Figure 7. Lesion area of the potato leaf infected with P. infestans pathogen and curdlan oligosaccharides treatments.

P. infestans, plants were treated with 10⁵ mL⁻¹ of Phytophthora infestans zoospores at 45-day of cultivation. 1 d+P.i., 250 µg/mL curdlan oligosaccharides (CurdOs, the mixture of glucopentaose, glucohexaose, and glucoseptaose) was sprayed on the potato leaves at 1 d before P. infestans treatment. Potato leaves were cut off from the plants and imaged with digital camera.