PENGARUH MACAM DAN KONSENTRASI BAHAN ORGANIK SUMBER ZAT PENGATUR TUMBUH ALAMI TERHADAP PERTUMBUHAN AWAL TEBU (Saccharum officinarum L.) THE EFFECTS OF TYPES AND CONCENTRATIONS OF ORGANIC MATERIALS AS NATURAL PLANT GROWTH REGULATOR SOURCES TO INITIAL GROWTH OF SUGARCANE (Saccharum officinarum L.)

The objectives of study were 1) to determine the effects of the types and concentrations of organic materials as natural plant growth regulator sources to the initial growth of sugarcane and 2) to determine the optimum concentration of each organic material to the initial growth of sugarcane. The experiment was conducted at Tridharma Field, Faculty of Agriculture, Gadjah Mada University, Banguntapan District, Bantul Region, D. I. Yogyakarta Province in December 2012 - April 2013. The research was arranged in randomized complete block design (RCBD) single factor with five blocks as replication. The treatments tested were types of organic materials as natural plant growth regulator sources, namely 25, 50, and 75 % of coconut water; 25, 50, and 75 % of dairy cow urine well as 25, 50, and 75 % of extracts of mung bean sprouts. The sugarcane seedlings that do not get organic materials were used as control. The observations were done on several elements of the micro-climate around the research site as well as the plant growth variables. Data were analyzed using analysis of variance (ANOVA) at 5 % level, and continued with Dunnet Test. The results showed that 25 % of coconut water could increase the plant height, leaf number, stem diameter, root fresh weight, shoot fresh weight, total fresh weight, root dry weight, shoot dry weight, the total dry weight, root volume and leaf area when compared to the control. Meanwhile, 50 and 75 % of dairy cow urine, and 25, 50 and 75 % of mung bean sprouts extracts were not significantly different from controls on all growth variables of sugarcane. Regression analysis provides information that 38.70 % of coconut water and 34.44 % of dairy cow urine were optimum for the initial growth of sugarcane.