An Efficient Protocol to Select Superior HS-Families in a Switchgrass Breeding Program.

Time is the most limiting resource in plant breeding programs. Unlike other resources such as labor or space it cannot be increased. Perennial grasses such as switchgrass upon seeding undergo a juvenile development phase followed by a stand maturation process with a fully productive stand being reached no sooner than two years after seeding lasting as long as four years. The objective of this study was to evaluate the effect of stand age on entry ranking for yield. Replicated trials involving 21 entries were established for three consecutive years at three locations in Alabama. Plants were seeded to conetainers in the greenhouse in February of each year and transplanted to the field in June or July. The spacing was 30 cm within rows and 60 cm between rows. I was thus able to compare the effect of stand age on entry ranks. Stands were fully productive the year following transplanting. We will present results based on individual year as well as cumulative yields.