EVALUATE THE PERFORMANCE OF DOUBLE, SINGLE HYBRIDS AND INBREDS OF MAIZE UNDER DIFFERENT PLANT POPULATION AND ESTIMATE HETEROSIS AND HYBRID VIGOR (SOME AGRONOMIC TRAITS)

Abstract

field experiment was conducted during the fall season 2017 at the fields of Field Crop Department - College of Agriculture - University of Baghdad in order to evaluate the performance of double, Single hybrids, and their inbreds of maize (ZM43WIZE, ZM60, ZM49W3E, ZM19, and CDCN5) in two plant densities. The Study included the comparison among five inbreds, ten single hybrids, and fifteen double hybrids. The experiments were conducted according to the randomized complete block design (RCBD) with four replication, using the spilt plot treatment arrangement, where the two densities 60 and 80 thousand plants h-1 were randomized in the main plots and the 30 genotypes in the subplots. The results showed the superiority of the single and double hybrids over their inbreds in all the studied traits. The earliest single hybrids (ZM43WIZE × ZM19) in tassling and silking reached 56.33 and 60.33 days respectively. The double hybrid (ZM43WIZE × ZM19) (ZM49W3E × CDCN5) To reach the tassling was 56 days and did not differ between the hybrids among them in access to silking and the earliest (ZM43WIZE × ZM49W3E) (ZM60 × CDCN5) with a period of 60.17 days. The earliest single hybrids and the double hybrids had negative heterosis and hybrid vigor (ZM49W3E × CDCN5), (ZM43WIZE × ZM49W3E) and (ZM43WIZE × ZM19) The highest mean plant height was 245.9, 233.9 and 231.6 cm respectively, which is higher than the general mean. (ZM43WIZE × ZM49W3E) The highest mean ear height was 107.87 cm followed by the hybrid (ZM49W3E × CDCN5) which reached 107.05 cm and the hybrid (ZM43WIZE × ZM19) which was 101.77 cm and did not differ significantly, the hybrid (ZM43WIZE × ZM60) (ZM49W3E × CDCN5) by giving the highest height of the plant reached 295.9 cm while the double hybrid gave the(ZM60 × CDCN5) (ZM49W3E × ZM19) the highest average ear height reached 112.45 cm followed by the double hybrid (ZM43WIZE × ZM19) (ZM60 × ZM49W3E). The single hybrid ) ZM60× ZM49W3E (giving it the highest mean of 16.28 leaves number followed by the hybrid (ZM60 × 5) by 16.03 leaves and did not differ significantly from the remaining hybrids except for the hybrids (ZM43WIZE × ZM19) and (ZM60 × ZM19) gave least leaves number (15.25 and 15.17) sequence. (ZM60 × ZM19) (ZM49W3E × CDCN5) by giving the highest number of leaves of 17.08 leaves followed by (ZM43WIZE × ZM19) (ZM49W3E × CDCN5), (ZM43WIZE × ZM60) (ZM19 × CDCN5) , (ZM43WIZE × CDCN5) (ZM60 × ZM19), (ZM49W3E × ZM60) ( ZM19 × CDCN5), (ZM60 × CDCN5) (ZM49W3E × ZM19) and (ZM43WIZE × CDCN5) (ZM49W3E × ZM19), reaching 16.48, 16.38, 16.37, 16.33 and 16 .27 and 16.23 respectively, which is higher than the general average and the average inbreds and the average of the single and double hybrids . Most of the single and superior double hybrids were characterized by the height of the plant and the ear and the number of leaves by the positive hetrosis and hybrid vigor in the desired direction.