Priorities in sweet corn trials

Most sweet corn breeders have in the past regarded sweet corn trials to mean simple yield trials. If sweetness and tenderness is evaluated, it is on one's own hybrids, seldom for the hybrids of someone else that are included in the trial.

Yet the consumer, the customer is much more interested in the sugar content and tenderness than he is in yield. The customer has demonstrated that he is more than willing to pay a much higher price for a higher quality sweet corn and the farmer a higher price for the seed. In the future corn breeders will be forced by competition to pay more attention to endosperm quality as measured by the use of hand-refractometers in their breeding nursery and hybrid trials. The hand-refractometer measures a combination of sucrose and WSP (water soluble polysaccharide or phytoglycogen) often giving readings up to 30% in su su se se combinations. In contrast the so-called super sweets based on sh2 without WSP may give readings of only 5 to 9% sucrose.

There are conflicts and contradictions in present breeding practices. While on the one hand the breeder is selecting for high yielding capacity in his trials, on the other he selects for completely-filled determinate ears that have a restricted potential to produce long ears and high yields. In the area of high eating quality, the seed producer wants a smooth pseudo-starchy type of kernel that can be roughly treated in harvesting and shelling. In other words, high eating quality is the opposite from high seed quality.

Walton C. Galinat

Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.

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