Andrews, Bethany Joann (2016-08). Evaluation of Photoperiod Sensitive Grain Sorghum Hybrids for Heterosis and Grain Quality Traits. Master's Thesis.
In many dry crop production regions of the world, food-insecure farmers rely on sorghum because of its drought tolerance and ability to yield with low inputs. In Central America and Sub-Saharan Africa, these farmers grow photoperiod sensitive (PS) sorghums, which match natural rainfall patterns with the varieties' growth and development so that they grow in the rainy season and mature into the dry season. Hybrids, despite their proven yield increases, have not been adopted in these regions. While there are several reasons for the absence of hybrids in these systems, an important factor is the complicated logistics of producing photoperiod-sensitive hybrids and the poor seed production systems in the region. To bypass these limitations, PS hybrids were created from photoperiod-insensitive (PI) parents, allowing the seed to be produced anywhere in the world. The objectives of the study were to 1) assess PS hybrids for heterosis and grain quality and 2) review and assess the potential of this seed production system. Results indicate that grain yield heterosis is present in PS hybrids at high enough levels to be economically viable. In addition, variability for grain quality and for grain yield suggests that further breeding progress can be made. Five hybrids have been chosen for further testing based upon their high yields.