By Ms. Susan M. Collins-Smith
Mississippi blueberry producers expect to see substantial yield losses in the state’s largest commercial fruit crop after the hard freeze that hit the state on the weekend of March 18.
Lows dropped into the mid and upper 20s on March 20, according to data from the National Weather Service in Jackson and two weather monitoring stations located on the grounds of the Mississippi State University South Mississippi Branch Experiment station in Poplarville.
A low of 25 or colder after March 20 has been observed only six times in Jackson since recordkeeping began in 1896, according to Eric Carpenter, senior meteorologist with the National Weather Service in Jackson. Those cold snaps were in 1915, 1955, 1965, 1966, 1968, and 1986.
Eric Stafne, fruit and nut specialist with the MSU Extension Service, said growers will see significant losses. The condition of the crop is poor based on what commercial growers are reporting to him and his observation of damage to blueberry plants at the South Mississippi Branch Experiment Station in Poplarville, where he is based.
Just how much fruit will be lost is difficult to say at this point, but Stafne estimates that at least 50% of the state’s commercial crop is lost.
“The number of berries we harvest usually ends up being more than we initially think in an event like this,” he said. “But it really depends on variety, stage of growth, minimum temperature and some other factors.”
Blueberry plant varieties that already had open blooms and set fruit will be the most affected. Flowers that were still closed at the time of the freeze appear to be fine, but flowers that were open and fruit that was already developing are damaged, Stafne said.
“Some varieties in some locations will be a near complete loss, whereas others will have a crop,” said Stafne, who also conducts research at the station, one of five Mississippi Agricultural and Forestry Experiment Station units located within the southeast region.
The most common blueberry varieties grown in Mississippi are rabbiteye and Southern highbush. There are several rabbiteye varieties with fruit maturity beginning in early, mid and late season. Southern highbush varieties were bred to bloom earlier in the season and are more susceptible to frosts and freeze events.
However, the early arrival of spring temperatures put blooming plants ahead of schedule by about two weeks, leaving both blueberry types more vulnerable to freezing temperatures.
Jeremy Edwards, owner of Great Southern Farms in Richton, said this year’s cold damage is the worst he has experienced on his 165-acre blueberry farm, where he and his family grow rabbiteye and Southern highbush varieties.
On March 24, after a few days of warm weather, which is needed to be able to assess damage, he estimated they will lose 80% or more of their crop. That’s about 600,000 pounds of berries that would have been headed to market in the next few weeks.
Edwards usually hires more than 60 workers at the height of the season to help with hand and mechanical harvest but anticipates employing only six people this year.
“Some years we take some losses on Southern highbush, but this year was the perfect storm,” he said. “The warm temperatures in February really pushed everything out well ahead of normal.
“This will be a tough year financially,” Edwards said.
That will be the case for most commercial growers, which are concentrated in the southern half of Mississippi, Stafne said.
“This freeze event is devastating for commercial growers. The overall crop will be reduced tremendously and even if there is some fruit in the field, it may not be economically viable to harvest it,” he said. “It all depends on the quality of the fruit and the overall market price at the time.”
Fruit quality after a freeze can range from scarring on the skin to berry rot, which causes fruit to collapse and fall off the bush. While scarred berries are edible, they are not commercially marketable. For later blooming varieties, berries could be larger even if the total yield is reduced, Stafne said.
Homeowners with blueberry bushes will see the same effects as commercial growers, Stafne said. While they are likely to have some crop, it probably will be smaller than usual.
“Early-season rabbiteye varieties will be the hardest hit, but later season varieties are likely to be better off,” Stafne said. “Since growth was initiated about two weeks early this year, the timing of the freeze coincided with a lot of already set fruit and full bloom in some varieties.”
For growers who have no harvestable crop, pruning can be done in late spring or early summer, Stafne said.
“This can help initiate more growth and set more fruiting buds for next season,” he said.
Source : msstate.edu