Postbloom fruit drop has reared its ugly head


IF YOU HAVE nerves of steel, a hardy soul, a resilient persona, and the patience of Job, there’s a better-than-average chance you would make a good citrus grower. That’s what a body has to have to handle the ever-constant challenges of the industry — and now more than ever.

With the Florida war against the highly destructive citrus greening disease now heading into its 12th year, growers have another battle on their hands this season — postbloom fruit drop (PFD).

PFD is caused by a fungus called Colletotrichum acutatum, and it shows itself during the citrus bloom period. The fungus affects the flowers and produces abscission of young fruitlets in many citrus species and cultivars. However, Navel and Valencia orange trees seem to be harmed the most, and that’s not good at all, because Valencias make up the largest variety of citrus grown in Florida. Fruit produced by trees attacked by the fungus will fall off the branches prematurely and be unsuitable for harvest, and the affected trees won’t be good fruit producers the next season. PFD has the potential to reduce fruit yields by up to 80 percent.

PFD is a serious problem in most humid citrus production areas of the Americas. It seems to have blossomed and spread in a particularly bad way this season in Florida as the result of El Niño, the weather pattern that brought an abnormally high number of rainy and foggy wintertime days to the Sunshine State. In addition, trees already weakened by the bacterium that causes citrus greening likely were more susceptible to the PFD fungus.

PFD was a problem for the first time in the Florida citrus industry in 1983. Growers who have been in the business for a long time will remember that 1998 was a particularly bad year for PFD. The citrus losses that season were severe, causing economic damage that rippled throughout Florida. Following a lull of almost 17 years, the problem had to be dealt with again in many areas of the state last year, and this year it’s worse.

Like greening, PFD is a real problem for the citrus industry because control options are limited and largely ineffectual. Fungicides can be used on affected trees, but one of the most effective ones, benomyl, is no longer approved for use. Other fungicides available today are only partially effective. The fungus has to be noticed very early on and attacked right away to save the citrus tree and maximize its fruit production.

Vigilant and eagle-eyed. You can add those to the list of qualities and characteristics necessary for anyone who wants to make citrus growing a lifelong and, for the most part, successful enterprise.

CREDIT

column by CHARLES COUNTER

BIO: Charles Counter started in the agriculture business in 1986. He is the Director of Field Operations for the Haines City Citrus Growers Association, managing more than 7,000 acres of ag land in Florida. Established in 1909, the HCCGA provides for Complete Grove Development and Management, is a Member of Florida’s Natural, and operates as Caretaker and Packer of Citrus, as well as Organic & Conventional Peaches and Blueberries. To contact Charles, call (863) 557-0510 or email charles@hilltopcitrus.com.