Authors
C. S. Rothrock,
S. A. Winters and
P. K. Miller, Department of Plant Pathology, University of Arkansas, Fayetteville 72701;
E. Gbur, Agricultural Statistics, University of Arkansas, Fayetteville 72701;
L. M. Verhalen and
B. E. Greenhagen, Department of Plant and Soil Sciences, Oklahoma State University, Stillwater 74078;
T. S. Isakeit, Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843;
W. E. Batson, Jr., Department of Entomology and Plant Pathology, Mississippi State University, Mississippi State 39762;
F. M. Bourland, Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Northeast Research and Extension Center, Keiser 72351;
P. D. Colyer, Red River Research Station, Louisiana State University AgCenter, Bossier City 71113;
T. A. Wheeler and
H. W. Kaufman, Texas AgriLife Research and Extension Center, Lubbock 79403;
G. L. Sciumbato and
P. M. Thaxton, Mississippi State University, Delta Research and Extension Center, Stoneville 38776;
K. S. Lawrence and
W. S. Gazaway, Department of Entomology and Plant Pathology, Auburn University, Auburn 36849;
A. Y. Chambers and
M. A. Newman, Department of Entomology and Plant Pathology, University of Tennessee, West Tennessee Research and Education Center, Jackson 38301;
T. L. Kirkpatrick and
J. D. Barham, Department of Plant Pathology, University of Arkansas, Southwest Research and Extension Center, Hope 71801;
P. M. Phipps and
F. M. Shokes, Virginia Polytechnic Institute and State University, Tidewater Agriculture Research and Extension Center, Suffolk 23437;
L. J. Littlefield, Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater 74078;
G. B. Padgett, Macon Ridge Research Station, Louisiana State University AgCenter, Winnsboro, 71295;
R. B. Hutmacher, University of California, Davis, Shafter Research and Extension Center, Shafter 93263;
R. M. Davis, Department of Plant Pathology, University of California, Davis 95616;
R. C. Kemerait and
D. R. Sumner, Department of Plant Pathology, University of Georgia, Tifton 31794;
K. W. Seebold, Jr., Department of Plant Pathology, University of Kentucky, Lexington 40546;
J. D. Mueller, Clemson University, Edisto Research and Education Center, Blackville 29817; and
R. H. Garber, USDA-ARS, Shafter 93263
Abstract
The importance of fungicide seed treatments on cotton was examined using a series of standardized fungicide trials from 1993 to 2004. Fungicide seed treatments increased stands over those from seed not treated with fungicides in 119 of 211 trials. Metalaxyl increased stands compared to nontreated seed in 40 of 119 trials having significant fungicide responses, demonstrating the importance of Pythium spp. on stand establishment. Similarly, PCNB seed treatment increased stands compared to nontreated seed for 44 of 119 trials with a significant response, indicating the importance of Rhizoctonia solani in stand losses. Benefits from the use of newer seed treatment chemistries, azoxystrobin and triazoles, were demonstrated by comparison with a historic standard seed treatment, carboxin + PCNB + metalaxyl. Little to no stand improvement was found when minimal soil temperatures averaged 25°C the first 3 days after planting. Stand losses due to seedling pathogens increased dramatically as minimal soil temperatures decreased to 12°C and rainfall increased. The importance of Pythium increased dramatically as minimal soil temperature decreased and rainfall increased, while the importance of R. solani was not affected greatly by planting environment. These multi-year data support the widespread use of seed treatment fungicides for the control of the seedling disease complex on cotton.
