effect of phosphonic acid and other fungicides on fungal...
TRANSCRIPT
Effect of Phosphonic Acid and Other Fungicides on Fungal
Diseases of Green Peas
Drs. Lyndon Porter and Debra Inglis, USDA-ARS and Washington State University
Rolling vs. Non-rolling Non-treated vs. Treated seed
Cultivar type
Photo Courtesy NDSU Carrington Reseach Extension Center
Aerial and Columbian
Phostrol(phosphorous acid)
Columbian
Aerial
Cultivar Type
Foliar applications
Objective of Research
• Identify phosphorus foliar treatments to manage seed and root rot of fresh and dry peas caused by Aphanomyces root rot and Pythium.
Application rates of Product• Phostrol at 2.5 or 4 pints/acre/application
– Mono- and dibasic sodium, potassium and ammonium phophites (53.6%)
– Other ingredients (46.4%)– Contains 6.69 pounds/gallon of the active
ingredients– Equivalent to 4.32 pounds phosphorous acid
per gallon (35.6% by weight).
0100000200000300000400000500000600000700000800000900000
Nontrea
ted
Captan/A
llegianc
e
T-22 Plan
ter Box
GB-34Head
s Up 1
Heads U
p 2Kod
iakMicr
o 108
Serena
de ASO
Phostr
ol infur
row
Phostr
ol infur
row/emerge
nce
Seed Treatment
Emer
genc
e (P
lant
s/ac
re)
2004 Mount Vernon 2005 Mount Vernon 2005 Prosser
*
* * ** * *
* = Significantly different from nontreatedcontrol
* **
Yield
0100020003000400050006000700080009000
10000
Nontre
ated
Captan/Alle
giance
T-22 Planter B
oxGB-34
Heads U
p 1Hea
ds Up 2
Kodiak
Micro 1
08Seren
ade ASO
Phostro
l infurro
w
Phostro
l infurro
w/emer...
Phostro
l emerge
nce/14 .
..
Treatment
lb/a
cre
2004 Mount Vernon (Fresh)
2005 Mount Vernon (Fresh)
2005 Prosser (Dry)
* = Significantly different from the nontreated control
** **
Impact of applications of phosphorous acid on dry root weight
Significantly increased(56.97% or 0.5 g)
Present
May or may not significantly increase(2 out of 10 foliar sig. increased)
Absent
Dry root weightDisease Pressure
Impact of applications of phosphorous acid on foliar dry weight
Always significantly increased (23.3% or 2.4 g)
Present
Not significantly increased (1 exception)
Absent
Foliar dry weightDisease Pressure
Impact of applications of phosphorous acid on plant height
Significantly increasedwith foliar applications (16.9% or 2.4 cm)
Present
Did not significantly increase (3 of 4 trials)
Absent
Plant heightDisease Pressure
2006 Field test in Mount Vernon, WA
• Planting density 355 lbs/acre
• Variety = Charo
• Phosphorous acid and Phosphoric acid
• Foliar applications at 35 gallons/acre using backpack sprayer
• Applications made at emergence and 14 days later
Application rates of Product• Phostrol at 2.5 pints/acre per application.
– Mono- and dibasic sodium, potassium and ammonium phophites (53.6%)
– Other ingredients (46.4%)– Contains 6.69 pounds/gallon of the active
ingredients– Equivalent to 4.32 pounds phosphorous acid
per gallon (35.6% by weight).
Application rates of Product• Phytoplus 12% Phosphorus• 8.87 pints/acre per application.
– 2.0% ammonical nitrogen– 1.0% Urea nitrogen– Available phosphoric acid (P2O5) 12%– Derived from urea, ammonium phosphate,
phosphoric acid and potassium phosphate.
Yield in pounds/acre
01000200030004000500060007000
NTS
Phosp
horo
us (P
S)
Phosp
horic
(PC)
Captan
/Alle
gianc
eC/A
+ PSC/A
+ PC
c c
bc abab
a
Total income in $/acre
0100200300400500600700
NTS
Phosp
horo
us (P
S)
Phosp
horic
(PC)
Captan
/Alle
gianc
eC/A
+ PSC/A
+ PC
$349 $352$437
$484 $530$603
Economics• Tenderometer = 100
– Fresh peas sold for $184/ton in 2006• Costs per acre
– Captan/Allegiance seed treatment • $10.31
– Phosphoric acid = $ 16.84– Phosphorous acid = $11.25 – Application costs = ?
Net income in $/Acre
0100200300400500600
NTS
Phosp
horo
us (P
S)
Phosp
horic
(PC)
Captan
/Alle
gianc
eCA +
PSCA +
PC
$349 $341$421
$473$509
$576
Average plant height/cm
02468
10121416
NTS
Phosp
horo
us (P
S)
Phosp
horic
(PC)
Captan
/Alle
gianc
eC/A
+ PSC/A
+ PC
b b b
a aa
Conclusions• Phosphorous and phosphoric acid can be
used to manage Aphanomyces root rot on peas based on greenhouse tests.
• Phosphoric acid performed the best in field tests in Mt. Vernon, WA.
• Use of phosphorus-based products appears to be economical.
Economics• Cost of the seed treatment = $5.50/acre• Cost of 2.5 pints of Phostrol per acre =
$5.63/acre (At $18.00/gallon)• Phosphorous acid tank-mixed with insecticide
Yield (lb/acre)
219 lbDifference in
Yield
122 lbDifference in
Yield
333 lbDifference in
Yield
122 lbDifference in
Yield
$6.75/cwt -$5.63
$7.00/cwt-$5.63
$6.75/cwt -$5.63
$7.00/cwt-$5.63
Net Profit$9.15/acre
Net Profit$2.91/acre
Net Profit$16.85/acre
Net Profit$2.91/acre
Standard867
Standard1075
Standard491
Standard781
R/TS/2.5P1086**
R/TS/2.5P1197
NR/TS/2.5P824*
1.NR/TS/2.5P903
Moscow, IDAerial
Moscow, IDColumbian
Kendrick, IDAerial
Kendrick, IDColumbian
Conclusions• Phosphorous acid appears to have a big impact on
yield of semi-leafless dry pea varieties and their susceptibility to root pathogens.
• Phosphorous acid significantly increased plant height of both Columbian and Aerial cultivars.
• Phosphorous acid may be important to enhancing the ease of harvesting semi-leafless types with a wheat bar.