Vol. 110 (1997): Proceedings of the Florida State Horticultural Society
Citrus

INCIDENCE OF TRISTEZA AND OTHER CITRUS DISEASES IN PARAGUAY

Published 1997-12-01

Keywords

  • toxoptera,
  • phytophthora,
  • xanthomonas

Abstract

Citrus tristeza virus (CTV) was detected in more than 96% of the citrus trees tested in the eastern regions of Paraguay. Toxoptera citricida (Kirkaldy), an efficient vector of the disease, was commonly observed in these regions. Symptoms on naturally infected limes and grapefruit were generally mild. In the Chaco (western) region, only two plants of the 190 tested were found to be CTV positive, and T. citricida was not observed. There were numerous grapefruit and sweet orange trees grafted on sour orange rootstock which were healthy. Of the other diseases, leprosis was a particularly serious disease in the Boquern department. Phytophthora foot and root rot was a common and serious disease in all regions of the country. Citrus canker was the most important foliar disease in the eastern region. Pink disease, areolate leaf spot, sweet orange scab, melanose, greasy spot, and postbloom fruit drop were also recorded in at least some areas in Paraguay.