Discussion on the Death of Pinus armandi in the Eastern Part of Sichuan Province Ⅱ. Tree Diseases

This paper detailed the relationship between tree diseases and death of Pinus armandi in the eastern part of Sichuan. Observations showed that the needle cast were induced by light yellow lesion in basal needle, but it did not appear in any fruiting body.In isolate culture, the rate of colony is only 10.2%~13.2%. Results of artificial inoculation test on needle show that pathogenic infection are negative. Sprayed with Bordeaux mixture etc, the yellow lesion also produced on the basal needle.According to the results of above 4 experiments, it might be considered that pathological change of needle basal yellow lesion does not belong to infectious disease.