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Below you'll see everything we could locate for your search of “phytophthora”
By Lorenzo Rossi, Ute Albrecht and Evan Johnson Citrus root systems are confronted with many challenges that limit resource availability needed for tree productivity. Challenges are compounded by huanglongbing (HLB), which now affects nearly all citrus trees throughout Florida’s production areas. Contrary to the above-ground portion of the tree, study of the below-ground portion is considerably more difficult. This article …
The March issue of Citrus Industry magazine gets to the root of the matter. Several articles cover the topic of root health. Citrus growers Ben Krupski and David Wheeler share successful strategies for stronger roots. Methods include the use of compost, more frequent irrigation and other techniques. Three University of Florida research articles in the March issue also address root-related …
By Lauren Diepenbrock While Asian citrus psyllids (ACP) are an ongoing concern in Florida citrus due to their role in spreading the bacterium associated with citrus greening, they are not the only pest of concern to growers. Citrus leafminer (CLM) and root weevils are two pests that have been raising concerns and adding to the challenge of managing productive citrus …
By Sarah Strauss and Ute Albrecht There is increasing discussion and interest in soil health from both growers and researchers. Soil health is generally synonymous with soil quality. It can impact not just sustainability, but also improve water-holding capacity, nutrient availability, yield and overall grove productivity. In citrus, soil health is particularly important because of the reduction of root mass …
Crop production consultant Hamed Doostdar spoke on a grower panel as part of a recent University of Florida Institute of Food and Agricultural Sciences workshop on lemons at the Citrus Research and Education Center. He summarizes some key points regarding lemon production practices. Doostdar says lemons grow very fast, often reaching 7 to 8 feet tall by 2 years of …
Lake Wales citrus grower Frank Thullbery, 88, says groves in his area have suffered badly from foot rot, or phytophthora, in recent years. He has also struggled with postbloom fruit drop (PFD). “I’ve seen half of the groves gone bad from foot rot, and a lot of people are not replacing their trees when they pull them out,” Thullbery says. …
By Evan G. Johnson The citrus canker season is quickly approaching again, so it is time to start planning your canker management program to avoid fruit drop and fresh-market quality loss. It is easy to forget the importance of controlling citrus canker with the current state of HLB in Florida. However, citrus canker can cause almost complete crop loss if …
University of Florida Institute of Food and Agricultural Sciences horticulturist Evan Johnson offers care tips for trees recovering from Hurricane Irma. A key suggestion is not to push the growth of trees damaged by the storm. Johnson notes that many trees suffered from standing in water for five days and more, and from having leaves blown off. Those issues lead …
By Jawwad A. Qureshi and Larry Duncan Root weevils are a major pest group for many kinds of plants, with at least nine species that colonize citrus. Species commonly infesting citrus include Diaprepes root weevil (Diaprepes abbreviates), blue-green citrus root weevils (Pachnaeus litus and Pachnaeus opalus), little leaf notcher (Artipus floridanus), Fuller rose beetle (Asynonychus godmani) and Sri Lanka weevil …
By Len Wilcox When Jim Shanley retired from his highly successful career in commodity trading, he knew what he wanted to do and where he wanted to do it: farm specialty crops in the hills overlooking Morro Bay, California. His choice of crops, however, was not so clear. He started with avocados, but it was a curious little fruit from …
By Stephen H. Futch and Ariel Singerman In May of 2017, we visited the northwestern citrus production region of Argentina in the provinces of Jujuy, Salta and Tucumán. The purpose of the trip was to learn more about Argentina’s citrus industry and programs being developed to deal with both the Asian citrus psyllid (ACP) and huanglongbing (HLB). Argentina has a …
University of Florida Institute of Food and Agricultural Sciences plant pathologist Evan Johnson tells how drastically HLB harms citrus tree roots and suggests some ways to prolong root longevity and improve tree health. “It (HLB) causes very substantial root loss, up to between 30 and 50 percent early in the disease process from before visual symptoms are present to early …
Recent studies shed light on foliar nutrient and irrigation practices. By Kelly T. Morgan and Said Hamido Most citrus growers are well aware that citrus greening (HLB) is one of the most devastating citrus diseases in many parts of the world. The disease is widespread in Florida, Texas, Brazil, Mexico and other major production areas, causing significant concerns about the …
By Jim Graham and Kelly Morgan Huanglongbing (HLB), greening and yellow shoot are names for the most devastating citrus disease in the world. Symptoms of HLB include a distinctive chlorotic mottle on fully expanded leaves. Infected shoots are stunted, and branches gradually die back as the symptoms appear in other sectors of the tree canopy. HLB reduces fruit size, weight …
By Megan M. Dewdney Again in 2016, postbloom fruit drop (PFD) caused widespread problems in Florida groves. There were multiple factors that contributed to the outbreak in 2016. The primary factor was likely the extended bloom that many saw because of a combination of tree stress caused by huanglongbing (HLB) and the very warm winter. Bloom in some groves was …
Another early-detection method being developed works by smelling huanglongbing infections in trees. This method detects the different scents plants give off. Researchers at the University of California, Davis have created a test that could lead to advances in fighting huanglongbing (HLB) disease in citrus. Researcher and professor of mechanical and aerospace engineering, Christina Davis, said the test looks for a …
By Mark A. Ritenour, Jiuxu Zhang and Megan M. Dewdney Decay of fresh citrus fruit is most often caused by fungal pathogens that grow and develop in the hot and wet conditions typical in Florida. While green and blue molds (Penicillium digitatum and Penicillium italicum) and sour rot (Galactomyces citri-aurantii) are the most common postharvest citrus diseases worldwide, the subtropical …
Another early detection and screening process for HLB has been developed at the University of California, Davis. Cristina Davis, professor of mechanical and aerospace engineering, is using volatile organic compounds (VOCs) as indicators of disease in trees. VOCs are odors that are emitted by all living things. These odors can be very meaningful, because they are distinctively different between a …
University of Florida professor Larry Duncan presented the latest research on using entomopathogenic nematodes (EPNs) to control Diaprepes root weevil (DRW) in citrus to approximately 30 growers on June 30 at the Hardee County Extension Service office in Wauchula. The combination of HLB with DRW intrusion has created a situation that will accelerate the destruction of most infected trees. DRW …
