Increased yield of cucumber cultivars has been due also to the improvement of qualitative traits such as gynoecious sex expression, improved fruit color (improved percentage marketable fruit), and direct yield improvement (Wehner, 1989).
To identify new sources of high yield in the cucumber germplasm collection for use in breeding, we are using a three-stage process: First, all available plant introduction accessions, cultivars, and breeding lines (hereafter collectively referred to as cultigens) are tested for combining ability with a gynoecious tester; second, all available cultigens are tested for yield per se; and third, the best cultigens are evaluated using larger trials with multiple harvests, seasons, and years.
Miller and Hughes (1969) reported that harvesting at 14 to 31% oversized fruit stage in a plot was found to be optimum for maximum value in once-over harvest for `Piccadilly' and `Southern Cross' gynoecious pickling hybrids in North Carolina.
Ethephon treatment of isogenic lines of cucumber differing in sex expression improved gynoecious rating, fruit number (total, early, and marketable), and fruit weight (total, early, and marketable) compared with the untreated control.
WI 2757 was included as a check representing late-maturing, low-yielding, gynoecious inbreds.