A meleira do mamoeiro no Trópico Semi-Árido

Abstract

In spite of Brazil to beIing the first producer of papaya (Carica papaya L.) in the world, its area is implanted basically on three varieties belonging to two groups, Solo and Formosa. As a result of that narrow genetic base, the culture becomes vulnerable to pests, diseases and climatic variations. The papaya tree is highly susceptible to fungi and viruses diseases, standing out the Papaya sticky disease virus, PSDV, causing serious damages to the producing areas. In the last years, it has been observed a high number of commercial plantations infested by this virus in the area of the Sub-medium San Francisco Valley, with a simultaneous action of fungi and virus affecting mainly in the irrigated plantations. The objectives of this work where: to generate information about the behavior of papaya genotypes to PSDV, by the evaluation of 16 genotypes of the Active Papaya Germplasm Bank (AGB-Papaya), at Embrapa Cassava and Tropical Fruits, in the conditions of semi-arid tropic, to evaluate the maintenance of the virus infectivity in stored latex, to identify virus and fungi in the plantations with Solo and Formosa varieties, and to present new symptoms associated with the PSDV. The accessions CMF 023, CMF 012 and CMF 008, were considered highly susceptible to PSDV, while the accessions accessions Tainung Nº 1, CMF 018 and CMF 054 were of low susceptibility. The pathogens observed were PSDV, the fungi Colletotrichum gloeosporioides (Pens) Sacc, Asperisporium caricae (Speg) Maubl., Fusarium sp, Lasiodiploidia theobromae el. & Ev., Phytophthora palmivora and Phomopsis sp. The infectivity of PSDV was verified in stored latex, evidencing its importance in the dissemination of the disease. The new symptoms associated to the PSDV (exudation and oxidation in the floral buttons and leaf nervures) should be included in the symptoms described for the disease. The obtained results can be utilized by papaya breeding programs, a source of information for the strategies of control of those diseases.