It was a vivid illustration of what this season has been like for North Carolina strawberry growers when the first berries of the year were delivered to the North Carolina State Farmers Market in Raleigh on St. Patrick's Day.
That's right: Strawberries in central Carolina on March 17.
“I can never remember strawberries produced outdoors arriving at the farmers market that early,” said Barclay Poling, North Carolina Extension strawberry specialist, a few days later. “It just shows the crop is earlier than we expected.”
Perhaps because of the relatively warm winter, the winter blooms were unusually healthy and allowed a quick start.
“It is unusual that we get a mid-February bloom we can count on,” Poling said. “But this year we had one we could put some stock in.”
Still, much of the crop was still in the field, and farmers were facing a potentially serious problem if the temperature dropped too low, because of very low irrigation ponds. “At the Clayton, N.C., research station, the pond level is only 30 percent of normal,” Poling said just after St. Patrick's. “So one of our important tools (for dealing with cold weather) is not at full strength.”
Many farmers responded by using row covers instead of irrigating. “There were several weather events in February where farmers would have preferred to run irrigation equipment,” he said. “But instead they turned to their row covers so they could preserve their water for more severe events.”
They certainly didn't want to run out of water and then have to deal with cold weather. So since the Easter Freeze of 2007, North Carolina growers have come to rely more on row covers than water.
“One lesson our growers have learned is that if you have high winds with extremely low temperature, you need the combination of row covers and sprinkler irrigation,” said Poling. “The row cover takes out the ‘wind effect,’ which is the evaporative cooling that turns irrigation into a refrigerator.”
There has been a tremendous increase in the use of row covers in the last two years, he said, “I am pleased to see that about 80 percent of the industry in this state now has them. Only in the eastern part of the state are growers holding back, and that is an area that usually has milder weather.”
The water shortage had earlier interfered with strawberry planting, Poling said. “We had a number of farmers who couldn't get as much planted as they intended in September because of the drought. Making the beds requires considerable moisture, and to get the soil moist enough, they needed to irrigate once or perhaps twice. Some of them didn't have the water to do it. As a result, two or three percent of the intended acreage didn't get planted.”
But there was a management strategy that could be implemented.
“We (in Extension) suggested changing to plug plants instead of freshly dug bare root plants,” said Poling. “The bare root takes a lot more water. They are highly perishable and must be irrigated within a half hour of planting. Many growers made the switch and we are glad they did. It helped cope with the continuing drought.”
In the big strawberry-producing area of southeast North Carolina, most of the crop was in heavy bloom in mid-March, said Poling.
“This crop looks like it will be a little smaller, maybe five percent below last year. But the industry was hoping for a five percent increase.”
Strawberry acreage in North Carolina has been inching up again in recent years, said Poling. “I would conservatively estimate that about 1,800 acres were planted in late summer/fall 2007 for the spring 2008 crop.”
A big problem for North Carolina strawberries last year was deer damage. “It was the worst I can remember,” said Poling. “Deer love strawberry plants. Fences, dogs, hunting — nothing has worked very well to control them.”
The bad news is that deer will become a bigger problem as more of their natural habitat is destroyed, he said.
Everyone in the strawberry industry was hoping there would be no repeat of the very late freeze that occurred on April 7-9, 2007. “I have never seen a freeze of this magnitude at this late a juncture in the season, and the winds made it much worse,” Poling said
It led to serious damage to the strawberry crop, but probably less than for most other fruit crops.
How is it, asks Poling, that the North Carolina strawberry industry managed to produce more than an 80 percent crop in spring 2007 despite the unprecedented Easter freeze that devastated tree fruit, bramble, blueberry and grape crops in North Carolina?
The most important reason the strawberry industry suffered so little injury relative to other fruit in the state probably is that the strawberry is a low-growing crop. “The support of an ice load from overhead sprinkling is not important as it often can be in tree fruit and vine crops. Unlike tall-growing plants, the strawberry is also an ideal candidate for floating row covers.”
But there was no reason for complacency. A unit of the U.S. Department of Energy said in March that the mild winter and springs the Southeast has been experiencing could set the stage for further damage.
The Oak Ridge (Tennessee) National Laboratory said that one of the reasons the Easter Freeze was so devastating was that plant development was two to three weeks earlier than normal because of an unusually warm March.
“The warm weather was as much a culprit for the damage as the cold,” said Lianhong Gu of the Laboratory's Environmental Sciences Division. “We see the paradox in that mild winters and warm, early springs make the plants particularly vulnerable to late-season frosts.”
This freeze should not be viewed as an isolated event, Gu said. “Rather, it represents a realistic climate change scenario that has long concerned plant ecologists.”