Use of Vigor Tests in Cucurbit Rootstock Cultivars

Late and non-uniform emergence of rootstock seeds affect grafting efficiency in cucurbit species. As seeds age, (vigor decreases) they emerge later and the time to get graftable stage becomes longer. Therefore determination of emergence potential of a seed lot before sowing is crucially important.

This study was conducted to test accelerated ageing (AA), controlled deterioration (CD), cold tests (CT), electrical conductivity (EC) and mean germination (MGT) tests for the discriminating vigor of cucurbit rootstock seeds. AA (41°C, 72 h, 100% RH), CD (45°C, 24% seed m.c, 24, 48,72 h) tests were found to be successful for the ranking of 13 different cucurbit rootstock cultivar seeds, 12 of which were interspecific (Cucurbita maxima X Cucurbita moschata) hybrids. Cold test (CT), mean germination time (MGT) and electrical conductivity (EC) were found to be unsuccessful for the ranking of the lots. The most vigorous lots were Neffiac, Nun 9075 and Shintosa; while 90-44 and Zorba were the lowest vigorous cultivars according to the ageing tests.