By Brenda Eubanks Burnette I was honored this year to be part of the Vero Heritage Center and Indian River Citrus Museum’s “Deeply Rooted” event, which was the kick-off for Indian River County’s Centennial Celebration. It made me think of this year’s Florida Citrus Hall of Fame inductees. They all have something in common with deep roots — Polk County! …
Survey Shows Popular Scions and Rootstocks
The Florida Citrus State of the Industry Survey seeks input from growers on key issues affecting their groves. The survey has been conducted for many years, has tracked the trajectory of HLB and reported on production practices. While not a scientific survey, it has reflected general trends over the years. Last month, we published results on trunk-injection therapy and the …
Assessing Tools for Citrus Soil Health
Soil microbiologist Sarah Strauss on Jan. 28 discussed the benefits, challenges and unknowns of cover crops, compost and humic acid for citrus soil health. Strauss is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor at the Southwest Florida Research and Education Center. She pointed out that Florida’s citrus soils are problematic because they are 98% …
Combine IPCs and Brassinosteroids to Prolong Young Tree Health
By Fernando Alferez and Saoussen Ben Abdallah The risk of citrus plantings to become infected with HLB is especially high for young trees, which flush frequently and attract more psyllids than mature trees. Individual protective covers (IPCs) are now being increasingly adopted to protect newly planted citrus trees from psyllid colonization. However, even though IPCs effectively protect young trees from …
Study Shows Impact of HLB Bacterium on Roots
A recent study sheds light on the significant effects of Candidatus Liberibacter asiaticus (CLas), the bacterium responsible for HLB, on the root systems of grafted Valencia orange trees. The findings reveal that root system reductions caused by the infection are more extensive than the corresponding aboveground declines. That finding underscores the hidden yet critical impact of the disease below the …
More SuperSour Rootstocks Under Study
“Superior New Rootstocks Can Make Citrus Profitable Again” is the headline of a recent U.S. Department of Agriculture Agricultural Research Service (USDA ARS) article. Kim Bowman, research geneticist at the USDA Horticultural Research Laboratory in Ft. Pierce, Florida, write the article. A slightly edited version follows: The rootstock and root system are what make trees strong enough to survive and …
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 …
The Relationship Between Roots and OTC Treatments
Back in the early days of the HLB fight, it was observed that what is going on underground in citrus tree root systems is just as important as what is happening aboveground. In 2013, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) and U.S. Department of Agriculture-Agricultural Research Service researchers published that 27% to 40% root loss due …
Growing Citrus With Soil Health in Mind
Herb Young enjoyed a 40-year career in the agricultural chemical industry, starting as a technical service representative and eventually becoming a product manager. During those years, he worked on various specialty crops across the country. About 25 years of his career was spent in field research roles. So, experimentation with crops and growing practices comes naturally to Young. He has …
Breeder Advice on Nutrition, Scions and Rootstocks
Citrus breeder Jude Grosser recently shared tips on tree nutrition and discussed some scion/rootstock combinations that should work well for trees producing juice oranges. NUTRITIONGrosser became very interested in citrus nutrition several years ago in an effort to keep his newly bred trees healthy in the face of HLB. The University of Florida Institute of Food and Agricultural Sciences professor …
Hairy Approach May Get to the Root of HLB
Developing disease-resistant, high-quality improved crop varieties may seem like a “hairy” task, but Texas A&M AgriLife Research scientists may have gotten to the root of the issue. A new biological technology that develops and multiplies disease-resistant citrus plants is under development by an AgriLife Research team led by Kranthi Mandadi. Mandadi is an associate professor at the Texas A&M AgriLife Research …
USDA Citrus Breeding Program Focused on Rootstock and Variety Solutions
The U.S. Department of Agriculture’s (USDA) U.S. Horticultural Research Laboratory in Fort Pierce, Florida, has been home to a citrus rootstock and variety breeding program for many years. Kim Bowman, a research geneticist, has been with the program for more than 30 years. More recently, Matthew Mattia, a geneticist, joined the breeding team. They provide an update on the program …
Using Cover Crops to Improve Soil Health
By Sarah Strauss, Emma Dawson and Elena Karlsen-Ayala The term “soil health” has become increasingly popular in the last several years. While there are many definitions of soil health, one of the more commonly cited ones is from the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS). It defines soil health as “…the continued capacity of a soil …
Citrus Root Weevil Intercepted
U.S. Customs and Border Protection (CBP) agriculture specialists intercepted a species of citrus root weevil for the first time in Wilmington, Delaware, on May 22. They found the Cleistolophus viridimargo (Champion, 1911) weevil, a significant actionable pest, while inspecting a shipment of pineapples from Honduras. CBP said citrus root weevils pose a serious threat to the $3.4 billion U.S. citrus …
Valencia on US-942 Rootstock Is Favored Florida Tree
For at least the last four years, the Valencia SPB-1-14-19 orange has been the most-produced citrus variety in Florida, and US-942 has been the favored rootstock. So, it makes sense that the Valencia SPB-1-14-19 on US-942 rootstock has been the most-produced tree combination for four years running. That information was provided at April’s Florida Citrus Growers’ Institute in Avon Park …
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 …
Citrus Root Structures: Lessons From Below
By Ute Albrecht There have been numerous reports of malformed roots in field-grown citrus trees recently. The rootstock propagation method is often suspected as the culprit. Before drawing quick conclusions, it is important to recognize that there are many different factors that can influence the root structure of a citrus tree aside from the propagation method. These include the genetic …
Progress in Developing Improved Citrus Rootstocks to Mitigate HLB
By Jude Grosser, Manjul Dutt and Fred Gmitter Exploiting citrus genetic diversity is the key to defeating HLB. Plant species have survived for millennia with evolving, hostile pathogens. This is possible through natural selection within genetically diverse populations. Tolerant or resistant individuals survive and intermate, get through the bottleneck, and the species evolves. Current citriculture is based on extremely limited …
An Update on Oak Mulch to Increase Soil Health
By Lukas M. Hallman, John M. Santiago and Lorenzo Rossi At first glance, one may not see how oak trees relate to citrus production. But in the early 2010s, growers and scientists reported seeing little to no HLB symptoms on citrus growing underneath the dripline of oak trees compared to citrus trees nearby but not directly under oak trees. These …
Consistency Is Key in Rootstock Field Trials
By Bill Castle Today, at least three things seem to be true about Florida citrus rootstock field trials: There is an unprecedented number of them underway or soon to be planted. The sponsors are many, including the University of Florida, U.S. Department of Agriculture, Citrus Research and Development Foundation, Citrus Research and Field Trial Foundation and the Multi-Agency Coordination Group. …




















