Blackpoint of wheat: Fungal associations, cultivar susceptibility, and effects on grain weight and germination

Abstract

There was considerable variation in the level of black point infection in grain samples from commercial crops of ‘Takahe’ and ‘Kopara’ wheats harvested in 1985 from Canterbury, Otago, and Southland. Alternaria alternata (Fr.) Keissler was the fungus most frequently isolated from blackpointed wheat harvested in 1985 and 1986. The fungus was isolated from both black pointed and symptomless grains, but grew most rapidly from darkened regions of black pointed grains. Wheat cultivars varied in their level of black point in field trials. Although some cultivars (especially ‘Takahe’, ‘Jasper’, and ‘Kopara’) were affected, most cultivars showed very low levels of blackpointed grain. Blackpointed grains were heavier than symptomless grains on average, partly as a result of their position within the head. There was no consistent effect of black point on germination of grain. Storage temperature and humidity did not affect black point severity.

Keywords:

• plant pathology
• plant diseases
• mycoses
• wheats
• grain crops
• cultivars
• disease resistance
• germination
• Triticum aestivum
• Alternaria alternata