Abstract

In this study, series of 2 seasonal experiments were conducted from 2011-2012 at the Department of Agronomy, Faculty of Agricultural Production in Maejo University. In order to develop and select corn single cross hybrid. The selected S2, S3 and S9 lines were dialleled cross to develop 30 corn single cross hybrids. The single cross hybrids, parents and check varieties were preminarily compared for their yield and quality using 7x7 double lattice design during the 2012 early rainy season. The results indicated that single crosses (DK9955S2-2-1 x Pac0390179S6-1-1-1-1-1-2)F1,   (NT6346S2-4-1 x Pac0390179S6-1-1-1-1-1-2)F1,  (B80S2-1-1 x DK9955S2-2-1)F1,  and (Pac0390179S6-1-1-1-1-1-2 x NT6346S2-4-1)F1 produced high grain weights at 14% moisture content by 1,548, 1,528, 1,513 and 1,508 kg/rai. The 4 single cross hybrids gave better grain weight than CP888 (check) by 7.6%, 6.3%, 5.2% and 4.9% respectively. The estimates of the general combining ability (GCA) for the trait was then calculated using diallel cross method I analysis. Results showed that three lines; Pac 039017S6-1-1-1-1-1-2, NT6346S2-4-1-1 and DK9955S2-2-1-1 gave high positive GCA effects for grain weights at 14% moisture content by +142.00, +11.44 and +2.94. The three lines were then selected as testers for the corn breeding program in Maejo University. It is suggested that parent seeds of the four corn F1 hybrids should be multiplied and should prefatorily produced the F1 hybrid seed and the compared with other commercial hybrids in standard yield trials as well as in farmer.  

Keywords:  breeding, corn, single cross, hybrid