Abstract
Selection for seed size is important in native, warm‐season grass improvement programs because of the positive correlation between seed size and seedling vigor. Bulk seed from a switchgrass (Panicum virgatum L.) population of 750 spaced plants from a field nursery was separated into four weight classes (174.1, 190.5, 209.5, and 225.8 mg/100 seeds) utilizing a South Dakota Seed Blower. A highly significant (P < 0.01) linear relationship was detected between mean 100‐seed weights of weight classes and mean seed weights of open‐pollinated, spaced‐planted progeny produced from these classes. Highly significant differences in mean seed weight also existed among plants within weight classes. In switchgrass, high seed weight was an effective selection criterion for increasing the seed weight of progeny from a bulk seed lot.