Last modified: 2019-10-08
Abstract
Pests Control in soybean field in general still uses synthetic pesticide. The use of this pesticide possess a variety of negative effects, including the physical and chemical structure of the soil and the diversity of the soil microbiotic. Soil microbiotic such as endemic bacteria are able to decompose pesticide residue in a certain amount of time. This research aims to find out the potency of isolated endemic bacteria from soybean field in Jombang, Lamongan, and Probolinggo in east java in decomposing profenos and clorantraniliprol pesticide.
The method used in the research was observation method. Bacteria sample was obtained from soybeans fields and aplicated by pesticide in 3 points, those were  in the water entry point, middle point, and water exit point of the soybean field that located in Jombang, Lamongan, and Probolinggo. Bacteria was grown in nutrient agar medium with profenofos  and clorantraniliprol insecticide addition, using pour plate method. The grown Bacteria that showed clear zone around the colony was isolated in oblique nutrient agar medium. Then the bacteria was tested separately of decomposing profenofos and/or clorantraniliprol capability with Agar well diffusion method.  The tested using nutrient agar medium that was added by profenofos (1 gr/l) and clorantraniliprol (2gr/l) and incubated in 1 day. The clear zone diameter was measured by a ruler with 1 mm precision. The area of the clear zone is determined by subtraction of clear zone diameter with well diffusion diameter.
The result of this research shows the isolate of endemic bacteria that grown in a medium with an addition of profenofos in Jombang, Lamongan and Probolinggo soils  as much as 15,19 and 16 respectively. While clorantraniliprol  addition medium as much as 21 in Jombang soil, 23 in Probolinggo soil, and 25 in Lamongan soil. The total number of endemic bacteria isolates that obtained from the soybean fields in those 3 areas that were able to decompose profenofos was 50 isolates and clorantranilipole was 69 isolates. The result of  further test of its decomposing pesticide potency was obtained by 18 isolates that were able to decompose profenos with clear zone  diameter  1,0 – 3,0 cm and by 13 isolates that were able to decompose clorantraniliprol with clear zone  diameter of 0,1-4,0 cm and by 1 isolate that were able to decompose both with clear zone of 3,9 and 4,0 cm ( table 1)
Table 1.The potency of the bacteria in decomposing profenofos and clorantraniliprol pesticide from soybean field in Jombang, Lamongan and Probolinggo
Location
The number of decomposer bacteria isolate
Sample Number
Sample code
Average clear zone diameter (cm)
Profeno-
fos
Chlorantraniliprol
Profenofos
Chlorantraniliprol
Lamongan
15
23
1
L1*/104A3
2,25
-
2
L1/104A4
-
3,1
3
L1/105A2
2,2
2,4
4
L1*/105A3
-
2,3
6
L2*/103A2
-
1,9
7
L2/103A2
-
0,1
8
L2*/104A1
3,9
4,0
9
L3/103A2
2,0
-
10
L3*/104A1
-
2,0
Jombang
19
21
11
J1*/104A2
2,85
-
12
J1*/104A3
2,35
2,0
13
J1/105A1
-
3,0
14
J2*/105A2
3,15
3,1
15
J2/104 A1
2,25
-
16
J3/104A2
2,65
-
17
J3*/105A1
-
-
Probolinggo
16
25
18
P1*/104A1
2,0
-
19
P1*/104A2
3,0
-
20
P1*/104A3
1,05
-
21
P2/104A1
3,0
-
22
P3/104A2
2,55
-
23
P3*/105A2
3,0
0,2
24
P3*/105A3
2,75
1,25
25
P3*/105A4
2,75
-
26
P3/105A4
2,50
2,7
Jumlah
50
69
18
13
From the result of the research it can be concluded that there were 31 endemic bacteria isolates from Jombang, Lamongan, and Probolinggo that were able to decompose pesticide. Those are consisted 18 isolates that were able to decompose profenofos with clear zone diameter  1,0 – 3,9 cm and 13 that were able to decompose clorantranilipole with clear zone diameter 0,1 – 4,0 cm and 1 isolate that were able to decompose both with clear  zone diameter 3,9 – 4,0 cm.