Mature tubers of the potato cultivars bred at Crop Research Division, DSIR, were assayed for total glycoalkaloid (TGA) content before and after exposure to light, and for chlorophyll content after exposure to light. Tubers were assayed soon after harvest and after storage for 2 and 4 months at 10°c. Although recoveries were somewhat variable, TGA content was generally low but was increased by exposure to light; the levels also increased slightly during storage and the longer tubers were stored the less the increase in response to illumination. Dno was the only cultivar to exceed 20 mg TGNIOO g whole tuber when exposed to light. Differences in chlorophyll accumulation were found, and cultivars which contained high chlorophyll levels were not necessarily those which accumulated most TGA. Chlorophyll accumulation after exposure to light was also less in stored tubers.

The cooking quality of three potato cultivars resistant to Globodera rostochiensis was investigated using potatoes from trials in Canterbury and Otago. Results from standard cooking tests and consumer surveys were used to compare 'Maris Anchor', 'Maris Court', and 'Pentland Meteor' with local cultivars. The two early cultivars, 'Maris Anchor' and 'Pentland Meteor', retained their 'new' potato character even after digging at full maturity. The maincrop cultivar 'Maris Court' was very similar to 'Ham Hardy' but tended to slough after boiling and steaming. None of the cultivars consistently processed into good potato crisps, but the two 'Maris' cultivars were reasonably good. All three cultivars produced attractive shallow-eyed and smooth-skinned tubers. In consumer acceptance trials 'Pentland Meteor' and 'Maris Anchor' were generally preferred to 'Ham Hardy'. There was no marked preference when 'Maris Court' was compared with 'Ham Hardy'.