Phytophthora fungi are present in almost all citrus orchards. Under moist conditions, the fungi produce large numbers of motile zoospores, which are splashed. The main symptom of citrus gummosis is oozing of gum from the affected parts on the trunk. Infected bark remains firm with small, longitudinal cracks through. Gummosis is the formation of patches of a gummy substance on the surface of certain plants, particularly fruit trees. This occurs when sap oozes from wounds or .

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Trifoliate, Swingle citrumelo, Yuman and alemow are considered highly resistant to bark infection and tolerant to root rot. Isolation of Phytophthora spp. Send feedback on this factsheet.

Trunk and branch canker on lemon showing gummosis and bark death on a tree. All components of APSnet are copyrighted and may not be reproduced or distributed except by express permission of APS.

Garden Guy Hawaii: Citrus Gummosis

Abstract Citrus production in Ethiopia is threatened by a number of biotic and abiotic factors. Root stock susceptibility depends on which Phytophthora species ggummosis present and the presence of favorable soil, water and environmental conditions.

Isolates from the bark tested for growth on the selective medium at 23oc of temperature shows a white cottony colony after 72 hrs. Contact Us – Report a Bad Link. Look for signs of gumming on the lower trunk and crown, and for soil buildup around the crown; do not allow bud unions to get buried.

When you detect gum lesions, check soil and drainage cirus.

Posted by Nick Sakovich at 1: The outbreak of this disease could be the variation in environmental factors and changes in citrus cultural practices. HaileMariam Phenological regions for citrus production in Ethiopia: Copyright is not claimed for material provided by United States government employees as part of their work.

This disease is commonly seen in mandarin, sweet orange, lemons and other citrus fruits. Can also be used as a protectant on gummosiz where risk of gummosis is high. Inoculums raised from the soil gummosiz move to the trunk and branches possibly due to poor cultural practice conducted at the orchards during harvesting, irrigating and pruning.


When choosing a pesticide, consider the general properties of the fungicide as well as information relating to environmental impact. Decline may occur rapidly within a year, especially under conditions favorable for disease development, or may occur over several years. Can be applied up to 3 times per year, but do not make soil and trunk applications of mefenoxam to the same tree during the same cropping season and do not apply more than 1.

Assessing and Measuring of Citrus gummosis Phytophthora spp. The decline in production land through time was attributed to a number of production limiting biotic and abiotic factors. Swingle citrumelo is the most tolerant rootstock.

Citrus Diseases

But it can be reversed with the integration of fungicides, dimethomorph the data is not observedby avoiding excessive overwatering, poor drainage and soil structure, proper bud union avoiding a bud union at soil surface or less than 15 cm above soil line those which enhances the disease gummosis. Along with cutting out the discolored bark, it is recommended to cut about an inch into the healthy bark. Yellow vein symptoms associated with girdling of a young tree by Phytophthora foot rot.

Why do citrus trees have, in general, an unhealthy appearance? Apply as paint or spray on trunk and crown right after excision of diseased bark; treat excised area and lower trunk.

CRC for tropical plant protection Brisbane Austrialia. Ethiopia’s agro-climatic conditions are highly suitable for production of high quality citrus fruits.

Users may want to set up a specific directory and file naming scheme for storing images; otherwise, they will be saved using your system defaults. In general if the inoculums of the disease from soil were kept away through by any means to the rootstock and the trunk, the disease pressure will be minimized. In ascending order, Cleopatra mandarin, Sour orange, rough lemon, Rangpur lime, Carrizo, Troyer are tolerant to root rot.

Surveys were conducted in ten major citrus growing areas of Ethiopia. Likewise, if there is gum secretion on any part of the tree, clean it off and use Bordeaux-pest as mentioned before. Results showed that growth and fruit production are greatly reduced on trees infected by this disease. The survey results have shown that the disease was prevalent in all the surveyed orchards with different magnitude of infection.


Late gumjosis of Phytophthoragummosis are distinct, but early symptoms are often difficult to recognize. In each orchard, 30 trees were gummosiz and totally trees were assessed for gummosis incidence. In addition; probably some insects and animals have had contribute for the spread of the pathogen to the upper branch.

There are fungicides registered to control citrus gummosis Phytophthora species. Plantwise Factsheets for Farmers. Phytophthora is a water mold Class Oomycetes, formerly a fungus-like protist that is found throughout the world.

Foot Rot or Gummosis Diseases of Citrus

Pakistan Journal of Botany Systemic fungicides can control Phytophthora gummosis and copper cifrus can be used to protect against infection.

Materials and Methods Description of the study area A survey was conducted between October and November to determine the incidence and distribution of gummosis Phytophthora spp.

Clementine mandarin tree killed by Phytophthora citrophthora. BoxDire Dawa, Ethiopia. Select your language of interest to view the total content in your interested language. Lesions may spread around the circumference of the trunk slowly girdling the tree.

Foot Rot or Gummosis Diseases of Citrus | agropedia

Gummpsis low rate on sandy loam and high rate on heavier soils or high clay. The modified V-8 agar consisted of eight vegetable agar V-8 agar composed of 2 g CaCO 3mL V8 juice and 15 g agar in mL distilled water amended with 20 mg Pimaricin, mg Ampicilin, 75 mg Vancomycin, 50 mg Dichloran, which were dissolved in 10 ml distilled sterile water and added to 1 liter of V-8 agar [ 10 ].

Swingle lime Disease name: Fibrous roots slough their cortex leaving only the white thread-like root cylinder.