Cold weather around Indiana is putting wheat, forage and fruit crops at risk of freeze damage and the State Climate Office at Purdue University says there is a possibility of low overnight temperatures throughout the next several weeks. HAT chief meteorologist Ryan Martin explains just how cold it might get this week.
“There were a lot of people who complained about what went on this weekend with the much colder air and the nasty weather in general. Take Sunday and Monday and multiply them by a factor of two and that’s probably what we’ve got this weekend. Temperatures will be way below normal and we may have some parts of the state struggling to get out of the 30’s for highs on Saturday. That’s not everywhere but that’s the kind of cold air we’ve got coming.”
He says moisture will move back in Friday night into Saturday morning.
“And I think air is going to be cold enough that at least over the northern quarter to third of the state we may have to watch for this coming as a bit of light snow, wet snow, and with anywhere from a few hundredths to two-tenths of an inch of liquid, I can’t say that it won’t stick in some spots. So be aware of that overnight Friday into Saturday. Farther south liquid precipitation again will be a few hundredths to about a tenth of an inch.”
“Plants from tillering stage to Feekes 5, can withstand quite cold temperatures in the 12-15-degree range without substantial damage to yield,” Casteel said.
More mature plants, however, could be at greater risk.
“At the jointing stage, Feekes 6-7, the temperatures that can cause damage are at the 24-degree mark and below,” Casteel said. “If you’re in that range for more than a couple of hours, the concern is beyond leaf tip burn.”
Providing adequate nutrients can help wheat plants cope with the cold, Casteel said.
“Wheat that has been top-dressed with nitrogen and taken it up fare better than those plants with nitrogen deficits,” he said. “Adequate nitrogen in the plant is almost like an antifreeze agent.”
Casteel said freeze damage might not be apparent for 7-10 days.
“You have to let the plants grow out a little bit before determining what damage has been done,” Casteel said. “If you are looking at yellow and brown leaves, that is mostly cosmetic and won’t cause significant yield damage at the current growth stages. Under more severe conditions, the growing points die and the lower stems split or bend. That could lead to moderate or severe yield loss.”
Extension forage specialist Keith Johnson advised producers to monitor their alfalfa and cool season grass crops carefully.
“If the weather forecasts are correct and we are looking at the possibility of early morning temperatures in the mid-20s for several days, the next few days could be problematic,” he said. “There could certainly be some vegetative burn and a reduction in early season yield.”
Johnson said forage crops that were harvested on time last fall would likely be in better shape to handle the cold stress.
“That’s why we tell people alfalfa should be harvested no later than Sept. 10,” he said. “The plant needs time to build up its energy reserves before winter dormancy.”
Many of the state’s fruit crops have already started to develop and are more vulnerable to freeze damage, said Peter Hirst, Extension tree fruit specialist.
“In more southern areas of the state, fruit crops have developed more and are at greater risk of cold damage,” Hirst said. “Peaches in the southern areas are at or past bloom and we expect to see significant amounts of damage to flowers. But right now there should be enough surviving flowers to still produce a crop.”
Apple trees are not as developed as peaches and could survive the cold snap in better shape.
“While there will be some flowers killed by the cold, we are still expecting full apple crops,” Hirst said.
Source: Purdue News