Stability of fruit yield in watermelon genotypes tested in multiple US environments

Watermelon (Citrullus lanatus [Thumb.] Matsum & Nakai) is a valuable crop grown throughout southern and western United States (US). We were interested in identifying watermelon cultivars having high stability for fruit yield and yield components over diverse environments in the US. A set of 40 genotypes was tested over 3 years (2009, 2010, and 2011) at 8 locations across the southern US in replicated, multi-harvest trials. Yield traits were summed over harvests, and measured as marketable yield, fruit count, % cull fruit, % early fruit, and fruit size. The influences of years and locations on yield performance and genotypes with high stability for yield were identified. Four genotypes including, 'Fiesta F1', 'Stars-N-Stripes F1', 'Stone Mountain' and 'Calhoun Gray' had a high trait mean performance and high phenotypic stability. These four stable genotypes had high marketable yield, average fruit count, low % cull fruit, above average early yield, and medium fruit size. Inbreds 'Big Crimson' and 'Legacy' would be good lines for breeding for high yield and stability.