Optimizing Gibberellic Acid Applications in Florida Citrus

Jim Rogers Fruit Drop, HLB Management

Tripti Vashisth, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor of horticultural sciences, has dedicated several years of research into the use of plant growth regulators like gibberellic acid (GA) to fight fruit drop in citrus. In the August All In For Citrus Podcast, Michael Rogers, director of the UF/IFAS Citrus Research and Education Center, interviewed …

Combined Treatment Reduced Drop and Increased Size

Jim Rogers Fruit Drop, HLB Management, Production

A combination of gibberellic acid (GA) and 2,4-D reduced preharvest fruit drop by 18% and improved fruit size but produced no statistical effect on yield, researcher Tripti Vashisth reported Aug. 30. The combination “seems promising,” the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) horticulturist stated. The report was based on first year results from a trial of …

all in for citrus podcast

All In For Citrus Podcast, August 2022

Jim Rogers All In For Citrus Podcast, Fruit Drop, HLB Management

The August episode of the All In For Citrus podcast takes listeners on a deep dive into the use of plant growth regulators like gibberellic acid (GA) to help fight fruit drop. The episode features an in-depth conversation between Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, and …

Impact of HLB on Fruit Growth and Retention

Jim Rogers Fruit Drop, HLB Management

By Tripti Vashisth and Mary Sutton Citrus trees affected by huanglongbing (HLB) consistently have small fruit and low fruit numbers at harvest. The low fruit numbers are largely attributed to the increased rates of preharvest fruit drop that accompany HLB. Small fruit is more likely to drop during this preharvest period, suggesting a link between fruit size and retention. To …

Tips to Keep Citrus Fruit on Trees

Jim Rogers All In For Citrus Podcast, Fruit Drop

By Frank Giles During the May All In For Citrus podcast, Michael Rogers, director of the Citrus Research and Education Center, discussed research on how applications of gibberellic acid (GA) can improve tree health and reduce fruit drop. The research is being conducted by Tripti Vashisth, an associate professor of horticultural sciences with the University of Florida Institute of Food …

Impact of Herbicides on Fruit Drop

Jim Rogers All In For Citrus Podcast, Fruit Drop, Herbicides

Growers know the negative impacts of any kind stress on trees infected by HLB. That raised a question: Can injury from herbicides make fruit drop worse? Ramdas Kanissery, an assistant professor of weed science with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), conducted a research project to help answer that question. Kanissery discusses the research in …

Fruit Flies Are Major Cause of Fruit Drop in Brazil

Jim Rogers Brazil, Fruit Drop, Pests

Brazil’s Fundecitrus recently pointed out that fruit flies, along with citrus fruit borers, are primarily responsible for the country’s citrus fruit drop. The organization suggested that monitoring and management must be taken to avoid economic damage, since fruit flies occur throughout the year. Fundecitrus described the fruit flies that cause damage in Brazil and suggested control measures.   Two species of …

All In For Citrus Podcast, May 2022

Jim Rogers All In For Citrus Podcast, Fruit Drop, Research

Fruit drop continues to plague Florida citrus groves. Growers and researchers are seeking ways to mitigate the problem. This was the topic of a number of presentations during the Florida Citrus Growers’ Institute held in Avon Park in April. Michael Rogers, director of the Citrus Research and Education Center in Lake Alfred, discusses those presentations during the May All In …

Herbicides and Fruit Drop

Jim Rogers Fruit Drop, Research, weeds

Weed scientist Ramdas Kanissery’s research has not shown evidence that herbicides, including glyphosate, increase citrus fruit drop or decrease yields. But in studies using different glyphosate rates, he did find that there is a relatively strong negative correlation with the fruit detachment force and the glyphosate amount applied. “That means there may be something happening with the higher glyphosate rate” …

Webinar to Address PGRs and Fruit Drop

Jim Rogers Fruit Drop

Florida citrus growers can learn more about the use of plant growth regulators (PGRs) in the fight against fruit drop at an upcoming online seminar. The webinar will be at 10 a.m., April 27 and will be presented by the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). Speakers at the webinar, titled “Gibberellic Acid Research Update and …

Be Prepared for Postbloom Fruit Drop

Jim Rogers Fruit Drop, Research

A La Niña weather pattern is most likely this spring, with higher-than-average temperatures and below-average rain predicted in Florida, researcher Megan Dewdney reported in a Feb. 24 presentation about postbloom fruit drop (PFD). That could have some influence on the severity of PFD, since its preferred climate is humid and subtropical, and the fungus moves with rain splash and wind-borne …

Florida Citrus Growers Seeking Solutions to Fruit Drop

Jim Rogers Citrus, Florida, Fruit Drop

Fruit drop has plagued Florida citrus groves in recent years. The problem has been a major factor in tumbling yields. The February 2022 U.S. Department of Agriculture’s citrus crop forecast put Florida’s orange estimate at 43.5 million boxes. If realized, it would represent an 18% decline in the crop from last season. Growers are turning over every stone to seek …

Can Zinc and Potassium Curb Fruit Drop?

Tacy Callies Fruit Drop

The Florida citrus industry has been focused on finding solutions to the fruit drop problem that has hit groves hard in recent years. During the 2022 Florida Citrus Show in Fort Pierce, Fernando Alferez, University of Florida Institute of Food and Agricultural Sciences, assistant professor of citrus horticulture, presented findings from a research trial aimed at reducing fruit drop. The …

Keep an Eye Out for Postbloom Fruit Drop This Spring

Jim Rogers Fruit Drop, Tip of the Week, Weather

By Megan M. Dewdney Postbloom fruit drop (PFD) is a flower disease mainly caused by the fungus Colletotrichum acutatum. The fungus is present on citrus trees throughout the year but survives by producing resting structures on leaves and stems. The fungus becomes stimulated to produce spores by substances from the early flowers. These early spores infect the initial flowers and …

Foliar Fungal Disease Round-up for 2022

Jim Rogers Diseases, Florida, Fruit Drop

By Megan Dewdney The 2021 foliar fungal season was an easier than average year. The La Niña weather pattern predicted last fall came to pass, and the spring was relatively dry from January to the end of May with some rain in February and April. While citrus trees in Florida were likely drought-stressed, the dry weather slowed the usual decomposition …

Freeze Damage Update for Florida Citrus

Jim Rogers Citrus, Florida, Fruit Drop, Weather

Cold temperatures the mornings of Jan. 29 and Jan. 30 did more citrus damage than an initial report indicated, Highlands County Citrus Growers Association Executive Director Ray Royce said. Royce issued the following update on Feb. 1: “The coldest weather in at least four to five years has left much more damage behind in parts of the South-Central Florida region …

Reducing HLB-Associated Preharvest Fruit Drop

Tacy Callies Fruit Drop

By Tripti Vashisth and Christopher Vincent This article summarizes current knowledge about HLB-associated preharvest fruit drop. Unfortunately, exactly how HLB induces preharvest fruit drop is still unknown. Nonetheless, this article links what we do know about HLB-associated fruit drop to fruit drop in HLB-free trees and how strategies, such as managing tree water status and use of gibberellic acid, can …

Steps for Reducing Fruit Drop

Ernie Neff Fruit Drop

Editor’s Note: Tripti Vashisth with share new information on the use of gibberellic acid treatments to improve health and yield of HLB-diseased trees in a virtual seminar on Sept. 21. Register here. Researcher Tripti Vashisth told the recent Citrus Expo audience how fruit drop might be reduced through the use of nutrition and irrigation strategies, gibberellic acid and increased fruit …

Fruit Drop Is Biggest Grower Concern

Ernie Neff Fruit Drop

Fruit drop “is probably the No. 1 concern” of the citrus growers he knows, says Ray Royce, executive director of Highlands County Citrus Growers Association (HCCGA). “Fruit drop and profitability are going hand in hand,” he adds. “There’s a tremendous struggle now to be profitable, given the relatively low harvest numbers,” Royce says. “I think growers believe that if they …