Crop diseases in barley farms found to be resistant to triazole-based fungicides

In Australia’s Great Southern, Barley owners faced a warning of been hit by several diseases which have begun to appear on crops in the region since the past few months.

Reports draw attention to a stubble-borne fungal disease similar to spot net type blotch (STNB) and net type net blotch (NTNB) which appeared on several farms in the vicinity of the region. Crops like barley scald and barley powdery mildew were mainly affected by the disease. In addition they are also affecting varieties of Planet and Rosalind.

The disease type net blotches and scald can further lead to reducing grain quality, in addition to affecting crop yield.

Experts suggest that the spores can travel with the direction of the wind and can thus spread fungus to the farms and paddocks from the neighborhood.

A lack of crop rotation was determined to be one of the biggest issues of the south coast, according to plant pathologist, Dr Kithsiri Jayasena of Department of Primary Industries and Regional Development.

The stubble from the previous year will produce spores and will then migrate to the next paddock as the rains start. “Our problem in this south coast environment is that farmers grow barley and they want to keep it going until the next season to feed livestock, but the regrowth barley can produce more of the disease.

“Some who sow the crop in May, they are approaching the stem extension stage, and the disease manifestation in the crop is also dependent on what sort of fungicides they have used,” commented Jayasena.

He pointed out that wet and warm conditions were the best for a fungus to grow. Moreover, it has been observed that both types of pathogens have become resistant to triazole-based fungicides which will thus require farmers to use chemicals to prevent such diseases.