North Central Regional Plant Introduction Station

Charlie Block

USDA Plant Pathologist
Ph.D., Iowa State University (1996)

Dr. Block has been employed at the Plant Introduction Station since 1979 and assumed full responsibility for the plant pathology program in 1991. Components of the plant pathology program include:

• evaluating germplasm for resistance to fungal and bacterial disease
• inspecting field plantings, testing transplants, and seed-health testing to help ensure that seed produced and distributed from NCRPIS is free from harmful pathogens
• assisting the curators in disease identification and management
• conducts research on the biology of seed transmitted diseases

Recent evaluation work has focused on testing popcorns for resistance to gray leaf spot (Cercospora zeae-maydis), northern leaf blight (Exserohilum turcicum), and eyespot (Kabatiella zeae); testing Amaranthus for resistance to Phomopsis leaf and stem blight; and testing sunflowers for resistance to Alternaria leaf blight and Septoria leaf spot. Seed research has focused on assessing risk of seed transmission of Pantoea stewartii (syn. Erwinia stewartii), the causal agent of Stewart's bacterial wilt of corn; eradication of Alternaria radicina (black rot) in carrot germplasm; and seed transmission of squash mosaic virus in pumpkins and squash.

Charlie Block may be emailed at: cblock@ars-grin.gov

Selected Publications:

Block, C. C., J. H. Hill, and D. C. McGee. 1998. Seed transmission of Pantoea stewartii in field and sweet corn. Plant Dis. 82: 775-780.

Block, C. C., J. H. Hill, and D. C. McGee. 1999. Relationship between late-season severity of Stewart's bacterial wilt and seed infection in maize. Plant Dis. 83: 527-530.

Sooby, J., R. Myers, D. Baltensberger, D. Brenner, R. Wilson, and C. Block. 1999. Amaranth Production Manual for the Central United States. Univ. of Neb. Coop. Ext. EC 98-151-S. 23 pp.

Shepherd, L. M., C. C. Block, and D. C. McGee. 1997. A new seed health assay for Clavibacter michiganensis subsp. nebraskensis. Phytopathology (Abstract) 87(6): S89.

Block, Charles C. 1997. Assessing risk of seed transmission of Stewart's wilt. Proceedings of the 51st Annual Corn and Sorghum Research Conference. pp. 181-190.

Block, Charles C. 1997. New insights into an old disease: Unraveling the biology of seed transmission of Stewart's disease of corn. Iowa Seed Science Newsletter 17: 4-5.

Block, C. C., D. C. McGee, and J. H. Hill. 1994. Assessing risk of seed transmission of Erwinia stewartii in maize. (Abstr.) Phytopathology 84:1153.

Block, C. C. 1993. Stewart's wilt in corn and seed transmission research. Proc. of the 15th Ann. Seed Tech. Conf., Iowa State Univ., Ames, pp. 65-79.

Block, C. C. 1992. Screening for resistance to Alternaria helianthi in the USDA germplasm collection. Proc. Sunf. Res. Workshop., pp. 64-66.