ARS | Publication request: EFFECT OF TEMPERATURE AND AGE OF THE SPHACELIUM ON THE VIABILITY OF CLAVICEPS AFRICANA CONIDIA

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2003
Publication Date: N/A

Technical Abstract: Conidia of Claviceps africana, (cause of sorghum ergot), originating from sphacelia of different ages, were assessed for survival at different storage temperatures. Intact sphacelia (collected 0, 1, 2, and 3 weeks after symptom appearance) were stored in petri dishes with silica gel at 0, 7, 14 and 21 degrees C. Surface and interior conidia were tested monthly for viability by plating onto water agar. After one month, viability of surface conidia declined from 46% to 7% at 21 C. Conidia stored at 0 and 7 degrees C did not lose viability after one month, but their viability declined to 6% after six months. Conidia from the interior of sphacelia stored at 0 and 7 degrees C were 10-13% viable after six months. Initially, viability of surface conidia from 0 and 1-week-old sphacelia was 60%, compared with 30% for 3-week-old sphacelia, but viability of conidia from all sphacelial ages declined to 2-5% after six months. Conidia from inside sphacelia of all ages had higher level (5-10%) of viability after six months.