With the thaught that pollen in tomato outcrosses might show a greater vigor than in selfings, outcrosses were made on the variety Red Jacket without emasculation. This variety is potato leaved and longstyled. The Red Jacket planting was isolated by atleast 500 feet.
A line of John Baer was used as male parent. Pollen of this male parent was used in hand pollinations on Red Jacket. Each flower was pollinated twice at an approximately 24-hour interval. Flowers were pollinated between 8:00 and 10:00 A. M. In all instances the first pollen application was made on freshly opened flowers as indicated by the pale yellow, turgid, open corolla. Natural pollination was relied upon in the selfing and sibbing that occured.
Seed from crossed fruits was planted. Hybrids were easily determined in the early seedling stage since the potato leaf character is recessive to the normal. A random count of 1739 seedlings showed that 542 or slightly over thirty-one per cent were hybrids.
This limited trial suggests that it would be practical to produce hybrid seed without emasculation if a marker character such as potato leaf of green stem is utilized and if the female parent has a stigma that protrudes above the anther tube or it is at least flush with it.
The male line that was used in this test was not a vigorous parent. It may well be that a more vigorous male parent particularly one with strong pollen tube growth would yield a higher percentage of hybrid seedlings by a tendency to be prepotent.