Grain Diseases Must Be Closely Monitored

Diseases are Always Evolving

By Patrick Cavanaugh, Farm News Director

Mark Lundy is a UC Cooperative Extension Specialist in grain cropping systems at UC Davis. Lundy runs trials on grain crops because California is such a diverse environment and there are different conditions from year to year so it’s important to be consistent in measuring yield and crop quality, grain diseases, and agronomic traits on small grains.

Lundy’s work is predominantly on California wheat, but there are many trials on barley.

“Improved varieties have been the mainstay of my work,” Lundy said. “I came at it from a water and nitrogen management background, and one of our goals is trying to disentangle the environment that you can’t control from the environment that you can control. But this is the second year where we have some of those gradients in there so we are trying to maintain the attributes we have, while also trying to add some value.”

And diseases have been closely monitored within the trial system, noted Lundy.

“We do try to keep track of disease, and so when there are diseases of concern such as stripe rust, which was historically a big problem for growers, it has been successfully addressed through breeding,” he said.

The breeding is spearheaded by Jorge Dubcovsky, a professor at UC Davis Department of Plant Sciences working on wheat genes.

“Stripe rust is still something we have to keep an eye on, and it’s certainly a disease that is always evolving,” Lundy said. “And because resistance is not permanent, we’re always looking for the big diseases that can be detrimental to the production system, such as stripe rust.”

“We also keeping track of leaf rust,” Lundy said. “I’m not a pathologist by training, so I’ve been learning on the job, and I’m grateful to the former UC Cooperative Extension Specialist Lee Jackson, who was a pathologist. He created a nice knowledge base for us to build on.”

Weedy Rice Challenges Some Rice Growers

Weedy Rice Crops Ups Again in Northern Calif. Rice Fields

 

By Patrick Cavanaugh, Farm News Director

 

In Northern California, rice growers typically prepare to start harvesting in mid-September, but some growers have endured a lot of weed pressure from weedy rice (Oryza), also known as red rice, according to Whitney Brim-DeForest, a UC Cooperative Extension Rice Farm Advisor in Sutter, Yuba, Placer, and Sacramento Counties who focuses particularly on weeds. Red rice is actually the same species as cultivated rice, but it produces far fewer grains per plant and is therefore considered a pest.

 

Brim-DeForest said weedy rice is common in the Southeast, but not in California. “We’ve been pretty lucky in California in that we actually don’t have a big problem with it,” she said. “It’s a big problem down in the southern U.S. and they have been dealing with it in for a long time; but we have had it crop up. I think the last time was in 2006, and we managed to deal with it. It somehow popped up again in the last couple of years, so we’re dealing with it again.”

 

How weedy rice reached California is apparently a mystery. “We don’t really know the source of it, to be honest,” said Brim-DeForest. “We’re investigating that through research, hopefully starting this fall,” she said.

 

Brim-DeForest said growers have few choices to control weedy rice. “Growers that have it will either have to rogue¹ it out, pull it out by hand or sacrifice that field and spray it with Roundup,” she said, “which would kill the rice as well. And, if the rice grower doesn’t know he has weedy rice in the field, it could hurt him later at the rice mill,” explained Brim-DeForest.

 

“Once harvested, the rice goes to the mill. If a certain amount of red rice bran (the outer layer surrounding the rice grain) is discovered, the mill will not accept it and could reject the entire load,” she said.


¹rogue (verb) to remove inferior or unwanted plants