Relationship of Cob characters with grain morphology in maize (Zea mays, Poaceae).

Twenty
varieties of maize (Zea mays, Poaceae) were studied through 11 attributes in three to seven
randomly selected plants of each variety with a view to understanding the effect of cob characters
on technologically desirable grain qualities. Canonical discriminant analysis showed that productivity
(determined by total grain weight~cob, cob diameter and average grain weighO was the
most discriminating among varieties followed by round grains fraction (represented by whole top
and middle fiat grains, number of rows and grain count~surface area), middle flat grains (composed
of middle fiat grains and grain count~surface area) and shape of the cob (determined by
shape index, total grain weight~cob and cob diameter), which accounted for 35.1, 18.3, 12.2,
and 9.8% of the total variance, respectively. In the light of these results, tentative norms have
been suggested to evolve maize varieties of superior technological properties and yet retain high
productivity. A cylindrical cob of large diameter with highest number of grains~area and smallest
possible number of rows together constituted an ideal combination to achieve the objectives. Such
possibilities in the light of available information are discussed.