Category: Citrus

Calcium (Ca) and Sulfur (S) for Citrus Trees

Figure 2. These fruit show calcium deficiency symptoms; they are undersized and misshapen with shriveled juice vesicles. Credit: Dr. R. C. J. KooCalcium and sulfur are sometimes called secondary nutrients. This term does not mean that these nutrients play a secondary role in citrus plant growth and development. Ca and S are as essential as N, P, K, Mg, and other nutrients for healthy plant growth. An inadequate supply of Ca and/or S can be a major constraint to crop production and quality. This 5-page fact sheet was written by Mongi Zekri and Tom Obreza, and published by the UF Department of Soil and Water Science, July 2013.
http://edis.ifas.ufl.edu/ss584

Potassium (K) for Citrus Trees

Figure 1. One symptom of potassium deficiency is small fruit. Credit: M. ZekriCitrus fruits remove large amounts of K compared to other nutrients. Potassium moves from leaves to fruit and seeds as they develop. Potassium is necessary for several basic physiological functions such as the formation of sugars and starch, synthesis of proteins, normal cell division and growth, and neutralization of organic acids. Potassium is important in fruit formation and enhances fruit size, flavor, and color. This nutrient also helps to reduce the influence that adverse weather conditions (such as drought, cold, and flooding) have on citrus trees. This 4-page fact sheet was written by Mongi Zekri and Tom Obreza, and published by the UF Department of Soil and Water Science, July 2013.
http://edis.ifas.ufl.edu/ss583

Phosphorus (P) for Citrus Trees

Figure 1. A thick rind and hollow core are both symptoms of P deficiency in citrus trees. Credit: Dr. R.C.J. RooPhosphorus deficiency is not common in Florida citrus groves. If it does occur, it is more difficult to diagnose than nitrogen (N) deficiency or other nutrient element deficiencies. Growth is reduced when P supply is too low. Phosphorus is highly mobile in plants, so when it is deficient, it may move from old leaves to young leaves and other actively growing areas where energy is needed to form seeds and fruit. This 4-page fact sheet was written by Mongi Zekri and Tom Obreza, and published by the UF Department of Soil and Water Science, July 2013.
http://edis.ifas.ufl.edu/ss581

Magnesium (Mg) for Citrus Trees

Figure 2. The leaves on this citrus tree show magnesium-deficiency symptoms. Notice how the leaves have an inverted V-shaped area pointed on the midrib. Credit: M. ZekriMagnesium deficiency has been a major problem in citrus production. In Florida, Mg deficiency is commonly referred to as “bronzing.” Trees with inadequate Mg may have no symptoms in the spring growth flush, but leaf symptoms develop as the leaves age and the fruit expand and mature in the summer and fall. Magnesium deficiency symptoms occur on mature leaves following the removal of Mg to satisfy fruit requirements. This 4-page fact sheet was written by Mongi Zekri and Tom Obreza, and published by the UF Department of Soil and Water Science, July 2013.
http://edis.ifas.ufl.edu/ss582

Nitrogen (N) for Citrus Trees

Figure 1. Nitrogen-deficient leaves. Credit: M. ZekriNitrogen is the key component in mineral fertilizers applied to citrus groves. N has more influence on tree growth, appearance, and fruit production/quality than any other mineral element. Nitrogen affects the absorption and distribution of practically all other elements, and it is particularly important to the tree during flowering and fruit set. This 3-page fact sheet was written by Mongi Zekri and Tom Obreza, and published by the UF Department of Soil and Water Science, July 2013.
http://edis.ifas.ufl.edu/ss580

Measuring Productivity of Citrus Hand Harvesters and Assessing Implications on Harvest Costs and Mechanical Harvesting Developments (FE933)

Figure 1. Continuous canopy shake and catch citrus mechanical harvesting system.Existing mechanical harvesters recover 70 to 95 percent of the available fruit crop. While changes can be made to increase fruit recovery percentages, mechanical systems will never equal the fruit recovery percentages from hand-harvesting crews, much less capture 100 percent of the available fruit. Whether or not to glean (to use manual labor to collect fruit not harvested by the machine) will remain an important question that growers will have to face with every block they choose to mechanically harvest. This study incorporated field harvesting data and developed a model that predicted the extent to which labor productivity would be affected by decreasing the number of oranges available for harvesting by manual labor. Given current market prices of fruit, recovery percentage of crops harvested using mechanical harvesting equipment can improve up to 99 percent and gleaning will remain a profitable activity.
This 6-page fact sheet was written by Fritz M. Roka and Barbara R. Hyman, and published by the UF Department of Food and Resource Economics, May 2013.
http://edis.ifas.ufl.edu/fe933

Sintomas de Cancro Citrico en Arboles de Vivero (PP307)

page 1This is a two-page illustrated identification sheet for citrus canker symptoms that appear in citrus nurseries. Written by Timothy D. Riley, Megan M. Dewdney, and Jamie D. Burrow, and published by the UF Department of Plant Pathology, May 2013.
http://edis.ifas.ufl.edu/pp307

Citrus peelminer Marmara gulosa Guillèn and Davis (Insecta: Lepidoptera: Gracillariidae) (EENY415/IN985)

Figure 1. Adult citrus peelminer, Marmara gulosa Guillèn and Davis.The citrus peelminer is a dark-gray moth with mottled white and brown markings and about 4 mm in length. This moth is considered native in the United States, attacking willow. It is believed that a host-shift occurred to multiple non-native plants including all varieties of citrus and cerain ornamentals, such as oleander. Citrus peelminer has been reported to occur in low numbers in Florida and at least three Marmara species have been identified in the state. Recent evaluations of an experimental pheromone lure that is still under development by researchers at the University of California, Riverside have confirmed captures of citrus peelminer (Marmara sp.) in Polk County, Florida. This 3-page fact sheet was written by Lukasz L. Stelinski, and published by the UF Department of Entomology and Nematology, April 2013.
http://edis.ifas.ufl.edu/in985

Citrus Canker Symptoms on Nursery Trees (PP304)

First page of identification sheetThis document is a two-page illustrated identification sheet for citrus canker symptoms that appear in citrus nurseries. Written by Timothy D. Riley, Megan M. Dewdney, and Jamie D. Burrow, and published by the UF Department of Plant Pathology, April 2013.
http://edis.ifas.ufl.edu/pp304

Beyond 'Earlygold': Juice Color and Quality of Additional Early-Maturing Sweet Orange Selections (HS1209)

Figure 2. Fruit of selections in mid-November and under evaluation at a site in Lake Alfred. Top row, L-R: 'Barao', 'Seleta Branca', and 'Serra D'Agua'; bottom row, L-R: 'Hamlin', 'Earlygold', 'Ouro', and 'Rosa'.This publication summarizes 5 years of juice quality information about 15 early-maturing sweet orange selections introduced to Florida and evaluated after ‘Earlygold’ became available. The trees were grown at a central Florida and Indian River location for about 10 years. Also presented are observations on tree development summarized across both locations and two rootstocks. This 8-page fact sheet was written by Horticultural Sciences, and published by the UF Department of William S. Castle, January 2013.
http://edis.ifas.ufl.edu/hs1209

Informacion para los propietarios: Cancro Citrico (PP298)

Figure 5. Lesiones marrones elevadas de cancro en fruta con unos particulares márgenes prominentes empapados de agua.El cancro cítrico es una enfermedad introducida en Florida y es muy perjudicial económicamente para la industria comercial. La enfermedad no está presente en todas las regiones tropicales y subtropicales productoras de cítricos donde el cancro cítrico puede ser problemático, por lo tanto, las restricciones para exportar fruta con cancro cítrico son muy estrictas. Esta enfermedad también concierne a los propietarios, no solo por sus efectos en la industria económica, sino también porque es altamente contagiosa y la mayoría de la fruta contagiada en un árbol muy afectado se cae de éste prematuramente. This 4-page fact sheet was written by M. M. Dewdney, P. D. Roberts, J. H. Graham, K. R. Chung, and M. Zekri, and published by the UF Department of Plant Pathology, January 2013.
http://edis.ifas.ufl.edu/pp298

Burrowing Nematode Radopholus similis (Cobb, 1893) Thorne, 1949 (Nematoda: Secernentea: Tylenchida: Pratylenchidae: Pratylenchinae) (EENY542/IN969)

Figure 7. Radopholus similis male head (A) and tail (B).The burrowing nematode is the most economically important nematode parasite of banana in the world. Infection causes toppling disease of banana, yellows disease of pepper and spreading decline of citrus. These diseases are the result of burrowing nematode infection destroying root tissue, leaving plants with little to no support or ability to take up water and translocate nutrients. Because of the damage that it causes to citrus, ornamentals and other agricultural industries, worldwide, burrowing nematode is one of the most regulated nematode plant pests. This 5-page fact sheet was written by Nicholas Sekora and William T. Crow, and published by the UF Department of Entomology and Nematology, November 2012.
http://edis.ifas.ufl.edu/in969

Evolution of Citrus Disease Management Programs and Their Economic Implications: The Case of Florida's Citrus Industry (FE915)

Oranges displaying evidence of Citrus Black Spot. 2010 Annual Research Report Photo. UF/IFAS File Photo.Managing new exotic endemic diseases is very costly, and it is imperative that state and federal governments focus on preventing the introduction of other diseases such as citrus variegataed cholorosis and citrus leprosis virus. This 6-page fact sheet focuses on the expanded costs of managing exotic citrus diseases as they become endemic or established within a citrus industry. Written by Ronald P. Muraro, and published by the UF Department of Food and Resource Economics, October 2012.
http://edis.ifas.ufl.edu/fe915

Fortunella spp., Kumquat (FOR300/FR368)

Figure 1. Kumquat (Fortunella spp.)Many people find kumquat trees attractive and useful yard specimens. Their dark green leaves and contrasting bright orange fruits give them ornamental quality, and their relatively small size makes them easy to care for once they’re established. Because kumquats generally require less care than other citrus trees, they may be a good choice for gardeners with less time or experience, but who still desire an attractive and tasty citrus tree. If space is an issue, kumquats also do well in containers as long as they receive proper sunlight and watering. This 2-page fact sheet was written by Michael G. Andreu, Melissa H. Friedman, and Robert J. Northrop, and published by the UF Department of School of Forest Resources and Conservation, July 2012.
http://edis.ifas.ufl.edu/fr368

Quick Sheet: Insecticides and Miticides Recommended for Use in the Florida Citrus Pest Management Guide (ENY854/IN807)

Quick Sheet: Insecticides and Miticides Recommended for Use in the Florida Citrus Pest Management GuideThis document is a two-page quick reference guide to citrus insecticides and miticides recommended in the Florida Citrus Pest Management Guide, their effects on important citrus pests, and their natural enemies. Written by M.E. Rogers, P.A. Stansly, L.L. Stelinski, and J.D. Yates, and published by the UF Department of Entomology and Nematology, January 2012.
http://edis.ifas.ufl.edu/in807

Identificacion de los sintomas del cancro citrico y procedimientos de descontaminacion (PP214SP/PP138)

Figure 1. Lesiones necróticas del cancro en los tallos, hojas y frutos de toronja.El cancro cítrico es una seria enfermedad de los cítricos. La mayoría de los cultivos de cítricos son susceptibles, la toronja, la lima mejicana y algunas naranjas tempranas son las más susceptibles. Una infección severa puede causar defoliación, una muerte regresiva de la rama, una decadencia general del árbol, una caída prematura de la fruta, y manchas en la misma. Los árboles severamente infectados se vuelven débiles, improductivos y no rentables. This 5-page fact sheet was written by Mongi Zekri, Megan Dewdney, Jamie Burrow, and Pamela Roberts, and published by the UF Department of Plant Pathology, August 2012.
http://edis.ifas.ufl.edu/pp138

Mancha negra de los citricos (PP295)

Mancha negra de los cítricos p. 1
Este documento es una hoja de dos páginas ilustrativas para la identificación de la mancha negra de los cítricos. This 2-page fact sheet was written by Megan M. Dewdney and Natalia A. Peres, and published by the UF Department of Plant Pathology, August 2012. http://edis.ifas.ufl.edu/pp295

Enfermedades Exoticos de los Citricos (PP296)

Enfermedades Exóticos De Los CitricosEste documento es una hoja de dos páginas ilustrativas para la identificación de las enfermedades exóticas de los cítricos. This 2-page fact sheet was written by M. M. Dewdney, J. D. Burrow, M.E. Rogers, and T. M. Spann, and published by the UF Department of Plant Pathology, August 2012.
http://edis.ifas.ufl.edu/pp296

Enfermedades fungicas foliares de los citricos para los patios y zonas residenciales (PP297)

Enfermedades fungicas foliares de los citricosEste documento es una hoja de dos páginas ilustrativas para la identificación de las enfermedades fúngicas foliares de los cítricos. This 2-page fact sheet was written by M. M. Dewdney and J. D. Burrow, and published by the UF Department of Plant Pathology, August 2012.
http://edis.ifas.ufl.edu/pp297

Manejo de las enfermedades fungicas foliares para las plantaciones de citricos comerciales (PP299)

Manejo de las Enfermedades Fungicas FoliaresEste documento es una hoja de dos páginas ilustrativas para la identificación y manejo de las enfermedades fúngicas foliares de los cítricos a nivel comercial. This 2-page fact sheet was written by Megan M. Dewdney and Jamie D. Burrow, and published by the UF Department of Plant Pathology, August 2012.
http://edis.ifas.ufl.edu/pp299