PREVENTIVE AND CURATIVE CONTROL OF Oidium eucalypti IN Eucalyptus benthamii CLONAL SEEDLINGS

Abstract

One of the main diseases occurring in clonal nurseries of Eucalyptus spp. is powdery mildew caused by the fungus Oidium eucalypti. This work evaluated the efficiency of biological products based on Trichoderma spp. and Bacillus spp. applied as preventive and curative treatments for the control of Oidium eucalypti in clonal seedlings of E. benthamii Maiden et Cambage. Treatments were: Trichoderma harzianum (THP), T. atroviride (TAI), T. harzianum (THE), Trichoderma spp. (TTA), Bacillus spp. (BNE), Sulfur (KUM), Difenoconazol (SCO) and distilled water (AD). Treatments were applied preventively by spraying seven days before inoculation of the pathogen, and in curatively, ten days after inoculation. Weekly evaluations of the incidence and severity of the disease were done. The analyzed variables were: Disease Index (ID) and Incidence (I), calculating the area under the disease curve (AUDPC) for each treatment. The results pointed BNE (Bacillus spp.) and TAI (isolate T. atroviride) as effective preventive treatments and BNE (Bacillus spp.), applied curatively for the control of O. eucalypti in E. benthamii seedlings, proving that treatments based on biological products may be effective for controlling eucalyptus powdery mildew in clonal nurseries.

Mini-tunnel models influence the productivity of eucalyptus mini-stumps?

“…This disease spreads through the air, by contact between healthy and sick plants, and via rain splashes. It occurs mainly in the dry season in the genus Eucalyptus, which in the studied area coincides with the cold period (Bovolini et al 2018).…”

The Threat of Pests and Pathogens and the Potential for Biological Control in Forest Ecosystems

“…Peptaibols exhibit antibiotic activity against bacteria and fungi [101]. Bovolini et al [108] reported the successful application of a strain of Bacillus, as a preventive and curative spray, on eucalyptus seedlings for the control of the fungus Oidium eucalypti Rostr. Furthermore, another strain of Bacillus (UnB1366) is highly effective against the phytopathogenic fungus Lasiodiplodia theobromae Grifon and Maubl., the causative agent of teak canker disease and a fungus that has not responded to other control methods.…”

“…A strain of Bacillus that was applied in vivo significantly reduced the incidence of diseases caused by Botrytis cinerea and Calonectria gracilis De Not. ; this result was attributed to the various volatile compounds that are produced by the Bacillus [108,109]. Bacillus velezensis, associated with the root microbiota of several plants, can produce a cascade of metabolites that have antagonist properties against Fusarium and Phytophthora, as well as promote plant growth [109].…”

Scientometric Analysis of the Main Eucalyptus Diseases

“…The fungus Pucciniapsidii, popularly known as rust, mainly attacks the sprouts of seedlings and young eucalyptus trees, causing losses of up to 30% in the annual development of the crop, the pathogens Botrytis spp. and Rhizoctonia spp., which occur with a higher incidence of seedlings, causing damage in commercial nurseries causing toppling and the fungus Oidium eucalypti, which is characterized by excessive sprouting and distorted leaves, seedlings die [9]. The database (Institute of Scientific Information -ISI) was developed between 1958 to 1960 with the purpose of providing quality and recent information to researchers [10].…”