Pemanfaatan methylobacterium spp. pada invigorasi dan teknik coating untuk meningkatkan vigor benih kedelai

Abstract

Soybean seed deterioration is one of the problem in supplying high seed quality in tropical environtment such as Indonesia. Methylobacterium spp. for invigoration and enhancing soybean seed storage by coating technique can be used to solve this problem. The aims of the research were: (1) to find out the potency of Methylobacterium spp. for soybean seed invigoration, (2) to get Methylobacterium spp coating formulation to enhancing soybean seed storage. (3) to enumerate viable Methylobacterium spp. in coated seed during open storage. Experiments were conducted in Soil Biology Laboratory and Screen House Indonesian Soil Research Institute (ISRI), PT. East West Seed Indonesia Laboratory, Seed Technology Laboratory IPB, Bogor from November 2011 to July 2012. The research materials were soybean seed (Argomulyo), four isolates of Methylobacterium spp namely TD-TPB3, TD-J7, TD-TM3 and TD-TM1. The research consisted of two experiment (1) Methylobacterium spp application for seed invigoration in different viability, (2) Methylobacterium spp. application with seed coating at various storage period. The first experiment using Randomized Complete Block Design factorial. The first factor were six levels invigoration aplication i.e: control, soaking seed by steril water, soaking seed by TD-TPB3, soaking seed by TD-J7, soaking seed by TD-TPB3 + TD-TM3, and soaking seed by TPB-3 + TD-J7. Second factor were different seed viabiliaty, i.e: V1 (seed germination: 78 %); V2 (seed germination: 83 %); V3 (seed germination: 94 %). The second experiment using Nested Design. The first factor was storage period, i.e: 0, 1, 2, 3, 4, 5, 6 month. Second factor were 11 level formulations: control, coating with arabic gum, coating with arabic gum + tochopherol 800 ppm, coating with arabic gum + TD-TM1, coating with arabic gum + TD-TM3, coating with arabic gum + TD-TPB3, coating with arabic gum + TD-TPB3 + TD-TM1, coating with arabic gum + TD-TPB3 + TD-TM3, coating with arabic gum + peat, coating with arabic gum + TD-TPB3 + TD-TM1 + peat, coating with arabic gum + TD-TPB3 + TD-TM3 + peat. The result showed that at laboratory level, invigoration enhancing vigor index 8.9-20.6 %, and hypocotyls length 1.5-2.5 cm compare to control. In screen house experiment there was no significant improvement for vegetative stage in soybean. Coating with formula arabic gum, arabic gum + tochopherol 800 ppm, and arabic gum+TD-TM3 consistently maintain significant higher seed germination (SG) and germination rate (GR) seed viability until 6 month storage compare to control also have no significant vigor index (VI) compare to control. Coating formula with peat resulting low SG (78.3-80.7 %), whereas coating formula with Methylobacterium spp resulting higher SG (81.3-86.7 %) compare to without coating (79.3 %) after 6 month storage. Methylobacterium spp. still viable in formula coated seed until 6 month storage. Colony number decrease from 5.00 x 104 - 1.80 x 107 cfu g-1 seed to 1 x 101 - 1.14 x 102 cfu g-1seed at 6 month storage.