Seed production potential of ICRISAT-bred parental lines of two sorghum hybrids in the central Rift-valley of Ethiopia

An experiment was carried out to study the seed production potential of the parental lines of two sorghum hybrids in the central Rift-valley of Ethiopia. The two important seed production attributes considered for the study were synchronization of flowering and row ratio of the parental lines and their interaction with the testenvironments. A total of 12 treatment combinations related to these attributes were organized. The ANOVA revealed significant differences among the treatments and among the environments for outcrossing percentage and seed yield. Although a 4:4 row ratio showed maximum outcrossing, a 2:6 row ratio gave maximum hybrid seedper hectare and thus is more profitable. Sowing date brought about variation in outcrossing percentage and yield in the parental lines of the two hybrids studied. In ICSA 15 × 3443-2-OP, regardless of the row ratio, yield decreased by 36.1% when the pollinator parent was sown 10 days later than the seed parent. The row orientationagainst the prevailing wind direction could have also contributed to variation in seed production of the parental lines. Therefore, when hybrid sorghum seed production is planned, synchronization of flowering and row ratio of the parental lines and the row orientation should be considered.