Abstract

Chitosan and BTH selected as inducers of systemic resistance against Sphaceloma ampelinum, the causal agent of grapevine anthracnose, are presented for biological control of multiple pathogens causing either foliar or root diseases of various economic crops. In the present study, chitosan and BTH were investigated for their ability to induce some defense related chemicals that protect grapevine from S. ampelinum infection. Salicylic acid was found to accumulate in grapevine leaf tissue, treated with chitosan and BTH and challenged by S. ampelinum when plants were 60-day-old. The accumulation of salicylic acid (13.08 and 12.15 µg g^-1 fresh weight) increased for seven days after fungal pathogen challenge inoculation and foliar treatment with chitosan and BTH. In pathogen inoculated plants of non-treated foliar, salicylic acid also accumulated for seven days with very low level of 2.90 µg g^-1 fresh weight. Moreover, chitosan and BTH reduce anthracnose disease severity up to 75 and 60%, respectively. These results show the potential of using chitosan and BTH to induce resistance of grapevine, and as active-elicitors for plant diseases management. Furthermore, the use of chitosan and BTH may minimize the cost of control strategies and reduce the risk associated with the high use of chemical pesticides in commercial grapevine production in Thailand.

Key words: Anthracnose, grapevine, induced resistance, salicylic acid, Sphaceloma ampelinum