Prolonged freezing temps could damage Kentucky crops

A snowy March day in 2015

PHOTO: Aimee Nielson, UK Agricultural Communications Specialist
LEXINGTON, Ky.

Kentucky has enjoyed a mild winter which has resulted in many trees, plants and crops beginning to sprout and bloom before their usual times. The forecast for the next several days is not good news for those early bloomers.

Meteorologists for the University of Kentucky Agricultural Weather Center are predicting low temps to reach into the 20s for at least five days in the upcoming week.

“The National Weather Service is issuing freeze warnings over the upcoming week,” said Matt Dixon, meteorologist in the UK College of Agriculture, Food and Environment. “We have to remember it’s still wintertime in Kentucky, even though recent temperatures have convinced us otherwise.”

Some Kentucky wheat has already reached the jointing stage.

“The recent warm temperatures have caused wheat crops to be at a more advanced stage of growth than they usually are this time of year,” said Chad Lee, director of the UK Grain and Forage Center of Excellence. “This is very concerning because at jointing, the growing point is above the soil surface and is vulnerable to damage. Kentucky wheat is at risk for severe damage if these forecasts hold true.”

Wheat in the jointing stage will be damaged if temperatures reach 24 degrees Fahrenheit and below for at least two hours. For wheat not yet in the jointing stage, temperatures would have to drop below 12 degrees.

Lee said the risk of freeze damage is still significant with six to nine weeks left in the typical freezing temperature window in Kentucky. More information about grain crops is available online in Carrie Knott’s blog post, https://graincrops.blogspot.com/2017/02/winter-wheat-at-advanced-growth-.... Knott is a UK grain crops extension agronomist.

On the horticulture side of things, UK horticulture specialist John Strang said crops have jumped ahead of schedule in many areas.

“The most advanced peaches at the UK Research and Education Center in Princeton are showing 80-percent bloom,” he said. “Critical temperatures for this stage are 27 degrees for 10 percent bud kill and 24 degrees for 90 percent bud kill. So we stand to lose a lot, if temperatures get too low or stay low for a long period of time.”

At the UK Robinson Center in Quicksand, UK horticulture specialist Shawn Wright said some peaches are even in petal fall, which would result in 10 percent kill for 28 degrees and 90 percent kill if temperatures drop to 25 degrees.

Strang and Wright said the most advanced apple trees are in the half-inch green stage and would suffer 10 percent kill at 23 degrees or 90 percent kill at 15 degrees, but most apples are still in the silver tip stage and would not be damaged by these low temperatures. They said plasticulture strawberries are beginning to bloom and growers need to cover them with floating row covers to reduce injury. Growers should also cover matted-row strawberries with straw to protect them from the cold.

Contact: 

Matt Dixon, 859-218-4363; John Strang, 859-257-5685; Chad Lee, 859-257-3203

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