CONTROL IN VIVO DE Phaeoacremonium parasiticum CON ANTAGONISTAS NATIVOS Bacillus, Trichoderma y actinomicetos Y SU EFECTO PROMOTOR DE CRECIMIENTO EN VID

Background: Phaeoacremonium parasiticum is a frequently species associated with "Petri's disease" in young plants of grapevine in Peru. One of the main limitations is the use of fungicides and the limited molecules for its control. In this scenario, biological control is an important alternative to integrate in the management of grapevine diseases. Objective: The objective of the research was to evaluate the in vivo efficacy of native antagonists to P. parasiticum and their growth promoting effect on grapevine. Methodology: Plant material from mother plants (R-110) underwent thermotherapy (52.5°C for 30 min). Subsequently, the antagonists (bacteria and fungi) were inoculated by partial immersion at a concentration of 1x106 cfu ml-1 (Colony forming units) for 3 h; 30 days later, P. parasiticum was inoculated, measuring shoot length before inoculation (SLBI). Seventy days after inoculation (DAI), shoot length (SL), length of necrotic stria (LNS), root dry weight (RDW) and root fresh weight (RFW) were measured. Results: Isolate Tr-5 (Trichoderma spp.) increased SLBI by 68%. Bacillus spp. (Bac-1, Bac-2), Trichoderma spp. (Tr-5) and T. harzianum (T-22) increase >40% SL 70 DDI. Tr-6 (Trichoderma spp.), T-22 and Act-2 (Actinomycete) reduce >50% LNS. Bacillus spp. (Bac-2: Bac-3) significantly increase RFW (59.29%: 49.39%) and RDW (60.41%: 55.08%). Implications: Biological control with native antagonists reduces the development of Petri disease and promotes grapevine growth. Conclusions: The native antagonists show growth-promoting effect and control of LEN caused by P. parasiticum at the nursery stage.