Timely Fungicides Help Battle Aschochyta

REGINA - May 16/05 - SNS -- Applying fungicides in a timely manner is critical to successfully battling ascochyta blight infestations in chickpeas, according to the University of Saskatchewan's Dr. Sabine Banniza.

"Chickpeas really started to become a significant crop in Saskatchewan around 1995," says Dr. Banniza. "At the time, ascochyta blight was not a major issue. Consequently, there was not a wide range of fungicides available. During the late 1990s, there was an explosion of chickpea production in the province. The total production went from perhaps 1,000 hectares to half a million hectares because prices were so good."

Chickpeas became a very attractive crop. However, 1999 and 2000 were particularly wet summers, and there was a dramatic increase in the occurrence of ascochyta blight as a result.

"This caught many chickpea producers by surprise. They didn't know how to handle the disease because not much information was available on how to handle it. We applied for funding to extend our knowledge of appropriate disease management strategies, and we were able to do just that starting in 2002."

Prior to 2003, only Bravo was registered for the control of ascochyta blight in chickpeas. Quadris and Headline became available for use in the 2003 crop season, and Lance arrived on the scene in 2004.

This broadened the choice for producers. Trials were conducted at Saskatoon, Swift Current, and in producers' fields at various locations in Saskatchewan to determine the optimum application times and the most effective combination and sequencing of different fungicides.

"This recent new generation of fungicides is known as the Strobilurin group. When they came on the market, there was a lot of buzz around them. But people we also asking us how they should be applied. Our project looked at the order of application itself and whether or not it matters, and at which stage of plant growth the spraying should occur."

After testing the products, Dr. Banniza's team confirmed that it is important to control the disease as early as possible — meaning before the plant begins flowering.

"Until this came to light, the recommended approach was to monitor for the disease when chickpeas entered the flowering stage, because previous research had shown that resistance to the disease breaks down during flowering. At that point, the disease can spread very quickly. However, once you are behind it, it becomes impossible to control. Therefore, pre-flower application is very important."

Her advice is to go out to the fields and keep looking for symptoms. "As soon as you see them, spray right away if wet weather is forecast."