Cause Ascochyta rabiei, a fungus carried in and on seed and in infested crop residue. Infection and blight develop rapidly on susceptible varieties in the presence of free moisture (rain and dew).
Symptoms Leaf and stem lesions initially are chlorotic, usually necrotic, and numerous. Developing lesions tend to coalesce and cause blight (death) of all aboveground plant parts. The fungus produces dark fruiting bodies (pycnidia), often arranged in concentric rings within developing lesions on leaves, stems, and pods. In the field, blight first appears in small patches in lowlands or under sprinkler irrigation. With available moisture and wind to disperse spores, the blight may spread to the entire field.
Cultural control
- Use only clean seed from crops and areas known to be free of blight.
- Resistant varieties such as Sanford and Dwelley (Kabuli types) and Myles (Desi type) are currently available.
- Destroy by deep tillage all infested chickpea residues and volunteer chickpea plants that may harbor the pathogen.
- Rotate 3 to 4 years between chickpea crops.
Chemical control
- Treating seed with approved fungicides reduces most surface inoculum but not will rid seed of internal infection.
- Mertect 340-F at 2.04 fl oz/100 lb seed plus a dye. 12-hr reentry.
- Foliar applications can help control disease.
- Aprovia Top (Group 7 + 3) at 10.5 to 11 fl oz/A on a 14-day interval. Do not apply more than two (2) sequential applications or two (2) application per year. Preharvest interval is 14 days. 12-hr reentry.
- Endura (Group 7) at 6 oz/A at the beginning of flowering. Make a second application 7 to 10 days later if disease persists or weather conditions are favorable for disease development. Preharvest interval is 21 days. 12-hr reentry.
- Inspire Super (Group 3 + 9) at 16 to 20 fl oz/A on 7- to 10-day intervals. Make no more than two (2) sequential applications. Preharvest interval is 14 days. 12-hr reentry.
- Proline 480 SC (Group 3) at 5.0 to 5.7 fl oz/A on 10- to 14-day intervals. Preharvest interval is 7 days. 12-hr reentry.
- Strobilurin fungicides (Group 11) are labeled for use. Do not make more than one (1) application of any Group 11 fungicide before alternating to a labeled fungicide with a different mode of action. Do not apply more than two (2) applications of any Group 11 fungicide per season.
- Headline at 6 to 9 fl oz/A at the beginning of flowering or at the onset of disease. Preharvest interval is 21 days. 12-hr reentry.
- Heritage at 3.2 to 8 oz/A on 7- to 14-day intervals. May be applied the day of harvest. 4-hr reentry.
- Quadris Flowable at 6 to 15.5 fl oz/A or Quadris Opti at 1.6 to 2.4 pints/A on 7- to 14-day intervals. Do not apply within 14 days of harvest. 4-hr reentry for Quadris Flowable, 12-hr reentry for Quadris Opti.
- Premixes of Group 3 + 11 fungicides are available for use. Do not make more than one (1) application of any Group 11 fungicide before alternating to a labeled fungicide with a different mode of action. Do not apply more than two (2) applications of any Group 11 fungicide per season.
- Quilt at 14 fl oz/A or Quilt Xcel at 10.5 to 14 fl oz/A on 7- to 14-day intervals for no more than three (3) applications. Preharvest interval is 14 days. 12-hr reentry.
- Quadris Top at 8 to 14 fl oz/Acre on 14-day intervals. Preharvest interval is 14 days. 12-hr reentry.
Reference Wiese, M.V, et al. 1995. Ascochyta Blight of Chickpea. University of Idaho Cooperative Extension System CIS 886.