Ascochyta blight has been discovered in some of Saskatchewan’s chickpea crops. This plant disease caused by the fungal pathogen Ascochyta rabiei (formerly known as Phoma rabiei) might threaten the livelihood of many Saskatchewan producers in the Southwest. On July 19, chickpea growers in the southern part of the province contacted Saskatchewan Pulse Growers to alert the group of a potential disease outbreak in their chickpea crops. Members from Agriculture and Agri-Food Canada, the Saskatchewan Ministry of Agriculture and the Crop Development Centre visited some of the affected fields to investigate and take samples of the blight for further research. The federal and provincial government teams concluded that there were signs of root rot found in some of the chickpea samples. Leaflet blighting had also been discovered.
The federal and provincial governments have been discussing the threat of Ascochyta with Saskatchewan’s producers. So far, the affected fields are found mostly east of Swift Current as well as in areas south of Highway Number 1. Additional reports say the outbreak of Ascochyta has affected chickpea fields in parts of the United States as well. The variety, CDC Orion, is said to be more in danger of contracting this disease than other types of chickpeas and pulses.
Growers are asked to investigate their chickpeas for the presence of Ascochyta by doing a walk through and logging any leaflet blighting seen on plants. Producers should pull out samples to find out if root rot has altered the plant’s health as well.
Anywhere in the fields where additional stress has condensed the growth of chickpeas are plausible areas to search for the disease’s presence. Farmers should begin scouting their fields for the blight by probing wet, low lying areas. Producers should also investigate compacted areas where machinery has been transported and check these places for traces of Ascochyta. In general, zones affected by moisture, farm machinery hail damage, heavy rain, winds, herbicide injuries (such as residual carry-over, tank contamination and drift, root issues and nutrient deficiencies) are all susceptible places for Ascochyta to take hold. If the disease is discovered, producers have a gap of 7-10 days to apply fungicides.
If chickpeas are green and are continuing to develop, farmers should continue with their disease management plans. Further on this point, producers should know the stages of their chickpea crops and realize the appropriate preharvest intervals to use when applying fungicides. Producers should also know what the appropriate fungicides are before spreading them over their chickpea crops. Single-action strobilurins aren’t recommended to use as a defence against Ascochyta, because this disease is capable of quickly building a resistance to these particular kinds of fungicides.
