WINTER HAVEN — Hurricane Irma continues to damage the 2017-18 Florida citrus crop, and the final chapter on the storm’s impact has yet to be written.

The U.S. Department of Agriculture lowered this season’s orange crop forecast from a month ago by 7.4 percent, or 4 million boxes, to 50 million boxes, according to a Thursday report.

It also reduced Florida’s projected grapefruit crop by 5 percent, or 250,000 boxes, to 4.65 million boxes and the tangerine/tangelo crop also by 5 percent to 950,000 boxes. The report was the first update since the USDA’s original crop forecast Oct. 12.

But those numbers will likely fall further in future USDA monthly crop updates until July, said Mark Hudson, head of the agency’s Florida Field Office in Maitland, which oversees the crop count.

“It’s hard to say if all the damage (from Irma) is accounted for,” Hudson said.

That’s because the storm damaged trees in ways that could affect future totals, such as weakened stems, he added. That could result in additional fruit drop in the coming months.

The new report significantly increased the projected drop rates through the rest of the season.

The orange drop rose from 45 to 49 percent in October, depending upon variety, to 51 to 59 percent currently. Grapefruit drop rose from 53 to 54 percent a month ago to 62 to 64 percent now.

Hudson declined to attribute the rise in drop rates to the hurricane.

“All we do is count,” he said.

Florida citrus officials widely believed the October estimate was too high because the USDA finished its crop survey before Irma swept across the entire citrus-growing region Sept. 10 and 11.

The only reliable estimate before then came in August from Kissimmee citrus consultant Elizabeth Steger, who pegged the 2017-18 orange crop at 75.5 million boxes. Many growers reported Irma blew at least 50 percent of their crop from the trees.

Growers continue to expect Thursday’s crop numbers will decline further because of Irma’s lingering effects.

“I think the final crop (in July) will be less,” said Larry Black, general manager of the Peace River Packing Co., a grower with more than 2,000 grove acres that runs a fresh citrus packinghouse in Fort Meade. “The challenge for the USDA will be in trying to estimate the drop.”

Black agreed with Hudson that Florida’s citrus trees sustained hurricane damages, such as broken limbs, that will affect future forecasts.

“I think the drop will continue to go up through the end of the season,” he said.

That would mirror Florida growers’ experiences following the 2004 and 2005 hurricanes, Black added.

“In the wake of Hurricane Irma, it is extremely difficult to estimate the size of this year’s crop,” said Mike Sparks, chief executive at Florida Citrus Mutual in Bartow, the growers’ trade group. “In reality we probably won’t have an accurate number until the middle of 2018 once all fruit is picked. Long term, the effects of Irma are going to take years to hash out.”

Shannon Shepp, executive director of the Florida Department of Citrus in Bartow, agreed.

“Unfortunately, I don’t think this will be the last decrease we see,” Shepp said in a news statement. “Hurricane Irma had widespread impact on our industry and growers are still trying to pick up the pieces. High winds and flooding rains damaged already weakened trees making it even more difficult to hold on to the fruit that’s left.”

Even if the current optimistic numbers hold, it would represent a 27 percent decline from the 2016-17 orange crop of 68.75 million boxes and the lowest orange harvest since the 1945-46 season, the USDA reported. The grapefruit crop would come in 40 percent lower than the 7.76 million boxes picked last season and the lowest harvest in 99 years.

The USDA will release its next citrus crop update Dec. 12.

 Kevin Bouffard can be reached at kevin.bouffard@directgates.com or at 863-401-6980.