nutrient availability

Keeping Soil pH at the Optimal Level

Josh McGillNutrition, soil

By Brandon White This time of year is the end of the peak nutrient demand for citrus trees. Regardless of the types of fertilizer or inputs applied in the groves, trees have been taking up nutrients while growing in full tilt during the spring season. One of the greatest factors determining how well trees take up nutrients is soil pH. …

Keep CTV Under Control

Josh McGillDiseases, Tip of the Week

By Amit Levy Citrus tristeza virus (CTV) infects the citrus phloem. CTV infects almost all citrus varieties, but it causes different disease symptoms depending on the virus isolate, the citrus variety and scion-rootstock combination. Florida has three dominant strains of CTV: T36, a decline-causing strain T30, which normally does not cause severe disease VT, a stem-pitting causing strain CTV is …

Citrus Nutrient Deficiencies? There’s an App for That

Josh McGillDiseases, Nutrition, Pests, Technology

While sending citrus tissue samples to the lab for analysis remains important, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has developed a smartphone application (app) that can supplement lab analysis to identify leaf symptoms of key nutrient deficiencies and certain pests and diseases. Arnold Schumann, a professor of soil and water science with UF/IFAS, demonstrated how …

Diagnosing Herbicide Phytotoxicity in Citrus

Josh McGillweeds

By Ramdas Kanissery, Nimal Timilsina and Ruby Tiwari Chemical weed control is an essential component of the toolbox to keep weeds in check in citrus groves. Citrus growers primarily rely on herbicide to manage weeds due to their efficacy and cost-effectiveness. Despite their benefits, herbicides may have a wide range of unintended effects on citrus. For instance, an herbicide-related injury …

Pests, Pathogens and IPCs

Josh McGillIPCs, Pests, Research

By Lauren Diepenbrock, Megan Dewdney, Fernando Alferez, Jawwad Qureshi and Ozgur Batuman Individual protective covers (IPCs) are becoming commonplace in citrus production to support the development of young trees after planting. IPCs are made of fine mesh and are intended to keep Asian citrus psyllids (ACP) off young plants. Because ACP can transmit the pathogen that causes citrus greening/huanglongbing, preventing …

CRDF Seeks Growers for Rootstock Trials

Josh McGillCRDF, Rootstocks

The Citrus Research and Development Foundation (CRDF) is seeking Florida citrus growers on the Ridge and in the flatwoods of Southwest Florida to potentially be grower-cooperators in large rootstock trials. The goal of the new trials is to identify plant material with the traits needed by growers to realize the highest possible pound solids per acre and increase tree viability …

Now Is the Time to Start Scouting for Rust Mites

Josh McGillPests, Tip of the Week

By Xavier Martini Rust mites are recurrent pests in Florida that pose problems mostly in fresh citrus production. While severe infestations can lead to fruit drop, leaf injury and abscission, rust mites cause aesthetic damage in the form of sharkskin or bronzing on the skin of fresh fruit (Figure 1A). Fresh fruit requires clean and undamaged skin, and any abrasions …

Speeding the Search for an HLB Solution

Josh McGillHLB Management, Research, Varieties

By J. Scott Angle, jangle@ufl.edu, @IFAS_VP My hope is that your new citrus breeding team scientist will be a new Bill Castle on warp speed for an HLB solution. That is, John Chater will accelerate the search for citrus varieties that hold up against HLB. He’s got tens of thousands of places to search. Fred Gmitter and Jude Grosser have …

Grower and Researcher CUPS Collaboration

Josh McGillAll In For Citrus Podcast, CUPS, HLB Management

The spread of HLB in Florida citrus groves has forced growers and researchers to try all sorts of practices to fight off the disease’s devastating effects. One of the most successful methods has been planting citrus under protective screen (CUPS). The screen excludes the Asian citrus psyllid (ACP) and keeps HLB out of plantings. CUPS also is a great example …

Don’t Forget Citrus Black Spot in Florida

Josh McGillDiseases

While HLB tops the agenda, Megan Dewdney, an associate professor of plant pathology and an Extension specialist with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), reminded growers that citrus black spot (CBS) remains a concern. This was the topic of a presentation she made during the Florida Citrus Growers’ Institute held in Avon Park in April. …

Preparing to Plant Cover Crops

Josh McGillCover Crops, Tip of the Week

By Sarah Strauss If you’ve been exploring methods to improve your soil health, chances are you’ve come across the use of cover crops. Even though we call them “crops,” these plants are not harvested and are only planted to improve soil health. The benefits of cover crops to soil health include increasing soil organic matter and microbial diversity and activity …

HLB Research Priorities

Josh McGillAll In For Citrus Podcast, HLB Management, Research

Michael Rogers, director of the University of Florida of Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred, discussed the recent Florida Citrus Growers’ Institute in the April All In For Citrus podcast. The event drew a good crowd of growers who came to learn about the latest research aimed at HLB. Rogers made …

How Weather Affects Pesticide Applications

Josh McGillCEU, Pesticides, Weather

By Matt Smith Editor’s note: This article grants one continuing education unit (CEU) in the Core category toward the renewal of a Florida Department of Agriculture and Consumer Services restricted-use pesticide license when the accompanying test is submitted and approved. Weather affects what pests you might be spraying for and the worker doing the spraying. There are environmental safety risks …

CRDF Focused on HLB Therapeutics

Josh McGillCRDF, HLB Management

The Citrus Research and Development Foundation (CRDF) held its April board of directors meeting to hear reports on projects involving 2,4-D, gibberellic acid, brassinosteroids and zinc. According to Rick Dantzler, chief operating officer of CRDF, the foundation is conducting a full-court press to study how these materials can combat fruit drop and improve quality. CRDF staff also presented a proposal …

Products Proven to Help With HLB

Josh McGillHLB Management, Research

Researchers offered updates on products proven to help against the devastating citrus disease HLB in a virtual seminar on April 27. University of Florida Institute of Food and Agricultural Sciences horticulturists Tripti Vashisth and Fernando Alferez discussed the benefits of gibberellic acid (GA) and brassinosteroids, respectively. Vashisth reported that GA-treated Valencia orange trees dropped less fruit and increased fruit yields …

Pruning Citrus in South Georgia

Josh McGillPruning

Jake Price with University of Georgia Extension in Lowndes County provided an update on pruning of South Georgia citrus trees in a recent Cold Hardy Citrus Connection newsletter. The newsletter is published by the University of Florida Institute of Food and Agricultural Sciences. His report follows: In February 2021, we pruned the Owari rootstock trial trees to where most limbs …

Sneak Peek: May 2022 Citrus Industry

Josh McGillHLB Management, Pesticides, Sneak Peek

While many citrus growers use similar strategies to cope with HLB, no two approaches are exactly the same. One grower who uses a very different method to manage citrus greening is Chip Henry. In the May cover story of Citrus Industry magazine, he tells how growing organically has helped him successfully fight the disease. Sometimes, production practices aimed at protecting …

Herbicides and Fruit Drop

Josh McGillFruit 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” …

Consistency Is Key in Rootstock Field Trials

Josh McGillRootstocks, Tip of the Week

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. …

Cold-Hardy Citrus Is New Researcher’s Focus

Josh McGillCold Hardy, Research

Muhammad Adnan Shahid in January joined the University of Florida Institute of Food and Agricultural Sciences’ (UF/IFAS) North Florida Research and Education Center (NFREC) as assistant professor of horticulture/fruit crops specialist. His Extension goal is providing fruit producers, particularly cold-hardy citrus growers, with relevant, research-based information for improving productivity, profitability and produce quality. Shahid is interested in evaluating new early …