Effects of leaf damage by apple leafcurling midge (Dasyneura mali) on photosynthesis of apple leaves.
The effect of damage by Dasyneura mali [Dasineura mali] on photosynthesis by apple cv. 'Braeburn' leaves was investigated in the field in Waikato, New Zealand, during November 1994. Photosynthesis was measured for healthy and damaged leaves of similar size and age. The rate of photosynthesis was not altered when there was less than 60% of the leaf area lost due to damage. In a 2nd trial at Havelock North, all the leaves on a tree were assessed for damage as well as their length and area. A relationship between leaf length and area for undamaged leaves was found and used to estimate that damaged leaves lost an average of 33% of their area. Leaf damage by D. mali to the Havelock North tree reduced carbon acquisition by 51.6 mg/h.