Suitable harvest times for Kaentawan (Helianthus tuberosus L.) Production

Abstract

Suitable harvest times for kaentawan (Helianthus tuberosus L.) have not been well understood undertropical conditions. The experiment was conducted with the objective of determining suitable harvest times for tuberyield and other agronomic charcters. One month-old seedlings were planted during November 2005 to February2006 under sprinkler irrigation. A randomized complete block design with four replications was used. Three harvesttimes (75 days after planting (DAP), 90 DAP and 105 DAP) were cmpared for plant height, stem diameter at groundlevel, stem diameter at middle stem, soluble solid index (brix) from stem, tuber and root, above ground dry matterper rai, leaf area (LA), leaf area index (LAI), tuber number per plant, tuber fresh weight per rai, tuber dry weightper rai, root dry weight per rai and harvest index (HI). No significant difference was observed for most charactersunder study except for root dry weight per rai. Above ground dry matter, LA and LAI, though not significant,trended to decrease at latter harvest times. Soluble solid index, tuber fresh weight, tuber dry weight wereunaffected by harvest times. Root dry weight was significantly decreased at latter harvest times, but HI trended toincrease at latter harvest times. For short-day planting season, harvest of kaentawan might be carried out as earlyas 75 DAP to 105 DAP without significant yield loss.