engleski

Importance of the earlier versions of the elite Bc lines in developing maize hybrids

Development of earlier high-yielding maize hybrids has manifold importance in production for grain. To keep grain yield at the same level while reducing harvest grain moisture in late hybrids, presents a crucial improvement in maize breeding. Early maturity provides safer grain yields of better quality. Therefore, incorporation of earliness into maize inbred lines and hybrids is a method frequently used in practical maize breeding. Bc5982 is our new hybrid, already accepted by producers. In its maturity group FAO 500 it achieves mean yields over 10 t per ha. Our purpose is to develop an earlier hybrid with about the same yielding capacity. High grain yield of a hybrid is achieved, as a rule, with late-maturing inbreds. In the group FAO 500, two Bc hybrids are registered each with a version of the line Bc741 as one of their component. These lines are of the same origin. Of the several Bc 741 versions some earlier ones were selected. They were tested in hybrid combinations and several experimental hybrids with desired characteristics were selected. The best is the newly registered hybrid Bc4982, in 1997, from the maturity group 400. Of the many versions of the line Bc741, an earlier one was used in this hybrid. The new hybrid Bc4982, in comparison with Bc5982, produces about the same yields while its grain moisture is by 2.0 percent lower on an average. Bc4982 was tested in field trials with different plant densities. High grain yields were obtained in larger densities, but it also tolerates poorer densities. In order to determine and compare yield and stalk quality, Bc4982 was planted, in 1997, in small scale trials at several locations also in FAO 300, i. e. at denser stands with 71,428 plants per ha at harvest. Bc 4982 achieved highest grain yields of 14.2 t per ha with grain moisture by 0.92 percent higher on an average as compared to standards, Eva and Marista.

maize; inbreds; hybrids; earliness

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