Lasiodiplodia theobromae causes vascular streak dieback (VSD)-like symptoms of cacao in Davao Region, Philippines

Samples of Theobroma cacao seedlings and mature trees with vascular streak dieback (VSD)-like symptoms were observed in Davao, Philippines in 2014. The symptoms were chlorosis and later necrosis of leaves, mostly those second or third from the stem tips. Abscission of these leaves occurred within 2 or 3 days of the first appearance of symptoms. Swelling of lenticels was distinct on the bark surface throughout the affected region. Cultural and morphological examinations and PCR assays revealed that the fungus associated with symptomatic leaves and branches was Lasiodiplodia theobromae. Pathogenicity was demonstrated by inoculation of healthy seedlings with a spore suspension of L. theobromae. This is the first report of L. theobromae as causal-pathogen of VSD-like symptoms in the Philippines.