Author:
This report was prepared by Dr. J. A. Wrather, University of
Missouri-Delta Center, P.O. Box 160, Portageville, MO 63873, and Dr. Steve
Koenning, North Carolina State University.
This project was supported by the farmer checkoff through the
United Soybean Board.
Introduction:
The objective of this project is to document the major
soybean disease problems in the United States during 1996-2006.
The goal is to provide this information to help agencies decide
which research projects to support and to help scientists focus
and coordinate research efforts.
Materials and methods:
Scientists from each soybean producing state were contacted
in October each year and asked for their estimates of soybean yields suppressed
by diseases caused in their state during these years. The methods used by
these scientists were field surveys, plant disease diagnostic
clinic samples, variety trial data, questionnaires to field
workers and extension staff, research plot data, grower
demonstrations, and reports of private crop consultants. Most
scientists used several of these methods and consulted with their
colleagues to develop an estimate.
Results:
Diseases reduced soybean production in the United States
each year from 1996-2006 (Table 1).
Table 1. Estimated soybean yields suppressed in the United
States due to diseases during 1996-2006.
| | (Yield loss (bushels)) |
|
| Diseases | 1996 |
1997 | 1998 |
1999 | 2000 |
2001 | 2002 |
2003 | 2004 |
2005 | 2006 |
|
| Anthracnose | 3,878,000 | 9,004,000 | 6,942,000 | 3,040,000 | 1,497,000 | 7,857,000 | 6,325,000 | 10,972,589 | 16,083,000 | 16,427,000 | 18,113,000 |
| Bacterial diseases | 772,000 | 910,000 | 994,000 | 480,000 | 378,000 | 378,000 | 672,000 | 358,589 | 751,000 | 1,122,000 | 3,731,000 |
| Brown spot | 3,246,000 | 4,562,000 | 6,138,000 | 2,949,000 | 7,090,000 | 2,661,000 | 2,438,000 | 2,850,889 | 25,163,000 | 7,158,000 | 1,972,000 |
| Brown stem rot | 30,778,000 | 24,006,000 | 14,655,000 | 10,335,000 | 10,194,000 | 12,439,000 | 7,404,000 | 11,535,889 | 15,660,000 | 7,916,000 | 18,284,000 |
| Charcoal rot | 12,350,000 | 16,625,000 | 38,101,000 | 40,389,000 | 30,246,000 | 18,875,000 | 31,694,000 | 77,802,611 | 10,849,000 | 13,060,000 | 25,637,000 |
| Downy mildew | 341,000 | 262,000 | 884,000 | 122,000 | 697,000 | 110,000 | 79,000 | 313,000 | 535,000 | 564,000 | 5,418,000 |
| Frogeye leaf spot | 835,000 | 1,288,000 | 3,905,000 | 719,000 | 809,000 | 244,000 | 7,021,000 | 9,882,589 | 11,407,000 | 6,913,000 | 12,682,000 |
| Fusarium root rot | 1,232,000 | 2,423,000 | 3,184,000 | 3,516,000 | 1,590,000 | 10,202,000 | 15,568,000 | 5,935,178 | 9,457,000 | 5,512,000 | 6,215,000 |
| Other diseases | 1,673,000 | 9,741,000 | 941,000 | 1,954,500 | 3,722,000 | 2,880,000 | 2,245,000 | 2,240,000 | 8,983,000 | 529,000 | 2,045,000 |
| Phomopsis seed rot | 3,451,000 | 1,586,000 | 8,961,000 | 2,549,000 | 8,048,000 | 10,420,000 | 13,844,000 | 4,472,944 | 10,790,000 | 5,056,000 | 4,485,000 |
| Phytophthora rot | 40,486,000 | 53,626,000 | 42,227,000 | 26,141,000 | 39,545,000 | 54,735,000 | 45,953,000 | 55,543,556 | 57,116,000 | 41,977,000 | 53,808,000 |
| Pod and stem blight | 5,131,000 | 12,742,000 | 5,278,000 | 13,956,000 | 7,474,000 | 25,853,000 | 5,946,000 | 6,008,356 | 7,141,000 | 3,464,000 | 7,655,000 |
| Purple stain | 7,981,000 | 3,699,000 | 4,132,000 | 5,068,000 | 1,956,000 | 4,056,000 | 7,257,000 | 4,606,589 | 3,858,000 | 3,563,000 | 3,132,000 |
| Rhizoctonia aerial blight | 1,738,000 | 1,311,000 | 4,097,000 | 620,000 | 170,000 | 1,180,000 | 960,000 | 1,170,000 | 1,120,000 | 380,000 | 460,000 |
| Root-knot and other nematodes | 5,917,000 | 4,936,000 | 4,705,000 | 4,467,000 | 3,662,000 | 5,569,000 | 4,991,000 | 5,346,000 | 5,484,000 | 4,181,000 | 7,919,000 |
| Rust | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 520,000 | 901,000 |
| Sclerotinia stem rot | 22,572,000 | 35,189,000 | 18,704,000 | 2,699,000 | 9,655,000 | 2,483,000 | 2,918,000 | 2,081,178 | 60,008,000 | 5,991,000 | 13,305,000 |
| Seed diseases | 4,510,000 | 290,000 | 1,682,000 | 491,000 | 406,000 | 378,000 | 337,000 | 514,944 | 174,000 | 2,588,000 | 680,000 |
| Seedling diseases | 31,345,000 | 24,508,000 | 28,550,000 | 12,317,000 | 21,946,000 | 33,311,000 | 21,840,000 | 28,307,444 | 44,082,000 | 32,638,000 | 39,885,000 |
| Southern blight | 206,000 | 246,000 | 339,000 | 260,000 | 330,000 | 170,000 | 180,000 | 250,000 | 290,000 | 210,000 | 190,000 |
| Soybean cyst nematode | 213,862,000 | 218,982,000 | 279,056,000 | 169,267,000 | 141,967,000 | 154,630,000 | 142,882,000 | 114,450,555 | 136,722,000 | 76,210,000 | 123,778,000 |
| Stem canker | 1,892,000 | 1,235,000 | 1,101,000 | 3,001,000 | 2,553,000 | 4,551,000 | 4,252,000 | 8,825,589 | 14,994,000 | 6,557,000 | 7,779,000 |
| Sudden death syndrome | 3,709,000 | 11,162,000 | 33,097,000 | 19,221,000 | 75,764,000 | 23,387,000 | 28,698,000 | 12,421,333 | 42,329,000 | 19,849,000 | 27,320,000 |
| Virus | 2,392,000 | 2,144,000 | 9,209,000 | 8,944,000 | 37,277,000 | 15,762,000 | 30,071,000 | 7,092,067 | 2,243,000 | 1,601,000 | 7,451,000 |
|
| Total | 400,297,000 | 440,477,000 | 516,882,000 | 332,505,500 | 398,656,000 | 392,131,000 | 383,575,000 | 372,981,889 | 485,239,000 | 363,987,000 | 401,593,000 |
|
