Nora Olsen, University of Idaho professor and extension potato specialist, said heat on top of longer days can be a lot for any crop, including potatoes.
In high temperatures, potatoes will shut down and stop growing. This can cause situations of start and stop growth patterns that are not ideal for growing potatoes.
Another thing growers are worried about with the early heat is a lack of ground covering. Once potatoes grow they touch each other and this helps keep the soil cooler. This is called row closure.
Olsen said some areas have reached row closure and others have not.
Hot soil and hot temperatures can cause a disorder called “sugar ends.”
“This is not a disorder we will see until harvest and when we make french fries out of them,” Olsen said.
Affected potatoes will show higher sugar content and make darker-colored french fries. This leads to concerns over quality.
Compounding the issue of heat can be water availability. It can be difficult to make sure you have enough water on the crop, Olsen said.
“We are like pulling our hair out right now trying to figure out how to irrigate the crop and to do it in a manner that both supplies water and tries to cool the crop down,” Olsen said.
She said the conditions this year are not ideal but they have seen events like this before.
Heat Impact on Cows
Robert Collier, department head for the University of Idaho Veterinary and Food Sciences, said dairy cows are the most at risk for heat stress.
“Pray for the dairyman. They are going to have a tough week,” Collier said.
Because of dairy cows’ body size, food intake and production rate, they can overheat quickly. In temperatures between 103 and 106 degrees, without any cooling measures, it wouldn’t take more than a few hours for the animal to overheat, Collier said.
Once a cow overheats, her milk production drops.
Farmers can track respiration rate to see if their animal is overheating. Cows are panting animals like dogs. He said normal respiration should be below 60 breaths a minute. Anything above 60 means the animal is experiencing some level of heat stress.
Another way to track temperature is to use an infrared gun on the cow’s skin. Anything above 80 degrees is getting too warm for the animal, Collier said.
If a farmer believes their animal is experiencing heat stress in temperatures over 101.5 degrees, using just a fan won’t help the animal. Because cows’ internal body temperature is 101.5 degrees, blowing air that is hotter onto the animal will only drive more heat in their direction.
Collier recommends using a fan and mist combination to provide relief from the heat. As the water evaporates it cools the air. Another option is soaking the animal and standing them in front of a fan.