By Keith Robinson
As Indiana frees itself from the grip of a harsh late winter, the State Climate Office says a developing weather pattern is likely to produce variable conditions this spring.
A developing El Niño - a cyclic warming of the Pacific Ocean along the equator - is the focus of climatologists giving a glimpse into potential conditions for planting season in April and May.
Studies by the State Climate Office, based at Purdue University, show that when an El Nino is in progress, April temperatures range from below normal in northern Indiana to above normal in the southern counties. April precipitation tends to be below normal in northern Indiana to above normal in the south.
Although some "seasonalization" in temperature patterns is expected, Indiana hasn't experienced "normal" conditions consistently for quite a while and isn't likely to see them anytime soon.
"We are in early days of the El Niño formation, so expect lot of variability and swings in the weather patterns," said Dev Niyogi, state climatologist. "There will be likely little 'normal' of this season as has been the norm for the last few seasons."
But cold temperatures and drier-than-normal conditions are expected through April 1.
This winter was not as severe as a year ago, so it has not been as damaging to plants. But harsh weather in February took its toll on peach buds in southern Indiana because temperatures dipped to 14 degrees below zero at one point.
"There very likely will be little or no crops of peaches in the south," said Peter Hirst, Purdue Extension fruit tree specialist.
Peach trees in the northern part of the state did not sustain as much damage because the temperature drop was not as severe at the time - if by only a less than 10 degrees.
"In the northern area we’ll see some peach crops," he said.
Although there are only about 500 acres of peach trees throughout the state, the peach crop can be valuable, Hirst said.
Indiana apple trees, which can withstand colder temperatures than peach trees, fared well over the winter. "The buds look good," he said.
Hirst said cool weather in the coming weeks actually would be good for fruit trees because it would make them less susceptible to cold that could follow an early spring warm-up.
Grape growers are finally getting the chance to help their grapevines recover from the exceptionally harsh cold of last year's winter. Indiana vineyards suffered severe winter injury in 2014; many vines were killed to the ground and since have regrown shoots from the base of the trunks. How to properly handle those vines to re-establish trunks and cordons for future years of production will be the main purpose of a Purdue Wine Grape Team workshop April 8 at Dulcius Vineyards in Columbia City.
There has been some damage this year to grape varieties tender to cold, but Extension viticulture specialist Bruce Bordelon said growers can adjust by pruning.
"It's not a good thing to have any damage while we are trying to retrain vines, but I don't expect it to be a major problem assuming that we get no more sub-zero temperatures," he said.
This winter's weather is unlikely to affect crop insect pests such as corn rootworm, the eggs of which overwinter and are well adapted to Indiana climate in most years, said Purdue Extension entomologist Christian Krupke.
A pattern of warm days followed by freezing in January and February can kill the eggs, but Indiana did not have that weather this year.
"What we are seeing now, a 'typical' warming period for the season, is unlikely to have any adverse effect on corn rootworm egg survival," he said.