NSHS Methods List & Codes

Printable PDF

DATE: Current as of 11.14.2025

Beans

PathogenMethodCodeClassNSHS VersionDate
Pseudomonas syringae pv. phaseolicolaDilution and plating, followed by Pathogenicity Test (ISTA 7-023: ver 1.5)Be 1.2St1.53/1/2024
Pseudomonas syringae pv. syringaeAgar Plate Assay (Mohan and Schaad, 1987)Be 2.1TSt1.012/2012
Xanthomonas axonopodis pv. phaseoliISTA Method (7-021: ver 3.3)Be 3.1St1.53/1/2024
Curtobacterium flaccumfaciens pv. flaccumfaciensSelective Media AssayBe 4.3TSt1.39/2025
Colletotrichum lindemuthianumISTA Method (7-006: ver 1.6)Be 5.1TSt1.33/1/2024

Pea

PathogenMethodCodeClassNSHS VersionDate
Ascochyta pisiISTA Method (7-005: ver 1.5)Pe 1.1St1.33/1/2024
Pea Seedborne Mosaic VirusISTA Method (7-024: ver 1.5)Pe 2.1St1.33/1/2024
Pea Early Browning VirusISTA Method (7-024: ver 1.5)Pe 3.1St1.33/1/2024
Pseudomonas syringae pv pisiISTA Method (7-029: ver 1.3)Pe 4.1St1.33/1/2024

Brassica

PathogenMethodCodeClassNSHS VersionDate
Xanthomonas campestris pv. campestrisISTA Method (7-019a: ver 6.0; 7-019b: ver 1.3)Br 1.1St1.31/1/2022
Phoma lingamFreeze Blotter (ISTA 7-004: ver 2.2)Br 2.1St1.43/1/2024

Carrots

PathogenMethodCodeClassNSHS VersionDate
Xanthomonas hortorum pv. carotaeNSHS MethodRb 1.1St2.12/19/2024
Alternaria dauci (2.1)ISTA Method (7-001a: ver 1.6; 7-001b: ver 1.6)Rb 2.1St1.33/1/2024
Alternaria dauci (2.2)Direct Plating/Blotter Method (Sunseeds)Rb 2.2St1.02002
Alternaria radicinaISTA Method (7-002a: ver 1.5)Rb 3.1St1.33/1/2024

Cucurbits

PathogenMethodCodeClassNSHS VersionDate
Acidovorax citrulli (1.1)Seedling grow-outCb 1.1St1.12017
Acidovorax citrulli (1.5)CSPL PCR AssayCb 1.5TSt1.012/2012
Acidovorax citrulli (1.6)ISHI Method (version 3.0, Oct. 2025)Cb 1.6St3.010/2025
Didymella bryoniae (2.1)PCR (Ling et al., 2010)Cb 2.1TSt1.012/2012
Didymella bryoniae (2.2)Vegetables Blotter AssayCb 2.2TSt1.02001
Cucumber green mottle mosaic virusISTA Method (7-026: ver 1.5)Cb 3.1TSt1.33/1/2024
Melon necrotic spot virusISTA Method (7-026: ver 1.5)Cb 4.1TSt1.33/1/2024
Squash mosaic virus (SMV)ISTA Method (7-026: ver 1.5)Cb 5.1TSt1.33/1/2024
Fusarium oxysporum f.sp. niveumFreeze Blotter (Syngenta)Cb 6.1TSt1.011/2014

Celery

PathogenMethodCodeClassNSHS VersionDate
Septoria apiicolaSeed Wash (STA Laboratories)Lcb 1.1St1.02001
Phoma apiicolaGrow-out (Hewitt, 1971)Lcb 2.1TSt1.02001

Spinach

PathogenMethodCodeClassNSHS VersionDate
Peronospora farinosa f.sp. spinaciae (3.1)Wash Test (Inaba et al., 1983)Lcb 3.1TSt1.012/2012
Peronospora farinosa f.sp. spinaciae (3.2)Wash Test (CDFA)Lcb 3.2TSt1.012/2012
Verticillium dahliae (4.1)Freeze Blotter, ISTA Method (7-032: ver 1.3)Lcb 4.1St1.33/1/2024
Verticillium dahliae (4.2)NP-10 Agar, ISTA Method (7-032: ver 1.3)Lcb 4.2St1.33/1/2024
Cucumber mosaic virusSeedling grow-out and ELISA (Yang et al., 1997)Lcb 5.1St1.012/2012
Stemphylium botryosum f. sp. spinaciaFreeze Blotter (Hernandez-Perez and du Toit, 2016)Lcb 6.1St1.012/2012

Coriander

PathogenMethodCodeClassNSHS VersionDate
Pseudomonas syringae pv. coriandricolaSelective Media Test (STA Laboratories)Lcb 7.1St1.02001

Lettuce

PathogenMethodCodeFormer CodeClassNSHS VersionDate
Lettuce mosaic virus (8.1)Chenopodium Assay (Kimble et al., 1975)Lcb 8.1Cv 1.1St1.02001
Lettuce mosaic virus (8.2)ISHI-Vegetables Method (version 4.3, July 2017)Lcb 8.2Cv 1.2St1.16/04/2021

Corn Salad

PathogenMethodCodeClassNSHS VersionDate
Acidovorax valerianellaeISTA Method ( 7-030: ver 1.3)Lcb 9.1St1.23/1/2024

Solanaceae (Tomato/Pepper)

PathogenMethodCodeClassNSHS VersionDate
Xanthomonas spp. (1.1)ISHI-Vegetables Method (pepper, version 5, 2013)So 1.1TSt1.205/2022
Xanthomonas spp. (1.2)ISHI-Vegetables Method (tomato, version 4, 2011)So 1.2TSt1.205/2022
Clavibacter michiganensis ssp. michiganensisISHI-Vegetables Method (version 4.3.1, 2017)So 2.1St1.107/2021
Pseudomonas syringae pv. tomatoCDFA MethodSo 3.1St1.02001
Pepino Mosaic VirusISHI Method (version 5 2021)So 4.1TSt2.005/2021
Tobamoviruses (TMV, ToMV, PMMov)ISTA Method (7-028: ver 1.4)-Tomato; ISF Jan 2007-PepperSo 5.1TSt1.43/1/2024
Pospiviroids (CLVd, PCFVd, PSTVd, TASVd, TCDVd and TPMVd)TaqMan RT-PCR Method, National Seed Health System (NSHS)So 6.1St1.403/2024
Tomato Brown Rugose (ToBRFV)TaqMan RT-PCR Method, National Seed Health System (NSHS)So 7.1St2.202/2024
Tomato Mottle Mosaic Virus (ToMMV)TaqMan RT-PCR Method, National Seed Health System (NSHS)So 8.1St1.009/2025

Onion

PathogenMethodCodeClassNSHS VersionDate
Alternaria porriAgar Plate Method (Aveling et al., 1993)On 1.1TSt1.012/2013
Stemphylium vesicariumS. vesicariumOn 2.1TSt1.012/2013

Maize

PathogenMethodCodeFormer CodeClassNSHS VersionDate
Stenocarpella maydisCulture plate (ISU)Mz 1.1Cf 1.1St1.02001
Cochliobolus carbonumISU Freezing Blotter Method (McGee, 1994)Mz 2.1Cf 2.1St1.02001
Cochliobolus heterostrophusISU Freezing Blotter Method (McGee, 1994)Mz 3.1Cf 3.1St1.02001
Ustilago maydis/Sphacelotheca reilianaWash Test (McGee, 1988)Mz 4.1 Cf 4.1St1.02001
Sclerophthora macrosporaDirect Visual method (CIMMYT)Mz 5.1Cf 5.1St1.02001
Peronosclerospora sorghiGrow-out (Adenle and Cardwell, 2000)Mz 6.1Cf 6.1St1.02001
FusariumBlotter (Singh et al., 1974)Mz 7.1Cf 8.2St1.02001
Penicillium oxalicumBlotter test (Handoo and Aulakh, 1979)Mz 8.1 Cf 9.1St1.02001
Clavibacter michiganensis ssp. nebraskensissCNS Culture Plate Method (Shepherd, 1999)Mz 9.1Cb 1.1St1.02001
Pantoea stewartiiELISA (Lamka et al., 1991)Mz 10.1Cb 2.1St2.203/2025
Maize Dwarf Mosaic VirusELISA (Iowa State University/Agdia Inc kit)Mz 11.1Cb 3.1TSt1.210/2020
Maize Chlorotic Mottle VirusELISAMz 12.1Cb 4.1TSt1.210/2020
Cercospora zeae-maydisCulture PlateMz 13.1Cf 10.1RNSP1.02001
Kabatiella zeaeCulture PlateMz 14.1Cf 11.1RNSP1.02001
Phyllosticta maydisCulture PlateMz 15.1Cf 12.1RNSP1.02001

Soybean

PathogenMethodCodeFormer CodeClassNSHS VersionDate
Cercospora kikuchii (1.1) Culture Plate (Jordan et al., 1986)Sb 1.1Sf 1.1St1.02001
Cercospora kikuchii (1.2)Blotter (McGee and Nyvall, 1984)Sb 1.2Sf 1.2St1.02001
Phomopsis/Diaporthe spp. (2.1)Culture plate (McGee, 1986)Sb 2.1Sf 2.1St1.02001
Phomopsis/Diaporthe spp. (2.2)Blotter (McGee and Nyvall, 1984)Sb 2.2Sf 2.2St1.02001
Sclerotinia sclerotiorumCulture plate (Totir, 2000)Sb 3.1Sf 3.1St1.02001
Pseudomonas syringae pv. glycinea (4.1)Soaked bulk seed – Biochemical confirmationSb 4.1Sb 2.1St1.12022
Pseudomonas syringae pv. glycinea (4.2)Ground bulk seed – Serological and pathogenicitySb 4.2 Sb 2.2St1.12022
Tobacco Ringspot Virus (5.1)ELISA (Iowa State University/Agdia Inc kit)Sb 5.1 Sv 1.1TSt1.210/2020
Tomato Ringspot Virus (6.1)ELISA (Iowa State University/Agdia Inc kit)Sb 6.1Sv 2.1TSt1.210/2020
Soybean Mosaic VirusELISA (Iowa State University/Agdia Inc kit)Sb 7.1Sv 3.1TSt1.210/2020
Bean Pod Mottle VirusELISA (Iowa State University/Agdia Inc kit)Sb 8.1Sv 4.1TSt1.210/2020

Approved methods are classified as follows:

St: Standard (A)
TSt: Temporary standard (B)
RNSP: Regulated non-seedborne pathogens