Marcia McMullen Dept. of Plant Pathology North Dakota State Univ. Fargo, ND Leaf Rust Detection in ND Wheat Surveys,

Importance of Surveys ND #1 in spring wheat and durum production Diseases = severe economic damage Producers need “real time” information to make informed management decisions Survey data provides such information + helps validate disease forecasting models + provides information about crop losses/quality; possible shifts in races

Real Time Information Provided  Ag Alerts for Growers  Weekly Crop and Pest Report  IPM Web Site

ND Wheat Surveys Collaborative Effort: NDSU Extension Area Specialists and 2 NDSU Extension State Specialists Denise Markel NCREC *Roger Ashley DREC Greg Endres CREC Terry Gregoire Devils Lake Area Marcia McMullen Jan Knodel SE area Funded by ND Wheat Commission, ND Dept. of Ag., APHIS –ARS Cooperative Pest Survey

The Wheat Survey Uses Technology to Improve Information Delivery 1. Field Scouts trained in pest ID & scouting methods Field records go from Excel database to mapping program. Interpolated Grid map Bulleted maps Record field data using iPAQs and GPS 2. 3.

# of Wheat Fields Surveyed from 2 Leaf - Soft Dough Stage of Kernel Development

Occurrence of Wheat Leaf Rust % of Surveyed Fields Positive for Leaf Rust Average % Severity of Leaf Rust over all Fields

NW NC NE SWSC WC CENT EC SE Data Reported the 9 Crop Reporting Districts of NASS (Ag. Statistical Service). All counties surveyed in each crop reporting district; at least one field per 10,000 acres

1999 Wheat Leaf Rust in ND Crop Reporting Districts % Fields with symptoms % Severity

Spring Wheat Variety Response - Spring Wheat Variety Response - Leaf Rust in ND ‘99 (Dr. Jack Rasmussen, NDSU) % coefficient of infection averaged over Langdon, Prosper, Carrington; 2375 especially low at Carrington; Reeder especially high at Carrington Coefficient of infection = severity x reaction type

Average Severity of Leaf Rust and Fungal Leaf Spots, ND 2001

Occurrence of Wheat Leaf Rust % of Surveyed Fields Positive for Leaf Rust Average % Severity of Leaf Rust over all Fields

National Weather Service Precipitation Map June 2005 Source: NOAA

Wet Weather Favored Diseases ~ 1300 wheat fields surveyed 56 fields with > 15% severity; Many with between 6-15%

Statewide: 2005 Wheat Leaf and Stripe Rust Stripe Leaf

Stripe Rust - HRSW Rxs one location data: Hettinger Research Extension Center 2005 % incidence

2005 Leaf Rust – HRSW cont. Dr. Jack Rasmussen & Jim Jordahl, NDSU Plant Path Dept. Coefficients of infection

2005 Leaf Rust – HRSW Dr. Jack Rasmussen & Jim Jordahl, NDSU Plant Path Dept.

Occurrence of Wheat Leaf Rust % of Surveyed Fields Positive for Leaf Rust Average % Severity of Leaf Rust over all Fields

10 fields with severity > 15% Most between 1-5%

Questions? Photo by Marcia McMullen