PENGARUH METODE STERILISASI DAN KONSENTRASI FILTRAT BAKTERI ENDOFIT TANAMAN TEBU UNTUK MENGENDALIKAN PENYAKIT BLENDOK (Xanthomonas albilineans (Ashby) Savulescu 1947)

Abstract

Leaf scald (Xanthomonas albilineans) is an important pathogen of sugar cane in Indonesia
and cause significant losses at several main sugarcane plantations. Some control measures, e.i.
bactericides smeared Lysol 20% or alcohol 70% on cutting knife seedling for disinfectant,
and hot water treatment at 50 minutes on 52,5ᵒC, have not given satisfactory results in
managing this leaf scald in sugarcane on the field. Biological control with filtrate of
endophytes bacterial were alternative to biocontrol agents Xanthomonas albilineans. The
objectives of this research were to determine: influence of sterilization methods and
endophytic bacterial filtrate dosages of sugarcane to control leaf scald (Xanthomonas
albilineans). This research was conducted in Phytopathology Laboratory at the Faculty of
Agriculture University of North Sumatra from April until December 2014. This research had
done with Completely Randomized Design (CRD) with three-factor: 1. type of endophytic
bacterial filtrates: filtrate of B2, B7 and B9 Sterilization methods of endophytic bacterial
filtrate: control (no sterilization), Sterilization by autoclave and Sterilization by filter
membrane, 3. Dosage of endophytic filtrate with four-level: 0,1%, 0,01%, 0,001% and
0,0001%. The result showed: 10 isolate endophytic bacteria had exploration were: B1, B2,
B3, B4, B5, B6, B7, B8, B9, and B10. Three isolates had a clear zone on Petri dish ≥ 20 mm in
vitro testing is B9, B7, and B2. The results showed that the membrane filter sterilization
method was better when compared to autoclave sterilization, namely: the highest inhibitory
zone diameter of endophytic bacteria in the treatment of B9 filtrate with a membrane filter
sterilization method 0,1% at 3 days after inoculation that was equal to 23.00 mm.