Lime applications increase extended sweetpotato transplant production in heated beds 1

This experiment was conducted to determine the effects of aged pine media (sawdust and bark) and lime amendments (0.0, 2.2, and 4.4 kg/m³) on the production of ‘Georgia Jet’ sweetpotato Ipomoea batatas (L.) Lam.] transplants at four harvests. At the first harvest, transplant production with aged pine sawdust and aged pine bark increased quadraticaly and linearly, respectively, with increasing lime rates. Aged pine media did not differ in their effects on transplant number or mean transplant weight and length at the early (first two harvests) or extended (four harvests) harvest periods. Transplant numbers increased linearly, but mean transplant length decreased linearly with lime application during both periods. A reduction in mean transplant weight was also observed. The results of this experiment provide evidence that the positive effect of amending aged pine sawdust and bark with lime continues through an extended harvest period. Transplant production, however, decreased considerably following the second harvest. Greatest early‐ and extended‐season transplant yields were 1840 and 2200 transplants/m², respectively. Media pH or leaf mineral nutrient concentrations did not adequately reflect the yield responses.