Results of the recent heat treatment, methyl bromide, and ProFume TM treatments at the Hal Ross Flour Mill Wat Chayaprasert Bh. Subramanyam Monika Brijwani Chelle Hartzer August 19-21, 2009 MB Alternatives Workshop: Focus on ProFume TM and other IPM Tactics IGP Conference Center
30
Embed
Results of the recent heat treatment, methyl bromide, and ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Results of the recent heat treatment, methyl bromide, and ProFumeTM
treatments at the Hal Ross Flour MillWat ChayaprasertBh. Subramanyam
Monika BrijwaniChelle Hartzer
August 19-21, 2009MB Alternatives Workshop: Focus on ProFumeTM and other IPM Tactics
IGP Conference Center
Introduction
• Comparison of MB, SF, and heat• Same building
– Hal Ross Flour Mill• Same sealing quality for fumigations
– Verified by building pressurization tests• Similar environmental conditions
– Three treatments within a 3-week period (May `09)
Fumigations
Setup• Pressurization test• Weather station (temp, RH, wind)• Temp/RH logger (one point on each floor)
Setup• Bioassay (5 bioassays on each floor)
Setup• Gas concentration (6 points on each floor
continuously)KSU Hal Ross Flour Mill
Building Layout
6
1
2
3
4
5
1-1
1-2
1-3
1-4
1-5/1-6
Pressurization test• Flow rate VS Pressure
– Good seal Lower flow rate at any given pressure• Sealing quality of the two fumigations was
identical
0
0.5
1
1.5
2
0 20 40 60 80 100Pressure (Pa)
Flow
rate
(m3 /s
)
MBSF
Better seal
Worse seal
Temperature
• Stable indoor temperatures– 22 – 23 C during MB fumigation– 23 – 26 C during SF fumigation
10
15
20
25
30
0 5 10 15 20 25Elapsed time (hr)
Tem
pera
ture
(C)
Flr 1Flr 2Flr 3Flr 4Flr 5Outside
10
15
20
25
30
0 5 10 15 20 25Elapsed time (hr)
Tem
pera
ture
(C)
Flr 1Flr 2Flr 3Flr 4Flr 5Outside
MB SF
Relative humidity
• Stable indoor RH– 39 – 50% during MB fumigation– 34 – 44% during SF fumigation
20
40
60
80
100
0 5 10 15 20 25Elapsed time (hr)
RH
(%)
Flr 1Flr 2Flr 3Flr 4Flr 5Outside
20
40
60
80
100
0 5 10 15 20 25Elapsed time (hr)
RH
(%)
Flr 1Flr 2Flr 3Flr 4Flr 5Outside
MB SF
0
5
10
15
20
25
30
0 5 10 15 20 25Elapsed time (hr)
Con
cent
ratio
n (g
/m3 )
Gas concentrations: MB
HLT 16.4 hr
HLT 10.2 hr
HLT 111 hr
Gas concentrations: SF
0
10
20
30
40
50
60
70
80
90
0 5 10 15 20 25Elapsed time (hr)
Con
cent
ratio
n (g
/m3 ) HLT 19.7 hr
0
3
6
9
12
15
18
0 5 10 15 20 25Elapsed time (hr)
Win
d sp
eed
(m/s
) Avg = 3.52 m/sAvg =
1.65 m/s
Wind velocity: MBAvg = 7.12 m/s
Wind velocity: SF
0
3
6
9
12
15
18
0 5 10 15 20 25Elapsed time (hr)
Win
d sp
eed
(m/s
) Avg = 3.67 m/s
Summary of results
MB SFExposure (hr) 24 24
Total gas used (kg) 181.4 (400 lb) 567.0 (1250 lb)Indoor temp (C) 22 - 23 23 - 26Indoor RH (%) 39 - 50 34 - 44
Conclusions• First head-to-head comparison between MB and
SF under nearly identical conditions in the same facility
• SF and MB showed similar gas dynamics and thus leakage characteristics
• Sealing effectiveness can be determined by pressurization testing ahead of a fumigation– It cannot perfectly predict HLT– It can differentiate a "well" vs "poorly" sealed facility
Temperatures attained in bioassay boxes on May 13-15, 2009
Rate to 50Rate to 50ooC (C (ooC/h)C/h)Time to 50oC (h)1.5 2.0 2.5 3.0 3.5 4.0
Tim
e to
100
% m
orta
lity
(h)
2
4
6
8
10
12Adults (r = -0.86) Larvae (r = -0.85)
Time above 50oC (h)22 24 26 28 30 32
Adults (r = -0.92)Larvae (r = -0.94)
Factors affecting insect mortalityFactors affecting insect mortality(Facility C)(Facility C)
There is an inverse relationship between insect mortality There is an inverse relationship between insect mortality and each of the two factorsand each of the two factors
Red flour beetlesRed flour beetles
Rate to 50Rate to 50ooC (C (ooC/h)C/h)
Heat treatment: % mortality of red flour beetle life stages (n = 1) (May13-15, 2009)
Heat treatment: %mortality of red flour beetle life stages (n = 1) (May13-15, 2009)
Thermal death kinetic model for the most heat tolerant stageThermal death kinetic model for the most heat tolerant stage
)()(log10
tt
dtt
TDdt
NN
where Nt-dt is the survival at t-dt time interval Nt is survival at time t upon integration equation becomes
t
t
t
t
dtt
TDdt
NN
00 10 )()(log
t
tt
o
TDdt
NN
0 )(log 10
t
t
t
TDt
NN
0
0
)(10
where No is the original number of insects; Nt is number of larvae at time t; ∆tis the incremental exposure time (1-min), D is the mean instantaneous D-value as a function of temperature (Tt), and Tt is time- dependent temperature profile
t
t
t
TDdt
NN
0 )(log
0
10
Boina, Subramanyam, & Alavi (2008)
Heating rate (2.12oC/h)
0 100 200 300 400 500 600 700 800 900
Num
ber o
f ins
ects
0
20
40
60
80
100
120N o
T tN t
Heating rate (2.44oC/h)
0 100 200 300 400 500 600 700 800
Tem
pera
ture
(o C)
0
20
40
60
80
100
120Temperature profilePredicted populationObserved population
No
T tN t
Heating rate (5.31oC/h)
0 50 100 150 200 250 300 350
Num
ber o
f ins
ects
0
10
20
30
40
50
60
70
No
T t
N t
Heating rate (12.02oC/h)
0 20 40 60 80 100 120 140 160 180 200
Tem
pera
ture
(o C)
0
10
20
30
40
50
60
70
No
Tt
N t
Time (minutes)
Time (minutes)
Observed and predicted survival of red flour beetle young larvae (Subramanyam & Mahroof, unpublished)
Data set 1
0 500 1000 1500 2000 2500 30000
20
40
60
80
100
O bserved su rvivalP red ic ted su rvivalTem perature (oC)
D ata S et 2
0 50 100 150 200 250 300
Tem
pera
ture
(o C)
0
20
40
60
80
100
0 100 200 300 400 5000
20
40
60
80
100
Surv
ival
(%)
Data S et 3 Data S e t 4
T im e (m inutes)
0 100 200 300 400 5000
20
40
60
80
100
Data set 5
0 100 200 300 400 5000
20
40
60
80
100
0 200 400 600 800 1000 1200 1400 16000
20
40
60
80
100Data set 6
0
20
40
60
80
100
Temperature (oC) Red flour beetleConfused flour beetle
HOBO 62b (Press Room)
0
20
40
60
80
100
HOBO 53 (Press Room)
0
20
40
60
80
100
HOBO 17 (Press Room)
0
20
40
60
80
100
HOBO 75 (Press Room)
Tem
pera
ture
(o C)
0
20
40
60
80
100
HOBO 80 (Press Room)
Inse
ct s
urvi
val (
%)
0
20
40
60
80
100
HOBO 57 (Press Room)
Time (hours)0 2 4 6 8 10 12 14 16 18
0
20
40
60
80
100
HOBO 39 (Press Room)
0 2 4 6 8 10 12 14 16 18
0
20
40
60
80
100
HOBO 16 (Press Room)
2.8 oC/hr 2.9 oC/hr
3.6 oC/hr3.5 oC/hr
3.7 oC/hr 3.9 oC/hr
4.2 oC/hr4.1 oC/hr
Predicted survival ofPredicted survival ofyoung larvae of young larvae of TriboliumTribolium castaneumcastaneum andandOld larvae Old larvae of T. of T. confusumconfusum in a in a pasta plant (Facility A)pasta plant (Facility A)
Location: Milling facility, Dept. of Grain Science and IndustryDate: 05/12/2008
Total time: 35 hoursHeat rate: 0.54℃ /hour
Species: Tribolium castaneum young larvae
Methyl bromide fumigation: % mortality of red flour beetle life stages (n = 1)