Wind-Driven Rain, Hail Spread Pluse Crop Blight in Montana

Lentils, chickpea and dry pea fields impacted.

Published on: Jan 15, 2013

Growers generally appreciate moisture, but wind-driven rain and hail have spread blight through Montana's lentil, chickpea and dry pea fields.

To protect their $1.2 billion industry from Ascochyta blight, growers should rotate their crops   with at least three years between pulse crops, get accurate diagnosis of problems, consider planting fungicide-treated seeds and be aware that pathogens can become resistant to fungicides, advises Mary Burrows.

"As we get more pulse acres in the state, disease issues will increase in importance, and   vigilance is imperative," adds the Montana State University plant pathologist.

"The species of Ascochyta blight are different between pulse crops," she notes. "The fungus will not infect a plant it is not adapted to cause disease on."

Ascochyta blight, such as that showing obvious symptoms on this lentil leaf, is causing high concern in Montana.
Ascochyta blight, such as that showing obvious symptoms on this lentil leaf, is causing high concern in Montana.

Montana produces about 500,000 acres of pulse crops, with the biggest concentration in the northeastern portion of the state, but the crops are produced in other regions, with acreage on the increase in the "Golden Triangle" area in the north central part.

Pulse crops – mainly lentils, chickpeas and dry peas, provide nitrogen to the soil,  do not use a lot of water, help control weeds and break cereal disease and insect cycles, all while providing crops that feed humans and livestock.

Ascochyta blight is damaging the crops, however. Infected crops, while remaining edible, bring less income than uninfected lots since the blight reduces yield, quality and cosmetics. Growers cannot sell their crops for seed if seeds fall below a certain quality level.

The blight has been around as long as there have been pulse crops, says Burrows, noting a blight outbreak in chickpea fields last summer. Low disease levels were also found in lentils, and a much more serious disease – anthracnose – also discovered.

She says she received "a ton" of plant samples, e-mails and text messages about bacterial blight in peas associated with hail.

And, heavy rains caused fungicides to become less effective in control of disease.