Evaluation of Organic Seed andEvaluation of Organic Seed and Drench Treatments for Damping‐off
in Organic Pea Crops
Ana Vida Alcala1, Lindsey du Toit1, and Lyndon Porter2
1WSU Mount Vernon NWREC, and 2USDA‐ARS, ProsserWSU Mount Vernon NWREC, and USDA ARS, Prosser
Background
Poor crop standSeed quality
S db thPoor crop stand Soilborne pathogens
Seedborne pathogens
p g
Pythium spp.
Fusarium spp.
Rhizoctonia spp.
Background 2009 WA organic vegetable grower interviews
f lSignificant losses to poor emergence. • replant entire fields • greater seeding rate than conventional crops g g p(weed control and poor stands)
Early planting = critical factor associated with poor stands.
Reasons for early planting :id d
y p g p
• avoid weeds• harvest and process before conventional crops • double cropping
Background2009 WA organic vegetable grower interviews
Organic seed treatments are not widely used: inconsistency.
$Growers’ willing to pay ≥ $100/acre for a treatment that consistently results in 30% increase in stand.
Pea cultivars planted early in the season in WA for processing markets.
Products must work in cold, wet soils.
Objectives1. Identify Pythium spp. associated with poor stands in organic vegetable crops in the Columbia Basin.
P. ultimumP. oligandrumP. catenulatum
P. intermedium
P. splendens P. camurandrumP. diclinum
P. radiosum
P. inflatunP. sylvaticum
P.aristosporum To beidentified
P. dissotocumP. violae
P. echinulatum
P. torulosum
P. adhaerens
P. middletonii
Pythium species identified (37 certified organic fields in Columbia Basin)
P. torulosum
P. irregulareP. abappressorium
Objectives1. Identify Pythium spp. associated with poor stands in organic vegetable crops in the Columbia Basin.
P. ultimum24.6 %
P. violae3.3 %
P. irregulare 15.1%
P. abappressorium
4.9 %
Pythium species identified (37 certified organic fields in Columbia Basin)
15.1%4.9 %
Objectives
2. Evaluate seed and drench treatments for control of damping‐off in organic pea crops.
Methods: 2011 Field trial locations
Boardman, Oregon
Soap Lake, Washington
Mount Vernon, WashingtonMount Vernon, WashingtonMount Vernon, WashingtonMount Vernon, Washington
MethodsTreatments: Boardman and Soap Lake trials (OMRI listed)
Seed treatments Drench treatmentsSeed treatments Drench treatments
Acadian Marine Seaplant Extract Serenade Soil
Actinovate STP Soilgard 12Gg
HeadsUp Plant Protection Stimplex Biostimulant
Mycoseed Treat Water drench (control)
Mycostop Mix
Natural II CO2 backpack sprayer
Nordox 75 WG Prestop WP
Primed seeds
T‐22 HC
Non‐treated seeds (control)
Methods
Seed treatments Drench treatments Control treatments
Treatments at Mount Vernon trial
Acadian Marine Seaplant Extract Serenade Soil Apron XL
Actinovate STP Soilgard 12G Non‐treated seeds (NTS), inoculated soilHeadsUp Plant Protection Stimplex BiostimulantHeadsUp Plant Protection Stimplex Biostimulant
Mycoseed Treat NTS, inoculated soil + water drenchMycostop Mix CO2 backpack sprayer
Natural II Prestop WP NTS, non‐inoculated soil
Nordox 75 WG NTS, non‐inoculated soil + soil‐oatmeal carrierPrimed seedsPrimed seeds
T‐22 HC
Germains’ II
Prestop Mix
Inoculated with Pythium ultimum
MethodsPlanting Boardman – Bistro
Soap Lake BoogieSoap Lake – BoogieMount Vernon – Ice Pack
MethodsDrench applications at planting and 14 dap
Methods
Weekly stand count 14 – 35 dap
Sampling and isolation ofSampling and isolation of pathogen from roots
35 dap
MethodsRoot rot rating, height, and shoot dry weight
at full bloomat full bloom
Rating scale: 0 ‐ 5 (0 = no symptoms & 5 = dead plant)
Methods
Harvest
Methods
Removal of seeds from pods
Seed weight Tenderometer reading
Results: Boardman trialEmergence
Ave. = 35% emergence (35 dap) Poor stand = Rhizoctonia and PythiumPoor stand = Rhizoctonia and Pythium
Results: Boardman trialYield (lb/A)
Results: Soap Lake trialEmergence
Ave. = 81% emergence
Results: Soap Lake trial Yield (lb/A)
Results: Mount Vernon trialEmergence
l d i h hi l iInoculated with Pythium ultimum
Results: Mount Vernon trialYield (lb/A)
20.00% Increase in Emergence
Compared to Non-treated Seed15.00
Nordox 6 4
Compared to Non-treated Seed
10.00
Nordox 6.4
Nordox 6.4 + Corn Flour
5.00
0.002007 2008A 2008B 2009A 2009B 2011A 2011B 2011C
‐5.00
‐10.00
40.00
50.00
% Increase in Yield Compared to Non-treated Seed
30.00
20.00
N d 6 4
10.00
Nordox 6.4
Nordox 6.4 + Corn Flour
0.002007 2008A 2008B 2009A 2009B 2011A 2011B 2011C
‐10.00
‐20.00
SummaryThree field environments:
• high disease pressure (Boardman trial)• low disease pressure (Soap Lake trial)• inoculated (cold and wet) site (Mount Vernon trial)
High disease site: Nordox and primed seed increased emergence Primed seed increased yield
Low disease site: No benefit from seed treatmentsDrench treatments reduced emergence
Inoculated site: No treatment worked against Pythium;Primed seed reduced emergence.
l i d d i i h d i lConclusion: Nordox and priming showed potential for damping‐off control.
Future work
Growth chamber trials: optimize primingGrowth chamber trials: optimize priming protocol, evaluate combined treatments (e.g., priming and Nordox).
2012 field trials: more effective seed ( l b )treatments (alone and in combination)
from 2011 field data.
Other aspects of damping‐off management.
Plant Disease Management Report (PDMR) vol. 6
Acknowledgement
•WSU CSANR•Organic vegetable growers and processors in WA and OR
•Manufacturers and distributors of the organic products
Some of the pesticides discussed in this t ti t t d d i t l presentation were tested under an experimental
use permit granted by WSDA.Application of a pesticide to a crop or site that Application of a pesticide to a crop or site that is not on the label is a violation of pesticide law and may subject the applicator to civil penalties m y j pp p
up to $7,500.In addition, such an application may also result
in illegal residues that could subject the crop to seizure or embargo action by WSDA and/or the
U S Food and Drug AdministrationU.S. Food and Drug Administration.It is your responsibility to check the label
before using the product to ensure lawful use before using the product to ensure lawful use and obtain all necessary permits in advance.
