Just when Mansford Plantation’s 130-acre pecan crop was beginning to recover from the damage caused by hurricanes Katrina and Rita, the Tallulah pecan plantation suffered a setback in August from Tropical Storm Isaac.

“We had a bumper crop last year,” said Kenneth Gunter, the plantation’s manager. “This year, we might be able to use 70 percent of the nuts.”

Like other pecan orchards in Louisiana, Mansford suffered damage from Isaac. The LSU AgCenter estimates Isaac, which was quickly downgraded from a hurricane to a tropical storm once it hit land in South Louisiana on Aug. 29, has cut Louisiana’s pecan harvest by 15 percent.

“I would say 15 percent loss (statewide) at least, although I might fudge a bit and say 20 percent,” Gunter said. “The damage wasn’t as bad as it was during Katrina and Rita in 2005.

“We lost two to three whole trees and a lot of small limbs. We had some trees split in half where they forked. Some of those trees were 100 years old. It takes 15 to 20 years for some varieties to mature before they can be harvested.”

Gunter said most of the pecans blown from the trees at Mansford during Isaac were Stewart variety that had not matured, adding many of the nuts on the ground still have the hulls and sat in water during the storm. Those nuts cannot be used.

“They’ll be picked up by the shakers when they shake the trees to get the nuts during harvest,” he said. “We have a pecan cleaner who works by weight, and with the hulls on, those immature nuts weigh the same as a ripe nut. That means they’ll have to be removed by hand, which is labor-intensive.”

David Ingram, an extension researcher/professor with Mississippi State University’s Central Mississippi Research and Extension Center in Raymond, estimated Mississippi’s potential harvest lost from Isaac at less than 15 percent.

Overall, he said, the state’s growers did not report a lot of damage to trees or limbs or nuts being blown off trees.

He cautioned, however, that the state’s crop loss could reach 15 percent if it becomes infected with pecan scab, a fungus that can affect nut development and the harvest.

The peak times for the disease are July and August, he said.

“We had a lot of rain (during Isaac). If farmers missed some fungicide applications, there could be a problem.”

Charlie Graham, professor for fruit and nut crops at LSU, said crop loss from Isaac would bring the harvest total to slightly more than 11 million pounds — down from pre-storm estimates of 13 million pounds, and prices are likely to be similar to 2011 levels.

Graham said he checked with growers from all parts of Louisiana during the first week of September, and damage in the southeastern portion of the state was higher than other regions of Louisiana.

He said damage was minimal in northwest Louisiana. Overall loss estimates were about 10 percent to 20 percent, rising to 20 percent to 30 percent for orchards in the hurricane’s path. One grower said he lost half his crop, Graham said.

The good news is that only a few trees were blown over.

“Most of the damage was limited to actual nuts being blown out of trees and numerous small limbs being broken in orchards,” Graham said.

Graham said shucks had begun splitting in early varieties such as Candy, Pawnee and Kanza.

Although Gunter will not be able to harvest the nuts that fell at Mansford, growers should be able to harvest these nuts blown down by the storm and use a knife to cut or scrape the shuck off of the nut, Graham said. He advised wearing rubber gloves to do that to avoid stained hands. The stain can linger for weeks, he said.

Those nuts will need to be dried for two to three weeks before they can be bagged and stored at room temperature.

Mid- and late-season varieties such as Elliott, Desirable, Moreland and Sumner have just about completed nut filling, but the shuck is still firmly attached to the shell. These varieties will require specialized equipment such as a dehuller to grind the shucks from fallen nuts.

“Allowing the shuck to dry on the nut does not result in the shuck being more easily removed,” Graham said. “Nuts which are not well ventilated will generally rot or suffer significant kernel deterioration.”