No Till Notes: 'Field Pea Disease'

This past week I spent a morning with Dr. Bob Harveson, University of Nebraska Panhandle Research and Extension Center plant pathologist, touring field pea fields in the Alliance area.

Harveson and I were looking for diseases in field peas. He is concentrating on diseases in field peas this year to see what concerns may develop for field pea producers in our area. So far the only disease that has shown up in field pea production in our area is blight.

I have spoken with numerous field pea producers this spring about this disease in field peas. The blight shows up on the lower leaves of the infected plants and spreads to the tendrils and stems of the plant. Seriously infected plants will begin to die off in severe cases in some locations of the field. This generally happens if the field peas have been standing in water from the high amounts of precipitation we have received this spring and early summer.

I’m almost certain that every field of peas has this disease to some extent across our region this year. I have observed this disease in our field peas occasionally over the past several years. The cool, wet weather that has been prevalent so far this growing season seems to really encourage this blight to develop in field pea seedlings.

Harveson explained to me that the majority of the broadleaf crops we grow in this region have a similar strain of this blight. Sugar beets as well as dry edible beans will show similar signs of this disease during their early growth cycle if conditions are favorable for this blight’s development.

Harveson collected samples from various fields around the Alliance area. He plans to take them back to his lab and attempt to identify the specific strain of this blight. He will also sample other fields around the Panhandle for this disease. He and I did observe some management practices that seemed to increase the severity of infection in the field pea fields we looked at. The severity of the blight infection seems to increase with the amount of residue in the field.

The worst cases of the disease were in fields where the field peas were planted into winter wheat stubble which had high amounts of residue. One field we looked at had a portion of the field peas planted into winter wheat stubble with the remainder of the field planted into corn stalks. The rate of blight disease was much higher in the field peas that had been planted into the winter wheat stubble. The severity of the outbreak was much less in the field peas planted into corn stalks.

We also looked at fields on our farm where all the peas were planted into corn stalks and the disease was much more prevalent in the early planted fields. The last field of peas we planted was done three weeks later than the first field. The field peas with the later planting date had a very low incidence of the disease compared to the earlier planted peas.

The good news with this disease is for the most part the field peas will outgrow the disease once the temperatures warm up to more normal temperatures. The majority of the field pea plants now have six inches of healthy growth above the diseased portion of the plant. The leaves and tendrils above the diseased portion of the plant look very healthy and the plant will continue to grow and produce a good crop.

Harveson stated that if this proves to be the only disease that develops in field peas in our area we will be fortunate. There are other diseases which can establish themselves in field peas. The disease of most concern may be ascochyta blight which is prevalent in chickpea production, but has not been a concern in field pea production in our area thus far. Harveson noted that root diseases in field peas seem to be the biggest concern in field pea production in North Dakota. I found my morning spent with Harveson to be very educational. I want to thank him and the UNL Panhandle research team for their work in field pea production in our area.