By Fernando Alferez and Divya Aryal Brassinosteroids (BRs) are a class of plant growth regulators with several effects on plant growth and development. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) work in the last few years has shown that BR treatments may influence internal maturity in Hamlin sweet orange if performed at the right time. Research has …
Reduce Post-Hurricane Fruit Drop With PGRs
By Tripti Vashisth and Taylor Livingston Hurricane Milton passed over many citrus-producing counties in Florida, resulting in canopy and fruit loss (especially in early varieties). HLB-affected trees undergo a lot of stress, and now the hurricane has added more abiotic stress to trees. High-speed winds caused significant fruit and leaf drop. The fruit and leaves that escaped the drop during the …
The Best Defense for Mitigating Preharvest Fruit Drop
By Tripti Vashisth Over the past decade, HLB-associated fruit drop has become a significant problem in Florida groves. Many growers opt to harvest the fruit before the peak fruit drop begins. However, the downside to this strategy is that the fruit does not get enough time for optimal Brix accumulation. Plant growth regulators, when applied at the right time, can …
PGRs Promote Tree Health
The use of plant growth regulators (PGRs) has been a popular method to treat HLB-infected citrus trees. The materials have continued to be applied in conjunction with trunk injection of oxytetracycline (OTC) to improve tree health. Tripti Vashisth, an associate professor of horticultural sciences with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), has been studying PGRs …
Podcast Addresses Recent Irrigation Research
It was a dry April in most of Florida’s citrus-production areas. That means irrigation is vital to keep HLB-infected trees adequately watered. The drier months of the year from February through May are when flowering and fruit set are occurring. If trees are stressed due to water deficit during this time, they are more likely to suffer fruit drop and …
PGRs for HLB-Affected Trees: An Update
Using the plant growth regulators (PGRs) cytokinin in spring, gibberellic acid (GA) in summer and 2,4-D in late fall can be helpful for HLB-affected trees, horticulturist Tripti Vashisth reported. Her PGR update came during a Feb. 21 OJ Break. Multi-county citrus Extension agent Chris Oswalt hosted the event at the University of Florida Institute of Food and Agricultural Sciences Citrus …
PGRs: Multipurpose Tools for Citrus Improvement
By Tripti Vashisth Canopy health of HLB-affected citrus has been directly related to disease severity, fruit drop and overall fruit production. Some success has been found with the use of certain plant growth regulators (PGRs) such as gibberellic acid (GA) and 2,4-dichlorophenoxyacetic acid (2,4-D) to achieve healthier trees with reduced fruit drop and increased production. HLB MANAGEMENT Application of these …
Combine Plant Growth Regulators for Most Benefit
Using the plant growth regulators (PGRs) gibberellic acid (GA), 2,4-D and cytokinin in combination can maximize the benefit for HLB-affected trees, researcher Tripti Vashisth reported recently. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor of citrus horticulture and production works at the Citrus Research and Education Center in Lake Alfred. She discussed the benefits of …
Treat HLB Trees With the Right PGR at the Right Time
By Tripti Vashisth, Wesley Webb and Taylor Livingston As trees become symptomatic for HLB, leaves experience an imbalance of plant hormones. This hormonal imbalance exacerbates HLB symptoms and can lead to more stem dieback, poor vegetative growth and fruit drop. This ultimately leads to reduced bearing wood, resulting in yield losses and tree decline. Thus, the use of growth-promoting hormones …
Using Gibberellic Acid in California Citrus
Craig Kallsen, University of California Agriculture and Natural Resources (UCANR) citrus and pistachio farm advisor for Kern County, offered suggestions for the use of gibberellic acid (GA3) on citrus in the San Joaquin Valley. Highlights follows: See Kallsen’s full article on gibberellic acid use here. Source: UCANR Sponsored ContentA Simpler, Safer and More Effective Way to Fight HLBOctober 25, 20245 …
Cytokinin Studied for Citrus Health Benefits
Tripti Vashisth, University of Florida Institute of Food and Agricultural Sciences associate professor, has been leading the research on how plant growth regulators (PGRs) can improve the health of HLB-infected trees. She’s conducted extensive research on the use of gibberellic acid. But she has recently begun to study another hormone, cytokinin. She gave an update on this work during the …
Gibberellic Acid Applications: Day vs. Night
By Alessandro Franco, Faisal Shahzad and Tripti Vashisth Gibberellic acid (GA) is one of the most commonly used plant growth regulators which affects flowering, fruit and vegetative growth. Multiple monthly GA foliar applications have reduced preharvest fruit drop and increased yield in huanglongbing (HLB)-affected sweet oranges. The potential impact of these findings is huge for commercial citrus production. However, there …
Gibberellic Acid Shows Promising Results on Hamlin
By Tripti Vashisth and Taylor Livingston Grower-led trials in 2022 showed positive results of gibberellic acid (GA) treatment on Hamlin trees in Florida. This article primarily discusses two growers’ trials in detail. Both sites showed improvement in fruit production from the GA application. Many growers have adopted GA applications in the past year as part of their grove management strategy. …
The Promise of Gibberellic Acid
Researcher Tripti Vashisth shed additional light on the promise of gibberellic acid (GA) applications in rejuvenating HLB-affected orange trees during a Jan. 11 presentation. Some of the important messages that the University of Florida Institute of Food and Agricultural Sciences associate professor highlighted were: VALENCIA TRIALIn a 2016 to 2022 Valencia field trial, GA applications made from September to January …
The Role of Plant Growth Regulators in Citrus
Multi-county citrus Extension agent Ajia Paolillo discussed the role of plant growth regulators (PGRs) in groves in a recent Extension newsletter. She cited University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) horticulturists Tripti Vashisth and Fernando Alferez as sources. Here’s a summary of Paolillo’s article: GIBBERELLIC ACIDGibberellic acid (GA) is one of the PGRs used in citrus. It …