Beberapa asek agronomi iles-iles (Amorphophallus muelleri Blume)

Abstract

The research was conducted to study several agronomic aspeds of ibsiles (Amorphophallus muellen' Blume), to update the description of the plant, to investigate the best growing medium, to determine the best harvesting time, to find out the best planting rnethds of tuber, and to study the response of plants on soil with high Alluminium content. A series of experiments were camed out at the experimental fields of Bogor Agricultural University, Darmaga from November, 1999 to May, 2003 and at the experimental field of the Agricuttural Technology Assesment Installation unit, Sukabumi from February 2001 to April, 2002. It was found that Amotphophallus mudlen Blume show positive responses shading; good drainage; liming for acid and high Atluminium content soils, combined with high application of manure (organic matter).The phenological study gave additional informations on describe of this species and also on cultivation aspcts such us: planting distance, planting depth, and the best time of harvest. Application of 7.5 tons ha" of manure and 4 tons hamo' f liming (pH 6) increase the yield up to 568.15 glm2. The application of P and K at time of planting did not increase the yield aller 14 month. The best harvesting time was found after three vegetatlf growth cycles and two dormant periods, when the stems fading and the leaves turned yellow (not neccessary the ieaf dried). Noma! planting of the tuber give the same result as if the tuber is planted upsidedown. Common practice by planting the tuber upside-down to give better yield was not proved here. It seems that soil tillage improved the aeration to the plant. Liming on high Alluminium acid soil at the dosage of 1 tons ha-' for each milliequivalent of Alluminium exchangable 100 g-' (20 tons of lime ha-') is necessary. Ail bulbil she can be use as planting material, however only large bulbils are recornended for direct planting. The quality of giucomannan was similar for all treatments; only the degree of whiteness of the glucomannan powder improved when harvesting times is extended.