High molecular weight chitosan oligomers decreased (P < 0.01) photosynthetic rates by 19%, with CHH at 0.01% having the greatest effect on day 1 after treatment.
CHH (0.01 %) treated plants had a reduced photosynthetic rate, particularly at days 1 and
2 after foliar application, relative to the control plants. Similarly treatment with CHH at
0.001 % resulted in values either less than or equal to the control plants, except on day 3 when it increased the photosynthetic rate.
The stomatal conductance and transpiration rate on days 1 and 2 after foliar application were reduced for CHH (0.001 %) treated plants, but increased (P < 0.01) on day 3, along with increased photosynthetic rate;however, the Ci value was not different from the control (Fig 5.3 A-D).