IMPROVEMENT OF SOME MAIZE TRAITS BY HONEYCOMB SELECTION

To investigate the effect of honeycomb selection in improving crop grain yield , field trials were undertaken for five seasons on the farm of Dept. of Field Crops, Coll. of Agric./Univ. of Baghdad during 2005-2007. Buhuth 106, Oh40, and pop corn were used. Seeds were planted in the first three seasons using honeycomb design of 1.3 m between furrows and 1.5 m between plants.The parameter used for selection was, ears/plant. Desired plants were selected, tagged and selfed. Seeds then taken, mixed, planted and hand cross-pollinated (panmixia). Growth rate of selected Oh40 maize was increased from 3.02 to 3.89 g/plant/d, plant dry matter from 328 to 421g, ear/plant for 1.15 to 1.5, kernel/ear from 530 to 611, at 60.000plant/ha and grain yield from 8.04 to 13.41 t/ha at 80,000 plant/ha. This implies that system capacity constant (SCC) was significantly improved. Grain yield of selected Buhuth 106 and popcorn were increased from 7.44 to 12.2, and 5.1 to 7.5 t/ha, respectively. Values of heritability for trait used was 37.5%, 42.3%, 31.4% for numbers of ear/plant for Buhuth 106, Oh40, and popcorn, respectively, after 2 cycles of selection. It was clear that additive gene action has improved SCC of selected plants. It was recommended to use honeycomb method to develop inbreds of high vigour better than those developed by conventional selection. Testing these new inbreds for GCA and SCA will lead to develop new elite hybrids.