An Attempt to Eliminate Spiroplasma-Like Agents Causing Valencia Orange Trees Stubborn Disease by Using Tetracycline Antibiotic.

Document Type : Original Article

Authors

1 Citrus Res. Department, Hort. Res. Instit., Agric. Res. Center, Giza, Egypt

2 Virus and Phytoplasma Res. Dept., Plant Patho .Res. Inst., ARC. Giza, Egypt

10.21608/hrj.2025.418299

Abstract

Citrus stubborn disease (CSD) is a severe disease in most citrus-growing regions and dramatically decreases the citrus yield. This study dealt with the positive impact of Tetracycline antibiotic to control CSD during two seasons (2021-2022) on twelve year’s old infected trees of Olinda Valencia orange. The results indicated that, tetracycline treatment at a concentration of 2000ppm was superior by achieving  the lowest fruit number reduction percentage  (30 and 31.4%)  as compared with the infected trees (47 and 52.7 %) during the two seasons (2021 and 2022), respectively, and  improved the physical and chemical properties of fruits, leaf mineral content compared with untreated disease trees. Also, the results revealed that, trees sprayed with tetracycline achieved a reduction in the percentage of infection rate. Therefore, reducing the causing agent means less infection or less disease pressure and thus the host plant produces healthy fruits with better biochemical quality characteristics. On the other hand, the ELISA test has been successfully used to detect stubborn disease in tissues of the studied trees. It can be applied to trees carrying the disease without obvious symptoms that can be reactivated under favorable conditions and as an indexing procedure for the eradication of infected trees and in any citrus cultivar improvement program by producing virus-free material. It could be recommended to adopt foliar application of tetracycline antibiotic at 2000 ppm on stubborn disease infected trees for increasing their life span beside achieving the best yield and high fruit quality.

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