Effect of combined applications of inorganic and organic fertilizer on growth and yield of Kaentawan (Helianthus tuberosus L.)

Abstract

Kaentawan or Jerusalem artichoke (Helianthus tuberosus L.) has been used as human food, animal feedand alternative fuel source for alcohol production in many countries. Introduction of this crop into Thailand is quiterecent, and commercial production has not been established. In order for studying feasibility to grow this cropprofitably in Thailand, this research was undertaken with the objective of investigating the effects of combinedapplications of inorganic and organic fertilizer on growth and yield of kaentawan. Five fertilizer treatments(no fertilizer, 25 kg of 12-24-12 chemical fertilizer, 50 kg of 12-24-12 chemical fertilizer, 500 kg of animal manureplus 25 kg of 12-24-12 chemical fertilizer and 500 kg of animal manure plus 50 kg of 12-24-12 chemical fertilizer)were assigned in a randomized complete block with four replications. At 50 days after emergence, no fertilizertreatment gave the lowest SPAD chlorophyll meter reading (SCMR) (32.9) and application of 500 kg of animalmanure plus 50 kg of 12-24-12 chemical fertilizer gave the highest SCMR (35.9), indicating the highest chlorophyllstatus. At 90 days after emergence, application of 500 kg of animal manure plus 50 kg of 12-24-12 chemical fertilizergave the highest branch number/plant (28.5), but fertilizer applications had no effects on plant height. Fertilizerapplications of 25 kg of 12-24-12 chemical fertilizer tended to give the highest tuber yield of 1682.18 kg/rai.