Banca de DEFESA: ALBERTO DOS PASSOS VIEIRA

POTENTIAL OF BIOPRODUCTS IN MANAGING DOWNFILL IN GRAPES

biological control; Plasmopara viticola; Vittis vinifera; Bacillus; Melaleuca alternifolia.

Viticulture plays an important socioeconomic role in Brazil and worldwide, 

but phytosanitary challenges can be an obstacle for winegrowers, leading to losses of up to 100%. 

Given the need for crop protection and the growing demand for more sustainable options for disease management, 

this study aims to evaluate the potential of bioproducts in the management of Plasmopara viticola, one of the main 

pathogens of the crop. In vitro experiments were conducted in the phytopathology laboratory of the Federal University of Agreste de Pernambuco, 

where the effect of direct contact of pathogen sporangia with the biological products Timorex Gold (formulation 

based on Melaleuca alternifolia extract) and Twixx-A (commercial biological formulation with Bacillus 

amyloliquefaciens strain) was evaluated at concentrations of 1, 2 and 3 mL.L-1, being evaluated for two periods 

(6 and 18 hours after incubation). The test was set up in a completely randomized design, with 3 replicates. 

A compatibility test was also performed between Twixx-A and fungicides containing copper hydroxide (Garra®), mancozeb 

(Manzate®), metalaxyl + mancozeb (Ridomil Gold®), cymoxanil + mancozeb (Galben®), dimethomorph (Forum®) 

and M. alternifolia oil (Timorex Gold®) at concentrations of 50, 100 and 150% of the manufacturers' recommendation. 

For each treatment, five plates were used, distributed in a completely randomized design, with the experimental 

unit consisting of a Petri dish. The evaluation of the efficiency of the products in the field was verified in an in vivo 

experiment, conducted in a commercial area to evaluate the effect of Timorex Gold and Twixx-A at doses of 2 and 3

 mL.L-1, with the area divided into 4 blocks and the treatments applied via foliar application once a week with 

assessment of incidence and severity every four days. In the in vitro tests, it was observed that Timorex Gold at the 

three doses tested and Twixx-A at a dose of 1 ml L-1 reduced the release of zoospores at 6 pm when compared to 

the control. In addition, the compatibility of Twixx-A with fungicides based on copper hydroxide, dimethomorph and 

tea tree oil was verified. In the field test, no statistically significant difference was observed between the treatments 

by the F test (p > 0.05). Given the results presented, new studies must be carried out in order to test new doses, 

forms and application intervals.