The Impact of Drought and Vascular-Inhabiting Pathogen Invasion inPinus taedaHealth
The complex interaction of various biotic and abiotic factors may put the overall stand health ofPinusspp. at risk. A study was designed to determine the combined impact of drought and vascular-inhabiting fungi (Leptographium terebrantisandGrosmannia huntii) inPinus taeda. Seedlings from twoP. taedafamilies were planted and watering treatments, (i) normal watering, (ii) moderate drought, and (iii) severe drought, were applied. One month following the initiation of watering treatments, seedling stems were artificially inoculated withL. terebrantisandG. huntii. Drought and fungal interaction significantly affected lesion length/seedling height, occlusion length/seedling height, and seedling fine root biomass.Leptographium terebrantiswas more pathogenic under moderate and severe drought than normal watering condition, whereas the pathogenicity ofG. huntiiremains unaltered. The susceptibility of the families to vascular-inhabiting fungi remained the same under different watering treatments. Drought and specific vascular-inhabiting fungi may negatively impactP. taedastand health.