soil solarization for control of soilborne diseases (and ...organics.tennessee.edu/pdf/soil...
TRANSCRIPT
Craig H. CanadayDept. of Entomology & Plant Pathology
West Tennessee Research and Education CenterJackson, Tennessee
Soil Solarization for Control of Soilborne Diseases
(and Weeds, too)
Some soilborne disease to control
Methods for Control of Soilborne Pathogens
• Biological Seed Treatments– Kodiak Concentrate (Bayer CropScience LP)– Actinovate AG (Natural Industries, Inc.)– Yield Shield (Bayer CropScience LP)– T-22 HC (BioWorks, Inc.)
• Cultural Practices– Resistant varieties– Planting date– Long term crop rotation– Composts, animal manures, and chicken litter– Plant density and row spacing
Soil Solarization
Soilborne Pathogens Controlled by Solarization• Fungi
– Pythium spp.– Rhizoctonia solani– Sclerotium rolfsii– Sclerotinia sclerotiorum– Thielaviopsis basicola– Verticillium dahliae
• Bacteria– Agrobacterium tumefaciens– Streptomyces scabies
• Nematodes– Paratylenchus spp.– Meloidogyne spp.
Soil Solarization
• It’s a preplant method for disinfecting soil for control of soilbornepathogens and weeds
• Involves covering the soil with transparent plastic sheeting during an appropriate summer fallow period
• It captures solar energy and raises the temperatures in the soil to levels lethal to many soilborne pests.
• Moisture is needed to increase the thermal sensitivity of target organisms, improve heat conductivity, and enable biological activity during solarization
• The major commercial use of solarization has been in regions with high solar radiation and high temperatures
West Tennessee Research and Education Center, Jackson, TNTypical Daily Soil Temperatures
35 C = 95 F 40 C = 104 F 45 C = 113 F 50 C = 122 F
First Tennessee Solarization Test - 1989 Creating the “gap” between the layers
Daily Maximum Soil Temperatures 1989
noneblackclearclear / blackclear (gap) clear
Tem
pera
ture
(°C
)
20
25
30
35
40
45
50
55
7/25
7/26
7/27
7/28
7/29
7/30
7/31 8/1 8/2 8/3 8/4 8/5 8/6 8/7 8/8 8/9
35 C = 95 F 40 C = 104 F 45 C = 113 F 50 C = 122 F
noneblackclearclear / blackclear (gap) clear
Tota
l # h
ours
(Jul
y 25
–A
ugus
t 9)
0
50
100
150
200
250
300
350
< 35°C 35- 40°C 40- 45°C 45- 50°C > 50°C
a
bbc
c
db
abb
c aab bc c
d
abb
cd b
abbb
Temperatures at 2" depth from July 25 to Aug 9, 1989
35 C = 95 F 40 C = 104 F 45 C = 113 F 50 C = 122 F
1989 Solarization Test
0
50
100
150
200
250
Treatment
none
clear
clear / black
black
clear (gap)clear
Populations of Pythium spp., 0 – 2 inches
Num
ber c
fu/ g
ram
soi
l
a
a
a
a
b
1989 Solarization Test
0
5
10
15
20
25
Treatment
none
clear
clear / black
black
clear (gap)clear
Number of Weeds after Solarization
Num
ber w
eeds
/ 1
kg s
oil a
b b
b b
Second Solarization Test - 1990Overview
Keeping Plastic Sheeting Clean
20
25
30
35
40
45
50
55
60
7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20
Maximum Soil Temperatures July 7-20, 1990
noneclear (gap) black clear (gap) clear
Tem
pera
ture
(°C
)
35 C = 95 F 40 C = 104 F 45 C = 113 F 50 C = 122 F
20
25
30
35
40
45
50
55
60
7/20 7/21 7/22 7/23 7/24 7/25 7/26 7/27 7/28 7/29 7/30 7/31
Maximum Soil Temperatures July 20-31, 1990
noneclear (gap) black clear (gap) clear
Tem
pera
ture
(°C
)
35 C = 95 F 40 C = 104 F 45 C = 113 F 50 C = 122 F
1990 Solarization Test
020406080
100120140160180
Treatment
none
clear
clear + clear
clear (gap)blackclear (gap)clear
Populations of Pythium spp., 0 - 2 inches
Num
ber c
fu/ g
ram
soi
l
a
b b b b
1990 Solarization Test
0
50
100
150
200
250
300
Treatment
none
clear
clear + clear
clear (gap)blackclear (gap)clear
Populations of Pythium spp., 4 - 6 inches
Num
ber c
fu/ g
ram
soi
l
a
b
b b b
What are the benefits of soil solarization for organic gardeners and growers in Tennessee?
Overview of 1993 gardens while solarizing
Creating the “gap” Securing the edges
After 5 ½ weeks Re-setting landscape timbers
Shallow rototilling of the soil Planting Fall Snap Beans, August 3, 1993
1993-94 Solarization Gardens
0
50
100
150
200
250
Treatment
none
clear
clear (gap)blackclear (gap)clear
Populations of Pythium spp., 0 – 2 inches, 15 September, 1993
Num
ber c
fu/ g
ram
soi
l
a
bb
b
Fall 1993 Snap Beans – Not Solarized
Fall 1993 Snap Beans - Solarized1993 Solarization Gardens
012345678
Treatment
none
clear
clear (gap)blackclear (gap)clear
Snap Bean Yield, 27 Sep – 8 Oct, 1993
Num
ber k
g / p
lot
a
bb
b
Fall 1993 Spinach – Not Solarized Fall 1993 Spinach - Solarized
1993 Solarization Gardens
0
1.776
3.552
5.328
Treatment
none
clear
clear (gap)blackclear (gap)clear
Spinach Yield, 10 December, 1993
Num
ber k
g / p
lot
a
a a
b
1993 Solarization Gardens
0100200300400500600700800900
Treatment
none
clear
clear (gap)blackclear (gap)clear
Weed infestations, 9 November 1993
Num
ber w
eeds
/ m
2
a
b b b
1994 Solarization Gardens
0
0.25
0.5
0.75
1
1.25
1.5
1.75
Treatment
none
clear
clear (gap)blackclear (gap)clear
Yield Spring Spinach, 6 May 1994
Num
ber k
g / p
lot
a
b
aa
Solarization Gardens – Summer 1994
Solarization Gardens – Summer 1994
Not Solarized Solarized
1994 Solarization Gardens
01020304050607080
Treatment
none
clear
clear (gap)blackclear (gap)clear
Lima Bean Stand, 1 June 1994
Perc
ent S
tand
a
b
aa
1994 Solarization Gardens
0
1
2
3
4
Treatment
none
clear
clear (gap)blackclear (gap)clear
Lima Bean Yield, 10 August 1994
Kg d
ry b
eans
/ pl
ot
a
b
a
a
1994 Solarization Gardens
05
1015202530354045
Treatment
none
clear
clear (gap)blackclear (gap)clear
Yield Summer Squash, 23 June – 9 Aug., 1994
Num
ber k
g / p
lot
a
b
b
a
1994 Solarization Gardens
0
10
20
30
40
Treatment
none
clear
clear (gap)blackclear (gap)clear
Yield losses to Choanephora Fruit Rot, 23 June – 9 Aug., 1994
Perc
ent L
oss
a
b
a
b
1994 Solarization Gardens - Sweet Corn
Not Solarized Solarized
1994 Solarization Gardens
0
2
4
6
8
10
Treatment
none
clear
clear (gap)blackclear (gap)clear
Yield Sweet Corn, 6 July – 2 Aug., 1994
Num
ber k
g / p
lot
a
a
aa
Fall 1994 Gardens
Not Solarized Solarized
1994 Solarization Gardens
3
4
5
Treatment
none
clear
clear (gap)blackclear (gap)clear
Yield Fall Spinach, 28 - 30 November 1994
Num
ber k
g / p
lot
a
aa
a
1994 Solarization Gardens
0
20
40
60
80
100
Treatment
none
clear
clear (gap)blackclear (gap)clear
Populations of Pythium spp., 0 - 2 inches
Num
ber c
fu/ g
ram
soi
l
a
b
b b
2 December 1994
Some Solarization Variations
Research at the Highland Rim Experiment StationSpringfield, TN
1994-96
Bricks for Spacers, Highland Rim Experiment Station
Bricks for Spacers, Highland Rim Experiment Station Bricks & Boards, Highland Rim Experiment Station
Bricks & Boards, Highland Rim Experiment StationHighland Rim Experiment Station
Solarization Research Results – Fall Spinach
0
2
4
6
8
10
Treatment
methyl bromidesolarized
0
10
20
30
40
50
Treatment
methyl bromidesolarized
0
2
4
6
8
10
Treatment
methyl bromidesolarized
Pythium (cfu/g)
Yield (lb/plot)% Stand 27 Oct
% Stand 21 Sep
A
B
B
A
NS
0
15
30
45
60
75
Treatment
methyl bromidesolarizedNS
2007 Solarization Experiment
• Three Treatments – each replicated nine times– Control (no plastic)– Black plastic– Clear plastic
• Narrow rows (not plots)
• Rows run North-South
• Measure effects on weeds, vegetable diseases,spinach and broccoli (a transplanted crop) growth & yield
2007 Solarization Experiment – Fall Spinach
01020304050607080
Treatment
noneblackclear
0
10
20
30
40
50
60
Treatment
noneblackclear
0
10
20
30
40
50
60
Treatment
noneblackclear
00.250.5
0.751
1.251.5
1.752
Treatment
noneblackclear
Weeds / sq. ft
Yield (lb/row)% Stand
% Emergence
B
A
A
A
C
B
B
BB
C B
A
2007 Solarization Experiment – Fall Broccoli
0
5
10
15
Treatment
noneblackclear
0
0.1
0.2
0.3
0.4
0.5
Treatment
noneblackclear
Leaf length (cm) Yield (lb/plant)
AAB
B AB AWhen is the best time for soil solarization in Tennessee?
Mean Daily Solar Radiation, 1986-2007, February – NovemberMaximum Daily Soil Temperature, 1986-2007, March-November
(bare soil, two-inch depth)
Twelve Steps for Successful Soil Solarization
1. Plan to solarize a portion of your garden when solar radiation is optimal (June through August).
2. Avoid areas with shadows or north-facing slopes.
3. Rototill the soil to incorporate current weeds, crop residues, compost, fertilizers, etc.
4. Remove any sharp sticks, stalks, etc. that could puncture the plastic.
5. Thoroughly moisten the soil (or wait for a good soaking rain).
6. Cover the moist soil with clear, polyethylene plastic sheeting.
Twelve Steps for Successful Soil Solarization - Continued
7. Bury the edges of the sheeting with soil, landscape timbers, etc. to prevent wind from getting underneath the plastic or hot air from escaping.
8. To achieve the highest solarization temperatures, cover the first sheet with another sheet of clear, polyethylene sheeting. (The first sheet may be black if the second sheet is clear.)
9. If you use two layers, create an air “gap” between the layers of sheeting with strips of insulation, small blocks of wood, bricks, etc. Avoid materials with sharp edges. Bury the edges of the second sheet.
10. Keep the top surface free of dust and water during the solarization period.
11. Remove the plastic after 4 to 6 weeks (perhaps sooner if hot, sunny clear days have been common).
12. When planting your garden, avoid the outer edge (1-2 ft) of the solarizedarea. Avoid rototilling soil deeper than two inches or digging deep holes.
Enjoy a healthier garden with fewer disease problems and fewer weeds!
References1. Soil Solarization by Jaacov Katan and James E. DeVay, 1991, CRC Press, Inc.
2. Soil Solarization for Gardens & Landscapes, University of California Agriculture and Natural Resources, Pest Notes, Publication 74145.
http://www.ipm.ucdavis.edu/PDF/PESTNOTES/pnsoilsolarization.pdf
3. University of California Solarization Informational Websitehttp://solar.uckac.edu/new_page1.htm
4. Soil Solarization – A Nonchemical Method for Controlling Diseases and Pests.http://ceamador.ucdavis.edu/files/942.pdf
5. Soil Solarization for Control of Nematodes and Soilborne Diseaseshttp://www.aces.edu/pubs/docs/A/ANR-0713
6. Solarization for Pest Management in Floridahttp://edis.ifas.ufl.edu/pdffiles/IN/IN82400.pdf
7. Organic Control of White Mold on Soybean, ATTRA Agronomy Technical Note.http://www.attra.org/attra-pub/PDF/whitemold.pdf
AcknowledgmentsThe collaborative assistance of Dr. Jim Wyatt;the technical and field support of Emily Gatch,
Lanny Davis, Mitchell Hatchett, Gordon Percell, and Richard Rosser; and the secretarial assistance of Virginia Stewart
and Angie Thorne are gratefully acknowledged.
Thanks also to the following student workers:Jon Lentz Vicki Meeks John WardJohn Jenkins Jeff Goodson Kary CookMatt Long Sheryl Cantrell Linda HiiRussell Cothran Julie Honeycutt Tamani PercellTony Driesling Beth Sanford Christopher ColemanAndy Reeves Sarah McGee Christie Peterson
Questions?