Using Cover Crops to Improve Soil Health

Josh McGillCover Crops, 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 …

HLB in Florida Is a Warning to California

Josh McGillCalifornia Corner, HLB Management

The damage that HLB has inflicted on Florida citrus groves and production over the past 18 years should serve as a warning for California producers, California’s Citrus Pest & Disease Prevention Program (CPDPP) stated recently. CPDPP noted that with HLB detected in thousands of California residential trees, it’s important for commercial growers to take steps to prevent the disease. According …

Considerations for High-Density Citrus Plantings

Josh McGillplanting, Tip of the Week

By Amir Rezazadeh Among all the factors that will affect the productivity and profitability of a citrus grove, choosing the optimal tree spacing is crucial. Florida citrus growers are planting trees at significantly higher densities than in the past. Due to negative impacts on plant health following the emergence of huanglongbing (HLB or citrus greening) in Florida, canopy growth substantially …

Gibberellic Acid Applications: Day vs. Night

Josh McGillHLB Management, PGRs, Tip of the Week

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 …

CUPS Irrigation and Fertilization for Grapefruit

Josh McGillCUPS, Nutrition, Tip of the Week

By Rhuanito S. Ferrarezi and Mark A. Ritenour Citrus under protective screen (CUPS) is a modern production system that excludes the Asian citrus psyllid and, consequently, the devastating disease citrus greening (huanglongbing or HLB) from plants cultivated in screenhouses. A recent study investigated the effect of different irrigation management strategies on fruit yield and quality of grapefruit grown in CUPS. …

Lessons Learned From HLB as an Immune-Mediated Plant Disease

Josh McGillHLB Management, Research

By Nian Wang How the huanglongbing (HLB) pathogen Candidatus Liberibacter asiaticus (CLas) causes damage to infected citrus trees has been widely debated. A recent study demonstrates that HLB is an immune-mediated plant disease (Ma et al., 2022). It was discovered that CLas infection of citrus stimulates systemic and chronic immune response in phloem tissues, including reactive oxygen species (ROS) production, …

Effects of Compost and Organic Amendments on Weed Control

Josh McGillResearch, weeds

By Ramdas Kanissery and Mahesh Bashyal Using compost and soil amendments is beneficial to Florida citrus groves. Florida soils are sandy and have a low organic matter and cation exchange capacity. Adding compost and organic amendments (e.g., humic acid) can enhance the soil’s ability to retain water and nutrients. These practices can also boost soil microbial activity and improve soil …

Trialing Tree Immunizations for HLB, Xylella

Josh McGillHLB Management, International, Research

Australia’s Hort Innovation has announced an $8.7 million investment to trial tree immunizations that protect Australia’s horticulture industries against the deadly huanglongbing (HLB) and Xylella diseases (including citrus variegated chlorosis). Hort Innovation is a grower-owned, not-for-profit research and development corporation for Australia’s horticulture industry. Hort Innovation Chief Executive Brett Fifield said the investment aims to safeguard key Australian horticulture industries by …

Sting Nematodes and IPCs

Josh McGillIPCs, Pests, Tip of the Week

By Larry Duncan and Fernando Alferez Newly planted citrus trees are far less tolerant of pests and diseases than when mature. Sting nematode (Belonolaimus longicaudatus) was not considered a serious economic threat to Florida citrus until successive hard freezes in the 1980s caused widespread replanting of groves. Patches of stunted, declining trees caused by the irregular distribution of sting nematodes …

Taking Care of Trees After the Five-Night Freeze

Josh McGillCold Hardy, freeze

“To some extent, every citrus variety has suffered from cold damage” due to the five-night freeze event that occurred in the cold-hardy citrus region Dec. 24–28. That report comes from Jake Price, Lowndes County Extension coordinator for University of Georgia Extension. “The site of our citrus research plots in Valdosta reached a low of 16 degrees, which is the lowest …

Citrus Breeding Program Funded in California

Josh McGillBreeding, California Corner

New federal funding of $1 million will establish a citrus breeding program in California. The program will be at the U.S. Department of Agriculture’s Agricultural Research Service (USDA ARS) field station in Parlier. It will identify new citrus varieties that are best suited for changing climatic pressures such as drought, consumer taste preferences, and resistance to pests and diseases such …

It’s Time to Target Adult Asian Citrus Psyllids

Josh McGillPests, Psyllids, Tip of the Week

By Lauren Diepenbrock Pest management is an ongoing effort in Florida citrus. Taking advantage of pest life cycles has been shown to be an effective tool for reducing populations of target pests. For many citrus growers, managing impacts of the Asian citrus psyllid (ACP), the vector of huanglongbing (HLB), is part of the annual management plan. As we enter the …

Guide Prepares California Growers for HLB Detection

Josh McGillCalifornia Corner, HLB Management, Regulation

California’s Citrus Pest and Disease Prevention Program (CPDPP) has developed a guide, Response for a Confirmed Huanglongbing Positive Detection in a Commercial Grove, to prepare growers for a finding of the disease. The guide is intended to educate growers about the California Department of Food and Agriculture’s (CDFA) huanglongbing action plan. The devastating citrus disease spread by the Asian citrus …

Updates for Citrus Nutrient Best Management Practices

Josh McGillBMPs, Nutrition

By Kelly T. Morgan, Davie Kadyampakeni and Tripti Vashisth This article reviews current University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus fertilizer recommendations and provides updated information about recently approved recommendations for secondary macronutrients and micronutrients. Citrus growers have been very concerned about fertilizer applications and nutrient management since citrus greening (huanglongbing or HLB) was found in …

Groundcovers Promote Water-Use Efficiency and Pest Management

Josh McGillIrrigation, Pests

By Sandra M. Guzmán, Larry Duncan, John Santiago and Lorenzo Rossi The implementation of pest management technologies might have an impact on other management areas in the grove. Landscape fabric groundcovers, for example, have been used for pest management in citrus production. Groundcovers also recently have been used to promote the homogeneous availability of water for uptake by roots, better …

Citrus Breeding Discussed During Field Day

Josh McGillBreeding, CUPS, Fresh

The focus of citrus breeding at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) differs for fruit produced for the juice market vs. fruit for the fresh market. Citrus breeder Jude Grosser, a UF/IFAS professor of plant cell genetics, spoke during the Cold-Hardy Citrus Field Day at the North Florida Research and Education Center in Quincy on …

diversification

Cold-Hardy Citrus Research Initiatives

Josh McGillCold Hardy, Research

The Fruit Crop Physiology Lab at the North Florida Research and Education Center (NFREC) in Quincy is focused on developing a sustainable and profitable cold-hardy citrus industry in the southern United States. To do that, it is conducting research-driven Extension projects. The NFREC is part of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). The lab collaborates …

Evolution of Sting Nematode Integrated Pest Management

Josh McGillPests, Research

By Homan Regmi, Larry Duncan and Johan Desaeger Two field trials were initiated in a Polk County, Florida, commercial grove of 15-month-old Valencia on Kuharske trees in 2019 to measure the effectiveness of integrated pest management (IPM) tactics for managing sting nematodes (Belonolaimus longicaudatus). Six chemical nematicides, many newly released, were compared in one trial. In the second, perennial peanut …

Quality Aspects of Citrus Juices

Josh McGillOrange Juice

By Renée Goodrich and Charles Sims In this era of huanglongbing (HLB), almost every scientific and popular press article alludes to HLB’s impact on fruit and juice quality. The citrus industry uses the term “high-quality” to denote a fruit, product or byproduct that has an array of positive, expected and measurable attributes. Consumers also use terms referring to quality, but …

Canker Resistance Progress May Help With HLB

Josh McGillBreeding, Diseases

A team of researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has successfully identified the CsDMR6 gene, which impacts a citrus tree’s reaction to the citrus canker pathogen. Zhanao Deng and Fred Gmitter, both professors and plant breeders, are members of that team.  By editing the CsDMR6 gene in the plant’s DNA to interfere with …