Method of seed harvest, closing date and height of closing cut affect seed yield and seed yield components in Paspalum atratum in Thailand

Hand knocking mature Paspalum atratum cv. Ubon seed from seed heads into bags every day produced 230 kg/ha seed, more than twice the amount produced by threshing or sweating seed heads. Heating seed at 40 degrees C for either 72 or 240 hours significantly increased seed germination at 2 and 4 months post harvest, respectively. Seed germination reached a maximum of more than 80% without seed treatment after 5 months postharvest storage. Cutting seed crops of P. atratum in August and September in Thailand produced little or no seed at all. Cutting and closing in July produced the best seed yields as earlier closed crops were more susceptible to lodging. The importance of juvenility and a long-day response for flowering in P. atratum is discussed.