Dr. Kalil To Speak On Scab Management In Durum During Wheat Show

At 10 a.m., Wednesday, Feb. 10, at the National Hard Spring Wheat Show in Williston, Dr. Audrey Kalil, NDSU Williston Research Extension Center plant pathologist, will be speaking about her research on fusarium head blight (scab) management in durum.

Dr. Kalil leads both basic and applied research programs focused on management of plant diseases on the economically important, highly diverse crops in western North Dakota. 

Her main goal with her research is to improve management of disease of crops grown in the MonDak region including durum, pulse crops and sugar beet. She has been performing research on fusarium head blight for five years.  

"Several studies I have conducted demonstrated the importance of genetic resistance to FHB (scab). While durum lacks the level of resistance that can be found in the resistant hard red spring wheat varieties available, there still are some varieties that accumulate less DON when exposed to scab. They are rated on a scale from 0-9 where a lower score indicates higher levels of resistance. I would recommend choosing a variety with a rating of 5, rather than a 6 or higher. While varietal resistance does not provide complete protection against disease or DON due to scab, by combining resistance with fungicides you can achieve much better control," added Kalil. These ratings can be found in the NDSU durum variety selection guide.

Kalil explained that fungicide timing is also critical. She said, "Application when 50% of the heads on the main stem are at early flowering or 4-7 days after this stage will provide the best suppression of both symptoms and DON in the harvested grain. In my studies to get the timing right, I randomly assess 40 heads in a plot and determine the percent that have initiated flowering. Applying before this time reduces the fungicide effectiveness. "

More recently Kalil concluded a three-year study across multiple locations to evaluate the effect of planting date on suppression of scab in durum. This project was part of Taheni Jbir's graduate thesis (NDSU Plant Pathology master's student). Dr. Frankie Crutcher (plant pathologist, MSU) and John Rickertsen (Hettinger REC agronomist) collaborated with the study as well. Kalil will be presenting some results from this work at the National Hard Spring Wheat Show. 

In addition to this, Kalil has recently concluded a three-year effort to understand the effect of using durum grain with low, moderate and high levels of deoxynivalenol (DON) as a seed source. She said, "Increasing levels of DON were associated with decreasing germination rates. At the highest level of DON (17-19 ppm), germination was reduced to 40-60% compared to mid 90s for the control that had no detectable DON. When the seed was planted to account for the low germination rate such that all plots received 1.6 million PLS/ac only the highest level of DON resulted in a yield loss in 1 out of 3 years. Although, the stand was reduced by DON contamination above 3 ppm in 2019 and 10 ppm in 2017, I still recommend using high quality seed, but if another scab epidemic comes to our region, growers may yet again be in the position where they need to find a way to re-purpose contaminated grain that they are unable to sell. This research provides guidance on the level of risk associated with using this grain as a seed source." 

If growers deal a lot with scab, Kalil suggests using an integrated management approach. Crop rotation, variety resistance and fungicide use when weather is conducive to disease. She explained, "Monitor weather conditions in the two weeks prior to flowering and in the week after the onset of flowering if you wish to delay the fungicide application slightly."

Kalil hopes to continue to compare durum and hard red spring wheat varieties for DON accumulation in the harvested grain. She also plans to continue evaluating fungicide products and fungicide timing for management of scab. "If growers have questions regarding management of disease, I encourage them to reach out to me. If I encounter a question to which I cannot find a good answer in the research literature, then these questions can help me develop a program of research that is most useful to the growers."