die back-probable suspects

Study was initiated during 2004 at the Peshawar UniversityCampus. Reconnaissance of the campus road side Shisham plantationwas conducted. Data of 5 randomly selected trees of road sideplantations, each of 1 km indicated that only 16% of the 535 treeswere healthy, 20% top die, 30% vertically half dead, 20% thinnedcanopy and 14% completely dead. There were observed the presenceof termite on 49%, black or red blood like exudation on 32%, insectborer or bore holes on 29%, canker on 26%, white threads or blackfungal material (especially on butt portion) on 13% of the totalavenue trees of 5 km. The number of dry patches, beneath the barkin the sapwood were maximum (5) in thinned canopy followed by topdie (3) and vertically half dead (1). The continuity of such patchestowards crown and root was confirmed by making the cross sectionsof stem logs and excavating root system of top die tree. Besides,there were recorded 9 dead roots in top die, 7 in thinned canopy, 6in vertically half dead and none in healthy. A maximum number oftermite royal chambers with fungal garden were noted in thinnedcanopy followed by completely dead, top die and healthy tree. Whiteor black fungal material and decay of roots were recorded on all thetree roots except completely dead. However no Rahizobial noduleswere noted on any of the tree root system. All cross sectionsdepicted the presence of white powdery streak at center or atperiphery of damaged central part. Small out growths directed fromheart wood into sapwood were noted in first 3 cross sections of first3 consecutive logs. Presence of i) white or black fungal materialboth on stem and root ii) exudation either of black or red bloodcolour iii) dry patches in stem/root and drying of roots and iv)white powdery streak in cross sections are leading to the conclusionthat there have been the possibility of some fungal attack resultingin blockage of conducting tissues, causing heart wood rot followedby termite attack and elimination of Rahizobial nodulation. Therefore,it is suggested to carry out an intensive field survey; study thebiology, physiology and ecology of the suspected fungi and Rhizobialnodulation pattern.